TWI576524B - Ball screw device and method for attaching part for circulation of the ball screw device - Google Patents

Description

Ball screw device, ball screw device, circulating member mounting method

The present invention relates to a ball screw device used as a mechanical element such as a weight moving device, a processing machine, a precision positioning device, or the like.

As a mechanism for converting a rotary motion into a linear motion, a ball screw device is known. Figure 33 is a cross-sectional view showing the configuration of a conventional ball screw device.

The ball screw device 1101 is composed of a linear screw shaft 1102 and a cylindrical nut 1103. A spiral ball rolling groove 1104 is formed on the outer peripheral surface of the screw shaft 1102. A ball rolling groove 1105 which is spirally opposed to the ball rolling groove 1104 of the screw shaft 1102 is formed on the inner circumferential surface of the nut 1103. The nut 1103 is fitted to the outer peripheral side of the screw shaft 1102 through a plurality of balls 1106 that are rollably mounted between the two ball rolling grooves 1104, 1105, and can be rotated to the shaft of the screw shaft 1102 by rotating the screw shaft 1102. Move in direction.

The peripheral wall of the nut 1103 is provided with a circulation member mounting hole 1107 formed in the radial direction through the peripheral wall, and a circulation member having a substantially S-shaped circulation passage 1108a for circulating the ball 1106 is fitted in the circulation member mounting hole 1107. Piece 1108. Thereby, the plurality of balls 1106 mounted between the two ball rolling grooves 1104, 1105 are guided to the ball circulation path inside the circulation member 1108 by the raised portion of the circulation member 1108 over the island portion 1102a of the screw shaft 1102. 1108a, through the ball circulation path 1108a, returns between the adjacent two ball rolling grooves 1104, 1105, and the balls 1106 circulate in this manner. In this way, the peripheral wall of the nut is provided with a substantially S for circulating the balls. The ball screw device of the type of the circulation member of the circulation path is called a circulation type ball screw device or an internal circulation type ball screw device.

In such a recirculating ball screw device or an internal recirculating ball screw device, there is a member having a retaining member held by a nut to prevent the recirculating member from coming off the nut. For example, Japanese Laid-Open Patent Publication No. 2005-9624 (hereinafter referred to as Patent Document 1).

FIG. 34 is a perspective assembled view showing the configuration of the nut 1110 of the ball screw device described in Patent Document 1. Moreover, FIG. 36 is a side view of the nut 1110 of the ball screw device described in Patent Document 1. As shown in FIG. 34, in Patent Document 1, a circulation member 1114 is fitted in a through hole 1112 provided in a peripheral wall of the nut 1110, and a circulation member 1114 is placed on the outer diameter side of the circulation member 1114 to prevent the circulation member 1114 from being held in the nut 1110. The recirculation member 1114 is a second member 1116 which is a retaining member that is detached from the outer side in the radial direction of the nut 1110.

In Patent Document 1, on the outer peripheral side of the peripheral wall of the nut 1110, the receiving groove 1118 for accommodating the retaining member, that is, the second member 1116, is formed along the predetermined chord of the nut 1110, and two of the receiving grooves 1118. At the bottom of the side, a pair of slots 1120, 1120 are formed extending along the chord. The second member 1116 is inserted into the receiving groove 1118 of the nut 1110 from the extending direction of the chord by using a pair of grooves 1120, 1120 as guides.

According to the above configuration, even if the load that is detached from the radial direction of the nut 1110 is applied to the circulation member 1114, the second member 1116 receives the load, so that the circulation member 1114 is held by the second member 1116 in the nut 1110, thereby preventing circulation. The piece 1114 is detached from the nut 1110.

Japanese Patent Publication No. 2007-211898 (hereinafter referred to as Patent Document 2) discloses a ball screw device in which a circulating member for circulating a ball is held in a mounting hole of a nut using an adhesive.

Patent Document 1: Japanese Patent Laid-Open Publication No. 2005-9624

Patent Document 2: Japanese Laid-Open Patent Publication No. 2007-211898

35 is a view showing a method of assembling the second member 1116 to the nut 1110 in the ball screw device described in Patent Document 1, wherein FIG. 35A shows a case where the outer diameter of the nut 1110 is small, and FIG. 35B shows a case of the nut 1110. In the case where the outer diameter is large, FIG. 35C shows a case where the outer diameter of the nut 1110 is larger. Further, the assembly of the second member 1116 to the nut 1110 is performed after the circulation member 1114 is assembled to the nut 1110.

When the outer diameter of the nut 1110 is small, as shown in FIG. 35A, the second member 1116 can be easily inserted into the receiving groove through the guiding groove 1120 from the outer circumferential side of the nut 1110 in the extending direction of the chord. 1118, the second member 1116 can be easily disposed at a predetermined position on the outer diameter side of the circulation member 1114.

However, in the case where the outer diameter of the nut 1110 is large, the receiving groove 1118 on the side of the nut 1110 must be formed large. That is, the receiving groove 1118 and the guiding grooves 1120, 1120 must be deepened. Thus, as shown in FIG. 35B, it is difficult to position the second member 1116 at a predetermined position on the outer diameter side of the circulation member 1114. In the case where the outer diameter of the nut 1110 is larger, the receiving groove 1118 must be made deeper. However, as shown in FIG. 35C, the receiving groove 1118 and the guiding groove 1120, 1120 are formed only in the peripheral portion of the through hole 1112, and the second member is formed. The 1116 is inserted into the accommodation groove 1118 in the vertical direction, and slides in the direction in which the string is extended while contacting the bottom of the accommodation groove 1118, and the second member 1116 is placed at a predetermined position. Even in this case, it is difficult to position the second member 1116 at a predetermined position on the outer diameter side of the circulation member 1114. As described above, depending on the size of the nut 1110, the assembly of the nut 1111 and the second member 1116 to the nut 1110 takes time.

Further, in the circulation member 1114 of Patent Document 1, as shown in FIG. 34, a pair of fin-shaped projecting portions 1117, 1117 projecting in a direction opposite to the direction in which the chord extends is formed in an assembled state. On the other hand, in the nut 1110, as shown in Fig. 36, a pair of groove portions 1119, 1119 are formed in a portion of the through hole 1112 which is connected to the receiving groove 1118 and which faces the inner wall of the chord extending direction. Each of the groove portions 1119 is opened to the accommodation groove 1118 at the outer circumferential side end portion of the nut 1110, and is closed at the inner circumferential side end portion of the nut 1110. When the circulation member 1114 is mounted, the pair of fin-shaped projections 1117, 1117 are engaged with the pair of groove portions 1119, 1119, thereby preventing the circulation member 1114 from falling on the inner diameter side of the nut 1110, and performing the pair of the circulation members 1114. The positioning of the nut 1110.

However, in the ball screw device of Patent Document 1, after the circulation member 1114 is positioned on the nut 1110, the second member 1116 is assembled to the nut, so that the assembly of the circulation member 1114 and the second member 1116 takes time.

Further, in the conventional ball screw device of Patent Document 2, since it takes about 24 hours for the adhesive to cure, the manufacturing time becomes long and it is time consuming.

The present invention has been made in view of the above problems, and an object of the invention is to provide a circulator member and a holding member for holding a circulator member in a nut so as to be easily assembled to a nut so that the circulator member can be prevented from coming off the nut. Ball screw device, ball screw device, cycle member mounting method.

In order to achieve the above object, a ball screw device according to the present invention includes a screw shaft having a spiral groove formed on an outer peripheral surface thereof and extending linearly, and a nut having an inner circumferential surface facing a spiral groove of the screw shaft. a spiral groove; and a plurality of balls rotatably disposed between the spiral groove of the screw shaft and the spiral groove of the nut; the nut is fitted to the screw shaft through the plurality of balls, and has a function So that the plurality of balls are between the groove of the screw shaft and the groove of the nut a circulating member having a retaining member for holding the circulating member to the nut outside the radial direction of the circulating member, wherein the circulating member has a radial direction restricting the circulating member by contacting the nut a moving restriction portion; and an engagement mechanism for engaging the circulation member with the holding member in the circulation member and the holding member.

Further, in the ball screw device of the present invention, the engaging mechanism is formed in a protruding portion formed on a surface of the outer diameter side of the switching member in an assembled state, and is formed in the holding member and is engaged with the protruding portion. Combined with the curved surface.

Further, preferably, in the ball screw device of the present invention, the protruding portion is a protrusion extending in the axial direction in an assembled state.

Moreover, it is preferable that the ball screw device of the present invention has a spherical shape in a part of the protruding portion.

Further, preferably, in the ball screw device of the present invention, the holding member is formed of a metal material.

Further, preferably, the ball screw device of the present invention is configured such that the protruding portion engages with the curved surface portion to position the holding member.

Further, preferably, in the ball screw device of the present invention, the circulation member is fixed to the nut, and thereafter the holding member is fixed to the nut by the engagement mechanism.

Further, in the ball screw device of the present invention, the engagement mechanism is formed by the first ridge and the second ridge formed on the outer diameter side of the exchange member in the assembled state. The holding member is configured to include a first groove portion that engages with the first ridge and a second groove portion that engages with the second ridge.

Further, preferably, the ball screw device of the present invention has the first ridge and the first The groove portion extends in an assembled state to the extending direction of the predetermined string of the nut.

Further, preferably, in the ball screw device of the present invention, a receiving groove for accommodating the holding member is formed on a peripheral wall of the nut; the first ridge has a peripheral edge facing the outer diameter side of the switching member a protruding portion protruding from the outside of the portion; the restricting portion is the protruding portion, and the surface on the inner diameter side of the protruding portion contacts the bottom surface of the receiving groove to restrict the circulation member from moving inward in the radial direction with respect to the nut.

Further, preferably, in the ball screw device of the present invention, the surface on the inner diameter side of the protruding portion and the surface on the outer diameter side of the circulation member are formed on the same plane.

Further, preferably, in the ball screw device of the present invention, the second ridge and the second groove portion extend in the axial direction of the nut in an assembled state.

Further, preferably, the ball screw device of the present invention is configured such that the first ridge is engaged with the first groove portion to position the nut by the circulation member.

Further, preferably, the ball screw device of the present invention is configured such that the second ridge is engaged with the second groove portion to position the circulator member.

Further, preferably, in the ball screw device of the present invention, the nut and the holding member are provided with a locking mechanism for locking the holding member to the nut.

Further, in the ball screw device of the present invention, the locking mechanism is formed in a locking groove provided in a peripheral wall of the nut and accommodating the receiving groove of the holding member, and is formed in the holding member and the card The locking protrusion of the groove is engaged.

Further, in the ball screw device of the present invention, the locking mechanism is formed in a tapered portion of the housing groove provided in the peripheral wall of the nut and housing the holding member, and is formed in the holding member and is accommodated The tapered portion of the groove is engaged with the tapered portion.

Further, preferably, in the ball screw device of the present invention, the holding member is formed of a resin.

Further, preferably, the ball screw device of the present invention has a mounting hole for mounting the circulation member in the nut; the holding member fixes the circulation member inserted into the mounting hole; the restricting portion is formed at the a circulation member that is locked to the nut to restrict a claw portion that moves outward in the radial direction of the circulation member; the engagement mechanism is formed by the engagement portion formed in the circulation member and used to mount the holding member The holding member is configured to be engaged with the engaged portion of the engaging portion of the circulating member; the mounting hole of the nut has a hole portion into which the circulating member can be fitted, and the engaging portion mounted on the circulating member The holding member abuts to restrict the buried portion of the circulating member moving inward in the radial direction.

Further, preferably, in the ball screw device of the present invention, the engaging portion of the circulating member is provided on the outer side of the circulating member which is located outside the radial direction of the nut when the circulating member is attached to the nut. The shaft portion is formed of a head portion which is thicker than the shaft portion and provided at a front end of the shaft portion. The engaged portion of the holding member is formed by an opening engageable with the engaging portion of the circulation member.

Further, preferably, in the ball screw device of the present invention, the holding member is elastically deformed between the buried portion of the nut and the head of the circulating member, and the circulating member is outwardly of the nut. Bullet pressure.

