JP6061578B2 - Friction drive device and geared motor - Google Patents

Description

  The present invention relates to a friction drive device including a friction mechanism, and a geared motor including the friction drive device.

  When transmitting the rotation of the motor via the gear, if an excessive load is applied to the driven side, problems such as damage to the gear occur. Therefore, a configuration has been proposed in which a friction mechanism for transmitting power by friction is provided between the two rotating members, and when the excessive load is applied, the two rotating members are idle (see Patent Document 1). .

  For example, in the friction drive device 1x according to the reference example shown in FIG. 9A, the rotation surface provided with the support surface 31x facing the one side L1 in the axial direction L is provided by the annular member 3x stopped in the middle portion in the axial direction L. The shaft 2x, a cylindrical rotating member 4x that is rotatably fitted to the rotating shaft 2x on one side L1 from the support surface 31x and is in contact with the supporting surface 31x, and the rotating shaft 2x is positioned on one side L1 from the cylindrical rotating member 4x. And an annular plate-like biasing member 5x fitted to the connecting shaft portion 23x. In the cylindrical rotating member 4x, a gear 45x is formed on the outer peripheral surface, a one-side convex portion 47x in contact with the plate-like urging member 5x is formed on the surface of the one side L1, and an annular member is formed on the surface of the other side L2. The other side convex part 49x which touches 3x is formed. The outer peripheral surface of the connecting shaft portion 23x is formed with a flat surface 23y in a part of the circumferential direction. As shown in FIGS. 9C and 9D, the outer peripheral shape of the connecting shaft portion 23x and the plate shape are attached. Each of the holes 50x into which the connecting shaft portion 23x fits in the force member 5x has a D shape. For this reason, the plate-like urging member 5x is prevented from rotating with respect to the rotating shaft 2x and rotates integrally with the rotating shaft 2x. Further, in order to fix the plate-like urging member 5x to the rotating shaft 2x, as shown in FIG. 9B, the annular member 3x, the cylindrical rotating member 4x, and the plate-like urging member 5x are attached to the rotating shaft 2x. After fitting, crimping by pressing is performed to plastically deform a portion of the connecting shaft portion 23x located on the one side L1 from the plate-like urging member 5x toward the other side L2. As a result, as shown in FIG. 9 (a), the plate-like urging member 5x is a portion located on the radially outer side as a result of the inner peripheral portion being pressed against the other side L2 by the deformed portion 23z of the connecting shaft portion 23x. Will be elastically in contact with the one-side convex portion 47x of the cylindrical rotating member 4x. Therefore, when the rotating shaft 2x rotates, the rotation is caused by the frictional force between the plate-like biasing member 5x and the cylindrical rotating member 4x and the frictional force between the annular member 3x and the cylindrical rotating member 4x. Since this is transmitted to the cylindrical rotating member 4x, the cylindrical rotating member 4x rotates. On the other hand, when an excessive load is applied to the cylindrical rotating member 4x side, between the plate-like biasing member 5x and the cylindrical rotating member 4x, and between the annular member 3x and the cylindrical rotating member 4x, Since idling occurs during this period, power transmission is interrupted. For this reason, even when an excessive load is applied to the cylindrical rotating member 4x side, damage to the gears can be prevented.

FIG. 8 of JP-A-9-107658.

  However, the outer peripheral shape of the connecting shaft portion 23x and the hole 50x of the plate-like biasing member 5x are D-shaped, and a portion of the connecting shaft portion 23x located on one side L1 from the plate-like biasing member 5x is pressed to be plastic. In the caulking to be deformed, there are a problem that the variation of the friction torque is large, a problem that abnormal noise is likely to occur, and a problem that the gear is easily damaged. As a result of the examination of the above problems by the inventor of the present application, in the connecting shaft portion 23x, no pressing force is applied to the side on which the flat surface 23y is formed, so that the rotating shaft 2x is formed with the flat surface 23y. It was bent to the opposite side to the side, and a new finding was obtained that the rotation shaft 2x and the cylindrical rotation member 4x cause fluctuations and variations in sliding pressure. Further, it has been found that such blurring is undesirable because it causes abnormal noise and damages to gears. The configuration shown in FIG. 9 is a reference example for the present invention and is not a conventional example.

  In view of the above problems, the problem of the present invention is that even when the plate-like biasing member fitted to the connecting shaft portion of the rotating shaft is fixed by plastically deforming the connecting shaft portion, the rotating shaft is bent. It is an object of the present invention to provide a friction drive device that is difficult to perform, and a geared motor including the friction drive device.

In order to solve the above-described problem, a friction drive device according to the present invention includes a rotating shaft provided with a support surface facing in the axial direction at an intermediate portion in the axial direction, and the rotating shaft provided on the one side with respect to the support surface. A cylindrical rotating member that is rotatably fitted to a rotating shaft and is in contact with the support surface, and an annular plate-shaped biasing member that is fitted to a connecting shaft portion that is located on the one side of the rotating shaft with respect to the cylindrical rotating member. The connecting shaft portion has a round bar shape whose outer surface is circular, and the inner peripheral edge of the hole into which the connecting shaft portion fits in the plate-like biasing member is rotationally symmetric with respect to the axis. The inner peripheral edge of the hole is formed with a locking recess for rotation that is recessed radially outward as viewed from the outer peripheral surface of the connecting shaft portion, and the one surface of the cylindrical rotating member Is in contact with the plate-like biasing member radially outward from the hole. Square-side protrusion is formed, by plastically deforming the entire circumference of the outer circumferential surface of the round bar portion located on the one side than the plate-like urging member toward the other side of the axial direction in the connection shaft section Due to the deformed portion, the inner peripheral portion of the plate-like biasing member is pressed to the other side, and the portion positioned radially outward from the inner peripheral portion has elasticity on the one convex portion of the cylindrical rotating member. A portion of the deformed portion that enters the inside of the engagement recess functions as a detent for the rotation of the plate-like biasing member with respect to the rotation shaft .

