JP2010281375A - Reverse input cutoff clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reverse input cutoff clutch using a method which causes an output-side member to be locked with respect to a reverse input torque, wherein a stable clutch operation can be secured over a long period of time in a simple structure even under working conditions where the direction of reverse input torque matches that of input torque. <P>SOLUTION: A wave washer 12 axially pressing an inner ring 3 which is part of output-side member 4 through the retainer 9 is provided between a pressor lid 7 and a retainer 9 integrally rotated with an input shaft 1. The inner ring 3 is pressed onto a housing 6 step on one end side of a fixing member 8 so as to give a rotational resistance to the rotation of the output-side member 4. Thus, relocking after lock release hardly occurs even when an input torque and output torque are applied in the same direction at the same time, so that the output-side member 4 can be smoothly rotated. Moreover, the simple structure eliminates time and manpower in assembly and maintenance. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reverse input cutoff 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 cutoff clutch connects an input side member and an output side member that rotate about the same axis so that torque can be transmitted, and a reverse input cutoff mechanism, that is, a positive side of an input side member to which torque is input is connected to the connecting portion. A mechanism is provided in which rotation in both reverse directions is transmitted to the output side member, and rotation of the output side member due to reverse input torque is not transmitted to the input side member. As such a reverse input cutoff clutch, there is a type in which the output side member is locked when a reverse input torque is applied to the output side member (see, for example, Patent Document 1).

  FIG. 6 shows an example of a reverse input cutoff clutch that locks the output side member against the reverse input torque as described above. In this clutch, the input side member and the output side member are connected so as to rotate around the same axis and transmit torque (not shown), and the outer side of the inner ring 51 constituting a part of the output side member. The outer ring 52 is provided with a fixed outer ring 52, and a cam surface 51a is provided on the outer periphery of the inner ring 51. A plurality of wedge-shaped spaces 53 that gradually narrow on both sides in the circumferential direction are formed between the inner peripheral cylindrical surface of the outer ring 52 and the outer peripheral surface of the inner ring 51. A pair of cylindrical rollers (rolling elements) 54 and a compression coil spring (elastic member) 55 that pushes the rollers 54 into the narrow portion of the wedge-shaped space 53 are incorporated in each wedge-shaped space 53, and the circumferential direction of each wedge-shaped space 53 The retainer column part 56 constituting a part of the input side member is inserted on both sides (positions facing the spring 55 with the roller 54 in between).

  In this clutch, each roller 54 is pushed into the narrow portion of the wedge-shaped space 53 by the elastic force of the spring 55, so that the roller 54 on the rear side in the rotational direction is connected to the outer ring 52 and the reverse side torque even when reverse input torque is applied to the output side member. By engaging with the inner ring 51, the inner ring 51 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 roller portion 56 pushes the roller 54 on the rear side in the rotation direction against the elastic force of the spring 55 to the wide portion of the wedge-shaped space 53, thereby causing the roller 54. And the outer ring 52 and the inner ring 51 are disengaged, the inner ring 51 is released from the locked state, and the rotation of the input side member is transmitted to the output side member (see the arrow in FIG. 6).

  By the way, when the input torque and the reverse input torque are simultaneously applied in the same direction to the reverse input cutoff clutch of the above-described method, the roller on the rear side in the rotational direction is pushed by the pillar portion of the cage and moves to the wide portion of the wedge-shaped space. When the output side member released from the locked state rotates (idling) at a rotational speed that exceeds the rotational speed of the input side member, the output side member is locked again when the rollers relatively return to the narrow portion of the wedge-shaped space. Immediately thereafter, the output side member may not rotate smoothly by repeating the operation of releasing the locked state by the rotation of the input side member.

