JP2006017201A - Double-row thrust needle-like roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-row thrust needle-like roller bearing, coping with high-speed rotation with low torque and having a long life. <P>SOLUTION: This double-row thrust needle-like roller bearing includes: a rolling element composed of an outer roller 303 disposed outside in the radial direction of the bearing between a pair of opposite raceway surfaces and an inner roller 302 disposed inside in the radial direction of the bearing; and a retainer 301 retaining the outer roller 303 and the inner roller 302. The retainer 301 is guided by the rolling elements 302 and 303 not to come into contact with the paired raceway surfaces. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thrust needle roller bearing used for an air conditioner compressor of an automobile, an automatic transmission, a continuously variable transmission, an electric brake of various vehicles such as an automobile and a motorcycle. This thrust needle roller bearing is installed in the rotating part of these parts or devices, and is used to support the thrust load applied to the rotating part.

  Thrust needle roller bearings are known as being able to achieve high load capacity and high rigidity with a simple structure, consisting of a plurality of needle rollers arranged between a pair of opposed raceway members and a cage. It has been. Further, thrust needle roller bearings have advantages such as a small axial height (thickness), and are therefore widely used in applications that require space saving.

  A main application in which a thrust needle roller bearing, which is a typical example of a thrust roller bearing, is used is a compressor for an air conditioner for an automobile. Japanese Patent Laid-Open No. 2003-97562 (Patent Document 1) discloses various types of compressors. For example, as shown in FIG. 1, a double swash plate type in which the piston 510 is reciprocated by a double-sided inclined plate 509 fixed to the input rotating shaft 508, and as shown in FIG. 2, a single-sided inclined plate 612 fixed to the input rotating shaft 611 A single swash plate type in which the piston 614 is reciprocated through the rod 613, and a variable in which the piston 718 is reciprocated through the rod 717 by a swash plate 716 attached to the input rotating shaft 715 in a variable angle as shown in FIG. There is a capacity swash plate type.

  As a specific bearing use example, in the case of the both swash plate type of FIG. 1, a needle roller bearing 519 with a cage and a thrust needle roller bearing 520 are used. The swash plate type in FIG. 2 uses a shell needle roller bearing 621 and a thrust needle roller bearing 622. Further, the variable capacity swash plate type of FIG. 3 uses a needle roller bearing 723 with a cage and a thrust needle roller bearing 724. As described above, the thrust needle roller bearing has advantages such as a low cross-sectional height, and therefore is used for applications such as compressors that require space saving.

  Another application in which thrust needle roller bearings are used is electric brakes. Electric brakes for various vehicles are disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-247576 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2000-238628 (Patent Document 3).

  In the electric brake disclosed in Japanese Patent Application Laid-Open No. 2003-247576, an advance / retreat operation mechanism is provided for advancing / retreating by the driving force of the electric motor to generate a pressing force on the pressing member of the friction pad. Is pressed and slid to perform braking. The electric brake includes a reduction gear mechanism that decelerates the driving force of the electric motor and transmits it to the advance / retreat operation mechanism. A reduction gear mechanism is disposed between the electric motor and the friction pad.

  In the electric brake described above, the reduction gear mechanism includes a planetary arm that is rotationally driven by an electric motor, a planetary gear that is rotatably supported on the outer periphery of the planetary arm, and a sun gear that has external teeth that mesh with the planetary gear. And a reduction gear disposed so as to face the sun gear, and a ball screw nut that rotates integrally with the reduction gear. A thrust needle roller bearing is disposed between the sun gear and the reduction gear on which the thrust load acts.

Japanese Patent Application Laid-Open No. 2000-238628 discloses a brake force holding device that can hold and release a brake force under certain conditions such as a temporarily stopped state of a vehicle and a parking brake operation. Also in the device disclosed in this publication, a bearing is disposed at a portion that relatively rotates while receiving a thrust load, but the structure of the bearing is not described in detail.
JP 2003-97562 A JP 2003-247576 A JP 2000-238628 A

  In the thrust needle roller bearing, differential slip occurs between the roller and the raceway because of its basic structure. More specifically, in the case of a thrust needle roller bearing, a cylindrical needle roller is arranged as a rolling element on a raceway having a flat raceway surface, and the roller and the raceway surface are in line contact. It has become. The center of rotation of the bearing coincides with the center of revolution of the roller. Although the roller has a predetermined length in the radial direction of the bearing, the peripheral speed on the rolling surface of the roller is the same speed. On the other hand, the circumferential speed of the raceway surface of the race which is in rolling contact with the roller increases from the center of rotation of the bearing toward the outer diameter direction. Therefore, the peripheral speed difference between the roller and the raceway surface of the raceway is maximized at both ends of the roller.