In the present invention, when one of the rotating shaft and the cylindrical rotating member (drive-side member) rotates, the rotation is caused by the frictional force between the plate-like biasing member and the cylindrical rotating member, and the support surface . Since the frictional force between the cylindrical rotating member and the cylindrical rotating member is transmitted to the other (driven member), the other rotates. On the other hand, when an excessive load is applied to the driven side member, idle rotation occurs between the plate-like urging member and the cylindrical rotating member and between the support surface and the cylindrical rotating member. As a result, power transmission is interrupted. For this reason, even when an excessive load is applied to the driven side member, it is possible to prevent damage to the driving side member and the gear provided on the driving side from the driving side member. The plate-like urging member has its inner peripheral portion pressed to the other side by a deformed portion obtained by plastic deformation of the entire circumference of the portion located on one side of the plate-like urging member in the connecting shaft portion toward the other side. As a result, the portion located on the outer side in the radial direction is in elastic contact with the cylindrical rotating member. In realizing such a structure, since the outer surface of the connecting shaft portion is rotationally symmetric with respect to the axis, it is possible to prevent a force applied during plastic deformation from being biased in the circumferential direction. Accordingly, it is possible to prevent the rotating shaft from being bent by the force of plastic deformation, so that the rotating shaft and the cylindrical rotating member are less likely to be blurred. Further, the inner peripheral edge of the hole into which the connecting shaft portion fits in the plate-like urging member is formed with an engagement portion for preventing rotation, but the inner peripheral edge of the hole has a rotationally symmetric shape with respect to the axis. For this reason, when the inner peripheral edge of the plate-like urging member is pressed by a deformed portion due to plastic deformation of the connecting shaft portion, a uniform force is reliably applied in the circumferential direction, so that the plate-like urging member is not easily tilted. Moreover, since the one side convex part which contact | connects a plate-shaped biasing member in the radial direction outer side from a hole is formed in the surface of one side of a cylindrical rotating member, between a cylindrical rotating member and a plate-shaped biasing member The contact area and the contact state can be set to a stable state. Therefore, the frictional force between the plate-like urging member and the cylindrical rotating member can be stabilized at an appropriate level.

In this case, it is preferable that the hole of the plate-like urging member is a round hole, and the engagement recess is formed on the inner peripheral edge. According to such a configuration, when the inner peripheral edge of the plate-like urging member is pressed by the deformed portion of the connecting shaft portion due to plastic deformation, a uniform force is applied in the circumferential direction, so that the plate-like urging member is not easily tilted. Therefore, the frictional force between the plate-like urging member and the cylindrical rotating member can be stabilized at an appropriate level. In this case, it is possible to adopt a configuration in which the engaging recesses are formed at equiangular intervals at a plurality of locations in the circumferential direction.

In the present invention, it is possible to adopt a mode in which the engaging concave portion has a semicircular shape and is recessed radially outward from the inner peripheral edge of the hole.
In this case, a mode may be adopted in which a plurality of engaging recesses are formed so as to occupy an angle range corresponding to 1/3 of the inner peripheral edge of the hole as a whole.
In the present invention, the engaging recess may have a triangular shape and is recessed radially outward from the inner periphery of the hole.
In this invention, the said hole and the said engagement recessed part may comprise a polygonal hole, and the aspect by which the said engagement recessed part is formed by the corner | angular of the said polygon may be employ | adopted. In this case, arbitrary preferred that the polygon is a regular polygon.

  In this invention, it is preferable that the other side convex part which protrudes toward the said other side and contacts the said support surface is formed in the said cylindrical rotation member around the said rotating shaft. According to such a configuration, the contact area and contact state between the cylindrical rotating member and the annular member can be set in a stable state, so that the frictional force between the cylindrical rotating member and the annular member is set to an appropriate level. It can be stabilized.

  In this invention, it is preferable that the said support surface consists of a surface which faces the said one side of the cyclic | annular member fitted by the said rotating shaft. According to this configuration, if the surface of the annular member is in an appropriate state, the frictional force between the cylindrical rotating member and the annular member can be stabilized at an appropriate level regardless of the surface roughness of the rotating shaft. Can do.

  The friction drive device according to the present invention is used in a geared motor including a motor unit and a gear train. In this case, the rotation shaft is a motor shaft of the motor unit or the motor shaft rotates in the gear train. One of the rotating shafts that rotates integrally with the transmitted gear.