  On the other hand, as a means for suppressing the occurrence of re-locking after unlocking, a second is one in which fluid resistance is applied to the rollers, or the movement of the rollers after unlocking toward the wide side of the wedge-shaped spaces is incorporated in each wedge-shaped space. A method of restricting with an elastic member has been proposed (see Patent Document 2). According to this method, the idling allowable amount of the output side member after unlocking is reduced, acceleration of the output side member is suppressed, and a state in which the rotation speed of the output side member exceeds the rotation speed of the input side member is unlikely to occur. Therefore, the occurrence of re-locking can be suppressed.

  Further, as another means for suppressing the occurrence of re-locking, there has been proposed a method in which a rotational resistance applying means is provided between the input side member and the output side member and rotational resistance is given to the relative rotation of both (patent) Reference 3). Even if this method is adopted, it is possible to prevent the output side member from rotating faster than the input side member after the lock is released, so that relocking is less likely to occur.

  However, in the method of imparting fluid resistance to the rollers described in Patent Document 2, the method of increasing the amount of grease enclosed in the clutch and using a grease having a high consistency is often employed. However, due to factors such as grease leaking to the outside as the input side member and output side member rotate, or due to degradation of the grease due to deterioration of the grease, the effect of fluid resistance can be sufficiently obtained as the service period increases. There is a problem that it becomes impossible. On the other hand, if a method of restricting the movement of the rollers with a second elastic member such as a spring or rubber material incorporated in each wedge-shaped space is adopted, an increase in the number of parts and a decrease in workability during assembly can be avoided. Absent.

  Moreover, in the method of giving rotational resistance with respect to the relative rotation of the input side member and the output side member described in Patent Document 3, it is necessary to increase the rotational resistance to such a degree that relocking can be sufficiently suppressed. However, as the rotational resistance is increased, a larger input torque is required when unlocking is performed (only the input side member is rotated from the locked state). For this reason, it is difficult to set the rotation resistance to an appropriate size and hold it, the clutch operation may become unstable due to changes in the rotation resistance during use, and the rotation resistance is adjusted during assembly and maintenance. There is a problem that it takes time and effort.

JP-A-2-271116 JP 2005-188558 A Japanese Patent Laid-Open No. 2004-19726

  An object of the present invention is a reverse input cutoff clutch of a type that locks an output side member against reverse input torque, and has a simple structure and stable clutch operation even in a usage situation where the directions of the reverse input torque and the input torque coincide. It is to be obtained over a long period of time.

  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. Are provided with cam surfaces that form wedge-shaped spaces that gradually become narrower in the circumferential direction between the cylindrical surfaces of the fixing members, and rolling elements are arranged in the respective wedge-shaped spaces, and between these rolling elements, An elastic member that pushes each rolling element into the narrow portion of the wedge-shaped space is incorporated at a predetermined location, and the input is placed at a position facing the elastic member with the rolling element sandwiched between the output side member and the fixed member. The cage column that forms part of the side member In the entered reverse input cutoff clutch, an urging member that presses the output side member in the axial direction and presses the output side member against one end of the fixed member is provided to provide rotational resistance to the rotation of the output side member. Adopted the configuration.

  That is, the rotation provided to the output side member from the fixing member even when the input torque and the reverse input torque are simultaneously applied in the same direction by the simple structure provided with the biasing member that presses the output side member against one end of the fixing member. The resistor acts as a brake that prevents the rotation speed of the output side member from increasing beyond the rotation speed of the input side member after unlocking, so that re-locking after unlocking does not easily occur. Further, according to this configuration, it is not necessary to consider the rotational resistance acting on the input side member as compared with the method of giving the rotational resistance to the relative rotation of the input side member and the output side member, and the output side Since the allowable range of the rotational resistance given to the members is wide, there is little effort for adjusting the rotational resistance during assembly and maintenance.

  In the above configuration, the urging member is arranged such that a recess is provided in at least one of the axially opposed surfaces of the input side member and the other end of the fixing member, and the urging member is accommodated in the recess. The biasing member may press the output side member via the input side member, or a recess is provided on at least one of the axially opposed surfaces of the input side member and the output side member. The urging member may be housed in the housing. In this way, it is possible to keep the clutch size almost the same as the conventional size. A wave washer can be used as the biasing member.

