JP2007211797A - Reverse input preventing clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reverse input preventing clutch without damaging a constituting member of a lock mechanism for locking an output side member even if excessive torque is inputted to the output side member. <P>SOLUTION: By forming an outer ring 6 being a part of a fixing member 8 out of a thin steel plate, when reverse input torque exceeding allowable torque is applied to an output shaft 2, the outer ring 6 pressed to a roller 10 on the rear side in the rotational direction is elastically deformed. An inner ring 3 rotates an input shaft 1 and a cage 9 while changing an engaging position with the roller 10. The roller 10 pressed to a column part 9a of the cage 9 slides with the outer ring 6, and prevents the occurrence of damage on the roller 10 constituting the lock mechanism, a cylindrical surface of the outer ring 6 and a cam surface 3a of the inner ring 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reverse input prevention clutch that transmits rotation of an input side member to an output side member and prevents rotation of the output side member from being transmitted to the input side member.

The reverse input prevention clutch transmits the rotation of the input side member to which the torque is input in both forward and reverse directions to the output side member, while preventing the rotation of the output side member due to the reverse input torque from being transmitted to the input side member. Is. As such a reverse input prevention clutch, torque transmission means for transmitting the rotation of the input side member to the output side member is provided between the input side member and the output side member that rotate about the same axis, and the output side member On the outer peripheral side or the inner peripheral side, there is provided a mechanism for locking the output side member when reverse input torque is applied to the output side member (see, for example, Patent Document 1).
JP 2004-204871 A

  However, in the reverse input prevention clutch provided with the lock mechanism as described above, when the reverse input torque exceeding the allowable torque is applied to the output side member, the member constituting the lock mechanism may be damaged.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a reverse input prevention clutch in which a component member of a lock mechanism that locks an output side member is hardly damaged even when an excessive torque is input to the output side member.

  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 the inner peripheral surface of the output side member. And a cam surface that forms a wedge-shaped space gradually narrowing in the circumferential direction between the fixing member and the cylindrical surface of the fixing member, and is connected to the input member between the output member and the fixing member. While inserting the pillar portion of the cage, rolling elements are arranged in each wedge-shaped space, and an elastic member is incorporated at a predetermined position between the rolling elements to push the rolling elements into the narrow portion of the wedge-shaped space. Therefore, reverse input torque is applied to the output side member. In the reverse input prevention clutch in which a lock mechanism for locking the output side member is formed, a part of the fixing member is formed of an annular member having the cylindrical surface and formed of a thin steel plate, and the output When a reverse input torque exceeding the allowable torque is applied to the side member, the annular member is elastically deformed by the cylindrical surface being pushed by the rolling element, so that the output side member is moved through the torque transmitting means. The input side member and the cage were rotated so that the rolling elements pushed by the pillar portion of the cage slide with the annular member.

  That is, by forming the annular member forming a part of the fixed member with a thin steel plate, when excessive torque is input to the output side member, the rolling element and the annular member slip due to elastic deformation of the annular member, and the lock mechanism The rolling element, the cylindrical surface of the annular member, and the cam surface of the output side member are prevented from being damaged.

  In the above-described configuration, the rolling elements are arranged such that two or three regions in the annular member are alternately deformed in the circumferential direction and regions that are elastically deformed in the circumferential direction. In this case, the annular member is easily elastically deformed, and damage to each component of the lock mechanism can be prevented more reliably.

  As described above, according to the present invention, the annular member forming a part of the fixing member of the reverse input preventing clutch is formed of a thin steel plate, and when excessive torque is input to the output side member, the annular member is elastically deformed. Since the rolling element and the annular member slide, each member constituting the lock mechanism is not easily damaged and can be used stably over a long period of time. In particular, the maintenance cost of the entire clutch can be greatly reduced by preventing damage to the output-side member cam surface, which is troublesome for processing.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6. 1 to 4 show a first embodiment. As shown in FIGS. 1 and 2, the reverse input preventing clutch includes an input shaft (input side member) 1, an output shaft 2 and an output side member 4 including an inner ring 3 having a plurality of cam surfaces 3a on the outer periphery. Both a housing 9, a fixing member 8 including an outer ring (annular member) 6 and a presser lid 7, a retainer 9 having two pillar portions 9 a inserted between the inner ring 3 and the outer ring 6, It is comprised with the cylindrical roller (rolling element) 10 and the spring (elastic member) 11 which are integrated between the column parts 9a. Here, the housing 5 forming a part of the fixing member 8 is made of plastic, and the outer ring 6 is made of a thin steel plate.