  Theoretically, pure rolling motion is performed only on the pitch circle of the bearing, and the peripheral speed difference between the roller and the raceway surface increases from the point on the pitch circle toward both ends of the roller, and differential slip increases. . This differential slip increases in proportion to the length of the roller.

  The differential sliding in thrust needle roller bearings is large compared to other types of bearings. Therefore, due to differential slip, edge stress is likely to occur between the roller edge and the bearing ring, and surface-origin separation is likely to occur at the edge of the roller rolling part of the bearing ring. .

  Further, when a differential slip occurs in the needle roller, the oil film is cut, and the roller and the race are in metal contact and generate heat. This heat generation tends to cause surface damage and surface-origin peeling. Such a tendency becomes more remarkable as the rotation speed becomes higher. As a result, it is recognized that the bearing life is shortened.

As a measure to alleviate the influence of differential slip between the roller and the raceway surface of the raceway, it is conceivable to shorten the length of the roller. However, if the length of the roller is simply shortened, the contact area of the roller becomes small, so that the contact surface pressure of the roller increases and there is a possibility that problems such as early peeling occur on the outer surface of the roller.
An object of the present invention is to provide a double-row thrust needle roller bearing that can cope with high-speed rotation with low torque and has a long life.

  A double-row thrust needle roller bearing according to the present invention includes an outer roller disposed on the radially outer side of the bearing between a pair of opposed raceway surfaces, and an inner roller disposed on the radially inner side of the bearing. And a cage for holding the outer roller and the inner roller. The cage is guided by the rolling elements so as not to contact the pair of raceway surfaces.

  When a double-row thrust needle roller bearing with the above configuration is used in a compressor for an air conditioner, an automatic transmission, a continuously variable transmission, an electric brake of a vehicle, etc., a plurality of rollers are arranged in the radial direction of the bearing. The differential slip of the roller can be suppressed, and the metal contact between the roller and the raceway surface due to the oil film breakage is prevented to suppress the heat generation of the bearing portion. Thus, it is possible to cope with high speed rotation. Further, since surface damage and surface-originating peeling can be prevented, the durability of the bearing can be improved. In addition to these advantages, heat generation of the bearing can be more effectively suppressed by using the cage as a rolling element guide so that the cage and the raceway surface do not contact each other.

  Thus, by disposing double rows of needle rollers in the radial direction, differential slip is suppressed, and the cage is used as a rolling element guide so that the member having the raceway surface and the cage are not in contact with each other. Since the bearings have low torque, it is possible to achieve the fuel saving that is the customer's needs.

  In order to use the cage as a rolling element guide, the height dimension of the cage along the rotational axis direction of the bearing is preferably smaller than the diameter of the roller.

  In one embodiment, the retainer of the thrust needle roller bearing includes a plurality of pockets provided at intervals in the circumferential direction, and an outer roller and an inner roller are accommodated in each of the plurality of pockets.

  In another embodiment, the retainer of the thrust needle roller bearing has a plurality of outer pockets spaced circumferentially at positions radially outside the bearing, and a position radially inside the bearing. A plurality of inner pockets spaced apart in the circumferential direction. The outer roller is accommodated in each of the plurality of outer pockets, and the inner roller is accommodated in each of the plurality of inner pockets.

  Paying attention to the end face shape of the roller, the outer roller has an F end face (plane) or an A end face (round face), and the inner roller has an F end face or an A end face. Accordingly, there are four combinations of the end face of the outer roller and the end face of the inner roller: F end face and F end face, A end face and A end face, A end face and F end face, and F end face and A end face.

  Paying attention to the length of the roller, the length of the outer roller and the inner roller may be the same, the outer roller may be longer than the inner roller, or the outer roller may be shorter than the inner roller. .

  Preferably, the shape of the corner portion of the roller holding portion of the cage is smoothly splayed. In this way, the needle roller can be stably guided and held without cutting the lubricating oil film formed on the surface of the needle roller.

  The double row thrust needle roller bearings as described above can improve the peeling life and bearing durability compared to the conventional single row roller type thrust bearings, so the roller size can be reduced and the number of rollers Can be reduced. When a plurality of rollers are arranged in one pocket of the cage, the number of rollers is not reduced, but the number of pockets is reduced. Accordingly, it is possible to reduce the weight and size of the bearing. In other words, as long as the bearings have the same size, the double row roller type thrust bearing can cope with a higher load condition than the conventional single row roller type thrust bearing.