Further, preferably, in the ball screw device of the present invention, the outer side surface of the circulation member has an elliptical shape; the holding member is formed of a rectangular plate-like member, and the length in the longitudinal direction is longer than the outer side surface of the circulation member. The length of the short side direction is large.

Further, preferably, the ball screw device of the present invention has the holding member and the long side The length is smaller than the length in the longitudinal direction of the outer side surface of the circulation member, and the length in the short side direction is smaller than the length in the short side direction of the outer side surface of the circulation member.

Further, preferably, in the ball screw device of the present invention, a groove portion extending in a short side direction is formed on the outer side surface of the circulation member; the groove portion restricts the holding member to the engagement portion by accommodating the holding member Rotate for the center.

Further, preferably, in the ball screw device of the present invention, on the outer side surface of the circulation member, a mountain portion is formed on both sides of the groove portion; the top of the mountain portion is opposite to the outer side surface of the circulation member The long sides extend in the direction of inclination and are parallel to each other.

Further, in the ball screw device of the present invention, the hole portion of the nut is coaxial with the buried hole portion; the hole portion is an elliptical through hole into which the circulation member can be fitted; the buried portion is The circular shape has a larger diameter than the longitudinal direction of the holding member.

Further, preferably, in the method of mounting a circulation member of the ball screw device of the present invention, the circulation member is inserted into the mounting hole of the nut from the radially inner side; and the mounting member is inserted into the nut from the outer side in the radial direction. The holes are mounted to the circulation member.

Further, preferably, in the cycle member mounting method of the ball screw device of the present invention, the retaining member is attached to the circulating member such that the longitudinal direction of the outer side surface of the circulating member coincides with the longitudinal direction of the holding member. Inserting the circulation member into the mounting hole of the nut from the inner side in the radial direction; and making the holding member in the cycle such that the longitudinal direction of the outer side surface of the circulating member is orthogonal to the longitudinal direction of the holding member The engaging portion of the member rotates center.

According to the present invention, it is possible to provide a circulation of a ball screw device and a ball screw device which can easily assemble a circulation member and a holding member for holding the circulation member to the nut so as to prevent the circulation member from coming off the nut. Component installation method.

101,301,504‧‧‧ nuts

103,203,303‧‧‧cycle components

105,305‧‧‧through holes

107,307,407‧‧‧stop components

109,309‧‧‧

111,311,411‧‧‧ housing trough

113,313‧‧‧ card slot

115,315‧‧‧Circular Road

117‧‧‧ protruding parts

119, 319‧‧‧ the side of the inner circumference

123,223,323‧‧‧The side of the outer diameter side

125‧‧‧

127‧‧‧ Surface section

139‧‧‧ slot department

245‧‧‧ convex

100,200,300,400‧‧‧Rolling screw device

318‧‧‧ protruding parts

324‧‧‧1st ridge

325‧‧‧2nd ridge

327‧‧‧ inner circumference

329‧‧‧1st engagement slot

331‧‧‧2nd engagement slot

408‧‧‧ Body Department

409‧‧‧ bulging

501,520‧‧‧Rolling screw device

502‧‧‧ Screw shaft

503‧‧‧ balls

504‧‧‧ nuts

505‧‧‧ mounting holes

505a‧‧‧through hole

505b‧‧‧ buried hole

505c‧‧‧Bottom of buried hole

507‧‧‧cycle components

509‧‧‧ fastening parts (clip nuts)

509a‧‧‧Gap section

512‧‧‧ slot department

513‧‧‧Protruding

514‧‧‧Mountain

515‧‧‧ claws

Fig. 1 is a perspective assembled view of a nut of a ball screw device according to a first embodiment.

Fig. 2A is a view showing a circulation member of the ball screw device of the first embodiment as seen from the inner peripheral side of the nut, Fig. 2B is a BB arrow view of Fig. 2A, Fig. 2C is a CC arrow view of Fig. 2A, and Fig. 2D is a view of Fig. 2C. The DD arrow view, Figure 2E is the EE arrow view of Figure 2D.

Fig. 3A is a view of the retaining member of the ball screw device of the first embodiment as seen from the inner peripheral side of the nut, Fig. 3B is a BB arrow view of Fig. 3A, and Fig. 3C is a CC arrow view of Fig. 3A, Fig. 3D is a view 3D DD arrow view, Figure 3E is Figure 3D EE arrow view. Fig. 3 is a five-side view of the retaining member of the ball screw device of the first embodiment.

Fig. 4 is a front view of the nut of the ball screw device of the first embodiment as seen from the axial direction.

Fig. 5 is a side view of the nut of the ball screw device of the first embodiment as seen from the outer diameter direction.

6A and 6B are respectively a cross-sectional view taken along line 6-6 of Fig. 5. Fig. 6A shows a state in which the circulation member and the retaining member are assembled in the nut, and Fig. 6B shows a state in which the circulation member and the retaining member are not assembled.

Fig. 7 is a view showing a method of assembling a retaining member to a nut in the ball screw device of the first embodiment.

Fig. 8 is a perspective assembled view of the nut of the ball screw device of the second embodiment.

Fig. 9A is a view showing a circulation member of the ball screw device of the second embodiment as seen from the inner peripheral side of the nut, Fig. 9B is a BB arrow view of Fig. 9A, Fig. 9C is a CC arrow view of Fig. 9A, and Fig. 9D is a Fig. 9C. The DD arrow view, Figure 9E is the EE arrow view of Figure 9D.

10A and FIG. 10B are respectively FIG. 6A and FIG. 1 of the first embodiment in the second embodiment. 6B corresponds to the figure, FIG. 10A shows the state in which the circulation member and the retaining member are assembled in the nut, and FIG. 10B shows the state in which the circulation member and the retaining member are not assembled.

Fig. 11 is a perspective assembled view of the nut of the ball screw device of the third embodiment.

Fig. 12A is a view showing a circulation member of the ball screw device of the third embodiment as seen from the inner peripheral side of the nut, Fig. 12B is a BB arrow view of Fig. 12A, Fig. 12C is a CC arrow view of Fig. 12A, and Fig. 12D is a Fig. 12C. The DD arrow view, Figure 12E is the EE arrow view of Figure 12D.

13A-E are a five-side view of the retaining member of the ball screw device of the third embodiment, and FIG. 13A is a view of the retaining member of the ball screw device of the third embodiment as seen from the inner peripheral side of the nut, FIG. 13B Figure 13A is a BB arrow view, Figure 13C is a CC arrow view of Figure 13A, Figure 13D is a DD arrow view of Figure 13C, and Figure 13E is an EE arrow view of Figure 13D.

Fig. 14 is a front view of the nut of the ball screw device of the third embodiment as seen from the axial direction.

Fig. 15 is a side view of the nut of the ball screw device of the third embodiment as seen from the outer diameter direction.

Fig. 16 is a side view of the nut of the ball screw device according to the third embodiment as seen from the outer diameter direction, showing a state in which a circulation member is assembled in one of the through holes.

17A and 17B are respectively a cross-sectional view taken along line 17-17 of Fig. 15, and Fig. 17A shows a state in which the circulation member and the retaining member are assembled in the nut, and Fig. 17B shows a state in which the circulation member and the retaining member are not assembled.

Fig. 18 is a view showing a method of assembling a retaining member to a nut in the ball screw device of the third embodiment.

Fig. 19 is a perspective assembled view of the nut of the ball screw device of the fourth embodiment.

Fig. 20A is a view showing the decoupling of the ball screw device of the fourth embodiment as seen from the inner peripheral side of the nut; Figure 20B is a B-B arrow view of Figure 20A, Figure 20C is a C-C arrow view of Figure 20A, Figure 20D is a D-D arrow view of Figure 20C, and Figure 20E is an E-E arrow view of Figure 20D.

Fig. 21 is a side view of the nut of the ball screw device of the fourth embodiment as seen from the outer diameter direction.

22A and 22B are cross-sectional views taken along the line 22-22 of Fig. 21. Fig. 22A shows a state in which the circulation member and the retaining member are assembled in the nut, and Fig. 22B shows a state in which the circulation member and the retaining member are not assembled.

Fig. 23 is a view showing a method of assembling a retaining member to a nut in the ball screw device of the fourth embodiment.

Fig. 24A is a partial cross-sectional view showing the configuration of a ball screw device according to a fifth embodiment of the present invention, and Fig. 24B is a view showing a circulation member in the nut from the outer side in the radial direction, and Fig. 24C is a CC sectional view of Fig. 24B, Fig. 24D. Figure 24C is an enlarged view.

25A, FIG. 25B, FIG. 25C, and FIG. 25D show the configuration of the circulation member, respectively, FIG. 25A is an external view, and FIG. 25B is a view of the circulation member of FIG. 25A viewed from the lower side, that is, a view showing the inner side surface, FIG. 25C Fig. 25D is a view of the circulation member of Fig. 25A as viewed from the upper side, that is, a view showing the outer side.

Fig. 26 is a view showing the mounting hole of the nut viewed from the outer side in the radial direction.

27A, 27B, 27C, and 27D show the structure of the fastening member, respectively, Fig. 27A is a side view in the longitudinal direction, Fig. 27B is a side view in the short side direction, and Fig. 27C is a front view, Fig. 27D is a Figure 27B is a side view of the opposite side of the short side.

28A and 28B are views showing a state in which the circulation member is attached to the nut in the fifth embodiment, and Fig. 28A is a view showing a state in which the circulation member is inserted into the mounting hole of the nut, and Fig. 28B shows that A diagram of how the fastening components are mounted on the circulation member.

29A, 29B, and 29C show a circulation member attached to a nut, and Fig. 29A is a view from the outer side in the radial direction, Fig. 29B is a view from the inner side in the radial direction, and Fig. 29C is a cross-sectional view from the side. Figure.

Fig. 30A is a partial cross-sectional view showing the configuration of a ball screw device according to a sixth embodiment of the present invention, and Fig. 30B is a view showing a circulation member in the nut from the outer side in the radial direction, and Fig. 30C is a CC sectional view of Fig. 30B, Fig. 30D. Figure 30C is an enlarged view.

31A, 31B, and 31C show a state in which a fastening member is attached to a circulation member in the sixth embodiment, and Fig. 31A shows a view of the outer side surface, Fig. 31B is a side view, and Fig. 31C shows a deformation of the outer side surface. Illustration of the example.

Figs. 32A and 32B show a state in which the fastening member attached to the circulation member is rotated in the sixth embodiment, Fig. 32A shows a front view before rotation, and Fig. 32B shows a view after rotation.

Figure 33 is a cross-sectional view showing the configuration of a conventional ball screw device.

Figure 34 is a perspective assembled view showing the construction of a nut of a conventional ball screw device.

35A, 35B, and 35C are views showing a method of assembling a second member to a nut in a conventional ball screw device, and Fig. 35A shows a case where the outer diameter of the nut is small, and Fig. 35B shows a case other than the nut. In the case of a large diameter, Fig. 35C shows a case where the outer diameter of the nut is larger.

Figure 36 is a side elevational view of a nut 1110 of a conventional ball screw device.

(First embodiment)

Hereinafter, a first embodiment of the ball screw device of the present invention will be described with reference to the drawings.

First, the direction of the constituent members of the ball screw device in this specification is defined. In this manual In the meantime, the direction of the constituent members of the ball screw device is the same as the axial direction, the radial direction, and the circumferential direction of the ball screw, that is, the ball screw groove formed in the nut, that is, the female screw.

Fig. 1 is a perspective assembled view of a nut 101 of the ball screw device 100 of the present embodiment.

The ball screw device 100 of the present embodiment is an internal circulation type ball screw device, and includes a linear screw shaft (not shown) in which a spiral ball rolling groove (not shown) is formed on the outer peripheral surface, and an inner peripheral surface thereof. A cylindrical nut 101 having a spiral ball rolling groove 137 (see FIG. 4 described later) opposed to the ball rolling groove of the screw shaft is formed, and the nut 101 is rotatably attached to the two ball rolling grooves. A plurality of balls (not shown) are fitted to the outer peripheral side of the screw shaft, and the screw shaft is rotated to move in the axial direction of the screw shaft. In addition, the screw shaft and the ball of the ball screw device 100 are the same as those of the conventional ball screw device, and thus the detailed description of the drawings and the configuration is omitted in the present specification.

