JP2006220296A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one-way clutch capable of sufficiently securing a stroke of a roller. <P>SOLUTION: The one-way clutch is provided with a inner side member, an outer side member arranged concentrically with the inner side member in a periphery of the inner side member, a plurality of rollers provided between an outer circumferential face of the inner side member and an inner circumferential face of the outer side member, and a spring elastically pressing the roller in directions engaging with both circumferential faces. An axial width of the spring is set wider than a width of the roller. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a one-way clutch, and more specifically, is incorporated in a starter, an alternator, a crank pulley, a compressor, and a pulley device used for driving an auxiliary machine at the time of engine idle stop. It relates to a one-way clutch.

  Conventionally, in a pulley device for driving an auxiliary machine such as an alternator, a one-way clutch is used for belt protection due to the influence of fluctuations in rotational angular velocity of an engine or acceleration / deceleration during traveling (for example, Patent Documents). 1). For example, the one-way clutch built in the pulley device has rollers arranged in a wedge space formed between the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring as cam surfaces, and the relative rotation of the inner and outer rings By engaging and disengaging the rollers according to the direction, power is transmitted and cut off from the drive source.

  As shown in FIGS. 7 and 8, the rollers 100 are respectively accommodated in a plurality of pockets 102 provided in the cage 101, and the direction in which the width of the wedge space is narrowed by the springs 103 supported by the cage 101, that is, It is pressed elastically in the locking direction. The cage 101 includes a pair of annular portions 104 provided at both axial ends, and a bridge portion 105 that connects the pair of annular portions 104. Both ends in the axial direction of the bridge portion 105 and an intermediate portion in the axial direction are provided with both end column portions 106 and a center column portion 107 projecting radially outward, and the spring 103 includes both the end column portions 106 and the center column portion 107. It is fixed by.

Further, as shown in FIG. 9, both end column portions 106 of the retainer 101 are formed so that the directions of the front surface 106 b of the both end column portions 106 that press the rollers 100 and the back surface 106 a that suppresses the adjacent rollers 100 are different. For example, the front surface 106b of the both-end column part 106 and the back surface 106a of the adjacent both-end column part 106 are substantially parallel. In this case, when the bisector of the wedge angle α formed by the tangent line at the contact point between the cam surface 108a of the inner ring 108 and the cylindrical surface 109a of the outer ring 109 and the point 100 is the wedge center direction P, the pressing direction of the spring 103 F faces downward with respect to the wedge center direction P. Thereby, the roller 100 at the time of torque transmission moves in the pressing direction F of the spring 103 and secures a moving distance as compared with the case where the spring 103 presses the wedge center direction P.
JP 2000-240688 A

  By the way, in the one-way clutch, in order to ensure a sufficient roller stroke, it is preferable to make the circumferential clearance of the cage pocket as large as possible. However, in the cage 101 as shown in FIG. 8, the spring 103 is supported by the both end column portions 106 and the central column portion 107 formed in the bridge portion 105, and thus the roller 100 in a direction away from the spring 103. Movement is restricted by the back surface 106a of the adjacent both-end column part 106, and it is desirable to secure a further stroke of the roller 100.

  Further, since the stroke of the roller 100 is regulated by the front surface 107a of the central column portion 107 and the back surfaces 106a of the both end column portions 106 formed in the adjacent bridge portions 105, the necessary rollers are secured while ensuring a sufficient stroke. To incorporate the number, it may be necessary to increase the size of the one-way clutch.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a one-way clutch capable of sufficiently securing a roller stroke.

The above object of the present invention can be achieved by the following constitution.
(1) An inner member, an outer member disposed concentrically with the inner member around the inner member, and a plurality of rollers provided between an outer peripheral surface of the inner member and an inner peripheral surface of the outer member. And a one-way clutch provided with a spring that elastically presses the roller in a direction to engage with both circumferential surfaces,
The one-way clutch characterized in that an axial width of the spring is wider than a width of the roller.
(2) A pocket having a pair of annular portions and a plurality of bridge portions connecting the pair of annular portions, and accommodating the rollers by the pair of annular portions and the bridge portions adjacent to each other. Further comprising a cage constituting
The one-way direction according to (1), wherein a distance between the pair of annular portions is substantially the same as a width of the roller, and the pair of annular portions each have a concave portion that holds the spring. clutch.
(3) The number of the plurality of bridge portions is the same as the number of the rollers, and the recess is formed at a position where the spring is disposed above the bridge portion in the pair of annular portions. The one-way clutch according to (2).
(4) One of the outer peripheral surface of the inner member and the inner peripheral surface of the outer member has a cam surface, and the other has a cylindrical surface.
The pressing direction of the spring is substantially parallel to a wedge center direction that is a bisector of a wedge angle formed by a tangent line at a contact point between the cam surface and the cylindrical surface and the roller ( 1-way clutch in any one of (3).
In addition, that the pressing direction of the spring is substantially parallel to the wedge center direction means that the springs intersect each other within ± 5 °.