In the present invention, when one of the rotating shaft and the cylindrical rotating member (drive-side member) rotates, the rotation is caused by the frictional force between the plate-like biasing member and the cylindrical rotating member, and the support surface . Since the frictional force between the cylindrical rotating member and the cylindrical rotating member is transmitted to the other (driven member), the other rotates. On the other hand, when an excessive load is applied to the driven side member, idle rotation occurs between the plate-like urging member and the cylindrical rotating member and between the support surface and the cylindrical rotating member. As a result, power transmission is interrupted. For this reason, even when an excessive load is applied to the driven side member, it is possible to prevent damage to the driving side member and the gear provided on the driving side from the driving side member. The plate-like urging member has its inner peripheral portion pressed to the other side by a deformed portion obtained by plastic deformation of the entire circumference of the portion located on one side of the plate-like urging member in the connecting shaft portion toward the other side. As a result, the portion located on the outer side in the radial direction is in elastic contact with the cylindrical rotating member. In realizing such a structure, since the outer surface of the connecting shaft portion is rotationally symmetric with respect to the axis, it is possible to prevent a force applied during plastic deformation from being biased in the circumferential direction. Accordingly, it is possible to prevent the rotating shaft from being bent by the force of plastic deformation, so that the rotating shaft and the cylindrical rotating member are less likely to be blurred. Further, the inner peripheral edge of the hole into which the connecting shaft portion fits in the plate-like urging member is formed with an engagement portion for preventing rotation, but the inner peripheral edge of the hole has a rotationally symmetric shape with respect to the axis. For this reason, when the inner peripheral edge of the plate-like urging member is pressed by a deformed portion due to plastic deformation of the connecting shaft portion, a uniform force is reliably applied in the circumferential direction, so that the plate-like urging member is not easily tilted.

It is explanatory drawing of the friction drive apparatus to which this invention is applied. It is explanatory drawing of each member used for the friction drive apparatus to which this invention is applied. It is a top view of the various plate-shaped urging members used for the friction drive device to which the present invention is applied. It is a graph of the result of having evaluated the relationship between the curvature amount of the plate-shaped biasing member in the friction drive device to which this invention is applied, and the deflection amount of the front-end | tip of a rotating shaft. It is a graph of the result of having evaluated the curvature amount and static friction torque of the plate-shaped urging member in the friction drive device to which the present invention is applied. It is a graph of the result of having evaluated the curvature amount and dynamic friction torque of the plate-shaped urging member in the friction drive device to which the present invention is applied. It is a graph of the result of having evaluated the reliability of the friction drive device to which the present invention is applied. It is explanatory drawing of the geared motor by which the friction drive device to which this invention is applied is mounted. It is explanatory drawing of the friction drive apparatus which concerns on the reference example of this invention.

  A friction drive device to which the present invention is applied will be described with reference to the drawings. In the friction drive device to which the present invention is applied, when power is transmitted between the rotating shaft and the cylindrical rotating member, one of the rotating shaft and the cylindrical rotating member is a drive side member, and the other is a driven side. It becomes a member. Therefore, in the following description, an example in which the rotation shaft is a drive side member and the cylindrical rotation member is configured as a driven side member will be described. However, the rotation shaft is a driven side member and the cylindrical rotation member is driven. You may apply this invention, when comprised as a side member.

(Configuration of friction drive device)
FIG. 1 is an explanatory view of a friction drive device to which the present invention is applied. FIGS. 1A and 1B are a partial sectional view of the friction drive device and a plate-like urging member fixed to a rotating shaft, respectively. It is explanatory drawing which shows a mode. In FIG. 1, in the friction drive device, the annular member, the cylindrical rotating member, and the plate-like urging member are shown in cross section. FIG. 2 is an explanatory view of each member used in the friction drive device to which the present invention is applied, and FIGS. 2 (a), (b), (c), (d), and (e) are respectively the rotation shafts. FIG. 4 is a side view, a plan view of the rotating shaft viewed from one side (tip side) in the axial direction, a plan view of an annular member, a sectional view of a cylindrical rotating member, and a plan view of a plate-like biasing member. FIG. 3 is a plan view of various plate-like urging members used in the friction drive device to which the present invention is applied. FIGS. 3A, 3B, 3C, and 3D are respectively a first example. The plan view of the plate-like urging member according to the above, the plan view of the plate-like urging member according to the second example, the plan view of the plate-like urging member according to the third example, and the plate-like urging member according to the fourth example FIG.

  A friction drive device 1 shown in FIG. 1A is generally composed of a rotating shaft 2, an annular member 3, a cylindrical rotating member 4, and a plate-like biasing member 5. As shown in FIGS. 1A and 1B and FIGS. 2A and 2B, the rotary shaft 2 has a large diameter portion 21 along the axial direction L and an axial direction with respect to the large diameter portion 21. A medium diameter portion 22 having a diameter smaller than the large diameter portion 21 on one side L1 of L, and a connecting shaft portion 23 having a diameter smaller than the medium diameter portion 22 on one side L1 in the axial direction L with respect to the medium diameter portion 22; A small diameter portion 24 having a smaller diameter than the connecting shaft portion 23 on one side L1 in the axial direction L with respect to the connecting shaft portion 23, and a smaller diameter than the small diameter portion 24 on one side L1 in the axial direction L with respect to the small diameter portion 24. And a shaft end portion 25 having a structure provided in this order. In the large diameter portion 21, a part in the circumferential direction is a flat surface 211 at the end portion on the other side L <b> 2, and is connected to the drive source side (upstream side of the power transmission path) using this end portion. Further, a part of the outer circumferential surface of the medium diameter portion 22 in the circumferential direction is a flat surface 221. On the other hand, the connecting shaft portion 23, the small diameter portion 24, and the shaft end portion 25 have a round bar shape, and the outer peripheral surface is rotationally symmetric about the axis.