As shown in FIG. 1, the ball screw device 100 of the present embodiment includes a circulation member 103 that is a recirculating member that is assembled to the nut 101. By the circulation member 103, a plurality of balls (not shown) attached between a ball rolling groove (not shown) of a screw shaft (not shown) and a ball rolling groove 137 of the nut 101 are returned to the adjacent two balls. Circulate between rolling grooves. The nut 101 is provided with a through hole 105 formed in a radial direction from the outer peripheral surface side toward the inner peripheral surface side. The through hole 105 has a substantially circular cross section and is assembled with a circulation member 103.

Further, as shown in FIG. 1, the ball screw device 100 of the present embodiment is provided with a circulation member 103 assembled in the through hole 105 and held by the nut 101 to prevent the circulation member 103 from coming off the outer side of the nut 101 in the radial direction. Disengagement member 107. The retaining member 107 is disposed on the outer diameter side of the circulation member 103 in contact with the circulation member 103 as will be described later.

The retaining member 107 is formed of a metal member such as a steel material, and is assembled in the nut 101 so that the extending direction of the predetermined string of the nut 101 is the long side direction, that is, the long side and the axial direction of the nut 101. It is a rectangular plate-shaped member which is a short side direction, that is, a short side. Here, in the present specification, "chord" means a string which is orthogonal to the central axis of the through hole 105 in the chord of the circle between the female screws of the nut 101.

A receiving groove 111 having a width in a predetermined axial direction for accommodating the retaining member 107 is formed on the outer peripheral side portion of the peripheral wall of the nut 101. The accommodating groove 111 is formed so as to traverse the through hole 105 in the extending direction of the chord and penetrate the outer peripheral side portion of the peripheral wall of the nut 101 in the extending direction of the chord. The receiving groove 111 has a bottom surface extending in the extending direction of the chord, and the cross-sectional shape as viewed from the axial direction of the nut 101 is formed into a circular arc shape, that is, a bow shape, in which the outer periphery of the nut 101 is an arc. At the bottom of both side faces of the arch-shaped receiving groove 111, a pair of locking grooves 113, 113 which are recessed in the direction opposite to the axial direction of the nut 101 are formed to extend along the bottom surface of the receiving groove 111. When the retaining member 107 is inserted into the arcuate receiving groove 111, the pair of locking grooves 113 and 113 have a function as a guide as will be described later.

Fig. 2 is a five-side view of the circulation member 103 of the present embodiment. In Fig. 2, Fig. 2A is a view seen from the inner peripheral side of the nut 101 in an assembled state. Figure 2B is a B-B arrow view of Figure 2A. Figure 2C is a C-C arrow view of Figure 2A. Figure 2D is a D-D arrow view of Figure 2C. Figure 2E is an E-E arrow view of Figure 2D. In addition, in the horizontal direction in FIG. 2A, that is, the left-right direction of the paper surface is the axial direction of the nut 101, and the vertical direction, that is, the circumferential direction of the paper surface, is the circumferential direction of the nut 101 or the extending direction of the chord.

As shown in each of FIG. 2, the circulation member 103 is formed in a substantially disk shape, and the surface 119 which is one of the front sides in FIG. 2A is disposed toward the inner peripheral side of the nut 101. A circulation path 115, which is a groove for circulating a ball (not shown), is formed on the inner peripheral surface 119 of the circulation member 103. As shown in FIG. 2A, the circulation path 115 extends in the substantially circumferential direction of the nut 101 and is formed in a substantially S-shape. In the circumferential direction of the circulation member 103, that is, the side surfaces on the upper and lower sides in FIG. 2A are respectively provided with a pair of fin-shaped projecting portions 117, 117 which protrude in a direction opposite to the circumferential direction. As shown in FIG. 2A, the shape of each fin-shaped protruding portion 117 as viewed from the inner peripheral side of the nut 101 is an arc shape of a semicircle at the tip end side.

The shape of each fin-like projection 117 is observed from the direction in which the chord extends, as shown in Fig. 2B, and is substantially rectangular. Moreover, the shape of the circulation member 103 is seen from the axial direction, and as shown in FIG. 2C, the inner surface side surface 119 of the circulation member 103 is formed in a concave shape. This concave surface is a cylindrical inner surface coaxial with the nut 101. Further, the shape of each of the protruding portions 117 viewed from this direction is formed in a rectangular shape. Further, the surface 123 on the outer diameter side of the circulation member 103 is a flat surface as shown in Figs. 2B to 2E. The surface on the outer diameter side of each of the protruding portions 117 is provided on the same plane as the surface 123.

In the center portion of the surface 123 of the circulation member 103, as shown in FIG. 2B to FIG. 2E, a protrusion 125 that protrudes outward in the radial direction and extends in the axial direction in a state of being assembled to the nut 101 is formed. . The ridge 125 has a cross-sectional shape as viewed in the axial direction and is formed in an arc shape.

Fig. 3 is a five-side view of the retaining member 107 of the present embodiment. In Fig. 3, Fig. 3A is a view as seen from the inner peripheral side of the nut 101. Figure 3B is a B-B arrow view of Figure 3A. Figure 3C is a C-C arrow view of Figure 3A. Figure 3D is a D-D arrow view of Figure 3C. Figure 3E is an E-E arrow view of Figure 3D. In addition, in the horizontal direction in FIG. 3A, that is, the left-right direction of the paper surface is the axial direction of the nut 101, and the vertical direction, that is, the circumferential direction of the paper, is the circumferential direction of the nut 101 or the extending direction of the chord.

As shown in FIG. 3A and FIG. 3D, the retaining member 107 has a substantially rectangular shape, and is formed at both end portions of the pair of long side edge portions so as to protrude in the axial direction in a state of being assembled to the nut 101. The protrusions 109, 109 of the member 107 extending in the longitudinal direction. Also, the length of the retaining member 107 The center portion in the side direction is a curved surface portion 127 as shown in FIG. 3C. In the state in which the curved surface portion 127 is assembled to the nut 101, the surface on the outer diameter side protrudes outward in the radial direction, the surface on the inner diameter side is recessed outward in the radial direction, and the cross-sectional shape as viewed in the axial direction is formed in a substantially arc shape. . The curved surface portion 127 is formed to extend in the axial direction of the nut 101, and the curved surface portion 127 has an arc shape, and the curvature of the surface on the inner diameter side is formed to be fitted to the protrusion 125 of the circulation member 103. Since the retaining member 107 is configured as described above, the shape viewed from the direction in which the string extends is substantially T-shaped as shown in FIGS. 3B and 3E.

Fig. 4 is a front view of the nut 101 as viewed from the axial direction. As shown in FIG. 4, a hole 135 extending along the axial center of the nut 101 and inserted into a screw shaft (not shown) is formed in a central portion of the nut 101. The holes 135 are formed in substantially the same inner diameter in the axial direction. A spiral ball rolling groove 137 is formed in the inner peripheral surface of the hole 135.

In the present embodiment, as shown in FIG. 4, the through hole 105 is separated by 180 in the circumferential direction of the nut 101. There are two. Each of the through holes 105 extends from the inner diameter side of the nut 101 toward the outer diameter side, and is opened in the arcuate receiving groove 111. Each of the through holes 105 is formed in a portion opposite to the receiving groove 111, and a pair of groove portions 139, 139 are formed to be recessed in the opposite direction to the direction in which the chord extends in the direction in which the chord extends. Each of the groove portions 139 is opened in the housing groove 111 at the outer peripheral end portion of the nut 101, and an end surface 141 parallel to the bottom surface of the housing groove 111 is formed at the inner circumferential side end portion of the nut 101 to be closed. The groove portions 139, 139 respectively receive one of the pair of fin members 117, 117 of the fin member 103. The circulation member 103 is engaged with the pair of groove portions 139 and 139 by the pair of fin-shaped projecting portions 117 and 117, and is restricted from being moved to the inner diameter side of the nut 101 and rotated relative to the nut 101 while being assembled in the through hole 105.

Fig. 5 is a side view of the nut 101 of the ball screw device of the first embodiment as seen from the outer diameter direction. As shown in FIG. 5, one of the through holes 105 is formed on the left side. The other side The hole 105 is formed by being separated from the one through hole 105 by 180° in the circumferential direction of the nut 101, and is formed on the right side. That is, one of the through holes 105 and the other through hole 105 are formed to be shifted in the axial direction.

6 is a cross-sectional view taken along line 6-6 of FIG. 5, FIG. 6A shows a state in which the circulation member 103 and the retaining member 107 are assembled in the nut 101, and FIG. 6B shows a state in which the circulation member 103 and the retaining member 107 are not assembled. .

As shown in FIG. 6A and FIG. 6B, the groove portion 139 is formed by recessing the inner wall of the through hole 105 in a rectangular shape in the extending direction of the chord. Further, as shown in FIG. 6A, the surface 123 of the outer diameter side of the circulation member 103 assembled in the through hole 105 is in contact with the surface of the inner diameter side of the retaining member 107 of the housing groove 111. Further, the protrusions 109, 109 of the retaining member 107 are respectively engaged with the locking grooves 113, 113 formed at the bottoms of both side faces of the housing groove 111.

Next, a method of assembling the circulation member 103 and the retaining member 107 to the nut 101 will be described. As shown in FIG. 1, the circulation member 103 and the retaining member 107 are assembled to the nut 101. First, the circulation member 103 is attached to the through hole 105 of the nut 101, and then the retaining member 107 is assembled in the housing groove 111.

The assembly of the circulation member 103 to the through hole 105 is such that the circulation member 103 is inserted into the through hole 105 from the outer side in the radial direction of the nut 101 toward the inner side in the radial direction. Next, the protruding portions 117, 117 are engaged with one of the pair of through holes 105 by the one of the circulation members 103, and the circulation member 103 is positioned in the through hole 105. At this time, the surface 119 on the inner peripheral side of the circulation member 103 is located on the same surface as the inner circumferential surface of the nut 101. Further, the protrusions 125 formed on the surface 123 on the outer diameter side of the circulation member 103 are arranged to extend in the axial direction in the through holes 105.

Regarding the assembly of the retaining member 107 to the receiving groove 111, FIG. 7 illustrates two assembling methods. First, in the first method, the retaining member 107 is moved from the outer peripheral side of the nut 101 to the receiving groove. The method of sliding the extending direction of the 111-string. In this method, the end portions of the protrusions 109, 109 on both sides of the retaining member 107 are inserted into the end portions of the pair of locking grooves 113, 113 formed on the side of the receiving groove 111, and in this state, the retaining member 107 is along the receiving groove. The method of sliding the bottom surface of 111 toward the direction in which the strings extend. At this time, the pair of locking grooves 113, 113 are engaged with the projections 109, 109 to guide the insertion of the retaining member 107. Then, after the end of one of the retaining members 107 reaches the ridge 125 of the circulating member 103, the retaining member 107, the end of the one of the ends passes over the ridge 125, and the portion abutting the ridge 125 is elastically deformed and simultaneously chords. The direction of extension extends. Next, after the curved surface portion 127 of the retaining member 107 reaches the ridge 125, the curved surface portion 127 is engaged with the ridge 125. Specifically, the ridge 125 is engaged with the inner diameter side of the curved surface portion 127. Thereby, the retaining member 107 is positioned at a predetermined position. In the above manner, the assembly of the nut 101 by the circulation member 103 and the retaining member 107 is completed.