According to the present invention, since the axial width of the spring is wider than the width of the roller, both-end column portions that support both ends of the spring are unnecessary, and the one-way clutch that can sufficiently secure the roller stroke is provided. Can be provided.
Moreover, according to this invention, the said structure can provide the one-way clutch which can incorporate a required number of rollers, ensuring sufficient stroke, without enlarging size.

  Hereinafter, a one-way clutch according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a pulley apparatus with a built-in one-way clutch in which a one-way clutch is incorporated. As shown in FIG. 1, a pulley device 10 with a built-in one-way clutch includes a sleeve 11 that can be fixed by being screwed to a rotation shaft (not shown) of an auxiliary machine such as an alternator, and a sleeve radially outside the sleeve 11. 11 and a pulley 12 having a belt groove 12a formed on the outer peripheral surface thereof. A drive belt (not shown) suspended from a drive pulley (not shown) fixed to the crankshaft of the engine is stretched over the belt groove 12a.

  A one-way clutch 13 is disposed between the outer peripheral surface of the sleeve 11 in the axial intermediate portion and the inner peripheral surface of the pulley 12 in the axial intermediate portion. A pair of support bearings 14 are arranged between the pulley 12 and the inner peripheral surface at both axial ends of the pulley 12 so as to sandwich the one-way clutch 13. A deep groove ball bearing is used as the support bearing 14 and supports the sleeve 11 and the pulley 12 so as to be relatively rotatable while supporting a radial load applied to the pulley 12.

  As shown in FIGS. 1 and 2, the one-way clutch 13 is press-fitted and fixed to the outer peripheral surface of the sleeve 11, and is press-fitted and fixed to the inner ring 15 that is an inner member that rotates together with the rotating shaft, and the inner peripheral surface of the pulley 12. The outer ring 16 is a cylindrical outer member disposed concentrically with the inner ring 15 around the inner ring 15, and is rotatably disposed between the outer peripheral surface of the inner ring 15 and the inner peripheral surface of the outer ring 16. And a plurality of rollers 17 serving as engaging members. The outer peripheral surface of the inner ring 15 forms a cam surface having a plurality of recesses 18 formed at equal intervals in the circumferential direction, and each roller 17 is formed between the cylindrical surface 19 of the outer ring 16 and each recess 18. Each wedge space 20 is arranged.

  The one-way clutch 13 includes a cage 21 having a plurality of pockets that individually accommodate the rollers 17 and a plurality of springs 22 that elastically press the rollers 17 in a direction that exerts a wedge action, that is, in a locking direction. And have.

  The pulley apparatus 10 with a built-in one-way clutch configured in this way has a tendency that the outer ring 16 rotates relative to the inner ring 15 in a predetermined direction when the rotational angular speed of the pulley 12 is faster than the rotational angular speed of the rotating shaft. In this case, the roller 17 bites in a wedge shape on the side where the recess 18 is shallow, that is, on the narrow side of the wedge space 20 based on the force received from the inner peripheral surface of the outer ring 16 and the spring force of the spring 22. Each roller 17 is engaged between the outer ring 16 and the inner ring 15. As a result, the pulley 12 and the sleeve 11 cannot be rotated relative to each other (in a locked state), and the rotational force of the engine is transmitted to the rotating shaft.

  On the other hand, when the rotational angular velocity of the pulley 12 is slower than the rotational angular velocity of the rotating shaft, the roller 17 is deepened against the spring force of the spring 22 based on the force received from the inner peripheral surface of the outer ring 16. It is displaced to the side, that is, the wide side of the wedge space 20, the engagement of the roller 17 is released, and the relative rotation between the pulley 12 and the sleeve 11 becomes free (overrun state).