  In this embodiment, the annular member 3 is fitted to the medium diameter portion 22, and the support surface 31 is formed by the surface of the one side L <b> 1 of the annular member 3. In this embodiment, the movement of the annular member 3 toward the other side L2 in the axial direction L is such that the surface 32 on the other side L2 of the annular member 3 is in contact with the step surface located between the medium diameter portion 22 and the large diameter portion 21. It is regulated by touching. In this embodiment, the outer peripheral surface of the medium diameter portion 22 is a flat surface in the circumferential direction, and the hole 30 in which the medium diameter portion 22 fits in the annular member 3 has the same cross-sectional shape as the medium diameter portion 22. It has a shape. More specifically, the intermediate diameter portion 22 has a flat surface 221 formed at two locations on the opposite sides of the outer peripheral surface of the round bar portion, and the other portion has an arc shape. For this reason, the annular member 3 has a circular outer peripheral shape, but the inner edge of the hole 30 has a shape in which both ends of two linear portions 30a extending in parallel to each other are connected to end portions of the arc portion 30b. . For this reason, the annular member 3 is prevented from idling only by being fitted to the medium diameter portion 22.

  The cylindrical rotating member 4 includes a disk part 41 in which a hole 40 into which the part protruding from the annular member 3 to the one side L1 in the axial direction L is formed in the middle diameter part 22 is formed in the center, and the outer peripheral edge of the disk part 41 The cylindrical portion 42 protrudes on both sides in the axial direction L, and external teeth 45 are formed on the outer peripheral surface of the cylindrical portion 42. Of the both surfaces of the disk portion 41, one surface 46 facing the one side L1 in the axial direction L is formed with a one-side convex portion 47 projecting in a semicircular cross section around the hole on the one side L1. In this embodiment, the one-side convex portion 47 is formed concentrically with the cylindrical portion 42 in an annular shape. Further, in the disk portion 41, the other side surface 48 facing the other side in the axial direction L is formed with the other side convex portion 49 that protrudes in a semicircular cross section around the hole 40 on the other side L2. In the present embodiment, the other-side convex portion 49 is formed concentrically with the cylindrical portion 42 in the same manner as the one-side convex portion 47, and the other-side convex portion 49 and the one-side convex portion 47 are the disc portion 41. Are formed so as to overlap each other. In this embodiment, the hole 40 of the cylindrical rotating member 4 is circular when viewed from the axial direction L, unlike the hole 30 of the annular member 3. For this reason, the cylindrical rotating member 4 is rotatable in the circumferential direction while being fitted to the medium diameter portion 22. In the disc part 41, the part located inside the one side convex part 47 and the other side convex part 49 is slightly thinner than the part located outside. That is, in the disc part 41, the inside of the one side convex part 47 and the other side convex part 49 is pushed into the plate-like urging member 5 described below, so that it is made thin for the purpose of taking a margin. On the other hand, the outer side from the one-side convex portion 47 and the other-side convex portion 49 is thickened to ensure strength.

  In this embodiment, the washer-like plate-like urging member 5 is fitted to the connecting shaft portion 23, and the sliding surface 52 is formed by the surface of the other side L <b> 2 of the plate-like urging member 5. Further, in the plate-like urging member 5, the inner peripheral edge of the hole 50 in which the connecting shaft portion 23 fits is a recess that is recessed toward the outside in the radial direction as viewed from the outer peripheral surface of the connecting shaft portion 23. A joint recess 50a is formed. More specifically, the plate-like biasing member 5 has a circular outer peripheral shape, but the inner edge of the hole 50 has a circular shape corresponding to the outer peripheral shape of the connecting shaft portion 23 and a part of the circumferential direction. An engaging recess 50a that is recessed radially outward is formed. In the present embodiment, the hole 50 has a shape in which engaging recesses 50a are formed at equiangular intervals at a plurality of locations in the circumferential direction, and the hole 50 has a rotationally symmetric shape about the axis. More specifically, the hole 50 has a shape in which engagement recesses 50a are formed at equal angular intervals at three locations in the circumferential direction. Here, the plate-like urging member 5 is in an idle state only by being fitted to the connecting shaft portion 23. Further, the plate-like urging member 5 can be moved to the one side L1 in the axial direction L simply by being fitted to the connecting shaft portion 23, and the sliding surface 52 and the one-side convex portion 47 of the cylindrical rotating member 4 can be moved. There is not enough friction between them. Further, only by fitting the plate-like urging member 5 to the connecting shaft portion 23, sufficient frictional force is not generated between the other side convex portion 49 of the cylindrical rotating member 4 and the support surface 31 of the annular member 3.

  Therefore, in this embodiment, the entire circumference of the portion located on the one side L1 from the plate-like biasing member 5 in the connecting shaft portion 23 is plastically deformed toward the other side L2 by pressing, and a deformed portion generated by the plastic deformation. By 23a, the inner peripheral part 56 of the plate-shaped urging member 5 is pressed against the other side L2. For this reason, in the plate-like urging member 5, the inner peripheral portion 56 is displaced to the other side L2 in the axial direction L from the portion located on the outer peripheral side. Accordingly, the plate-like urging member 5 is deformed so that the portion 57 positioned radially outward from the inner peripheral portion 56 is in elastic contact with the one-side convex portion 47 of the cylindrical rotating member 4. Moreover, since the cylindrical rotating member 4 is pressed to the other side L2 of the axial direction L, the other side convex part 49 of the cylindrical rotating member 4 is in contact with the support surface 31 of the annular member 3 with elasticity. Become. Accordingly, a sufficient frictional force is generated between the sliding surface 52 and the one side convex portion 47 of the cylindrical rotating member 4, and the other side convex portion 49 of the cylindrical rotating member 4 and the support surface 31 of the annular member 3. Sufficient friction force is generated between

  In this embodiment, an engagement recess 50a that is recessed radially outward is formed on the inner peripheral edge of the hole 50 of the plate-like biasing member 5, and the deformed portion 23a generated by plastic deformation in the connecting shaft portion 23 is Then, it enters the inside of the engaging recess 50a and exhibits the function of preventing the plate-like urging member 5 from rotating.

