JP2015152089A - reverse input prevention clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a torque required to perform transmission of rotation from an input side to an output side while assuring a lock performance of a lock-type reverse input prevention clutch.SOLUTION: An axial motion of a roller 10 installed in a wedge-shaped space 14 between an outer ring 5 of a stationary member 8 and an inner ring 3 of an output side member 4 is restricted by a holder 9 and a roller restricting part 6b of a housing 6. An opposing surface of the roller restricting part 6b against the roller 10 is provided with an annular salient 6c to cause a sliding resistance between the roller 10 and the roller restricting part 6b to be made low without reducing resilient force of a spring 11 pushing the roller 10 into a narrow part of the wedge-shaped space 14. With this arrangement, it is possible to reduce a torque required for performing transmission of rotation from the input side to the output side while assuring the lock performance and to save electrical power.

Description

  The present invention relates to a reverse input prevention clutch that transmits rotation of an input side member to an output side member when input torque is applied, and prevents the input side member from rotating with respect to reverse input torque.

  The reverse input prevention clutch transmits its rotation to the output side member when input torque is applied to the input side member, and prevents the input side member from rotating when reverse input torque is applied to the output side member. It is to make. Among them, the method of locking the output side member with respect to the reverse input torque (hereinafter, this method is referred to as “locking type”) even if the motor that applies the input torque to the input side member is turned off (the motor). Are often used in applications where it is required to maintain the position of the output side member.

  As such a lock type reverse input preventing clutch, the rotation of the input side member between the input side member and the output side member rotating around the same axis is slightly delayed in the output side member. A torque transmission means for transmitting is provided, a fixed outer ring having a cylindrical surface on the inner peripheral side is arranged on the radially outer side of the output side member, a plurality of cam surfaces are provided on the outer peripheral surface of the output side member, and the inner periphery of the fixed outer ring is provided. A wedge-shaped space that gradually narrows on both sides in the circumferential direction is formed between the cylindrical surface and each cam surface of the output-side member, and a pair of rollers as an engagement member and the rollers in the respective wedge-shaped spaces are narrowed in the wedge-shaped space. It is well known that a spring is incorporated as an elastic member to be pushed into, and a cage having pillar portions inserted on both sides in the circumferential direction of each wedge-shaped space is connected to rotate integrally with the input side member (for example, , See Patent Document 1).

  In the reverse input prevention clutch configured as described above, each roller is pushed into the narrow part of the wedge-shaped space by the elasticity of the spring, so that the roller on the rear side in the rotational direction is fixed even when reverse input torque is applied to the output side member. By engaging the outer ring and the output side member, the output side member is locked, and the input side member does not rotate.

  On the other hand, when an input torque is applied to the input side member, the retainer column that rotates integrally with the input side member pushes the roller on the rear side in the rotation direction against the elastic side of the spring toward the wide side of the wedge-shaped space. Thus, the engagement of the roller with the fixed outer ring and the output side member is released, the output side member is released from the locked state, and rotation is transmitted from the input side member to the output side member by the torque transmitting means. (At this time, the roller on the front side in the rotational direction moves relative to the wide portion of the wedge-shaped space, so that it does not engage with the fixed outer ring and the output side member).

Japanese Patent No. 4965871

  In the lock type reverse input prevention clutch as described above, in order to prevent the roller from coming off in the axial direction, the cage restricts the movement of the roller toward one end in the axial direction and the other end in the axial direction of the roller. A roller restricting portion (a lid portion covering the other end side in the axial direction of the wedge-shaped space) that restricts the movement to the fixed outer ring is provided integrally.

  However, during rotation transmission from the input side to the output side, the roller also rotates (revolves) together with the input side member and the output side member, so that the roller slides with the fixed roller regulating portion. For this reason, the torque required to transmit the rotation is increased by the amount of contact resistance with the restricting part, which saves power (reduces the power consumption of the motor that applies input torque to the input side member). Therefore, it is required to reduce the required torque.