  The double-row thrust needle roller bearing according to the present invention is used for an air conditioner compressor of an automobile, an automatic transmission, a continuously variable transmission, an electric brake of various vehicles such as an automobile and a motorcycle. In the case of the double swash plate type compressor shown in FIG. 1, a double-row thrust needle roller bearing according to the present invention is used as the thrust needle roller bearing 520. In the case of the swash plate type compressor shown in FIG. 2, the double-row thrust needle roller bearing according to the present invention is used as the thrust needle roller bearing 622. The raceway surface of the thrust needle roller bearing 622 is directly formed on the surfaces of the single-side inclined plate 612 and the rod support member 615. In the case of the variable capacity swash plate type compressor shown in FIG. 3, the double-row thrust needle roller bearing according to the present invention is used as the thrust needle roller bearing 724.

  A basic structure of an example of an electric brake to which the double row thrust needle roller bearing according to the present invention is to be applied is disclosed in Japanese Patent Laid-Open No. 2003-247576. First, the basic structure of this electric brake will be described. FIG. 4 shows FIG. 1 of Japanese Patent Application Laid-Open No. 2003-247576 almost as it is.

  A disc rotor 101, which is a component of the electric brake shown in FIG. 4, is connected to the driving wheels of an automobile and rotates integrally. Inside the tire wheel 105, a pair of friction pads 103 and 104 are arranged so as to be able to contact the friction surfaces 102 on both sides of the disk rotor 101. Further, the bracket 106 is fixed to the vehicle body so as to face the disc rotor 101, and the friction pads 103 and 104 are attached to the caliper support arms protruding from the fixed side and straddling the outer periphery of the disc rotor 101 to the opposite side. It is slidably arranged.

  A caliper body 108 that presses the friction pads 103 and 104 against the disc rotor 101 is connected to a caliper support arm of the bracket 106 by a pair of slide pins so that the caliper body 108 can advance and retreat. The caliper body 108 has an action portion 110 disposed on the back surface of one friction pad 103 and a reaction portion 112 provided with a reaction force claw 111 disposed on the back surface of the other friction pad 104, with the disc rotor 101 interposed therebetween. The bridge portion 113 connects the action portion 110 and the reaction portion 112 across the outer periphery of the disk rotor 101.

  The action unit 110 includes an electric motor 115 in the cylinder 114, a ball screw mechanism 116 as an advancing / retreating operation mechanism that generates a pressing force of the friction pads 103 and 104, and a driving force of the electric motor 115 to the ball screw mechanism 116. A reduction gear mechanism 117 that transmits the information by reducing the speed is housed. The reduction gear mechanism 117 includes a planetary arm 118 that can be rotated by the driving force of the electric motor 115, a planetary gear 123 that is pivotally supported by the planetary arm 118, and a sun gear that rotates the planetary gear 123. 126.

  A ball screw nut 134 of the ball screw mechanism 116 is accommodated in the planetary arm 118 via a bearing portion 158 so that the ball screw nut 134 can rotate but cannot advance or retract. The ball screw nut 134 has a reduction gear 135 having fewer teeth than the sun gear 126 fixed to the outer periphery of the rear end disposed on the large diameter side of the planetary arm 118. The reduction gear 135 is engaged with the second gear portion of the planetary gear 123, and the ball screw nut 134 can be rotated by the rotation of the planetary gear 123.

  A ball groove is provided in the center of the ball screw nut 134, and a ball screw shaft 138 is screwed through a plurality of balls 137 so as to be able to advance and retreat. The ball screw shaft 138 has a flat pad pressing plate 140 connected to the tip as a pressing member of one friction pad 103. With this pad pressing plate 140, the friction pad 103 can be pressed in a wide area without concentrating the pressing force on a part thereof and can be pressed in parallel with the disk rotor 101.

  When the driver of the automobile depresses the brake pedal to perform a braking operation, the electric motor 115 is driven according to the amount of depression, and the planetary arm 118 rotates in the cylinder 114. By the rotation of the planetary arm 118, the planetary gear 123 that meshes with the sun gear 126 on the first gear portion rotates on the outer periphery of the sun gear 126. By the rotation of the planetary gear 123, the ball screw nut 134 that meshes the reduction gear with the second gear portion rotates.

  Due to the action of the ball screw mechanism 116, the rotational force is converted into a sliding force of the ball screw shaft 138, and the friction pad 103 on the action part 110 side is pressed and slid through the pad pressing plate 140 and pressed against the disc rotor 101. Further, since the caliper body 108 is retracted by the reaction force of the sliding movement of the ball screw shaft 138, the reaction force claw 111 of the reaction portion 112 presses and slides on the friction pad 104 on the reaction portion 112 side, and the disc rotor 101 is moved. By pressing, braking is performed.