  The input shaft 1 is formed with two plane portions 1a parallel to each other on the outer periphery of the tip portion, and the tip portion is passed through the disc portion 9b of the retainer 9 and inserted into the shaft insertion hole 3b of the inner ring 3. At the same time, a small-diameter cylindrical portion 1b projecting from the center of the tip surface is fitted into a hole 2a provided at the center of the end surface of the output shaft 2, and rotates around the same axis as the output shaft 2. .

  The output side member 4 is provided with a flange portion 2b on the distal end side of the output shaft 2, and convex portions 2c formed at four locations on the inner peripheral side of the flange portion 2b are respectively formed into concave portions 3c formed on one end surface of the inner ring 3. By fitting, the output shaft 2 and the inner ring 3 are coupled so as to be integrally rotatable. In addition, the connection structure of the output shaft and the inner ring is not limited to the structure in which the convex portions and the concave portions of the two are fitted as in this embodiment, and any structure may be used as long as both are connected to be integrally rotatable. It may be adopted.

  The fixing member 8 has an outer ring 6 and a presser lid 7 fitted in order on the inner periphery of the housing 5, and four protrusions 5 a and an annular groove 5 b are formed on the inner peripheral surface of one end of the housing 5. The recess 5a formed on the flange portion at one end of the outer ring 6 is fitted into the protrusion 5a to restrain the rotation of the outer ring 6, and the annular protrusion 7a formed on the outer periphery of the presser lid 7 is fitted into the annular groove 5b. 6 is retained. Further, the lid portion 6b at the other end of the outer ring 6 and the lid portion 5c at the other end of the housing 5 opposite thereto form a flange restraining portion that sandwiches the flange portion 2b of the output shaft 2 from both sides in the axial direction with a slight gap. Thus, even if a radial load or an axial load is applied to the output shaft 2, the output shaft 2 is not greatly inclined with respect to the fixed member 8 or moved in the axial direction.

  The cage 9 is provided with a column part 9a at a position opposite to the periphery of the disk part 9b through which the tip part of the input shaft 1 passes, and a hole 9c formed at the center of the disk part 9b is formed in the input shaft 1. It fits in the tip part without a gap and rotates together with the input shaft 1.

  On the other hand, the shaft insertion hole 3b of the inner ring 3 has substantially the same cross-sectional shape as the tip end portion of the input shaft 1, but as shown in FIG. 3A, a slight gap is generated when the input shaft 1 is inserted. The rotation of the input shaft 1 is transmitted to the output shaft 2 connected to the inner ring 3 with a slight angular delay. The fitting shape of the inner ring and the input shaft tip is not limited to the shape of this embodiment, and it is sufficient that the rotation can be transmitted with a slight angular delay. Therefore, for example, it is possible to adopt a fitting shape such as serration with a large amount of play in the rotational direction.

  Further, as shown in FIG. 3A, each cam surface 3a of the inner ring 3 has a shape inclined in the circumferential direction, and a wedge-shaped space 12 gradually narrowing in the circumferential direction between the inner circumferential cylindrical surface of the outer ring 6. Is forming. In each wedge-shaped space 12, three cam surfaces 3 a having the same inclination direction, that is, three having the same narrowing direction are formed in the circumferential direction, and the cylindrical roller 10 is arranged in each. Further, the spring 11 is incorporated in the space between the rollers 10 formed at the locations where the wide portions of the wedge-shaped space 12 face each other, and each of the springs 11 abuts three rollers 10 on both sides thereof. It is pushed into a narrow part of the wedge-shaped space 12. On the other hand, in the space between the rollers 10 formed at the locations where the narrow portions of the wedge-shaped space 12 face each other, the column portion 9a of the retainer 9 is inserted with the rollers 10 on both sides with a slight gap.