In this embodiment, as shown in FIG. 2 (e) and FIG. 3 (b), the engaging recess 50a has a substantially semicircular shape and is recessed radially outward, but as shown in FIG. An engagement recess 50a that is recessed outward in the radial direction so as to have an arc corresponding to about 1/3 of a circle having a larger radius of curvature than the engagement recess 50a shown in 3 (b) may be employed. That is, you may form so that the several engagement recessed part 50a dented in the radial direction outer side may occupy the angle range equivalent to 1/3 of the inner periphery of the hole 50 consisting of a round hole. Moreover, as shown in FIG.3 (c), you may employ | adopt the engagement recessed part 50a dented in the radial direction outer side with a substantially triangular shape.

  Further, from the viewpoint of forming an engagement recess 50a that is recessed radially outward when viewed from the outer peripheral surface of the connection shaft 23 on the inner peripheral edge of the hole 50 into which the connection shaft 23 is fitted in the plate-like biasing member 5. For example, as shown in FIG. 3D, the hole 50 may be a polygon. According to the hole 50 having such a shape, the corner 50 c can function as an engagement recess 50 a that is recessed outward in the radial direction when viewed from the outer peripheral surface of the connecting shaft portion 23. Moreover, if the hole 50 is a regular polygon, the some engagement recessed part 50a can also be provided in an equiangular space | interval.

(Operation and main effects of this form)
In the friction drive device 1 configured as described above, when the rotary shaft 2 rotates around the axis, the rotation is caused by a frictional force between the plate-like biasing member 5 and the one-side convex portion 47 of the cylindrical rotary member 4. And the frictional force between the convex portion 49 on the other side of the cylindrical rotating member 4 and the support surface 31 of the annular member 3 is transmitted to the cylindrical rotating member 4, so that the cylindrical rotating member 4 rotates around the axis. To do. On the other hand, when an excessive load is applied to the cylindrical rotating member 4 side, between the plate-shaped urging member 5 and the cylindrical rotating member 4, and between the annular member 3 and the cylindrical rotating member 4, Since idling occurs during this period, power transmission is interrupted. For this reason, even when an excessive load is applied to the cylindrical rotating member 4 side, it is possible to prevent damage to the rotating shaft 2 and the gear provided on the driving side from the rotating shaft 2.

  Here, the plate-like urging member 5 has an inner periphery by a deformed portion 23a obtained by plastically deforming the entire circumference of the portion located on the one side L1 from the plate-like urging member 5 in the connecting shaft portion 23 toward the other side L2. The portion 56 is pressed against the other side L2. Here, since the outer peripheral surface is a round bar shape, the connecting shaft portion 23 is rotationally symmetric about the axis. For this reason, it can prevent that the force at the time of carrying out plastic deformation is biased and applied in the circumferential direction. Therefore, since it can prevent bending to the rotating shaft 2 with the force at the time of plastically deforming, blurring is hard to generate | occur | produce in the rotating shaft 2 or the cylindrical rotating member 4 so that an evaluation result may mention later. In addition, an engagement recess 50a that is recessed outward in the radial direction when viewed from the outer peripheral surface of the connection shaft portion 23 is formed on the inner peripheral edge of the hole 50 in which the connection shaft portion 23 is fitted in the plate-like biasing member 5. The deformed portion 23a due to plastic deformation enters the inside of the engaging recess 50a. For this reason, even if the connecting shaft portion 23 has a round bar shape, it is possible to prevent the plate-like urging member 5 from rotating around the rotating shaft 2.

  Further, the hole 50 of the plate-like urging member 5 has a shape in which an engagement recess 50a is formed on the inner periphery of the round hole. However, the hole 50 has a rotationally symmetric shape about the axis. Yes. For this reason, when the inner peripheral edge of the plate-like urging member 5 is pressed by the deformed portion 23a due to plastic deformation of the connecting shaft portion 23, a uniform force is applied in the circumferential direction, so that the plate-like urging member 5 is not easily tilted. Therefore, the frictional force between the plate-like urging member 5 and the cylindrical rotating member 4 can be stabilized at an appropriate level. In addition, since the engagement recesses 50a are formed at equiangular intervals at a plurality of locations in the circumferential direction, it is possible to reliably prevent the plate-like biasing member 5 from rotating freely with respect to the rotary shaft 2 and to connect the connecting shaft portion 23. When the inner peripheral edge of the plate-like urging member 5 is pressed by the deformed portion 23a due to the plastic deformation, the plate-like urging member 5 is not easily tilted because a uniform force is reliably applied in the circumferential direction. The cylindrical rotating member 4 is in contact with the sliding surface 52 of the plate-like urging member 5 and the support surface 31 of the annular member 3 via the one side convex portion 47 and the other side convex portion 49. For this reason, since the contact area and contact state of the cylindrical rotating member 4 and the plate-like biasing member 5 can be set in a stable state, the gap between the plate-like biasing member 5 and the cylindrical rotating member 4 can be set. The frictional force can be stabilized at an appropriate level. Further, the support surface 31 is a surface facing the one side L <b> 1 of the annular member 3 fitted to the rotating shaft 2. For this reason, if the surface of the annular member 3 is set to an appropriate state, the frictional force between the cylindrical rotating member 4 and the annular member 3 is stabilized at an appropriate level regardless of the surface roughness of the rotating shaft 2. be able to.