In the second method, the retaining member 107 is pressed into the receiving groove 111 from the outer peripheral surface side of the nut 101 in a direction substantially perpendicular to the bottom surface of the receiving groove 111, and then the retaining member 107 is advanced along the bottom surface of the receiving groove 111. The method of sliding the direction of the string. In this method, first, the retaining member 107 is press-fitted into the receiving groove in the vertical direction from the position on the outer side in the radial direction of the circulating member 103 of the nut 101 and slightly offset from the center of the nut 101 toward the bottom surface of the receiving groove 111. Within 111. Then, the retaining member 107 reaches the bottom surface of the accommodating groove 111, and the ridges 109 and 109 of the detaching member 107 are engaged with the pair of locking grooves 113 and 113, and then, similarly to the first method, the retaining member 107 is placed along the accommodating groove. The bottom surface of 111 slides toward the direction in which the strings extend. At this time, the pair of locking grooves 113, 113 are engaged with the projections 109, 109 to guide the insertion of the retaining member 107. Next, similarly to the above-described first method, the retaining member 107 is slid before the curved surface portion 127 of the retaining member 107 is engaged with the protrusion 125 of the circulating member 103. Thereby, the retaining member 107 is positioned at a predetermined position. In the above manner, the assembly of the nut 101 by the circulation member 103 and the retaining member 107 is completed.

As described above, according to the present embodiment, the retaining member 107 disposed on the outer diameter side of the nut 101 of the circulation member 103 can be easily disposed at a predetermined position. As a result, the assembly time of the circulation member 103 and the retaining member 107 to the nut 101 can be reduced, and the manufacturing cost can be reduced. Further, according to the present embodiment, even if the outer diameter of the nut is increased, the retaining member 107 can be easily placed at a predetermined position by the method illustrated in Fig. 7 .

Further, according to the present embodiment, the load transmitted from the inner peripheral side of the nut 101 to the circulation member 103 through the ball (not shown) is transmitted to the retaining member 107, but the retaining member 107 is penetrated from the circulating member 103. Since the insertion direction of the hole 105 is different, that is, the direction in which the chord of the nut 101 extends, the nut 101 is inserted, so that the stopper member 107 does not fall off due to the load in the direction in which the circulation member 103 is to be pulled out. In other words, the retaining member 107 is engaged with the locking grooves 113, 113 of the receiving groove 111 extending in the extending direction of the string by the ridges 109, 109, thereby preventing the nut 101 from coming off the outer side in the radial direction. Therefore, the falling of the circulation member 103 can be prevented.

As described above, according to the present embodiment, the circulation member 103 and the retaining member 107 that holds the circulation member 103 in the nut 101 can be assembled to the nut 101 in a time-consuming and easy manner to prevent the circulation member 103 from coming off the nut 101. .

(Second embodiment)

Next, a second embodiment of the ball screw device of the present invention will be described.

Fig. 8 is a perspective assembled view of the nut 101 of the ball screw device 200 of the second embodiment. The ball screw device 200 according to the second embodiment will be described mainly with a configuration different from that of the first embodiment, and the same configurations as those of the first embodiment will not be described redundantly. The same members as those in the first embodiment will be described using the same reference numerals. As shown in FIG. 8, the ball screw device 200 of the second embodiment has an example in which the configuration of the circulation member 203 is different from that of the first embodiment. The other configuration is the same as that of the first embodiment.

Fig. 9 is a five-side view showing a circulation member 203 of the ball screw device 200 of the second embodiment. In Fig. 9, Fig. 9A is a view as seen from the inner peripheral side of the nut 101 in an assembled state. Figure 9B is a B-B arrow view of Figure 9A. Figure 9C is a C-C arrow view of Figure 9A. Figure 9D is a D-D arrow view of Figure 9C. Figure 9E is an E-E arrow view of Figure 9D. In addition, in the horizontal direction in FIG. 9A, that is, the left-right direction of the paper surface is the axial direction of the nut 101, and the vertical direction, that is, the circumferential direction of the paper, is the circumferential direction of the nut 101 or the extending direction of the chord.

As shown in each of the second embodiment, in the center portion of the outer surface side surface 223 of the circulation member 203, a substantially spherical shape that protrudes outward in the radial direction in the state of being assembled to the nut 101 is formed. The convex portion 245. The other configuration of the circulation member 203 is the same as that of the first embodiment.

Figs. 10A and 10B are views corresponding to Figs. 6A and 6B of the first embodiment, and Fig. 10A shows a state in which the circulation member 203 and the retaining member 107 are assembled to the nut 101, and Fig. 10B. The state in which the circulation member 203 and the retaining member 107 are not assembled is shown.

As shown in FIG. 10A, the surface 223 of the outer diameter side of the circulation member 203 of the through hole 105 is in contact with the surface of the inner diameter side of the retaining member 107 of the arched receiving groove 111. Further, the protrusions 109, 109 of the retaining member 107 are respectively engaged with the locking grooves 113, 113 formed at the bottoms of both side faces of the housing groove 111. Further, the convex portion 245 of the circulation member 203 is engaged with the curved surface portion 127 of the retaining member 107. As described above, in the second embodiment, the point where the convex portion 245 of the circulation member 203 is engaged with the curved surface portion 127 of the retaining member 107 is different from that of the first embodiment.

In the second embodiment, the method of assembling the retaining member 107 to the receiving groove 111 and the first 1 embodiment is the same (see Fig. 7). In the second embodiment, in the first method and the second method, the retaining member 107 is moved along the bottom surface of the receiving groove 111 before the curved surface portion 127 of the retaining member 107 is engaged with the convex portion 245 of the circulating member 203. Just fine.

As described above, in the second embodiment, as in the first embodiment, the retaining member 107 disposed on the outer diameter side of the circulation member 203 can be easily disposed at a predetermined position. As a result, the assembly time of the circulation member 203 and the retaining member 107 to the nut 101 can be reduced, and the manufacturing cost can be reduced. Further, in the present embodiment, even if the outer diameter of the nut 101 is increased, the retaining member 107 can be easily placed at a predetermined position as in the first embodiment.

Further, in the present embodiment, the load transmitted from the inner peripheral side of the nut 101 to the circulation member 103 through the ball (not shown) is transmitted to the retaining member 107, but the retaining member 107 is penetrated from the circulating member 203. Since the insertion direction of the hole 105 is different, that is, the direction in which the chord of the nut 101 extends, the nut 101 is inserted, so that the stopper member 107 does not fall off due to the load in the direction in which the circulation member 203 is to be pulled out. In other words, the retaining member 107 is engaged with the locking grooves 113, 113 of the receiving groove 111 extending in the extending direction of the string by the ridges 109, 109, thereby preventing the nut 101 from coming off the outer side in the radial direction. Therefore, the falling off of the circulation member 203 can be prevented.

As described above, according to the present embodiment, the circulation member 203 and the retaining member 107 that holds the circulation member 203 in the nut 101 can be assembled to the nut 101 in a time-consuming and easy manner to prevent the circulation member 203 from coming off the nut 101. .

(Third embodiment)

Next, a third embodiment of the ball screw device of the present invention will be described.

Fig. 11 is a perspective assembled view of the nut 301 of the ball screw device 300 of the present embodiment. The ball screw device 300 of the third embodiment is the same as the internal one of the first embodiment. Ring ball screw device. The ball screw device 300 according to the third embodiment will be described mainly with a configuration different from that of the first embodiment, and the same configurations as those of the first embodiment will not be described redundantly. As shown in FIG. 11, the ball screw device 300 of the third embodiment has a configuration in which the circulation member 303, the retaining member 307, and the through hole 305 are different from those of the first embodiment. The other configuration is the same as that of the first embodiment.

As shown in Fig. 11, the ball screw device 300 of the present embodiment includes a circulation member 303 which is a recirculating member that is assembled to the nut 301. The nut 301 is provided with a through hole 305 which is formed in a radial direction from the outer peripheral surface side toward the inner peripheral surface side. The through hole 305 is formed in a substantially circular cross section, and a circulation member 303 is assembled.

Further, as shown in FIG. 11, the ball screw device 300 of the present embodiment is provided with a circulation member 303 that is assembled in the through hole 305 and held by the nut 301 to prevent the circulation member 303 from coming off the outer side of the nut 301 in the radial direction. Disconnect member 307. The retaining member 307 is disposed on the outer diameter side of the circulation member 303 in contact with the circulation member 303 as will be described later.

The retaining member 307 of the present embodiment is made of an engineering plastic. When the retaining member 307 is assembled to the nut 301, the member extending toward the extending direction of the predetermined chord of the nut 301 is formed such that the surface of the inner peripheral side is formed by the direction in which the chord extends, that is, the long side, that is, the long side. Further, the axial direction is a substantially rectangular shape in which the short side direction is the short side, and the outer peripheral side surface is formed into a curved surface. Here, "chord" means a chord which is orthogonal to the central axis of the through hole 305 in the chord of the circle between the female screws of the nut 101.

A receiving groove 311 having a width in a predetermined axial direction for accommodating the retaining member 307 is formed on the outer peripheral portion of the peripheral wall of the nut 301. The accommodating groove 311 is formed so as to traverse the through hole 305 in the extending direction of the chord and penetrate the outer peripheral side portion of the peripheral wall of the nut 301 in the extending direction of the chord. The receiving groove 311 has a bottom surface extending in a direction in which the chord extends, and a cross-sectional shape viewed from the axial direction of the nut 301 It is formed in a partial circular shape in which the outer circumference of the nut 301 is a circular arc, that is, at the bottom of both side surfaces of the receiving groove 311 formed into a bow shape, and is recessed in a direction opposite to the axial direction of the nut 301. The locking grooves 313, 313 are formed to extend along the bottom surface of the arcuate receiving groove 311. The bow-shaped receiving groove 311 and the pair of locking grooves 113, 113 are respectively configured in the same manner as the receiving groove 111 and the locking grooves 113, 113 of the first embodiment. When the pair of locking grooves 313 and 313 are inserted into the receiving groove 311, the pair of locking grooves 313 and 313 have a function as a guide.

Fig. 12 is a five-side view of the circulation member 303 of the embodiment. In Fig. 12, Fig. 12A is a view seen from the inner peripheral side of the nut 301 in an assembled state. Figure 12B is a B-B arrow view of Figure 12A. Figure 12C is a C-C arrow view of Figure 12A. Figure 12D is a D-D arrow view of Figure 12C. Figure 12E is an E-E arrow view of Figure 12D. In addition, in the horizontal direction in FIG. 12A, that is, the left-right direction of the paper surface is the axial direction of the nut 301, and the vertical direction, that is, the circumferential direction of the paper surface, is the circumferential direction of the nut 301 or the extending direction of the chord.

As shown in each of FIG. 12, the circulation member 303 is formed in a substantially disk shape, and the surface 319 which is one of the front sides in FIG. 12A is disposed toward the inner circumferential side of the nut 301. As shown in FIG. 12C, the surface 319 on the inner peripheral side of the circulation member 303 is formed in a concave shape as viewed from the axial direction of the nut 301. This concave surface is a cylindrical inner surface coaxial with the nut 301. On the surface 319, a circulation path 315 which is a groove for circulating a ball (not shown) is formed. As shown in FIG. 12A, the circulation path 315 extends in the substantially circumferential direction of the nut 301, and is formed in a substantially S-shape.

The outer surface side surface 323 of the circulation member 303 is a flat surface as shown in Figs. 12B to 12E. In the surface 323, as shown in each of FIG. 12, a first ridge 324 which protrudes outward in the radial direction and has a substantially rectangular cross-sectional shape is formed. The first ridge 324 extends through the center portion of the face 323 in the direction in which the chord extends. The two ends of the first rib 324 are respectively formed to extend the outer edge of the face 323 toward the chord Projecting portions 318, 318 projecting outwardly of the direction. The front end portions of the protruding portions 318, 318 are formed in an arc shape. The faces on the inner diameter side of the projections 318, 318 are disposed on the same plane as the face 323.

Further, as shown in FIG. 12B to FIG. 12E, the surface 323 of the circulation member 303 is formed with a pair of second ridges 325 and 325 which are protruded outward in the radial direction and have a substantially arc-shaped cross-sectional shape. The second ridges 325 and 325 are formed to extend from the central portion of the surface 323 in a direction opposite to the axial direction, and the end portion on the central portion side of each surface 323 is connected to the first ridge 324. Further, the end portions of the second ridges 325 and 325 opposite to the center portion of the surface 323 extend to the outer edge of the surface 323, respectively. According to the above configuration, the first ridge 324 and the second ridges 325 and 325 have a substantially cross shape that intersects at the center of the surface 323. The height of the second ridges 325, 325 is formed to be lower than the height of the first ridges 324. That is, the amount of protrusion of the first protrusion 324 toward the outer side in the radial direction of the nut 301 is larger than that of the second protrusions 325 and 325. Further, the width of the second ridges 325, 325 is formed to be wider than the first ridge 324.