  In the electric brake having the structure shown in FIG. 4, a double-row thrust needle roller bearing 180 according to an embodiment of the present invention is disposed between the sun gear 126 and the reduction gear 135 that rotate relative to each other.

  5 to 7 show embodiments of double-row thrust needle roller bearings to be used for a compressor for an air conditioner of an automobile, an automatic transmission, a continuously variable transmission, an electric brake, and the like, respectively. Moreover, FIGS. 8-10 has each shown the arrangement | positioning form of a different roller. In these drawings, the same reference numerals indicate the same or corresponding elements. Further, in these drawings, the bearing ring or the bearing member of the bearing is not shown.

  First, the basic structure of a double-row thrust needle roller bearing will be described with reference to FIG. The double-row thrust needle roller bearing is disposed between a stationary side race ring (track member) (not shown), a rotation side race ring (track member) (not shown), and both race rings by a cage 301. A plurality of rollers 302 and 303 are provided. A plurality of rollers 302 and 303 are arranged in the radial direction of the bearing. The roller 302 is disposed inside as viewed in the radial direction, and the roller 303 is disposed outside as viewed in the radial direction. Therefore, in the following description, they are referred to as an inner roller 302 and an outer roller 303.

  Basically, there are three types of arrangement of the inner roller 302 and the outer roller 303 shown in FIGS.

  The cage 301 shown in FIG. 8 includes a plurality of pockets 311 provided at intervals in the circumferential direction, and an inner roller 302 and an outer roller 303 are disposed in each pocket 311.

  The cage 301 shown in FIG. 9 has a plurality of outer pockets 312 provided at intervals in the circumferential direction at positions outside the bearing in the radial direction, and a gap in the circumferential direction at positions inside the bearing in the radial direction. A plurality of inner pockets 313, outer rollers 303 are accommodated in each of the plurality of outer pockets 312, and inner rollers 302 are accommodated in each of the plurality of inner pockets 313. In the form shown in FIG. 9, the number of inner rollers 302 is the same as the number of outer rollers 303.

  As in the cage shown in FIG. 9, the cage 301 shown in FIG. 10 includes a plurality of outer pockets 312 that are provided at circumferentially spaced positions on the outer side in the radial direction of the bearing, and the radial direction of the bearing. A plurality of inner pockets 313 provided at intervals in the circumferential direction at an inner position of each of the plurality of outer pockets. The outer rollers 303 are accommodated in each of the plurality of outer pockets 312, and the inner rollers 302 are accommodated in each of the plurality of inner pockets 313. Is housed. In the form shown in FIG. 10, the number of inner rollers 302 is different from the number of outer rollers 303. Specifically, in the illustrated form, the number of outer rollers 303 is greater than that of inner rollers 302.

  8 to 10, two rollers are arranged in the radial direction, but three or more rollers may be arranged in the radial direction. Further, the thrust needle roller bearing does not necessarily have the fixed-side raceway and the rotation-side raceway, and may have a structure having a rolling surface directly on the other side of the member to be incorporated.

  In each embodiment shown in FIGS. 5 to 7, the only difference is the form of the holder 301. In the embodiment shown in FIG. 5 and FIG. 7, the retainer 301 includes a plate-like first member 301 a and a second member 301 b that are joined one above the other. In the case of the retainer 301 shown in FIG. 5, the outer peripheral portion of the first member 301a is bent so that the outer peripheral portion of the second member 301b is crimped, and the inner peripheral portion of the second member 301b is bent and the first member 301a is bent. The inner periphery of the sword is clamped and clamped.

  In the case of the cage 301 shown in FIG. 7, the outer peripheral portion and the inner peripheral portion of the ring-shaped first member 301a are bent toward the second member 301b, and the outer peripheral portion and the inner peripheral portion of the second member 301b are bent to the first member. It is bent toward the 301a side. The bent outer peripheral portion and the inner peripheral portion of the first member 301a are fitted into the bent outer peripheral portion and the inner peripheral portion of the second member 301b.

  The cage 301 shown in FIG. 6 is a single part formed of, for example, resin.

  In each embodiment shown in FIGS. 5 to 7, what is common is that the cage 301 is guided by the rolling elements 302 and 303 so as not to contact a pair of track surfaces (track members) (not shown). It is that. In other words, the outer roller 303 and the inner roller 302 hold the retainer 301 so as not to contact the pair of raceway surfaces. The raceway having a raceway surface may be a component part of a double row thrust needle roller bearing, or the counterpart member that is supported by rolling as shown in FIG. 2 may have a raceway surface directly.