  To meet this requirement, it is effective to reduce the elasticity of the spring that presses the roller to reduce the contact resistance with the restricting portion. However, the elasticity of the spring is reduced because it affects the locking performance. Has its limits. That is, if the elasticity of the spring is too small, when reverse input torque is applied, the rollers are difficult to engage with the fixed outer ring and the output side member, and the output side member may not be locked.

  Accordingly, an object of the present invention is to reduce the torque required to transmit rotation from the input side to the output side while ensuring the locking performance of the lock type reverse input prevention clutch.

  In order to solve the above-described problems, the present invention provides a torque for transmitting the rotation of the input side member to the output side member with a slight angular delay between the input side member and the output side member rotating around the same axis. A transmission member is provided, and a fixing member having a cylindrical surface on the inner peripheral side or the outer peripheral side is arranged so that the cylindrical surface faces the outer peripheral surface or inner peripheral surface of the output side member, and the fixing is performed on the output side member. A plurality of cam surfaces that are radially opposed to the cylindrical surface of the member are provided in the circumferential direction, and a wedge-shaped space gradually narrowing in the circumferential direction is formed between the cylindrical surface and each cam surface. A cage that incorporates a roller and an elastic member that pushes the roller into a narrow portion of the wedge-shaped space, has column portions that are inserted on both sides in the circumferential direction of each wedge-shaped space, and restricts movement of the roller toward one end in the axial direction Are coupled to rotate integrally with the input side member, In the reverse input prevention clutch in which the fixing member is provided with a roller restricting portion that restricts the movement of the roller toward the other end in the axial direction, the roller restricting portion of the fixing member and at least one of the opposing surfaces of the roller are convex. A part or a recess was provided.

  That is, in the lock-type reverse input prevention clutch, the opposing surfaces of the roller disposed in the wedge-shaped space between the fixed member and the output side member and the roller restricting portion of the fixed member that restricts the axial movement of the roller. By providing a convex portion or a concave portion on at least one of these, the sliding resistance between the roller and the roller regulating portion is reduced without reducing the elasticity of the elastic member that pushes the roller into the narrow portion of the wedge-shaped space. It is.

  As a specific configuration, an annular convex portion or an annular concave portion is provided on the surface of the roller restricting portion facing the roller, or the entire other end surface of the roller facing the roller restricting portion is formed in a hemispherical shape. Good.

  As described above, the reverse input preventing clutch according to the present invention includes a roller disposed in a wedge-shaped space between the fixing member and the output side member, and a roller restricting portion of the fixing member that restricts axial movement of the roller. By providing a convex or concave portion on at least one of the opposing surfaces, the sliding resistance between the roller and the roller restricting portion is reduced, so that rotation from the input side to the output side is ensured while ensuring locking performance. It is possible to reduce power consumption by reducing the torque required for transmission.

Vertical front view of reverse input prevention clutch of embodiment Sectional view along the line II-II in FIG. Longitudinal front view showing a variation of the roller end face shape a to c are longitudinal sectional front views showing modified examples of the roller restricting portions.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the reverse input preventing clutch includes an input shaft (input side member) 1, an output side member 4 in which an output shaft 2 and an inner ring 3 are integrally formed, and a radially outer side of the inner ring 3. A plurality of columns inserted between the inner ring 3 and the outer ring 5, and a fixing member 8 comprising a two-stage cylindrical housing 6 integrally formed with the outer ring 5 and a presser lid 7 through which the input shaft 1 passes. The cage 9 is basically composed of a cage 9 having a portion 9a, a roller 10 and a spring (elastic member) 11 incorporated between the column portions 9a of the cage 9. The spring 11 is a compression coil spring.