  Therefore, when reverse input torque is applied to the output shaft 2, the inner peripheral cylindrical surface of the outer ring 6 in which the roller 10 on the rear side in the rotational direction pushed into the narrow portion of the wedge-shaped space 12 by the spring 11 is formed of a thin steel plate. In the range where the elastic deformation of the outer ring 6 is small, the engagement between the roller 10 and the inner peripheral surface of the outer ring 6 and the outer peripheral surface of the inner ring 3 is maintained, the inner ring 3 is locked, and the rotation of the output shaft 2 is input. It is not transmitted to the shaft 1. That is, when the reverse input torque is less than or equal to the allowable value, a lock mechanism that locks the inner ring 3 works.

  Further, as shown in FIG. 3B, when the reverse input torque (in the case of clockwise rotation in the figure) exceeds the allowable torque, the elasticity of the outer ring 6 pushed by the roller 10 on the rear side in the rotation direction in the direction of the arrow in the figure. By increasing the deformation, the inner ring 3 is slightly rotated integrally with the output shaft 2 while changing the engagement position with the roller 10, and the flat portion of the shaft insertion hole 3 b of the inner ring 3 is changed with the flat portion 1 a of the input shaft 1. After the engagement, the input shaft 1 and the cage 9 also rotate together. In this example, since each roller 10 is arranged so that two regions of the outer ring 6 are deformed to the outer diameter side and two regions of the inner ring side are alternately formed in the circumferential direction, the outer ring 6 is deformed. It is easy to do. Then, after the column portion 9a of the cage 9 that has slightly rotated contacts the roller 10 on the rear side in the rotation direction, the amount of elastic deformation of the outer ring 6 does not increase, and the roller 10 pushed by the cage column portion 9a The state where the output shaft 2 and the input shaft 1 rotate integrally with each other is made to slide with the outer ring 6.

  On the other hand, when an input torque is applied to the input shaft 1, the column portion 9 a of the cage 9 that rotates integrally with the input shaft 1 causes the rollers 10 on the rear side in the rotation direction to resist the elasticity of the spring 11 and to form a wedge-shaped space. 12 is pushed toward the wide side, so that the engagement between the roller 10 and the inner peripheral surface of the outer ring 6 and the outer peripheral surface of the inner ring 3 is released. When the input shaft 1 further rotates and the flat surface portion 1 a engages with the flat surface portion of the shaft insertion hole 3 b of the inner ring 3, the rotation of the input shaft 1 is transmitted to the output shaft 2 via the inner ring 3.

  This clutch has the above-described configuration. When reverse input torque exceeding the allowable torque is applied to the output shaft 2, the inner ring 3 rotates the input shaft 1 and the cage 9 due to elastic deformation of the outer ring 6, and the cage 9 Since the roller 10 pushed by the column portion 9a slides with the outer ring 6, the roller 10 constituting the lock mechanism, the cylindrical surface of the outer ring 6, and the cam surface 3a of the inner ring 3 are not easily damaged.

  When the rotation start position of the device connected to the output shaft 2 is determined, the output shaft 2 is rotated by applying a reverse input torque exceeding the allowable torque to the output shaft 2 in advance. Can be set at a predetermined position.

  FIG. 4 shows a modified example of the arrangement of the rollers 10. In this modification, two cam surfaces 3 a having the same inclination direction are formed continuously in the circumferential direction on the inner ring 3, and a cylinder is formed in a wedge-shaped space 12 formed between each cam surface 3 a and the cylindrical surface of the outer ring 6. Rollers 10 are arranged. As a result, when reverse input torque is applied, three regions of the outer ring 6 that are deformed to the outer diameter side and three regions that are deformed to the inner diameter side are alternately generated in the circumferential direction. Accordingly, the outer ring 6 can be easily elastically deformed even with this roller arrangement, although it does not reach the example shown in FIGS. 1 to 3.

  In the above-described embodiment, the housing 5 is made of plastic so that the outer ring 6 is likely to be elastically deformed. However, when a material having a high design rigidity must be adopted, the outer ring 6 is likely to be deformed. Thus, it is preferable to appropriately provide a recess on the fitting surface with the outer ring 6.