  If a sintered bearing for rotatably supporting the output side member is provided at one end of the fixed member, and the output side member is pressed against the end surface of the sintered bearing, the rotational accuracy of the output side member can be improved. it can. This is because sintered bearings generally have high flatness and runout accuracy at their end faces. Further, if a sintered oil-impregnated bearing impregnated with lubricating oil in advance is used as the sintered bearing, the output side member can be rotated more smoothly to prevent seizure.

  If a sliding member made of synthetic resin is arranged between the output side member and one end portion of the fixing member, and the output side member is pressed against one end portion of the fixing member through the sliding member, The rotational resistance applied to the output side member can be further stabilized.

  Further, by pressing the output side member against one end portion of the fixing member over the entire circumference around the axis thereof, a gap between the output side member and the fixing member is eliminated, and one end of the fixing member of the lubricant enclosed in the clutch Leakage from the side can be prevented.

  As described above, according to the present invention, in the reverse input cutoff clutch of the type in which the output side member is locked with respect to the reverse input torque, the re-lock after the lock release is performed even in the usage situation where the directions of the reverse input torque and the input torque coincide. Since it was made hard to produce, an output side member can be rotated smoothly. In addition, the structure for this is simply a provision of a biasing member that presses the output side member against one end of the fixed member, so that the number of parts is small and the clutch operation can be stabilized over a long period of time. it can. In addition, since the allowable range of the rotational resistance given to the output side member is wide, it does not take time to adjust the rotational resistance during assembly or maintenance.

Longitudinal front view of the reverse input cutoff clutch of the first embodiment FIG. 1 is a partially cutaway right side view of the clutch. Longitudinal front view of the reverse input cutoff clutch of the second embodiment Vertical front view of the reverse input cutoff clutch of the third embodiment Vertical front view of the reverse input cutoff clutch of the fourth embodiment Cross section of the main part explaining the structure of a general reverse input cutoff clutch and the operation when unlocking

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment. The reverse input shut-off clutch includes an input shaft 1, an output side member 4 integrally formed with an output shaft 2 and an inner ring 3, and a presser lid 7 on the large diameter side of a two-stage cylindrical housing 6 formed integrally with an outer ring 5. , A retainer 9 having a plurality of column portions 9a inserted between the inner ring 3 and the outer ring 5, and a cylindrical roller (rolling element) 10 incorporated between the column portions 9a of the retainer 9. And a compression coil spring (elastic member) 11. A wave washer (biasing member) 12 is provided between the retainer 9 and the presser lid 7, and a synthetic resin annular slide is provided between the inner ring 3 and the stepped portion of the housing 6 on one end side of the fixing member 8. A moving member (not shown) is arranged.

  In the input shaft 1, the front half of the engaging portion 13 having two flat portions parallel to each other on the outer periphery is inserted into the engaging hole 14 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 14 of the inner ring 3 has substantially the same cross-sectional shape as the engagement portion 13 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 inner ring 3 and the output shaft 2 with a slight angular delay.

  The cage 9 is fitted into the rear half of the engaging portion 13 of the input shaft 1 and constitutes an input side member together with the input shaft 1. The wave washer 12 sandwiched between the retainer 9 and the presser lid 7 on the other end side of the fixing member 8 is accommodated in a recess 7a formed on the inner surface of the presser lid 7 (the surface facing the retainer 9 in the axial direction). The inner ring 3 is pressed through the cage 9. As a result, the inner ring 3 is pressed against the stepped portion of the housing 6 through the sliding member and receives rotational resistance.

  The recess for storing the wave washer 12 may be formed on the axially facing surface of the retainer 9 with the presser lid 7 or may be formed on the axially facing surfaces of both the retainer lid 7 and the retainer 9. Also good. In order to stabilize the rotational resistance received by the inner ring 3, it is desirable to arrange a sliding member between the inner ring 3 and the housing 6 as in the embodiment, but the inner ring 3 may be pressed directly against the housing 6. Good.