(Evaluation result 1)
FIG. 4 is a graph showing a result of evaluating the relationship between the amount of warpage P (spring warpage amount) of the plate-like biasing member 5 and the amount of deflection of the tip of the rotating shaft 2 in the friction drive device 1 to which the present invention is applied. 4 (a), (b), (c), and (d) are graphs showing the evaluation results of the friction drive device 1 of the reference example shown in FIG. 9, respectively. In the friction drive device 1 to which the present invention is applied, FIG. The graph which shows the evaluation result at the time of using the plate-shaped biasing member 5 shown to (a), and the case where the plate-shaped biasing member 5 shown in FIG.3 (b) is used in the friction drive apparatus 1 to which this invention is applied. It is a graph which shows the evaluation result at the time of using the plate-shaped biasing member 5 shown in FIG.3 (c) in the friction drive apparatus 1 to which this invention is applied, and the graph which shows an evaluation result. FIG. 5 is a graph showing a result of evaluating the warpage amount and static friction torque of the plate-like biasing member 5 in the friction drive device 1 to which the present invention is applied. FIGS. 5 (a), 5 (b), and 5 (c). , (D) are graphs showing the evaluation results of the friction drive device 1 of the reference example shown in FIG. 9, and the plate-like urging member 5 shown in FIG. 3 (a) is used in the friction drive device 1 to which the present invention is applied. FIG. 3B is a graph showing an evaluation result in the case of using the plate-like biasing member 5 shown in FIG. 3B in the friction drive device 1 to which the present invention is applied, and a friction in which the present invention is applied. It is a graph which shows the evaluation result at the time of using the plate-shaped biasing member 5 shown in FIG.3 (c) in the drive apparatus 1. FIG. FIG. 6 is a graph showing the results of evaluating the warpage amount and dynamic friction torque of the plate-like urging member 5 in the friction drive device 1 to which the present invention is applied, and FIGS. 6 (a), 6 (b), and 6 (c). , (D) are graphs showing the evaluation results of the friction drive device 1 of the reference example shown in FIG. 9, and the plate-like urging member 5 shown in FIG. 3 (a) is used in the friction drive device 1 to which the present invention is applied. FIG. 3B is a graph showing an evaluation result in the case of using the plate-like biasing member 5 shown in FIG. 3B in the friction drive device 1 to which the present invention is applied, and a friction in which the present invention is applied. It is a graph which shows the evaluation result at the time of using the plate-shaped biasing member 5 shown in FIG.3 (c) in the drive apparatus 1. FIG. In the evaluation results shown in FIGS. 4, 5, and 6, the warping amount of the plate-like biasing member 5 is equal to the inner peripheral side and the outer periphery of the plate-like biasing member 5 as shown in FIG. This is the shift amount in the axial direction L with respect to the side.

  FIG. 7 is a graph showing the result of evaluating the reliability of the friction drive device 1 to which the present invention is applied. FIGS. 7A and 7B respectively rotate the rotating shaft 2 clockwise, stop, and counterclockwise. FIG. 6 is a graph showing the relationship between the number of cycles and static friction torque, and the graph showing the relationship between the number of cycles and dynamic friction torque, with the surrounding rotation and stop taken as one cycle. In FIG. 7, data indicated by a long broken line L10 is an evaluation result when the plate-like biasing member 5 shown in FIG. 3A is used in the friction drive device 1 to which the present invention is applied, and is indicated by a solid line L20. The data shown is an evaluation result when the plate-like urging member 5 shown in FIG. 3B is used in the friction drive device 1 to which the present invention is applied, and the data indicated by a short broken line L30 is applied to the present invention. FIG. 3 is an evaluation result when the plate-like urging member 5 shown in FIG. 3C is used in the friction drive device 1, and the data indicated by the alternate long and short dash line L40 is the evaluation result of the friction drive device 1x of the reference example shown in FIG. It is.

As can be seen from FIGS. 4B to 4D, in the friction drive device 1 to which the present invention is applied , the configuration of the plate-like biasing member 5 is changed to the structure shown in FIGS. 3A to 3C. As compared with the friction drive device 1x of the reference example described with reference to FIGS. 9 and 10, the amount of deflection at the tip of the rotating shaft 2 is small and the amount of warping of the plate-like biasing member 5 changes. The amount of deflection at the tip of the rotating shaft 2 does not change greatly and is stable.

As can be seen from FIGS. 5B to 5D , even if the configuration of the plate-like biasing member 5 is changed to the structure shown in FIGS. 3A to 3C , the upper limit value of the static friction torque (for example, It was confirmed that it did not exceed 2500 gf-cm). Further, in the friction drive device 1 to which the present invention is applied, when the plate-like urging member 5 shown in FIG. 3A is used, the configuration example shown in FIGS. 3B and 3C is compared. Thus, it was confirmed that the change of the static friction torque when the amount of warping of the plate-like urging member 5 changed was small and stable. Further, when the plate-like urging member 5 shown in FIGS. 3A to 3C is used, a static friction torque of 1600 gf-cm or more is obtained even when the amount of warpage of the plate-like urging member 5 is small. I was able to. Further, when the plate-like urging member 5 shown in FIGS. 3B and 3C is used, the warpage of the plate-like urging member 5 as compared with the plate-like urging member 5 shown in FIG. It was confirmed that the static friction torque increases as the amount increases.