Fig. 13 is a five-side view of the retaining member 307 of the embodiment. In Fig. 13, Fig. 13A is a view as seen from the inner peripheral side of the nut 301. Figure 13B is a B-B arrow view of Figure 13A. Figure 13C is a C-C arrow view of Figure 13A. Figure 13D is a D-D arrow view of Figure 13C. Figure 13E is an E-E arrow view of Figure 13D. In addition, in the horizontal direction in FIG. 13A, that is, the left-right direction of the paper surface is the axial direction of the nut 301, and the vertical direction, that is, the circumferential direction of the paper surface, is the circumferential direction of the nut 301 or the extending direction of the chord.

As shown in each of Fig. 13, the retaining member 307 is a member extending in the extending direction of the chord, and the inner peripheral side surface 327 is formed in a plane having a substantially rectangular shape in the longitudinal direction of the chord extending direction. The inner peripheral side surface 327 is formed in an arc shape at both end portions in the direction in which the chord extends. Both sides of the retaining member 307, that is, both sides of the axial direction side are formed to be parallel to each other. Further, the outer diameter side surface of the retaining member 307 is formed as a curved surface as shown in FIG. 13C, and the curved surface has a suitable nut 301. The curvature of the outer peripheral surface. Therefore, the shape of the retaining member 307 is viewed from the axial direction, and is formed into a bow shape as shown in FIG. 13C.

At both end portions of the side edge portion of the inner circumferential surface 327 of each side surface of the retaining member 307, a projection that protrudes in the axial direction and is extended in the longitudinal direction of the retaining member 307 in a state of being assembled to the nut 301 is formed. Article 309,309. The edge of the ridges 309 and 309 is formed in an arc shape continuous with the arc shape of the end portion of the inner peripheral side surface 327. According to the above configuration, the shape of the retaining member 307 as viewed from the direction in which the chord extends is substantially T-shaped as shown in Figs. 13B and 13E.

The surface 327 on the inner peripheral side of the retaining member 307 is formed with a first engaging groove 329 that extends through the center portion of the surface 327 and extends in the direction in which the string extends. The first engagement groove 329 is formed in a substantially rectangular cross section. Both end portions of the first engagement groove 329 are open to the outside in the extending direction of the chord of the retaining member 307. Further, the first engagement groove 329 has a width and a depth to be fitted to the first protrusion 324 of the circulation member 303, and has a length longer than the length dimension of the first protrusion 324.

Further, the surface 327 on the inner peripheral side of the retaining member 307 is formed to extend from the central portion of the surface 327 to the second engaging groove 331, 331 which extends in a direction opposite to the axial direction and has a substantially circular arc shape in cross section. The end portions on the central portion side of the surface 327 of the second engagement grooves 331, 331 are opened in the first engagement groove 329, respectively. Further, the second engagement grooves 331, 331 respectively penetrate the side faces of the retaining member 307. According to the above configuration, the first engagement groove 329 and the second engagement grooves 331, 331 have a substantially cross shape that intersects the center portion of the surface 327. The depth of the second engagement grooves 331, 331 is formed to be shallower than the depth of the first engagement groove 329. Further, the second engagement grooves 331, 331 have widths and depths in which the second protrusions 325 and 325 can be fitted.

Fig. 14 is a front view of the nut 301 as seen from the axial direction. As shown in Fig. 14, a hole 335 extending along the axial center of the nut 301 and inserted into a screw shaft (not shown) is formed in a central portion of the nut 301. The holes 335 are formed in substantially the same inner diameter in the axial direction. Formed on the inner circumference of the hole 335 A spiral ball rolling groove 337. In the present embodiment, as shown in FIG. 14, the through hole 305 is separated by 180 in the circumferential direction of the nut 301. There are two. Each of the through holes 305 extends from the inner diameter side of the nut 301 toward the outer diameter side, and is opened in the arcuate receiving groove 311.

Fig. 15 is a side view of the nut 301 of the ball screw device 300 according to the third embodiment as seen from the outer diameter direction. As shown in FIG. 15, one of the through holes 305 is formed on the left side. The other through hole 305 is separated from one of the through holes 305 by 180 in the circumferential direction of the nut 301. Formed, formed on the right side. That is, one of the through holes 305 and the other through hole 305 are formed to be shifted in the axial direction.

16 is a side view of the nut 301 of the ball screw device 300 according to the third embodiment as seen from the outer diameter direction, and shows a state in which the circulation member 303 is assembled in one of the through holes 305.

As shown in FIG. 16, the circulation member 303 is assembled to the through hole 305 of the nut 301 so that the first protrusion 324 extends in the direction in which the string extends and the second protrusions 325 and 325 extend in the axial direction. The both ends of the first ridge 324, that is, the protruding portions 318, 318, the surface on the inner diameter side contact the bottom surface of the arcuate receiving groove 311. The circulation member 303 is in contact with the bottom surface of the accommodation groove 311 by the surface on the inner diameter side of the protruding portions 318, 318, and restricts the movement of the nut 301 to the inner diameter side in the state of being assembled in the through hole 305. That is, positioning in the radial direction is performed. As described above, the protruding portions 318, 318 are configured to correspond to the fin-like projections 1117, 1117 (see Fig. 34) in the conventional ball screw device.

17 is a cross-sectional view taken along line 17-17 of FIG. 15, FIG. 17A shows a state in which the circulation member 303 and the retaining member 307 are assembled in the nut 301, and FIG. 17B shows a state in which the circulation member 303 and the retaining member 307 are not assembled. .

As shown in FIGS. 17A and 17B, the protrusions 309 and 309 of the retaining member 307 are respectively engaged with the locking grooves 313 and 313 formed at the bottoms of both side faces of the arch-shaped receiving groove 311. Also, the circulation member 303 The first protrusion 324 is engaged with the first engagement groove 329 of the retaining member 307. Further, the second protrusions 325, 325 of the circulation member 303 are engaged with the second engagement grooves 331, 331 of the retaining member 307. As described above, the outer surface side surface 323 of the circulation member 303 is in contact with the inner surface side surface 327 of the retaining member 307.

In the present embodiment, the circulation member 303 is engaged with the first engagement groove 329 of the retaining member 307 by the first protrusion 324, and the position with respect to the nut 301 is determined, and the rotation with respect to the nut 301 is restricted. Further, the retaining member 307 is engaged with the second protrusions 325 and 325 of the circulation member 303 by the second engagement grooves 331, 331 to position the circulation member 303.

Next, a method of assembling the circulation member 303 and the retaining member 307 to the nut 301 will be described. As shown in FIG. 11, the circulation member 303 and the retaining member 307 are assembled to the nut 301. First, the circulation member 303 is attached to the through hole 305 of the nut 301, and then the retaining member 307 is assembled to the receiving groove 311.

The assembly of the circulation member 303 to the through hole 305 is such that the circulation member 303 is inserted into the through hole 305 from the outer side in the radial direction of the nut 301 toward the inner side in the radial direction. At this time, the first ridge 324 extends in the direction in which the chord extends, and the pair of second ridges 325 and 325 are inserted in the direction in which the axial direction extends. Next, the protruding portions 318, 318 of the first ridge 324 are in contact with the bottom surface of the receiving groove 311, and the circulation member 303 is positioned in the radial direction of the nut 301. At this time, the surface 319 on the inner peripheral side of the circulation member 303 is located on the same surface as the inner circumferential surface of the nut 301. Also, at this stage, the positioning of the nut 301 by the circulation member 303 is not performed.

Next, the retaining member 307 is assembled to the receiving groove 311. Regarding the assembly of the retaining member 307 to the receiving groove 311, FIG. 18 illustrates two assembling methods. First, the first method is a method in which the retaining member 307 is slid from the outer peripheral surface side of the nut 301 toward the direction in which the receiving groove 311 extends, that is, in the direction in which the chord extends. This method inserts the ends of the protrusions 309, 309 on both sides of the retaining member 307 In a state in which one of the side faces of the receiving groove 311 faces the locking grooves 313, 313 and in this state, the retaining member 307 is slid along the bottom surface of the receiving groove 311 in the direction in which the string extends. At this time, the pair of locking grooves 313, 313 are engaged with the projections 309, 309 to guide the insertion of the retaining member 307.

Then, after the end of one of the retaining members 307 reaches the end of the first protrusion 324 of the circulation member 103, the retaining member 307, the first engaging groove 329 and the first protrusion 324 are engaged and extended toward the string. Slide in the direction. At this stage, the position of the circulation member 303 with respect to the nut 301 is determined. Then, after the end of one of the retaining members 307 reaches the second ridges 325 and 325 of the circulation member 103, the retaining member 307 passes over the second ridges 325 and 325 and the portion that abuts the second ridges 325 and 325. Elastic deformation and advance toward the direction of the string. Then, after the second engagement grooves 331 and 331 of the stopper member 307 reach the second protrusions 325 and 325, the second engagement grooves 331, 331 are engaged with the second protrusions 325 and 325. Thereby, the retaining member 307 is positioned at a predetermined position on the outer diameter side of the circulation member 303. Further, the first protrusion 324 of the circulation member 303 is engaged with the first engagement groove 329 of the retaining member 307, and the positioning of the circulation member 303 to the nut 301 is completed. In the above manner, the assembly of the nut 301 by the circulation member 303 and the retaining member 307 is completed.

In the second method of assembling the retaining member 307 to the receiving groove 311, the retaining member 307 is pressed into the receiving groove 311 from the outer peripheral surface side of the nut 301 in a substantially vertical direction with respect to the bottom surface of the receiving groove 311. The detaching member 307 slides along the bottom surface of the receiving groove 311 in the direction in which the chord extends. In this method, first, the retaining member 307 is pressed into the receiving groove in the vertical direction from the position on the outer side in the radial direction of the circulating member 303 of the nut 301 and slightly offset from the center of the nut 301 toward the bottom surface of the receiving groove 311. Within 311. When the retaining member 307 is press-fitted into the receiving groove 311, the first engaging groove 329 of the retaining member 307 is partially engaged with the first protrusion 324 of the circulating member 303 from the outer side in the radial direction. After the retaining member 307 is further pressed in, the retaining member 307 reaches the receiving groove On the bottom surface of the 311, the protrusions 309, 309 of the retaining member 307 are engaged with the pair of locking grooves 313, 313. At this stage, the position of the circulation member 303 with respect to the nut 301 is determined.

Thereafter, similarly to the first method described above, the retaining member 307 is slid along the bottom surface of the receiving groove 311 in the direction in which the string extends. At this time, the pair of locking grooves 313, 313 are engaged with the projections 309, 309 to guide the insertion of the retaining member 307. Then, similarly to the above-described first method, the second engagement grooves 311, 311 of the retaining member 307 are slid by the retaining members 307 before being engaged with the second protrusions 325, 325 of the circulation member 303. Thereby, the retaining member 307 is positioned at a predetermined position, and then the positioning of the circulating member 303 is completed. In the above manner, the assembly of the nut 301 by the circulation member 303 and the retaining member 307 is completed.

When the circulation member 303 and the retaining member 307 are assembled to the nut 301, the load transmitted from the inner peripheral side of the nut 301 to the circulation member 303 through the ball (not shown) is transmitted to the retaining member 307, but The retaining member 307 is inserted into the nut 301 from a direction different from the direction in which the circulating member 303 is inserted into the through hole 305, that is, the direction in which the chord of the nut 301 extends. Therefore, the retaining member 307 does not have to be pulled out of the circulating member 303. The direction of the load is heavy and falls off. Therefore, the falling off of the circulation member 303 can be prevented. Further, the retaining member 307 is prevented from coming off the outer side of the nut 301 in the radial direction by the ribs 309 and 309 being engaged with the engaging grooves 313 and 313 of the receiving groove 311 extending in the extending direction of the string.