  As shown in FIG. 2, the fixing member 8 has a plurality of claws 7 b formed on the outer peripheral edge of the presser lid 7, and these pawls 7 b are formed on the outer peripheral edge of the flange on the other end of the housing 6. The presser lid 7 is fixed to the housing 6 by being fitted into the notch 6a and bent.

  Further, cam surfaces 3a are provided on the outer periphery of the inner ring 3 so that the slopes are alternately reversed in the circumferential direction, and on both sides in the circumferential direction between the inner peripheral cylindrical surface of the outer ring 5 and the outer peripheral surface of the inner ring 3. A plurality of wedge-shaped spaces 15 that are gradually narrowed are formed. A pair of rollers 10 is arranged in each wedge-shaped space 15 with a spring 11 for pressing each roller 10 into a narrow portion of the wedge-shaped space 15, and both sides in the circumferential direction of each wedge-shaped space 15 (with the rollers 10 interposed). The column portion 9a of the cage 9 is inserted at a position facing the spring 11).

  Therefore, even if reverse input torque is applied to the output shaft 2, the roller 10 on the rear side in the rotational direction is pushed into the narrow portion of the wedge-shaped space 15 by the elasticity of the spring 11 and is engaged with the outer ring 5 and the inner ring 3. The inner ring 3 is locked, and the rotation of the output shaft 2 is not transmitted to the input shaft 1.

  On the other hand, when an input torque is applied to the input shaft 1, the column portion 9 a of the retainer 9 that rotates integrally with the input shaft 1 opposes the elastic force of the spring 11 against the roller 10 on the rear side in the rotational direction. Therefore, the engagement between the roller 10 and the outer ring 5 and the inner ring 3 is released, and the inner ring 3 is released from the locked state. When the input shaft 1 further rotates and the engaging portion 13 engages with the engagement hole 14 of the inner ring 3, the rotation of the input shaft 1 is transmitted to the output shaft 2 through the inner ring 3.

  Even when the input torque and the reverse input torque are simultaneously applied in the same direction, when the roller 10 on the rear side in the rotation direction is pushed by the column portion 9a of the cage 9 and moves to the wide portion of the wedge-shaped space 15, the inner ring 3 The rotational resistance applied to the roller 10 acts as a brake that prevents the rotational speed of the inner ring 3 released from the locked state from increasing beyond the rotational speed of the cage 9, so that the roller 10 is relatively narrow in the wedge-shaped space 15. There is little possibility of returning to the lock state again.

  As described above, the reverse input cutoff clutch prevents the re-locking after the unlocking from occurring even when the input torque and the reverse input torque are simultaneously applied in the same direction, so that the output side member 4 rotates smoothly. Can be made. Moreover, since the structure for this is simply a wave washer 12 that presses the inner ring 3 against the housing 6, there is little increase in the number of parts, and the clutch operation can be stabilized over a long period of time. In addition, it is not necessary to consider the rotational resistance acting on the input side member as compared with the conventional case in which the rotational resistance is applied to the relative rotation of the input side member and the output side member. Since the range is wide, it does not take time to adjust the rotation resistance during assembly and maintenance.

  Further, since the inner ring 3 is pressed against the housing 6 through the annular sliding member over the entire circumference around the shaft center, the grease (lubricant) enclosed in the clutch is prevented from leaking from one end of the housing 6. There is also an advantage of being able to do it.

  The second embodiment shown in FIG. 3 is obtained by changing the arrangement of the wave washer 12 of the first embodiment. That is, in this embodiment, the wave washer 12 is housed in the recess 3b formed on the axially facing surface of the inner ring 3 with the cage 9, and the wave washer 12 directly presses the inner ring 3. The configuration of the other parts is the same as in the first embodiment. In addition, the recessed part which accommodates the wave washer 12 may be formed in the axial direction opposing surface with the inner ring | wheel 3 of the holder | retainer 9, and may be formed in the axial direction opposing surface of both the inner ring | wheel 3 and the holder | retainer 9. .