Focusing on dimensional relationships, to the retainer 301 and the rolling element guide, preferably, a height dimension T ₁₀ of the retainer 301 along the rotation axis direction of the bearing, the diameter of the inner roller 302 and outer roller 303 smaller than the T _20.

  Thus, by using the cage 301 as a rolling element guide so that the cage 301 and the raceway surface (track member) do not come into contact with each other, the heat generation of the bearing portion can be more effectively suppressed.

  When attention is paid to the end face shapes of the outer roller 303 and the inner roller 302, the outer roller has an F end face (plane) or an A end face (round face), and the inner roller has an F end face or an A end face. Therefore, there are the following four combinations of the end face of the outer roller and the end face of the inner roller.

  (1) The outer roller 303 is an F end surface, and the inner roller 302 is an F end surface.

  (2) The outer roller 303 is an F end surface, and the inner roller 302 is an A end surface.

  (3) The outer roller 303 is the A end surface, and the inner roller 302 is the F end surface.

  (4) The outer roller 303 is the A end surface, and the inner roller 302 is the A end surface.

  When attention is paid to the lengths of the outer roller 303 and the inner roller 302, they are usually set to the same length. However, depending on the use conditions, the lengths of both may be different. Specifically, the length of the inner roller 302 may be longer than that of the outer roller 303 under use conditions where the surface pressure increases. Moreover, the length of the outer side roller 303 may be made longer than the inner side roller 302 on the use conditions in which roller slip becomes large.

  When attention is paid to the shape of the roller holding portion of the cage, it is preferable that the corner portion holding the needle roller from the side is smoothly slid. If the needle rollers are held by such a loose holding portion, the needle rollers can be stably guided and held without cutting the lubricating oil film.

  When attention is paid to the shape of the rollers, crowning may be formed on at least one of the outer roller 303 and the inner roller 302. In this way, the addition of the crowning shape can shorten the effective length of the roller and enhance the differential slip reduction effect. Furthermore, there is an effect of reducing the load on the edge portion in the crowning shape, and the friction torque of the bearing can be reduced.

When the double-row thrust needle roller bearing has a bearing ring, the bearing ring has a particle diameter of 0.6 μm or more to a depth of at least 0.1 mm on the surface layer, and 10000 / mm ² or more and 40000 / mm per unit area. You may make it have less than ^two . In such a race, since carbides act as deformation resistance, the material strength of the surface layer is improved. Furthermore, the occurrence of plastic flow can be suppressed even if the raceway surface generates heat due to differential sliding between the rollers and the raceway or poor lubrication.

  With reference to FIGS. 11-17, the detailed structure of the double row thrust needle roller bearing used for a compressor, an automatic transmission, a continuously variable transmission, an electric brake, etc. is demonstrated exemplarily.

  FIG. 11 is a view showing an example of a double-row thrust needle roller bearing according to an embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view taken along line Ib-Ib of (a). (C) is the principal part enlarged view of (b), (d) is the principal part enlarged view of the pocket part of (a), (e) is the expanded sectional view along the Ie-Ie line of (b). is there.

  The double row thrust needle roller bearing 1 includes a plurality of needle rollers 2 and two annular cages 3 and 4 that hold the needle rollers 2 at a predetermined pitch in the circumferential direction. Here, each of the two cages 3 and 4 has a plurality of rectangular pockets 5 and 6 that are longer than the length L of the needle roller 2 in the radial direction, and cold rolled steel plate (SPCC). A steel plate made of is formed by press working. Roller holding portions 5a and 6a projecting in opposite directions are formed on both side edges of the pockets 5 and 6, and the needle rollers 2 are held between the roller holding portions 5a and 6a in the vertical direction. In addition, the cages 3 and 4 may be formed by drawing a steel strip such as SCM415 with a press.

  The needle roller 2 is composed of a needle roller 2 a on the outer diameter side and a needle roller 2 b on the inner diameter side, and is arranged in double rows in the pockets 5 and 6. In each of the needle rollers 2a, 2b, the revolution peripheral speed difference between the outer diameter side portion and the inner diameter side portion becomes small, and slippage with the raceway surface (not shown) is suppressed, so that heat generation at the contact portion is small, Surface damage and surface-origin peeling can be prevented. Here, the lengths of the double-row needle rollers 2a and 2b are the same, but the outer needle roller 2a is longer than the inner needle 2b, for example, 1.2 times as long. By doing so, the load capacity on the outer diameter side may be increased. Moreover, although the end surface shape of the needle rollers 2a and 2b is a flat F end surface, it may be a convex spherical A end surface, or a combination of the F end surface and the A end surface.