As described above, in the present embodiment, the first ridge 324 is provided on the outer surface side surface 323 of the circulation member 303, and the inner diameter side faces of the protruding portions 318 and 318 are formed at both end portions of the first ridge 324. The bottom surface of the receiving groove 311 which contacts the bow shape restricts the movement of the circulation member 303 toward the inner diameter side. Further, the retaining member 307 prevents the circulation member 303 from coming off the nut 301 and performs positioning of the circulation member 303. Since the above configuration is made, it is not necessary to form the projections 318, 318 in the nut 301. The structure used for snapping. Specifically, it is not necessary to provide the engaging structure of the protruding portions 318 and 318 in the through hole 305 and the receiving groove 311 of the nut 301. As a result, the processing portion of the nut 301 is smaller than in the related art, and the manufacturing cost can be reduced.

Further, in the present embodiment, the retaining member 307 can be easily disposed at a predetermined position on the outer diameter side of the circulation member 303. According to the above configuration, by assembling the retaining member 307 to the nut 301, the positioning of the circulating member 303 can be easily performed at the same time as the assembly. As a result, the time required for the circulation member 303 and the retaining member 307 to be assembled to the nut 301 can be reduced, and the manufacturing cost can be reduced.

As described above, according to the present embodiment, the circulation member 303 and the retaining member 307 that holds the circulation member 303 in the nut 301 can be assembled to the nut 301 without time and effort, thereby preventing the circulation member 303 from coming off the nut 301. .

(Fourth embodiment)

Next, a fourth embodiment of the ball screw device of the present invention will be described.

Fig. 19 is a perspective assembled view of the nut 301 of the ball screw device 400 of the fourth embodiment. The ball screw device 400 according to the fourth embodiment will be described mainly with a configuration different from that of the third embodiment, and the same configurations as those of the third embodiment will not be repeatedly described. The same members as those in the third embodiment will be described using the same reference numerals. The ball screw device 400 according to the fourth embodiment is an example in which the configuration of the stopper member 407 and the shape of the bow-shaped receiving groove 411 are different from those of the third embodiment. The other configuration is the same as that of the third embodiment.

Fig. 20 is a five-side view of the retaining member 407 of the embodiment. In Fig. 20, Fig. 20A is a view as seen from the inner peripheral side of the nut 301. Figure 20B is a B-B arrow view of Figure 20A. Figure 20C is a C-C arrow view of Figure 20A. Figure 20D is a D-D arrow view of Figure 20C. Figure 20E is a diagram 20D E-E arrow view. In addition, in the horizontal direction in FIG. 20A, that is, the left-right direction of the paper surface is the axial direction of the nut 301, and the vertical direction, that is, the circumferential direction of the paper surface, is the circumferential direction of the nut 301 or the extending direction of the chord.

As shown in each of Fig. 20, the retaining member 407 is a member extending in the direction in which the chord extends, and the inner peripheral side surface 327 of the main body portion 408 is formed into a substantially rectangular plane whose longitudinal direction is the direction in which the chord extends. . The inner peripheral side surface 327 is formed in an arc shape at both end portions in the direction in which the chord extends. Further, as shown in FIG. 20C, the outer surface side of the main body portion 408 is formed into a curved surface having a curvature suitable for the outer peripheral surface of the nut 301. Therefore, the shape of the retaining member 407 is viewed from the axial direction, and is formed into an arch shape as shown in FIG. 20C.

The both side surfaces of the main body portion 408, that is, the two sides on the axial direction side, are formed with bulging portions 409, 409 which bulge in the axial direction at both end portions in the direction in which the chord extends. The edge portion on the inner peripheral side of each of the bulging portions 409 is formed in an arc shape continuous with the arc shape of the end portion of the inner peripheral side surface 327. In the main body portion 408, a total of four bulging portions 409 are formed. As shown in Figs. 20A and 20D, one pair of bulging portions 409 and 409 are provided in the axial direction across the main body portion 408, and are disposed at the ends of the chord extending direction. A group. The side faces of the pair of bulging portions 409, 409 are formed in a tapered shape in which the distance between them is inclined in the direction from the inner peripheral surface 327 side toward the outer diameter side. Therefore, the shape of the retaining member 407 is observed from the direction in which the strings extend, and is formed in a substantially trapezoidal shape as shown in FIGS. 20B and 20E.

Further, on both side faces of the retaining member 407, portions between the bulging portions 409, 409 of the respective side faces are formed to be parallel to each other. Further, the configuration of the first engagement groove 329 and the second engagement groove 331, 331 which are formed on the inner circumferential side surface 327 is the same as that of the third embodiment.

Fig. 21 is a side view of the nut 301 of the ball screw device of the fourth embodiment as seen from the outer diameter direction. 22A and 22B are 22-22 arrow cross-sectional views of Fig. 21, Fig. 22A The state in which the circulation member 303 and the retaining member 407 are assembled in the nut 301 is shown, and FIG. 22B shows a state in which the circulation member 303 and the retaining member 407 are not assembled.

As shown in Fig. 21, in the nut 301 of the fourth embodiment, two through holes 305 are formed in the same manner as in the third embodiment, and the two through holes 305 are formed to be shifted in the axial direction. Moreover, as shown in FIG. 22A and FIG. 22B, the bow-shaped accommodation groove 411 has a substantially trapezoidal cross-sectional shape as viewed from the direction in which the strings extend. In other words, the two side faces of the bow-shaped receiving groove 411 are formed such that the distance between them is inclined in the direction from the inner diameter side toward the outer diameter side, and corresponds to the side surface of the bulging portion 409 of the retaining member 407.

Further, as shown in FIG. 22A, one of the side portions of the retaining member 407, which is a tapered portion of the bulging portions 409, 409, is engaged with the tapered side portions of both side faces of the receiving groove 411, that is, both side faces. Further, the first protrusion 324 of the circulation member 303 is engaged with the first engagement groove 329 of the retaining member 407. Further, the second protrusions 325, 325 of the circulation member 303 are engaged with the second engagement grooves 331, 331 of the retaining member 407. As described above, the surface 323 on the outer diameter side of the circulation member 303 is in contact with the surface 327 on the inner diameter side of the retaining member 407.

In the present embodiment, as in the third embodiment, the circulation member 303 is engaged with the first engagement groove 329 of the retaining member 407 by the first protrusion 324, and the position of the nut 301 is determined, and the relative position is restricted. The rotation of the nut 301. Further, the retaining member 407 is engaged with the second protrusions 325, 325 of the circulation member 303 by the second engagement grooves 331, 331 to position the circulation member 303.

Next, a method of assembling the circulation member 303 and the retaining member 407 to the nut 301 will be described. The assembly of the nut 301 by the circulation member 303 and the retaining member 407, as shown in FIG. 19, first attaches the circulation member 303 to the through hole 305 of the nut 301, and then assembles the retaining member 407. In the receiving groove 411. The assembly of the circulation member 303 to the through hole 305 is the same as that of the third embodiment.

After the circulation member 303 is assembled to the through hole 305, the stopper member 407 is assembled to the accommodation groove 411. Regarding the assembly of the retaining member 407 to the receiving groove 411, FIG. 23 illustrates two assembling methods. First, the first method is a method in which the retaining member 407 is slid from the outer peripheral surface side of the nut 301 toward the extending direction of the chord extending from the receiving groove 411. In this method, the end of one of the retaining members 407 is inserted into the end of the receiving groove 411, and in this state, the retaining member 407 is slid along the bottom surface of the receiving groove 411 in the direction in which the string extends. At this time, the tapered side portion of the accommodation groove 411, that is, the both side surfaces and the one of the retaining member 407 are engaged with the tapered surfaces of the bulging portions 409, 409, that is, the respective side faces, and the insertion preventing member 407 is inserted.

Then, after the end of one of the retaining members 407 reaches the end of the first protrusion 324 of the circulation member 303, the retaining member 407, the first engaging groove 329 and the first protruding strip 324 are engaged and extended toward the string. Slide in the direction. Then, similarly to the first method of the third embodiment, the stopper member 407 is slid before the second engagement grooves 331 and 331 of the stopper member 407 are engaged with the second protrusions 325 and 325 of the circulation member 303. Thereby, the retaining member 407 is positioned at a predetermined position. Next, the positioning of the nut 301 by the circulation member 303 is completed. In the above manner, the assembly of the nut 301 by the circulation member 303 and the retaining member 407 is completed.

In the second method of assembling the retaining member 407 to the receiving groove 411, the retaining member 407 is pressed into the receiving groove 411 from the outer peripheral surface side of the nut 301 in a substantially vertical direction with respect to the bottom surface of the receiving groove 411. The detaching member 407 slides along the bottom surface of the receiving groove 411 in the direction in which the chord extends.

In this method, first, the retaining member 407 is directed from the outer side of the radial direction of the circulating member 303 of the nut 301 and slightly displaced from the center of the nut 301 toward the receiving groove 411. The bottom surface is pressed into the receiving groove 411 in the vertical direction. Here, the retaining member 407 is formed with a portion of the bulging portion 409, and the dimension in the axial direction is larger than the other portions. Further, both side faces of the accommodation groove 411 are formed in a tapered shape in which the distance between them is inclined toward the outer diameter side, so that the axial direction width of the outer diameter side is narrowed. Therefore, it is preferable that the portion of the accommodating groove 407 from the bulging portion 409, 409 of the end portion on which the retaining member 407 is formed on the receiving groove 407 is a position corresponding to the through hole 305 and the other side is formed. The portion of the bulging portion 409, 409 at the end portion of the side is press-fitted into the accommodating groove 411 (see FIG. 23) at a position on the outer side of the chord in the end portion of the accommodating groove 411.

After the retaining member 407 is pressed into the receiving groove 411, the first engaging groove 329 of the retaining member 407 is partially engaged with the first protrusion 324 of the circulating member 303 from the outer side in the radial direction. Next, after the retaining member 407 reaches the bottom surface of the receiving groove 411, the position of the circulating member 303 with respect to the nut 301 is determined at this stage. Thereafter, similarly to the first method described above, the retaining member 407 is slid along the bottom surface of the receiving groove 411 in the direction in which the string extends. At this time, the two side faces of the accommodation groove 411 are engaged with the respective side faces of the bulging portions 409, 409 by one of the retaining members 407, and the insertion of the retaining member 407 is guided. Then, similarly to the first method, the second engagement grooves 331 and 331 of the retaining member 407 are slid to the second protrusions 325 and 325 of the circulation member 303 before being slid. Thereby, the retaining member 407 is positioned at a predetermined position, and then the positioning of the nut 301 by the circulating member 303 is completed. In the above manner, the assembly of the nut 301 by the circulation member 303 and the retaining member 407 is completed.

In the present embodiment, when the circulation member 303 and the retaining member 407 are assembled to the nut 301, the load transmitted from the inner peripheral side of the nut 301 to the circulation member 303 through the ball (not shown) is transmitted to the stop. In the member 407, the retaining member 407 is inserted into the nut 301 from a direction different from the direction in which the circulating member 303 is inserted into the through hole 305, that is, the direction in which the chord of the nut 301 extends. Therefore, the retaining member 407 does not fall off due to the load in the direction in which the circulating member 303 is to be pulled out. Therefore, the falling off of the circulation member 303 can be prevented. Further, the retaining member 407 is prevented from being detached from the outer side of the nut 301 in the radial direction by the tapered side portions of the pair of bulging portions 409, 409, that is, the respective side faces are engaged with the tapered side portions of the receiving groove 411. .

As described above, in the present embodiment, as in the third embodiment, the first ridge 324 is provided on the outer surface side surface 323 of the circulation member 303, and the both ends of the first ridge 324, that is, the projections are formed. The surface on the inner diameter side of 318, 318 contacts the bottom surface of the housing groove 411, and restricts the circulation member 303 from moving toward the inner diameter side. Further, the retaining member 407 prevents the circulation member 303 from coming off the nut 301 and performs positioning of the circulation member 303. Because of the above configuration, it is not necessary to form the nut 301 with the projections 318, 318 for engaging. Specifically, it is not necessary to provide the engaging structure of the protruding portions 318 and 318 in the through hole 305 and the receiving groove 411 of the nut 301. As a result, the processing portion of the nut 301 is smaller than in the related art, and the manufacturing cost can be reduced.