  The third embodiment shown in FIG. 4 is based on the second embodiment and is fitted with a sintered oil-impregnated bearing 16 that rotatably supports the output shaft 2 in the small diameter portion of the housing 6 at one end of the fixing member 8. The inner ring 3 is pressed against the end face of 16. Since this sintered oil-impregnated bearing 16 has an end face with a flatness and runout accuracy of about 0.005 to 0.015 mm, the rotational accuracy of the output side member 4 is higher than in the first and second embodiments. Yes. Further, since the lubricating oil impregnated in the bearing 16 in advance is supplied to the inner ring 3 while the clutch is used, the output side member 4 rotates more smoothly than the first and second embodiments, and seizure hardly occurs. .

  In the fourth embodiment shown in FIG. 5, instead of the output side member 4 of the first embodiment, an output side member 19 in which the output shaft 17 and the inner ring 18 are formed separately and connected so as to be integrally rotatable is used. Is. The output shaft 17 and the inner ring 18 are connected by fitting recesses and protrusions formed on the surfaces facing each other in the axial direction. The fixing member 20 is different from the first embodiment in that the outer ring 22 and the presser lid 23 are fitted and fixed to the inner periphery of a covered cylindrical housing 21 having a fixing flange portion 21a. . The flange portion 17 a of the output shaft 17 is pressed against the lid portion at one end of the housing 21. Other configurations and clutch operations are the same as those in the first embodiment.

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Output shaft 3 Inner ring | wheel 3a Cam surface 3b Recessed part 4 Output side member 5 Outer ring 6 Housing 7 Presser lid 7a Recessed part 8 Fixing member 9 Cage 9a Pillar part 10 Roller (Rolling element)
11 Spring (elastic member)
12 Wave washer (biasing member)
13 Engagement part 14 Engagement hole 15 Wedge-shaped space 16 Sintered oil-impregnated bearing 17 Output shaft 18 Inner ring 19 Output side member 20 Fixing member 21 Housing 22 Outer ring 23 Presser lid

Claims (8)

  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, and rolling elements are arranged in each wedge-shaped space, and each rolling element is placed at a predetermined position between these rolling elements. A retainer column that forms part of the input side member at a position facing the elastic member with the rolling element between the output side member and the fixing member. In the reverse input cutoff clutch with the part inserted, A reverse input blocker characterized in that an urging member is provided for pressing the output side member in the axial direction and pressing the output side member against one end of the fixed member to provide rotational resistance to the rotation of the output side member. clutch.   A recess is provided in at least one of the axially opposed surfaces of the input side member and the other end of the fixed member, and the biasing member is accommodated in the recess, and the biasing member outputs via the input side member. The reverse input cutoff clutch according to claim 1, wherein the side member is pressed.   2. The reverse input cutoff clutch according to claim 1, wherein a recess is provided in at least one of axially opposed surfaces of the input side member and the output side member, and the biasing member is housed in the recess.   The reverse input cutoff clutch according to any one of claims 1 to 3, wherein a wave washer is used as the urging member.   5. A sintered bearing that rotatably supports the output side member is provided at one end of the fixed member, and the output side member is pressed against an end surface of the sintered bearing. The reverse input cutoff clutch according to claim 1.   6. The reverse input cutoff clutch according to claim 5, wherein the sintered bearing is a sintered oil impregnated bearing impregnated with lubricating oil in advance.   A synthetic resin sliding member is arranged between the output side member and one end of the fixing member, and the output side member is pressed against the one end of the fixing member through the sliding member. The reverse input cutoff clutch according to any one of claims 1 to 6,   The reverse input cutoff clutch according to any one of claims 1 to 7, wherein the output side member is pressed against one end of the fixed member over the entire circumference around the axis.

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