  The fixing member 8 has a plurality of claws 7 a formed on the outer peripheral edge of the presser lid 7, and these claw 7 a is fitted into a notch 6 a formed on the outer peripheral edge of the flange at one end of the housing 6 and bent. The presser lid 7 is fixed to the housing 6. A bearing 12 that rotatably supports the output shaft 2 is fitted into the inner periphery of the small diameter portion at the other end of the housing 6, and the input shaft is inserted into the inner periphery of the cylindrical portion formed on the presser lid 7 as will be described later. A bearing 13 is rotatably fitted to rotatably support the cage 9 that rotates integrally with the motor 1. In addition, attachment holes 7 b are provided in the three tongue-shaped projecting portions that project from the outer periphery of the presser lid 7.

  In the input shaft 1, the front half of the engaging portion 1 a having two flat portions parallel to each other on the outer periphery is inserted into the engaging hole 3 a provided in the center of the inner ring 3, and the small-diameter cylindrical portion at the tip is the output shaft 2. Is fitted in a hole in the center of the end face of the output shaft 2 and rotates about the same axis as the output shaft 2. Here, the engagement hole 3a of the inner ring 3 has substantially the same cross-sectional shape as the engagement portion 1a of the input shaft 1, but is formed so that a slight rotational clearance is generated when the input shaft 1 is inserted. The rotation of the input shaft 1 is transmitted to the output shaft 2 integrated with the inner ring 3 with a slight angular delay. In addition, a retainer 9 is fitted into the rear half of the engaging portion 1a of the input shaft 1 so that the input shaft 1 and the retainer 9 rotate integrally.

  A plurality of cam surfaces 3b that are radially opposed to the inner peripheral cylindrical surface of the outer ring 5 are provided on the outer peripheral surface of the inner ring 3 between the cam surfaces 3b and the inner peripheral cylindrical surface of the outer ring 5. A wedge-shaped space 14 that is gradually narrowed on both sides in the circumferential direction is formed. Further, pillar portions 9 a of the cage 9 are inserted on both sides in the circumferential direction of each wedge-shaped space 14, and in each wedge-shaped space 14, a pair of rollers 10 has springs 11 that push each roller 10 into a narrow portion of the wedge-shaped space 14. It is arranged in a sandwiched state.

  Further, in order to prevent the rollers 10 arranged in each wedge-shaped space 14 from falling off in the axial direction, a portion between the column portions 9a adjacent to each other in the circumferential direction of the retainer 9 is directed to one axial end side of the rollers 10. A lid portion that restricts the movement and covers the other axial end side of the wedge-shaped space 14 between the small diameter portion of the other end of the housing 6 and the outer ring 5 serves as a roller restricting portion 6b toward the other axial end side of the roller 10. The movement is restricted. And the annular convex part 6c is provided in the opposing surface with the roller 10 of the roller control part 6b of the housing 6. As shown in FIG.

  This reverse input prevention clutch has the above-described configuration, and each roller 10 is pushed into the narrow portion of the wedge-shaped space 14 by the elasticity of the spring 11, so that even if reverse input torque is applied to the output shaft 2, the rotation direction When the rear roller 10 is engaged with the outer ring 5 of the fixing member 8 and the inner ring 3 of the output side member 4, the output side member 4 is locked, and the input shaft 1 does not rotate.

  On the other hand, when input torque is applied to the input shaft 1 from a motor (not shown), the column portion 9a of the retainer 9 that rotates integrally with the input shaft 1 resists the elasticity of the spring 11 against the roller 10 on the rear side in the rotation direction. By pushing out toward the wide side of the wedge-shaped space 14, the engagement between the roller 10, the outer ring 5 and the inner ring 3 is released, and the output side member 4 is released from the locked state. Then, when the input shaft 1 further rotates and the engaging portion 1a engages with the engaging hole 3a of the inner ring 3, the rotation of the input shaft 1 is transmitted to the output shaft 2 via the inner ring 3. (At this time, the roller 10 on the front side in the rotational direction moves relative to the wide part of the wedge-shaped space 14, and therefore does not engage with the outer ring 5 and the inner ring 3).