Further, in the present embodiment, as in the third embodiment, the retaining member 407 can be easily disposed at a predetermined position on the outer diameter side of the circulation member 303. According to the above configuration, by assembling the retaining member 407 to the nut 301, the positioning of the circulating member 303 can be easily performed at the same time as the assembly. As a result, the time during which the circulation member 303 and the retaining member 407 are assembled to the nut 301 can be reduced, and the manufacturing cost can be reduced.

As described above, according to the present embodiment, the circulation member 303 and the retaining member 407 that holds the circulation member 303 in the nut 301 can be assembled to the nut 301 without time and effort, thereby preventing the circulation member 303 from coming off the nut 301. .

(Fifth Embodiment)

Next, a fifth embodiment of the ball screw device of the present invention will be described. Rolling of this embodiment The bead screw device is an internal circulation type ball screw device similar to that of the first embodiment.

As shown in FIG. 24A, the ball screw device 501 of the fifth embodiment has a screw shaft 502 and a nut 504 that is screwed to the screw shaft 502 through a plurality of balls 503.

The screw shaft 502 is composed of a metal member of an elongated cylindrical shape. A screw groove having a substantially circular arc shape in cross section is formed spirally on the outer peripheral surface of the screw shaft 502.

The nut 504 is formed of a substantially cylindrical metal member formed with a circular through hole having a larger outer diameter than the screw shaft 502. On the inner circumferential surface of the nut 504, a screw groove having a substantially circular arc shape in cross section is formed in a spiral shape corresponding to the screw groove of the screw shaft 502.

The screw shaft 502 is inserted through the through hole of the nut 504, and the screw grooves of the opposite sides form a ball rolling path. The rolling path is filled with a plurality of balls 503 made of metal, whereby the screw shaft 502 is screwed to the nut 504.

According to the above configuration, by rotating either of the screw shaft 502 and the nut 504, the plurality of balls 503 roll in the rolling path, and the other can be linearly moved in the axial direction. Here, the nut 504 is provided with a circulation member 507 that forms a circulation path for returning the rolling ball 503 to a predetermined point of the rolling path. Therefore, a plurality of balls 503 can circulate in the rolling path through the circulation path.

As shown in Figs. 24A to 24D, the circulation member 507 is inserted into a mounting hole 505 formed in the nut 504, and is fixed by a fastening member.

The circulation member 507 is made of metal, and as shown in Figs. 25A to 25B, is composed of a columnar member having an elliptical cross section. Further, it is preferable that the material of the circulation member 507 is suitable for sintering, and specifically, a metal material such as Fe-2Ni-C or Fe-8Ni or a resin material is preferable.

As shown in FIGS. 25A to 25B, an S-shaped groove 511 having a substantially circular arc shape in cross section is formed on the inner side surface of the circulation member 507. Further, in the present embodiment, the cyclic structure shown in FIG. 25A is used. The lower side and the upper side of the part are referred to as the "inner side" and "outer side" of the circulating member, respectively.

As shown in FIG. 25C to FIG. 25D, the groove portion 512 is formed so that the center portion of the outer surface of the circulation member 507 traverses the outer side surface in the short-side direction. The width of the groove portion 512 is slightly larger than the width of the short-side direction of the fastening member 509 to be described later. A projection 513 is provided at a central position of the groove bottom of the groove portion 512. The projection 513 is constituted by a cylindrical shaft portion 513a extending in the direction of the central axis of the circulation member 507, that is, in the horizontal direction of FIG. 25C, and a head portion 513b having a larger diameter than the shaft portion 513a.

Further, on the outer surface of the circulation member 507, as shown in Fig. 25D, mountain portions 514, 514 are formed on both sides of the groove portion 512. The tops 514a, 514a of the mountain portions 514, 514 extend in a direction inclined with respect to the longitudinal direction of the outer side surface and are parallel to each other. Specifically, the inner inclined surface 514b on the side of the protrusion 513 when the mountain portion 514 is divided by the top portion 514a has a substantially triangular shape, and the outer side inclined surface 514c has a substantially semicircular arc shape on the opposite side of the inner side inclined surface 514b.

On the side surface of the circulation member 507, as shown in Figs. 25A to 25D, a flange-shaped claw portion 515 is formed at the end portion on the inner side. The claw portions 515 are provided at two places so as to face each other across the central axis of the circulation member 507.

In the nut 504, as shown in Figs. 24A and 26, a mounting hole 505 for mounting the circulation member 507 is formed. The mounting hole 505 is formed of an elliptical through hole 505a that penetrates the radial direction of the nut 504 and is fitted into the circulation member 507, and a buried hole 505b that is circular and coaxial with the through hole 505a. The buried hole 505b is formed from the outer side in the radial direction of the nut 504 toward the inner side, and has a diameter larger than the length in the short side direction of the outer surface of the circulation member 507 and the length in the longitudinal direction of the fastening member 509 to be described later. Further, the shape of the buried hole 505b is not limited to a circular shape, and may be a rectangle or an ellipse.

The fastening member 509 is a clip nut shown in Fig. 27 in which a rectangular metal plate is formed by fixing the circulation member 507 to the mounting hole 505 of the nut 504. detailed As shown in FIG. 27C, the fastening member 509 has two notches extending in the longitudinal direction at the center of the metal plate, and then a notch portion 509a having a quadrangular shape is formed so as to connect the notches to each other. There are two extensions 509c, 509c having a front end V-shaped and extending toward the center. Further, as shown in Fig. 27D, the fastening member 509 is bent from the side to the upper side of Fig. 27D in a mountain shape, and the two extending portions 509c, 509c are bent at the base portion, and the front end reaches the upper side of Fig. 27D. Tilted ground.

The length of the long-side direction of the fastening member 509 is larger than the length of the outer side surface of the circulation member 507, and is smaller than the length of the outer side surface in the longitudinal direction. Further, the length of the short-side direction of the fastening member 509 is smaller than the length of the outer side surface of the circulation member 507 in the short-side direction. When the notch portion 509a of the fastening member 509 is attached to the protruding portion 513 of the circulation member 507 and the longitudinal direction of the outer surface of the circulation member 507 is orthogonal to the longitudinal direction of the fastening member 509, the fastening member 509 is Both end portions 509b and 509b in the longitudinal direction protrude from the outer side surface of the circulation member 507 in the short side direction (see Fig. 29A). When the longitudinal direction of the outer surface of the circulation member 507 is aligned with the longitudinal direction of the fastening member 509, the fastening member 509 does not protrude from the outer side surface of the circulation member 507 in the short side direction and the long side direction (refer to the figure). 31A).

In the ball screw device 501 of the present embodiment configured as described above, the attachment of the circulation member 507 to the nut 504 is performed in accordance with the mounting sequence shown in FIG. Further, the attachment of the circulation member 507 to the nut 504 is performed before the screw shaft 502 and the ball 503 are assembled to the nut 504.

Sequence 1: As shown in FIG. 28A, the circulation member 507 is inserted into the mounting hole 505 of the nut 504 from the radially inner side. Thereby, as shown in FIG. 29B, the adjacent screw grooves 504a, 504a of the inner circumferential surface of the nut 504 are connected by the S-shaped groove 511 of the circulation member 507 to complete the above-mentioned balls. 503 cycle road. Further, as shown in FIG. 24D, the claw portions 515, 515 of the circulation member 507 abut against the inner circumferential surface of the nut 504, and the restriction circulation member 507 is moved outward in the radial direction in the attachment hole 505 of the nut 504.

Sequence 2: As shown in Fig. 28B, the fastening member 509 is inserted into the mounting hole 505 of the nut 504 from the outer side in the radial direction. Next, the notch portion 509a of the fastening member 509 is attached to the protruding portion 513 of the circulation member 507 while elastically deforming the extending portions 509c, 509c. At this time, as shown in FIG. 29A, the fastening member 509 is dropped into the groove portion 512 of the circulation member 507 such that the longitudinal direction of the outer surface of the circulation member 507 is orthogonal to the longitudinal direction of the fastening member 509. Thereby, the both end portions 509b, 509b in the longitudinal direction of the fastening member 509 abut against the buried bottom surface 505c of the mounting hole 505 (refer to FIG. 24D), and the fastening member 509 is circulated at the bottom surface 505c of the mounting hole 505. The head 513b of the protrusion 513 of the member 507 is elastically deformed. Therefore, the circulation member 507 is maintained in a state of being biased outward in the radial direction in the mounting hole 505 of the nut 504 by the fastening member 509. Thereby, the position and posture of the circulation member 507 in the radial direction of the nut 504 in the mounting hole 505 of the nut 504 are fixed, and the mounting of the circulation member 507 to the nut 504 is completed. Further, the fastening member 509 attached to the circulation member 507 is engaged with the head portion 513b of the protruding portion 513 of the circulation member 507, so that it does not fall off from the circulation member 507.

According to the above sequence, the circulation member 507 can be attached to the mounting hole 505 of the nut 504 without using an adhesive. Therefore, the manufacturing time can be greatly shortened. Further, the ball screw device 501 does not cause a malfunction or malfunction of the ball screw device 501 due to defects such as inclination or positional deviation of the circulation member 507 in the mounting hole 505 of the nut 504 during the curing of the adhesive agent as in the above-described conventional ball screw device. .

Moreover, the circulation member 507 is in the nut by the claw portions 515, 515 and the fastening member 509. The position and posture in the radial direction of the mounting hole 505 of 504 are constantly fixed. Therefore, even if vibration or the like is generated when the ball screw device 501 is used, it is possible to prevent the occurrence of defects such as the detachment of the circulation member 507 from the mounting hole 505 of the nut 504 or the inclination or positional deviation in the mounting hole 505, thereby effectively preventing the ball screw device 501 from being effectively prevented. Poor action or malfunction.

Further, as described above, the fastening member 509 is housed in the groove portion 512 of the circulation member 507. Therefore, even if the fastening member 509 rotates around the protruding portion 513 of the circulation member 507, the side wall of the groove portion 512 can be abutted to restrict the rotation. Therefore, the fastening member 509 is not rotated when the ball screw device 501 is used, and the outer surface of the circulation member 507 is overlapped with the fastening member 509 from the outer side in the radial direction of the nut 504, and the fastening member 509 is rotated. 507 fixed release situation.

Further, since the adhesive is not used in the above-described mounting order, the fastening member 509 can also be removed from the circulation member 507. Therefore, after the ball screw device 501 is used for a long period of time, maintenance such as removal of impurities, lubrication, or replacement of the circulation member 507 can be performed.

As described above, according to the present embodiment, the circulation member 507 and the fastening member 509 holding the circulation member 507 in the nut 504 can be assembled to the nut 504 in a time-consuming and easy manner to prevent the circulation member 507 from coming off the nut 504. .

(Sixth embodiment)

The ball screw device 520 according to the sixth embodiment shown in Fig. 30A is not described in the same manner as the above-described fifth embodiment, and the different portions will be described in detail.

In the ball screw device 520 of the present embodiment, the attachment of the circulation member 507 to the nut 504 is performed in accordance with the following mounting sequence. Further, the attachment of the circulation member 507 to the nut 504 is performed before the screw shaft 502 and the ball 503 are assembled to the nut 504 as in the fifth embodiment.

In the first step, as shown in FIG. 31A and FIG. 31B, the notch portion 509a of the fastening member 509 is attached to the protruding portion 513 of the circulation member 507 in advance while elastically deforming the extending portions 509c, 509c. At this time, the longitudinal direction of the outer side surface of the circulation member 507 coincides with the longitudinal direction of the fastening member 509.