  As shown in FIG. 11 (d), the radial length La of the roller holding portions 5a, 6a is shorter than the roller length L, and the recesses 5b formed at both ends of the roller holding portions 5a, 6a, The lubricating oil can easily pass through 6b. Note that the end surfaces of the needle rollers 2a and 2b are not limited to flat shapes, and may be formed as arcuate surfaces.

  Further, as shown in FIG. 11 (e), the corners of the roller holding portions 5a and 6a are formed to be slack when the pockets 5 and 6 are punched with a press, or the inner edge portion is subjected to surface pressing after punching. To smooth the corners. The needle rollers 2a and 2b can be stably guided and held without cutting the lubricating oil film formed on the surfaces of the needle rollers 2a and 2b.

  Of the two cages 3 and 4, the radially outer side of the roller holder 5 a of the upper cage 3 is inclined and bent from the outer end of the roller holder 5 a as shown in FIG. The protruding portion 3a and the outer plate portion 3b bent in the radial direction from the lower end of the inclined extending portion 3a. Further, the radially inner side of the roller holding portion 5a of the upper cage 3 is similarly inclined extending portion 3c bent from the inner end of the roller holding portion 5a, and radially extending from the lower end of this inclined extending portion 3c. The inner plate portion 3d is bent.

  Further, the outer side in the radial direction of the roller holder 6a of the lower holder 4 that is pocketed with the same type as the upper holder 3 is an inclined extending part 4a bent from the outer end of the roller holder 6a, and this inclined part. It is comprised by the outer side board part 4b bent toward the radial direction from the lower end of the extension part 4a. Further, the radially inner side of the roller holding portion 6a of the upper cage 4 is similarly inclined and extended from the inner end of the roller holding portion 6a and from the lower end of the inclined and extended portion 4c in the radial direction. The inner plate part 4d is bent.

  The two retainers 3 and 4 superimpose the outer plate portions 3b and 4b in the vertical direction, and bend the outermost end portion of the outer plate portion 4b upward to form the crimped portion 7. The inner plate portions 3c and 4c are also superposed in the vertical direction, and the innermost end portion of the inner plate portion 3d is bent downward to form the crimped portion 8. The two cages 3 and 4 are firmly integrated by crimping and fixing the inner and outer ends by these crimping portions 7 and 8, so that the two cages 3 and 4 are separated even during operation. Never do. Further, in the outer plate portions 3b and 4b and the inner plate portions 3d and 4d, the contact area between the end surface of the needle roller 2 and the pockets 5 and 6 can be increased, and drilling wear can be suppressed.

In a state where the two cages 3 and 4 are fixed, the thickness T ₁ in the vertical direction of both the radially outer portion and the inner portion with respect to the roller holding portions 5a and 6a formed by the two cages 3 and 4 is determined. , _{T 2} is inclined extension portion 3a, 4a and 3c, since 4c is present, roller retaining portions 5a, thinner than the thickness _{T 0} of the vertical 6a.

  As shown in FIG. 12, the thrust needle roller bearing 1 having the above configuration is formed between the raceway surface 9 a of the first shaft (rotary shaft) 9 and the raceway surface 10 a of the second shaft (fixed shaft) 10. As the needle roller 2 rolls, it is fitted with the caulking portion 8 of the upper cage 3 as a guide surface. When the first shaft 9 rotates, the cages 3 and 4 also rotate with the first shaft 9, and the needle rollers 2 roll between the track surface 9 a of the first shaft 9 and the track surface 10 a of the second shaft 10. Move. Here, it is supplied into the thrust needle roller bearing 1 via an oil passage from a hydraulic supply source (not shown).

  The lubricating oil passes through the oil passage as indicated by arrow a, and then the gap between the raceway surface 10a of the second shaft 10 and the inner portion in the radial direction with respect to the roller holding portion 6a of the lower cage 4 is indicated by arrow b. Pass through. Thereafter, the lubricating oil passes through the circumference of the needle roller 2 and the space formed by the cages 3 and 4 as indicated by an arrow c, and the side surfaces of the needle rollers 2 and the roller holding portions 5a of the cages 3 and 4 are obtained. 6b, between the end surface of the needle roller 2 and between the side surface of the needle roller 2 and the raceway surfaces 9a, 10a, and the raceway surface 10a of the second shaft 10 and the rollers of the cage 4. The arrow d passes between the holding portion 6a and the outer portion in the radial direction and between the raceway surface 9a of the first shaft 9 and the outer portion in the radial direction with respect to the roller holding portion 5a of the cage 3. So that it is discharged.