As can be seen from FIGS. 6B to 6D , if the structure of the plate-like urging member 5 is changed to the structure shown in FIGS. 3A to 3C , the dynamic friction torque becomes a lower limit (for example, 1300 gf). -Cm). Further, in the friction drive device 1 to which the present invention is applied, when the plate-like urging member 5 shown in FIG. 3A is used, the configuration example shown in FIGS. 3B and 3C is compared. Thus, it was confirmed that the change of the dynamic friction torque when the warpage amount of the plate-like urging member 5 changed was small and stable. Further, when the plate-like urging member 5 shown in FIGS. 3A to 3C is used, a dynamic friction torque of 1600 gf-cm or more should be ensured even when the amount of warpage of the plate-like urging member 5 is small. I was able to. In particular, when the plate-like biasing member 5 shown in FIGS. 3B and 3C is used, the plate-like biasing member 5 is compared with the plate-like biasing member 5 shown in FIG. It was confirmed that the dynamic friction torque increases as the amount of warpage increases.

As can be seen from FIGS. 7A and 7B , even if the configuration of the plate-like urging member 5 is changed to the structure shown in FIGS. 3A to 3C , the static friction torque and the dynamic friction torque can be stabilized. It was confirmed that the property (durability) is equal to or higher than that of the friction drive device 1x of the reference example shown in FIG . Further, when the structures shown in FIGS. 3A to 3C are compared, the smaller the engagement recess 50a, the better the stability (endurance performance) of the static friction torque and the dynamic friction torque. That is, the engagement recess 50a shown in FIG. 3B is smaller than the engagement recess 50a shown in FIG. 3A, and the plate-like biasing member 5 shown in FIG. 3B is used (in the solid line L20). The characteristics shown in FIG. 3 are smaller than those in the case where the plate-like biasing member 5 shown in FIG. 3A is used (characteristic shown by the long broken line L10), and the static friction torque and the dynamic friction are smaller. It tends to be excellent in torque stability (endurance performance). Further, the engagement recess 50a shown in FIG. 3C is smaller than the engagement recess 50a shown in FIGS. 3A and 3B, and the plate-like biasing member 5 shown in FIG. 3C is used. (Characteristics indicated by a long short broken line L30) is more static friction than when the plate-like biasing member 5 shown in FIGS. 3A and 3B is used (characteristics indicated by a long broken line L10 and characteristics indicated by a solid line 20). Changes in torque and dynamic friction torque are small, and the stability (endurance performance) of static friction torque and dynamic friction torque tends to be excellent.

(Other embodiments)
FIG. 3 shows a structure in which the outer peripheral surface of the connecting shaft portion 23 and the hole 50 of the plate-like urging member 5 have a rotationally symmetric shape, and the plate-like urging member 5 has an anti-rotation engaging portion. In addition to the configuration shown, convex portions are formed at equal angular intervals on the outer peripheral surface of the connecting shaft portion 23, while a concave portion (an engagement portion for rotation prevention) in which the convex portion fits into the hole 50 of the plate-like biasing member 5 is provided. A structure formed at an angular interval, or a concave portion formed on the outer peripheral surface of the connecting shaft portion 23 at an equal angular interval, while a convex portion that fits into the concave portion in the hole 50 of the plate-like biasing member 5 (an engaging portion for rotation prevention) A structure in which is formed at equiangular intervals may be adopted. Moreover, you may employ | adopt the structure which used the outer peripheral surface of the connection shaft part 23, and the hole 50 of the plate-shaped biasing member 5 as a regular hexagon or a regular octagon. In that case, in the hole 50 of the plate-shaped urging member 5, a structure may be adopted in which a plurality of sides are recessed every other side in the radial direction to form a gap.

(Example of mounting on a geared motor)
FIG. 8 is an explanatory diagram of a geared motor on which the friction drive device 1 to which the present invention is applied is mounted.

  A geared motor 100 shown in FIG. 8 is a stepping motor including a stator portion 102, a rotor portion 103, a gear transmission mechanism 104 serving as a reduction gear train, an output shaft 105, and a terminal portion 106. The stator portion 102 and the gear transmission mechanism 104 is arranged adjacently. Stator portion 102 has pole teeth 107 arranged in a circular shape by the tip portions of two stators interleaving, pole teeth 108 arranged alongside these pole teeth 107, and outer circumference of pole teeth 107. A coil 109 wound around the outer periphery of the pole teeth 108, a cylindrical case 111 also serving as a stator, and an upper case 112 also serving as a stator. The coil 109 is wound around the pole teeth 107 via the coil bobbin 109a, and the coil 110 is wound around the pole teeth 108 via the coil bobbin 110a. The rotor unit 103 includes a rotor shaft 113 and a rotor 114 that is rotatably supported by the rotor shaft 113 and has a magnet 114a.