In the second step, the circulation member 507 attached to the fastening member 509 in the above-described procedure 1 is inserted into the mounting hole 505 of the nut 504 from the radially inner side as shown in FIG. 30A. As a result, as shown in FIG. 29B of the fifth embodiment, the adjacent screw grooves 504a and 504a of the inner circumferential surface of the nut 504 are connected by the S-shaped groove 511 of the circulation member 507 to complete the circulation path of the balls 503. Further, as shown in FIG. 30D, the claw portions 515, 515 of the circulation member 507 abut against the inner circumferential surface of the nut 504, and the restriction circulation member 507 is moved outward in the radial direction in the attachment hole 505 of the nut 504.

In the third step, as shown in FIG. 32A and FIG. 32B, the fastening member 509 is formed by the projection 513 of the circulation member 507 so that the longitudinal direction of the outer surface of the circulation member 507 is orthogonal to the longitudinal direction of the fastening member 509. The center rotates counterclockwise, causing the fastening member 509 to fall into the groove portion 512 of the circulation member 507. Thereby, the both end portions 509b, 509b in the longitudinal direction of the fastening member 509 abut against the buried bottom surface 505c of the mounting hole 505 (refer to FIG. 30D), and the fastening member 509 is circulated at the bottom surface 505c of the mounting hole 505. The head 513b of the protrusion 513 of the member 507 is elastically deformed. Therefore, the circulation member 507 is maintained in a state of being biased outward in the radial direction in the mounting hole 505 of the nut 504 by the fastening member 509. Thereby, the position and posture of the circulation member 507 in the radial direction of the nut 504 in the mounting hole 505 of the nut 504 are fixed, and the mounting of the circulation member 507 to the nut 504 is completed. Further, the fastening member 509 attached to the circulation member 507 is engaged with the head portion 513b of the protruding portion 513 of the circulation member 507, so that it does not fall off from the circulation member 507.

According to the above installation sequence, the same effect as the fifth embodiment described above can be achieved. fruit.

Further, as described in the fifth embodiment, on the outer surface of the circulation member 507, as shown in Fig. 32A, the mountain portions 514, 514 are formed on both sides of the groove portion 512. Further, the tops 514a, 514a of the mountain portions 514, 514 extend in a direction inclined with respect to the longitudinal direction of the outer side surface and are parallel to each other. According to this configuration, in the present embodiment, when the fastening member 509 is rotated about the projection 513 of the circulation member 507, it is easy to rotate in the counterclockwise direction, and the above-described operation of the third step can be performed more easily.

Further, the present invention is not limited to the above embodiments, and can be appropriately modified within the scope thereof. For example, in the above-described first to fourth embodiments, the through holes 105 and 305 for assembling the circulation members 103, 203, and 303, and the storage grooves 111, 311, and 411 for arranging the bow-shaped retaining members 107, 307, and 407 are respectively provided as two examples. The through holes 105, 305 and the receiving grooves 111, 311, 411 can be appropriately changed in number depending on the size of the ball screw device.

Further, instead of the accommodation groove 111 of the first and second embodiments, the peripheral wall of the nut 101 may be provided with a size that can be inserted into the retaining member 107 that extends across the through hole 105 and extends in the direction in which the chord of the nut 101 extends. aisle. According to this configuration, when the diameter of the nut 101 is increased, the rigidity of the nut 101 can be suppressed from being lowered as compared with the case where the receiving groove 111 is formed large.

Further, in the fifth and sixth embodiments described above, the clip nut is used as the fastening member 509. However, the fastening member 509 is not limited thereto, and in order to restrict the movement of the circulation member 507 to the inner side in the radial direction of the nut 504, it is sufficient that the bottom surface 505c of the mounting hole 505 of the nut 504 can be abutted. Therefore, in the fifth embodiment, the attachment hole that can be attached to the opening 513 of the circulation member 507, such as a clamp ring, protrudes from the outer surface of the circulation member 507 in the short-side direction and can abut against the nut 504. The size of the buried bottom surface 505c of the 505 can be. In addition to the above-described conditions, the sixth embodiment is stored in the outer side of the circulation member 507 in the above-described order 1. The size of the face can be. Furthermore, in the fifth and sixth embodiments, the fastening member 509 is preferably elastically deformed by biasing the circulation member 507 outward in the radial direction of the nut 504. Thereby, the circulation member 507 can be more restricted from moving in the radial direction of the nut 504. Specifically, in the fifth embodiment, a retaining nut or a circular clip nut or the like may be used as the fastening member 509.

Further, in the fifth and sixth embodiments, the shape of the mountain portions 514, 514 provided on the outer side surface of the circulation member 507 is not limited to the above description. In the fifth embodiment, the outer portions of the circulation member 507 do not have the mountain portions 514 and 514, and the cost can be reduced. In the sixth embodiment, as shown in Fig. 31C, the top portion 514a may be provided such that the area of the inner slope 514b of the mountain portion 514 is substantially smaller than the area of the outer slope 514c. In this case, in the above-described procedure 3, the fastening member 509 is easily rotated clockwise around the projection 513 of the circulation member 507. Further, the inclination of the inner slope 514b may be inclined more gently than the outer slope 514c. In particular, the inner inclined surface 514b may not be inclined, that is, a horizontal plane substantially perpendicular to the central axis of the circulation member 507, whereby the cost can be reduced.

Further, in each of the above embodiments, the outer diameter of the nut is a cylindrical shape. However, the outer shape of the nut may be a rectangular shape or a polygonal shape, and may be appropriately changed depending on the use or attachment position of the ball screw device. .

101‧‧‧ nuts

103‧‧‧Circular components

105‧‧‧through holes

107‧‧‧Stop member

109‧‧‧

111‧‧‧ Reception trough

113‧‧‧ card slot

125‧‧‧

127‧‧‧ Surface section

139‧‧‧ slot department

100‧‧‧Rolling screw device

Claims (21)

A ball screw device comprising: a screw shaft having a spiral groove formed on an outer peripheral surface and extending linearly; and a nut having a spiral groove facing the spiral groove of the screw shaft on the inner circumferential surface; and a plurality of a ball that is rotatably disposed between the spiral groove of the screw shaft and the spiral groove of the nut; the nut is fitted to the screw shaft through the plurality of balls, and has a ball for the plurality of balls a circulation member that circulates between the groove of the screw shaft and the groove of the nut, and a holding member for holding the circulation member to the nut on a radially outer side of the circulation member, wherein the circulation member has a restriction portion for restricting movement of the circulation member in the radial direction by contacting the nut; and an engagement mechanism for engaging the circulation member with the holding member in the circulation member and the holding member in order to hold the circulation member The engagement mechanism is a first protrusion and a second protrusion formed on the outer diameter side surface of the exchange member in an assembled state, and is formed in the holding member and engaged with the first protrusion The first groove portion and the first 2 The second groove portion of the protrusion is engaged. The ball screw device according to claim 1, wherein the first ridge and the first groove extend in a direction in which the predetermined chord of the nut extends in an assembled state. The ball screw device according to claim 1, wherein a peripheral groove of the nut is formed with a receiving groove for accommodating the holding member; the first protruding strip has a surface larger than the outer diameter side of the switching member. The edge protrudes from the protrusion on the outer side; The restricting portion is the protruding portion, and the surface on the inner diameter side of the protruding portion contacts the bottom surface of the receiving groove to restrict the circulation member from moving inward in the radial direction with respect to the nut. The ball screw device according to claim 3, wherein the surface on the inner diameter side of the protruding portion and the outer diameter side surface of the circulation member are formed on the same plane. The ball screw device according to claim 1, wherein the second ridge and the second groove extend in an axial direction of the nut in an assembled state. The ball screw device of claim 1, wherein the first protruding bar is engaged with the first groove portion to position the nut with the circulating member. The ball screw device according to claim 1, wherein the holding member is positioned by the holding member by the engagement of the second protrusion with the second groove. A ball screw device according to claim 1, wherein the nut and the holding member are provided with a locking mechanism for locking the holding member to the nut. The ball screw device of claim 8, wherein the locking mechanism is formed in a locking groove provided in a peripheral wall of the nut and accommodating the receiving groove of the holding member, and is formed on the holding member and The locking groove of the locking groove is engaged. The ball screw device of claim 8, wherein the locking mechanism is formed in a tapered portion of the receiving groove provided in the peripheral wall of the nut and housing the holding member, and is formed on the holding member and The tapered portion of the receiving groove is engaged with the tapered portion. The ball screw device of claim 1, wherein the holding member is formed of a resin. A ball screw device comprising: a screw shaft, a spiral groove formed on an outer peripheral surface, and extending linearly; a nut having a spiral groove facing the spiral groove of the screw shaft on the inner circumferential surface; and a plurality of balls rotatably disposed between the spiral groove of the screw shaft and the spiral groove of the nut The nut is fitted to the screw shaft through the plurality of balls, and has a circulating member for circulating the plurality of balls between the groove of the screw shaft and the groove of the nut, in the diameter of the circulating member a retaining member for retaining the circulation member in the nut at a direction outer side, wherein the circulation member has a restriction portion for restricting movement of the circulation member in a radial direction by contacting the nut; in order to maintain the circulation member An engagement mechanism for engaging the circulation member with the holding member is provided in the circulation member and the holding member; the engagement mechanism is formed to be radially outward when the circulation member is attached to the nut The outer side surface of the circulation member is configured to be engaged with the engaging portion of the holding member, and the engaged portion of the engaging portion formed on the holding member and engaged with the circulating member; the outer side of the circulating member Present Rounded; the outer surface of the loop member is formed of a groove portion extending toward an outer side surface of the short-side direction; the receiving groove portion by the holding member of the holding member to limit the engagement portion rotates. The ball screw device of claim 12, wherein the nut forms a mounting hole for mounting the circulation member; the holding member fixes the circulation member inserted into the mounting hole; the restricting portion is formed at The circulation member is locked to the nut to restrict a claw portion of the circulation member that moves outward in the radial direction; the mounting hole of the nut has a hole portion into which the circulation member can be fitted, and is mounted on the circulation structure The holding member of the engaging portion of the member abuts to restrict the buried portion of the circulating member moving inward in the radial direction. The ball screw device according to claim 13, wherein the engaging portion of the circulating member is formed by a shaft portion provided on an outer side surface of the circulating member, and is thicker than the shaft portion and disposed at a front end of the shaft portion. The head portion is configured; the engaged portion of the holding member is formed by an opening that is engageable with the engaging portion of the circulating member. The ball screw device of claim 14, wherein the holding member is elastically deformed between the buried portion of the nut and the head of the circulating member, and the circulating member is oriented in the radial direction of the nut The outer side is pressed. The ball screw device according to claim 15, wherein the holding member is formed of a rectangular plate-like member, and a length in a longitudinal direction is larger than a length in a short side direction of the outer side surface of the circulating member. The ball screw device of claim 16, wherein the holding member has a length in a longitudinal direction that is smaller than a length in a longitudinal direction of the outer side surface of the circulating member, and a length in a short side direction is larger than a length of the circulating member. The length of the short side of the outer side is small. The ball screw device of claim 12, wherein on the outer side surface of the circulation member, a mountain portion is formed on both sides of the groove portion; the top portion of the mountain portion is opposite to the outer side surface of the circulation member The long sides extend in the direction of inclination and are parallel to each other. The ball screw device of claim 16, wherein the hole portion of the nut is coaxial with the buried hole portion; The hole portion is an elliptical through hole into which the circulation member can be fitted; the buried portion is circular and has a larger diameter than a longitudinal direction of the holding member. A ball screw device of a ball screw device, which is the ball screw device of claim 13; the pipe member is inserted into the mounting hole of the nut from the inner side in the radial direction; the retaining member is from the radial direction The mounting hole of the nut is inserted outside to be mounted to the circulation member. A ball screw device of a ball screw device, wherein the ball screw device is the ball screw device of claim 17; wherein a longitudinal direction of the outer side surface of the circulating member is consistent with a longitudinal direction of the holding member The holding member is attached to the circulation member; the circulation member is inserted into the mounting hole of the nut from the inner side in the radial direction; and the longitudinal direction of the outer side surface of the circulation member is orthogonal to the longitudinal direction of the holding member The holding member is rotated about the engaging portion of the circulating member.