When lubricating each part with this lubricating oil, as shown in FIG. 11 (c), with respect to the roller holding parts 5a and 6a formed by the two cages 3 and 4, the radially outer part and the inner part in the vertical direction. The thicknesses T ₁ and T ₂ are formed thinner than the vertical thickness T ₀ of the roller holding portions 5 a and 6 a, so that the raceway surface 10 a of the second shaft 10 and the roller holding portion of the lower cage 4 The cross-sectional area of the space between the inner portion in the radial direction with respect to 6a is larger than that of the conventional one, and not only the outflow property of the lubricating oil but also the inflow property is improved. Therefore, seizure of each part of the bearing can be reliably prevented, and drilling wear between the end surface of the needle roller 2 and the pockets 5 and 6 of the cages 3 and 4 can be suppressed. Also, the cages 3 and 4 are less likely to block the passage of the lubricating oil, so that the lubricating oil is less likely to stay, the rise in oil temperature can be suppressed, and the durability of the bearing combined with the increased strength of the cage. Property can be further improved.

  Of the outermost and innermost ends in the radial direction of the two cages, at least the innermost end is fixed, and the hardened layer has a surface hardness of 600 Hv or more over the entire circumference of the cage. May be formed. By doing so, it is possible to suppress drilling wear of the end face of the needle roller and the pocket of the cage and wear of the guide surface. Therefore, the durability of the bearing can be further improved in combination with the increase in strength of the cage.

  In the above, when the outermost or innermost end of the cage 3 or 4 is caulked by bending it partially or entirely in a C shape as shown in FIG. However, the shape of caulking by bending is not limited to this, and may be shapes as shown in FIGS.

  FIG. 14 shows a cage 403 made of resin. The cage 403 has a plurality of rectangular pockets 405 longer than the radial length L of the needle rollers 402. Roller holding portions 405a and 405b projecting in opposite directions are formed on both side edges of each pocket 405. The needle rollers 402 are held by these roller holding portions 405a and 405b.

  15 is an enlarged plan view of the pocket portion of FIG. 14, and FIG. 16 is a cross-sectional view taken along line IV-IV of FIG. The needle rollers 402 are configured by needle rollers 402 a on the outer diameter side and needle rollers 402 b on the inner diameter side, and are arranged in double rows in the pocket 405.

  Here, the length La of the roller holding portions 405a and 405b in the radial direction is shorter than the roller length L, so that the lubricating oil can be easily supplied by the recesses 405c formed at both ends of the roller holding portions 405a and 405b. Can be passed.

  FIG. 17 is a partial cross-sectional view illustrating a use state of the double row thrust needle roller bearing according to the embodiment of the present invention. The double row thrust needle roller bearing 401 has an inner end portion 403a of the cage 403 so that the needle roller 402 rolls between the raceway surface 409a of the rotating shaft 409 and the raceway surface 410a of the fixed shaft 410. It is fitted as a guide surface. When the rotary shaft 409 rotates, the cage 403 also rotates with the rotary shaft 409, and the needle rollers 402 roll between the raceway surface 409a of the rotary shaft 409 and the raceway surface 410a of the fixed shaft 410. Here, lubricating oil is supplied into the double-row thrust needle roller bearing 401 from a hydraulic supply source (not shown) via an oil passage.

  After the lubricating oil passes through the oil passage as indicated by arrow a, the gap between the raceway surface 410a of the fixed shaft 410 and the radially inner portion with respect to the roller holding portion 405b on the lower side of the cage 403 is indicated by the arrow b. Pass through. Thereafter, the lubricating oil passes through the circumference of the needle roller 402 and the space formed by the cage 403 as indicated by an arrow c, so that the side surface of the needle roller 402 and the roller holding portions 405a and 405b of the cage 403 are connected. And between the end surfaces of the needle rollers 402 and between the side surfaces of the needle rollers 402 and the raceway surfaces 409a and 410a. And between the raceway surface 410a of the fixed shaft 410 and the radially outer portion with respect to the roller holding portion 405b of the cage 403, and against the raceway surface 409a of the rotary shaft 409 and the roller holding portion 405a of the cage 403. And is discharged as indicated by an arrow d through the radially outer portion.