  Here, as shown in FIGS. 3 to 5, the cage 21 of the present embodiment includes a pair of annular portions 23 arranged with a substantially same interval as the width of the rollers 17, and a pair of annular rings. A plurality of bridge portions 24 equal in number to the rollers 17 connecting the portions 23 are provided, and a pair of annular portions 23 and the bridge portions 24 adjacent to each other constitute each pocket. Convex portions 25 that engage with both axial ends of the concave portion 18 are formed on the inner peripheral surfaces of the pair of annular portions 23, and the cage 21 and the inner ring 15 are fixed integrally with each other.

  On the inner surface side of the pair of annular portions 23, a central column portion 26 that protrudes radially outward from the outer peripheral surface of each bridge portion 24 is formed at the axially intermediate portion of each bridge portion 24. Further, the pair of annular portions 23 are respectively formed with digging portions 27 which are a pair of concave portions for accommodating the bent portions 22a of the bent springs 22 at positions where the springs 22 are disposed above the bridge portions 24. ing. Therefore, the spring 22 is formed so that its axial width is wider than the width of the roller 17, and the base 22 b is fixed by the central column portion 26 and the pair of dug portions 27, and the bent ends. The pressing portion 22c contacts the roller 17 and presses the roller 17 in the locking direction.

The pair of annular portions 23 are provided with retaining claws 28 that cover the springs 22 on the radially outer side of the contact surfaces of the upsetting portions 27 with which the back surfaces 22d of the springs 22 abut. The spring 22 is prevented from coming off due to the above. Furthermore, an inclined surface 29 is formed on the surface opposite to the contact surface of the upsetting portion 27 so that the upsetting portion 27 spreads toward the bridge portion 24. Interference is prevented.
The upsetting portion may be formed without providing the inclined surface 29. In this case, the mold shape for molding the cage 21 is simplified. In addition, as shown by the one-dot chain line in FIG. 4, the strength of the mold is increased and interference with the spring 22 is prevented by providing the upsetting portion 27a having a wider circumferential width.

  Further, the movement of the roller 17 in the narrow direction of the wedge space 20 is restricted by the back surface 22 d of the spring 22 positioned in front of the roller 17. Therefore, in the present embodiment, the direction in which the roller 17 is pressed coincides with the direction in which the roller 17 is suppressed, and the movable range of the roller 17 varies depending on the direction in which the spring 22 presses.

As shown in FIG. 6A, the wedge angle α of each wedge space 20 is constituted by tangents T ₁ and T ₂ at contact points a and b of the cam surface 18 and the cylindrical surface 19 with the rollers 17. Here, in the present embodiment, the pressing direction P of the spring 22 is substantially parallel to the wedge center direction X that is a bisector of the wedge angle α (−5 ° to +5) so that the movable range of the roller 17 is maximized. The range that intersects at °). Specifically, the pressing direction P of the spring 22 is given by the upper surface of the bridge portion 24 that supports the spring 22 and the contact surface of the concave portion 27. Strictly speaking, it is preferable that the pressing direction P of the spring 22 is directed upward by about 1 ° with respect to the wedge center direction X.

  On the other hand, as in the reference example of the present embodiment shown in FIGS. 6B and 6C, the pressing direction P of the spring 22 is directed upward or downward beyond 5 ° with respect to the wedge center direction X. When the roller 17 is present, the movable range of the roller 17 is smaller than that in FIG.

The spring 22 installed in the cage 21 configured in this way has its axial width set wider than the width of the roller 17 and is held without providing both end column portions 106 as shown in FIG. The roller 17 can move in the circumferential direction from the front surface 26a of the central pillar 26 to the position of the back surface 22d of the adjacent spring 22, and expands the movable range from the conventional stroke l to the stroke L shown in FIG. Can do. This makes it difficult for the roller 17 to interfere with the retainer 21 when the clutch is engaged, so that the roller set position variation tolerance is increased, and the variation tolerance of the inner and outer rings 15, 16 due to manufacturing can be increased. You can go down.
Alternatively, the number of the rollers 17 can be increased while securing the same stroke of the rollers 17 as the conventional one, and the torque capacity can be increased with the same dimensions.
Further, even when the pressing direction P of the spring 22 is set substantially parallel to the wedge center direction X, the movable range of the rollers 17 can be increased, and the above-described effects can be further achieved.