  5 and 6 show a second embodiment. In this embodiment, as shown in FIG. 5, the outer ring (annular member) 14 of the fixing member 13 and the housing 15 are integrally formed of a thin steel plate, and a presser lid 16 is attached to a flange portion at one end of the outer ring 14. Yes. On the other hand, the output shaft 18 and the inner ring 19 of the output side member 17 are formed separately and are connected so as to be integrally rotatable. The cage 21 is fitted into the outer diameter of the input shaft (input side member) 20 and the column portion 21a is inserted between the outer ring 14 and the inner ring 19 as in the first embodiment.

  Further, as shown in FIG. 6, the cam surfaces 19a of the inner ring 19 are formed in six pairs in the circumferential direction, with a pair of members having different inclination directions. Then, four rollers (rolling elements) 23 form springs (elastic members) 24 one by one in a wedge-shaped space 22 formed by four pairs of cam surfaces 19a at opposite positions formed between the inner peripheral cylindrical surface of the outer ring 14. Rollers 23 and springs 24 are not arranged in the wedge-shaped space 22 that is arranged in a sandwiched state and is formed by the other two pairs of cam surfaces 19a. As a result, when reverse input torque is applied to the output shaft 18, as in the first embodiment, the outer ring 14 has a region that deforms to the outer diameter side and a region that deforms to the inner diameter side alternately 2 in the circumferential direction. This occurs one by one, and the outer ring 14 is easily deformed. Further, the operation of the clutch when torque is applied to the input shaft 20 and the output shaft 18 is the same as that in the first embodiment.

The disassembled perspective view of the clutch of 1st Embodiment 1 is a longitudinal front view of the clutch of FIG. a is a cross-sectional view taken along line III-III in FIG. 2, and b is a cross-sectional view illustrating the operation of the clutch corresponding to a. 1 is a longitudinal front view showing a modification of the roller arrangement of the clutch in FIG. Longitudinal front view of the clutch of the second embodiment Sectional view along line VI-VI in FIG.

Explanation of symbols

1 Input shaft (input side member)
DESCRIPTION OF SYMBOLS 1a Plane part 2 Output shaft 2b Flange part 3 Inner ring 3a Cam surface 3b Shaft insertion hole 4 Output side member 5 Housing 6 Outer ring (annular member)
7 Presser lid 8 Fixing member 9 Cage 9a Column 10 Roller (rolling element)
11 Spring (elastic member)
12 Wedge-shaped space 13 Fixing member 14 Outer ring (annular member)
15 Housing 16 Presser lid 17 Output side member 18 Output shaft 19 Inner ring 19a Cam surface 20 Input shaft (input side member)
21 Cage 21a Column 22 Wedge-shaped space 23 Roller (rolling element)
24 Spring (elastic member)

Claims (2)

  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 so that the cylindrical surface faces the outer peripheral surface or the inner peripheral surface of the output side member, and a predetermined position of the output side member is placed with the cylindrical surface of the fixing member. A cam surface that forms a wedge-shaped space that gradually narrows in the circumferential direction is provided between the output side member and the fixing member, and a pillar portion of the cage connected to the input side member is inserted between the output side member and the fixing member. A rolling element is arranged in each wedge-shaped space, an elastic member is assembled at a predetermined position between these rolling elements, and each rolling element is pushed into a narrow portion of the wedge-shaped space, whereby a reverse input torque is applied to the output side member. Lock the output side member when In the reverse input prevention clutch having a hook mechanism, a part of the fixed member is formed of an annular member having the cylindrical surface and formed of a thin steel plate, and the reverse input exceeding the allowable torque is applied to the output side member. When torque is applied, the annular member is elastically deformed by the cylindrical surface being pushed by the rolling elements, so that the output member rotates the input member and the cage via the torque transmitting means. The reverse input preventing clutch, wherein the rolling element pushed by the pillar portion of the cage slides with the annular member.   Each of the rolling elements is arranged such that a region elastically deforming toward the outer diameter side and a region elastically deforming toward the inner diameter side are alternately formed in the circumferential direction in the circumferential direction by two or three each. The reverse input prevention clutch according to claim 1.

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