  While the rotation is transmitted from the input side to the output side as described above, the roller 10 also rotates (revolves) together with the input shaft 1 and the output side member 4. At this time, since the roller 10 slides with the annular convex portion 6c provided on the roller restricting portion 6b of the housing 6, compared with the conventional case where the entire roller end surface is in contact with the roller restricting portion, the roller 10 The sliding resistance with the roller restricting portion 6b is small. As a result, the torque required to transmit the rotation is also reduced, so that it is possible to save power, that is, reduce the power consumption of the motor that applies the input torque to the input shaft 1.

  Further, in order to reduce the sliding resistance between the roller 10 and the roller restricting portion 6b, it is not necessary to reduce the elasticity of the spring 11 that pushes the roller 10 into the narrow portion of the wedge-shaped space 14. Performance can also be secured.

  In the embodiment described above, the annular restricting portion 6c is provided on the roller restricting portion 6b of the housing 6. However, as shown in FIG. 3, the roller restricting portion 6b has a flat surface facing the roller 10, and the roller restricting portion of the roller 10 is restricted. The entire other end surface facing the portion 6b may be formed in a hemispherical shape.

  On the other hand, as shown in FIG. 4, the shape of the roller restricting portion 6 b can be changed without changing the end face shape of the roller 10. 4A, the thickness of the portion of the roller restricting portion 6b where the annular convex portion 6c is provided is made substantially the same as the thickness of the other portions of the housing 6. In the modification shown in FIG. . FIG. 4B shows an example in which the outer peripheral portion of the roller restricting portion 6b is bent to form an annular convex portion 6d, and FIG. 4C shows the annular shape on the outer peripheral side by bending the roller restricting portion 6b. The example which provided the recessed part 6e is shown. In each of these modified examples, the annular protrusions 6c and 6d and the annular recess 6e can be easily formed as compared with the examples shown in FIGS.

1 Input shaft (input side member)
DESCRIPTION OF SYMBOLS 1a Engagement part 2 Output shaft 3 Inner ring 3a Engagement hole 3b Cam surface 4 Output side member 5 Outer ring 6 Housing 6b Roller control part 6c, 6d Annular convex part 6e Annular concave part 7 Presser lid 8 Fixing member 9 Cage 9a Column part 10 Roller 11 Spring (elastic member)
14 Wedge-shaped space

Claims (3)

  Torque transmission means for transmitting the rotation of the input side member to the output side member with a slight angular delay is provided between the input side member and the output side member that rotate around the same axis, on the inner peripheral side or the outer peripheral side. A fixing member having a cylindrical surface is arranged such that the cylindrical surface faces the outer peripheral surface or inner peripheral surface of the output side member, and the cam surface faces the output side member in a radial direction with the cylindrical surface of the fixing member. Are provided in the circumferential direction, and wedge-shaped spaces gradually narrowing in the circumferential direction are formed between the cylindrical surface and the cam surfaces, and the rollers and the rollers are pushed into the narrow portions of the wedge-shaped spaces. A retainer that incorporates an elastic member and has column portions that are inserted on both sides in the circumferential direction of each wedge-shaped space, and that restricts the movement of the rollers toward one end in the axial direction, rotates integrally with the input-side member. Connect and fix the other end side of the roller in the axial direction to the fixing member In the reverse input prevention clutch provided with the roller restricting portion for restricting the movement of the roller, the reverse input is characterized in that a convex portion or a concave portion is provided on at least one of the opposing surfaces of the roller restricting portion of the fixing member and the roller. Prevent clutch.   The reverse input prevention clutch according to claim 1, wherein an annular convex portion or an annular concave portion is provided on a surface of the roller restricting portion facing the roller.   The reverse input prevention clutch according to claim 1, wherein the other end surface of the roller facing the roller restricting portion is formed in a hemispherical shape.

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