  The gear transmission mechanism 104 includes a pinion 114 b formed on the rotor shaft 113, a first wheel 115 engaged with the pinion 114 b, a second wheel 116 engaged with the first wheel 115, and a third wheel engaged with the second wheel 116. The vehicle 117 includes a fourth wheel 118 that meshes with the third wheel 117, and a gear 105 a that is provided on the output shaft 105 so as to mesh with the fourth wheel 118. The output shaft 105 is made of a resin such as POM which is lighter than a metal such as SUS, and a gear 105a is formed by integral molding. One end 105b of the output shaft 105 is a center plate disposed adjacent to the upper case 112. It is rotatably supported by the cylindrical portion 119a by the squeezing process 119. In addition, the center of the output shaft 105 is rotatably supported by a support cylindrical portion 120 a formed by squeezing the flat case 120. The other end 105c of the output shaft 105 is engaged with an air conditioner louver drive mechanism or the like.

  Here, when a strong force is applied to the output shaft 105 from the outside, for example, when a person operates the louver of the air conditioner with a strong force, the rotation of the output shaft 105 is transmitted to the rotor 114 side. However, the reluctance torque between the stator portion 102 and the magnet 114a causes a force to maintain the position of the rotor 114, and the rotor 114 does not start rotating unless the force is too large. For this reason, the gear transmission mechanism 104 may be broken due to tooth breakage or the like at any of the gear portions.

  Therefore, in this embodiment, for example, the friction drive device 1 to which the present invention is applied is provided between the rotating shaft of the gear transmission mechanism 104 and the cylindrical rotating member. For example, between the rotor shaft 113 and the pinion 114b, between the rotation shaft and the tooth portion of the first wheel 115, between the rotation shaft and the tooth portion of the second wheel 116, and the rotation shaft and the tooth portion of the third wheel 117 The friction drive device 1 to which the present invention is applied is provided between the rotating shaft and the tooth portion of the fourth wheel 118 engaged with each other, or between the output shaft 105 and the gear 105a.

  According to this configuration, even when a strong force is applied to the output shaft 105 from the outside, problems such as damage to the gear portion of the gear transmission mechanism 104 can be prevented. Further, the friction drive device 1 to which the present invention is applied may be provided between the output shaft 105 and a cylindrical rotating member such as a gear on the louver drive mechanism side of the air conditioner.

DESCRIPTION OF SYMBOLS 1 Friction drive apparatus 2 Rotating shaft 3 Annular member 4 Cylindrical rotating member 5 Plate-shaped biasing member 23 Connection shaft part 23a Deformation part 31 by plastic deformation Support surface 47 One side convex part 49 The other side convex part 50 Hole 50a Engaging concave part (Engagement part)
56 Inner circumference L Axial direction L1 One side L2 The other side

Claims (11)

A rotating shaft provided with a support surface facing toward one side in the axial direction in the middle of the axial direction;
A cylindrical rotating member that is rotatably fitted to the rotation shaft on the one side from the support surface and is in contact with the support surface;
An annular plate-shaped urging member fitted to a connecting shaft portion located on the one side of the cylindrical rotating member in the rotating shaft;
Have
The connecting shaft portion has a round bar shape whose outer surface is circular ,
The inner peripheral edge of the hole into which the connecting shaft portion fits in the plate-like biasing member is rotationally symmetric with respect to the axis, and the inner peripheral edge of the hole is radially outward as viewed from the outer peripheral surface of the connecting shaft portion. Engagement recesses for detents that are recessed toward are formed,
On the one side surface of the cylindrical rotating member, a one-side convex portion that is in contact with the plate-like biasing member is formed on the outer side in the radial direction from the hole,
In the connecting shaft portion , the plate-like urging force is generated by a deformed portion obtained by plastically deforming the entire outer periphery of the round bar portion located on the one side of the plate-like urging member toward the other side in the axial direction . The inner peripheral part of the member is pressed to the other side, and the part located radially outward from the inner peripheral part is in elastic contact with the one-side convex part of the cylindrical rotating member , and among the deformed parts The friction drive device is characterized in that the portion that enters the inside of the engaging recess functions as a detent for the plate-like urging member with respect to the rotating shaft . 2. The friction drive device according to claim 1, wherein the hole of the plate-shaped biasing member is a round hole, and the engagement recess is formed in an inner peripheral edge . The friction drive device according to claim 2, wherein the engaging recesses are formed at equiangular intervals at a plurality of locations in the circumferential direction . 4. The friction drive device according to claim 2 , wherein the engaging recess has a semicircular shape and is recessed radially outward from an inner peripheral edge of the hole . 5. 5. The friction drive device according to claim 4, wherein a plurality of the engaging recesses are formed so as to occupy an angle range corresponding to 1/3 of the inner peripheral edge of the hole as a whole . 4. The friction drive device according to claim 2 , wherein the engaging recess has a triangular shape and is recessed radially outward from an inner peripheral edge of the hole . 5. The hole and the engagement recess constitute a polygonal hole,
The friction drive device according to claim 1, wherein the engagement recess is formed by a corner of the polygon . The friction drive device according to claim 7, wherein the polygon is a regular polygon . The said tubular rotating member, any one of claims 1 to 8, characterized in that the other side protruding portion in contact with the supporting surface protrudes toward the other side is formed around the rotary shaft The friction drive device according to item . The friction drive device according to any one of claims 1 to 9, wherein the support surface includes a surface facing the one side of the annular member fitted to the rotation shaft . A friction drive device according to any one of claims 1 to 10, a motor unit, and a geared motor including a gear train,
The geared motor, wherein the rotating shaft is either a motor shaft of the motor unit or a rotating shaft that rotates integrally with a gear to which the rotation of the motor shaft is transmitted in the gear train .

Images