  The cage 403 is made of, for example, a synthetic resin containing glass fiber in polyphenylene sulfide. Since polyphenylene sulfide has the property of not hydrolyzing, when a thrust needle roller bearing is used in a moisture-rich atmosphere, the cage is difficult to absorb moisture, and the cage changes in size and strength. Is prevented. Moreover, since glass fiber has high mechanical strength, the strength and heat resistance of the cage can be improved by including the glass fiber. In addition, a synthetic resin containing glass fibers in polyphenylene sulfide is easily melted by heating and is easily solidified by cooling, and thus is suitable for manufacturing a cage by injection molding. Furthermore, since synthetic resin including glass fibers in polyphenylene sulfide is excellent in chemical resistance and oil resistance, it becomes possible to use a thrust needle roller bearing in an atmosphere where chemicals or oil adheres.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and changes can be made to the illustrated embodiment within the same range as the present invention or within an equivalent range.

  The present invention can be advantageously applied as a thrust needle roller bearing used in a compressor for an air conditioner of an automobile, an automatic transmission, a continuously variable transmission, an electric brake of a vehicle, and the like.

It is a longitudinal cross-sectional view which shows the both swash plate type compressor for air conditioners. It is a longitudinal cross-sectional view which shows the swash plate type compressor for air conditioners. It is a longitudinal section showing a variable capacity swash plate type compressor for an air conditioner. It is sectional drawing which shows an example of an electric brake. It is sectional drawing which shows one form of the double row thrust needle roller bearing which concerns on this invention. It is sectional drawing which shows the other form of the double row thrust needle roller bearing which concerns on this invention. It is sectional drawing which shows the further another form of the double row thrust needle roller bearing which concerns on this invention. It is a top view which shows an example of the arrangement | positioning form of a some roller. It is a top view which shows the other example of the arrangement | positioning form of a some roller. It is a top view which shows the further another example of the arrangement | positioning form of a some roller. It is a figure which shows a double row thrust needle roller bearing, (a) is a top view, (b) is sectional drawing along line Ib-Ib line of (a), (c) is a principal part expansion of (b). FIG. 4D is an enlarged view of a main part of the pocket portion of FIG. 4A, and FIG. 4E is a cross-sectional view taken along line Ie-Ie of FIG. It is a fragmentary sectional view explaining the use condition of a double row thrust needle roller bearing. It is sectional drawing which shows various types of the bending shape for caulking in the outermost end part or innermost end part of a holder | retainer. It is a principal part perspective view of a holder | retainer. It is the top view which expanded the pocket part of the holder | retainer. It is sectional drawing along the IV-IV line of FIG. It is a fragmentary sectional view explaining the use condition of a double row thrust needle roller bearing.

Explanation of symbols

180, 213, 217 Double row thrust needle roller bearing, 301 cage, 301a first member, 301b second member, 302 inner roller, 303 outer roller, 311 pocket, 312 outer pocket, 313 inner pocket.

Claims (9)

A rolling element comprising an outer roller disposed on the outer side in the radial direction of the bearing between a pair of opposed raceway surfaces, and an inner roller disposed on the inner side in the radial direction of the bearing;
A cage for holding the outer roller and the inner roller;
The double row thrust needle roller bearing is characterized in that the cage is guided by the rolling elements so as not to contact the pair of raceway surfaces. The double row thrust needle roller bearing according to claim 1, wherein a height dimension of the cage along a rotation axis direction of the bearing is smaller than a diameter of the roller. The cage includes a plurality of pockets provided at intervals in the circumferential direction,
The double row thrust needle roller bearing according to claim 1 or 2, wherein the outer roller and the inner roller are accommodated in each of the plurality of pockets. The cage includes a plurality of outer pockets spaced circumferentially at positions radially outside the bearing, and a plurality spaced circumferentially at positions radially inside the bearing. Including the inside pocket,
The outer rollers are accommodated in each of the plurality of outer pockets,
The double-row thrust needle roller bearing according to claim 1 or 2, wherein the inner roller is accommodated in each of the plurality of inner pockets. The double row thrust needle roller bearing according to any one of claims 1 to 4, wherein the outer roller has an F end surface or an A end surface, and the inner roller has an F end surface or an A end surface. The double row thrust needle roller bearing according to any one of claims 1 to 5, wherein the outer roller and the inner roller have the same length. The double row thrust needle roller bearing according to any one of claims 1 to 5, wherein the outer roller is longer than the inner roller. The double row thrust needle roller bearing according to any one of claims 1 to 5, wherein the outer roller is shorter than the inner roller. The double row thrust needle roller bearing according to any one of claims 1 to 8, wherein a corner portion of a roller holding portion of the cage is smoothly splayed.

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