  In addition, since the axial width of the spring 22 is set to be wider than the width of the roller 17, the conventional spring acting point distance w shown in FIG. It is possible to increase the distance W between the action points shown, and to prevent the rollers 17 from being skewed.

Therefore, according to the one-way clutch 13 of the present embodiment, since the axial width of the spring 22 is wider than the width of the roller 17, both end column portions that support both ends of the spring 22 are not required, and the stroke of the roller 17. Can be secured sufficiently.
Further, according to the one-way clutch 13 of the present embodiment, the above configuration can incorporate the necessary number of rollers while ensuring a sufficient stroke without increasing the size.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
In the present embodiment, the pressing direction P of the spring 22 is set by the upper surface of the bridge portion 24 of the cage 21 and the contact surface of the concave portion 27, but the cam surface 18 constituting the wedge center direction X is used by the cam surface 18. You may adjust so that the pressing direction P and the wedge center direction X may become substantially parallel.

  In the present embodiment, the one-way clutch of the present invention has been described using the pulley device with a built-in one-way clutch that is mounted between the rotating shaft of the alternator and the driven pulley, but the present invention is mounted between the pulley of the starter and the rotating shaft. It may be applied to a pulley device with a built-in one-way clutch such as for a starter. In this case, the outer peripheral surface of the inner ring is a cylindrical surface, and a cam surface is formed on the inner peripheral surface of the outer ring. Only when the inner ring tends to rotate relative to the outer ring in a predetermined direction, the rotational force can be transmitted between the inner ring and the outer ring.

In this embodiment, the inner ring of the one-way clutch is used as the inner member and the outer ring is used as the outer member. However, the sleeve formed integrally with the inner ring is used as the inner member, or the pulley formed integrally with the outer ring is used as the outer member. good.
In the present invention, the support bearings disposed on both axial sides of the one-way clutch may be rolling bearings of a type other than the deep groove ball bearing.

It is a longitudinal cross-sectional view of the one-way clutch built-in type pulley apparatus in this embodiment. It is a cross-sectional view of the one-way clutch in FIG. It is a perspective view of the retainer of a one-way clutch. It is a principal part perspective view of the retainer of a one way clutch. It is a principal part front view which shows the positional relationship of the retainer of a one-way clutch, a spring, and a roller. (A) is the schematic of the one way clutch of this embodiment for showing the pressing direction of the spring 22, FIG.6 (b) and FIG.6 (c) are the one way clutches of the reference example of this embodiment. FIG. It is a principal part perspective view of the retainer of the conventional one-way clutch. It is a principal part front view which shows the positional relationship of the retainer of a conventional one-way clutch, a spring, and a roller. It is a cross-sectional view of a conventional one-way clutch.

Explanation of symbols

10 One-way clutch built-in pulley device 11 Sleeve
DESCRIPTION OF SYMBOLS 12 Pulley 12a Belt groove 13 One-way clutch 14 Support bearing 15 Inner ring 16 Outer ring 17 Roller 18 Concave part 19 Cylindrical surface 20 Wedge space 21 Cage 22 Spring 23 Ring part 24 Bridge part 27 Digging part (concave part)

Claims (4)

An inner member, an outer member disposed concentrically with the inner member around the inner member, a plurality of rollers provided between an outer peripheral surface of the inner member and an inner peripheral surface of the outer member; A one-way clutch comprising a spring that elastically presses a roller in a direction to engage with both circumferential surfaces,
The one-way clutch characterized in that an axial width of the spring is wider than a width of the roller. A pair of annular portions and a plurality of bridge portions connecting the pair of annular portions, and the pair of annular portions and the bridge portions adjacent to each other constitute a pocket for accommodating the rollers. Further comprising a cage,
2. The one-way device according to claim 1, wherein a distance between the pair of annular portions is substantially the same as a width of the roller, and the pair of annular portions each have a concave portion that holds the spring. clutch.   The number of the plurality of bridge portions is the same as that of the rollers, and the concave portion is formed at a position where the spring is disposed above the bridge portion in the pair of annular portions. The one-way clutch according to 2. One of the outer peripheral surface of the inner member and the inner peripheral surface of the outer member has a cam surface, and the other has a cylindrical surface,
The pressing direction of the spring is substantially parallel to a wedge center direction which is a bisector of a wedge angle formed by a tangent line at a contact point between the cam surface and the cylindrical surface and the roller. Item 4. The one-way clutch according to any one of items 1 to 3.

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