JPH11270594A - One-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably keep the posture of a roller, and to stabilize the clutch action in a one-way clutch. SOLUTION: A holding member 7 to give the repulsive energizing force of a coil spring 5 in an approximately uniformly distributed manner in the axial direction of a roller 4 is interposed between the roller 4 to be stored in a pocket 3a of a holder 3 and the coil spring 5. Because the repulsive energizing force of the coil spring 5 does not form the skew force relative to the roller 4, the rolling action can be smoothly achieved while keeping the appropriate posture of the roller 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a one-way clutch. This one-way clutch is not only a feed mechanism of various functional devices, but also a crank pulley of an engine of an automobile or the like,
It is built into pulleys and the like that are equipped on accessories that are driven via a belt from the crankshaft. Examples of the aforementioned auxiliary equipment include a compressor for an air conditioner of an automobile, a water pump, an alternator, a cooling fan, and the like.

[0002]

2. Description of the Related Art In a conventional one-way clutch, rectangular pockets in plan view are provided at several places on the circumference of a retainer so as to penetrate in and out in the radial direction. The energizing coil spring is housed.

[0003] The coil spring is housed in a compressed state, and resiliently urges the rollers with its extension restoring force. As the coil spring, a general one in which a spring wire is wound into a cylindrical shape is used, and is in contact with an axially intermediate region of the rollers.

[0004]

By the way, the form of contact with the coil spring is such that the end turn portion at one end in the direction of expansion and contraction of the coil spring is brought into contact with the peripheral surface of the roller at two locations in the longitudinal direction (axial direction). Has become. As the coil spring, a commercially available cylindrical spring is usually used, and such a coil spring is usually helical, and each winding portion is inclined without being orthogonal to the direction of expansion and contraction. For this reason, the resilient urging forces of the coil springs acting at two locations in the length direction (axial direction) of the roller may become uneven, which may give a skew force to the roller. By the way, if the roller receives a skew force, the locking and free operation tend to be unstable, such as the inclination of the roller's posture.

[0005] In addition, it is pointed out that the contact portion of the coil spring in the roller is easily damaged with time because the coil spring is directly in contact with the roller.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a one-way clutch in which the roller attitude is stably maintained and the clutch operation is stabilized.

[0007]

A one-way clutch according to the first aspect of the present invention switches between a locked state in which two inner and outer rings arranged concentrically are synchronously rotated and a free state in which the two rings are relatively rotated. A cage disposed in a radially opposed space between the two inner and outer annular bodies and having a plurality of radially inwardly and outwardly penetrating pockets corresponding to wedge-shaped spaces provided at several locations around the radially opposed space; A plurality of rollers accommodated in each of the cage pockets so as to be able to roll in the circumferential direction, and a plurality of rollers accommodated in each of the cage pockets in a compressed state and elastically urge each roller toward the lock side by the extension restoring force. And a plurality of pressing members interposed between the respective rollers and the respective coil springs and for applying the elastic biasing force of the coil springs substantially uniformly in the axial direction of the rollers.

According to a second aspect of the present invention, in the one-way clutch according to the first aspect, the pressing member is formed integrally with a band plate portion abutting widely along the axial direction of the roller and on the back side of the band plate portion. And a leg fitted into the inner periphery of the coil spring.

According to a third aspect of the present invention, in the one-way clutch according to the second aspect, a guide projection is provided on an inner wall surface on one side in a circumferential direction of the pocket of the retainer, the guide projection projecting in a direction of expansion and contraction of the coil spring. The guide projection is engaged with the leg of the pressing member in a state where the leg is slid and guided, and in a state where the amount of sliding to the roller side is regulated.

The one-way clutch according to a fourth aspect of the present invention is the one-way clutch according to the third aspect, wherein the coil spring is provided so as to surround the guide protrusion and the leg, and both ends of the coil spring in the direction of expansion and contraction are provided on the band plate portion. The rear surface and the retainer are in contact with the inner wall surface on which the guide protrusion is formed.

According to a fifth aspect of the present invention, in the one-way clutch according to any one of the first to fourth aspects, the roller contact surface of the pressing member is formed as a concave curved surface along the outer peripheral surface of the roller.

As described above, in the present invention, in short, the coil spring is not in direct contact with the rollers but indirectly through the pressing member. And
The pressing member is also configured so that the elastic urging force of the coil spring is not used as a skew force against the rollers.

In particular, in the second aspect, when the roller rolls to the free state side to compress the coil spring, the leg of the holding member abuts against the inner wall surface of the retainer pocket, so that the amount of compression of the coil spring is reduced. It will be regulated. This makes it possible to avoid collision of each of the winding portions of the coil spring.

According to the third aspect, since the slide of the holding member is guided by the guide projection, the movement of the holding member can be stabilized.

According to the fourth aspect, the displacement of the coil spring in the vertical and horizontal directions can be prevented by the pressing member and the guide projection. Thereby, buckling of the coil spring can be prevented.

According to the fifth aspect of the present invention, the contact area with the holding member is further increased, and the contact pressure can be reduced as much as possible.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Description will be made based on the embodiment shown in FIG.

1 to 5 relate to an embodiment of the present invention. FIG. 1 is a side view showing a cross section of an upper half of a one-way clutch, and FIG. 2 is a line (2)-(2) in FIG. Arrow view of the cross section,
FIG. 3 is a developed plan view of the pocket portion of the retainer, and FIG.
FIG. 5 is an exploded perspective view showing a retainer and a coil spring, and FIG. 5 is a perspective view of a slider alone.

In the figure, A indicates the entire one-way clutch. The one-way clutch A includes an inner ring 1, an outer ring 2, a retainer 3, a roller 4, and a coil spring 5. The operation is such that the rollers 4 roll according to the rotational speed difference between the inner ring 1 and the outer ring 2 to transmit power by synchronously rotating the inner and outer rings 1 and 2, and to transmit power by relative rotation. It is designed to switch to the blocking state.

Hereinafter, each of the above components will be described in detail.

The inner ring 1 is provided with a cam surface 6 formed of a flat key-shaped notch at several places on the inner circumferential surface thereof.
Slit-shaped notches 1a, 1a are provided at two places on one end face of the inner ring 1 that face each other by 180 degrees.

The outer race 2 is formed in a cylindrical shape on both the inner and outer peripheral surfaces, and is disposed concentrically on the outer periphery of the inner race 1 via a required facing space. The inner peripheral surface of the outer ring 2 and the cam surface 6 of the inner ring 1
Thus, a wedge-shaped space is formed.

The retainer 3 is provided with a pocket 3a penetrating inward and outward in the radial direction at a position corresponding to the cam surface 6 of the inner ring 1. Notches 1 of the inner ring 1 are provided at two locations 180 ° opposite to each other on one axial side surface of the pocket 3a of the retainer 3.
a, 1a are provided with protrusions 3b, 3b which are press-fitted to the notches 1a, 1a.
, The retainer 3 is positioned in the circumferential direction and the axial direction with respect to the inner ring 1.

The rollers 4 are wedges formed between the cam surface 6 of the inner race 1 and the inner peripheral surface of the outer race 2 in a state in which the rollers 4 are housed one by one in the pockets 3a of the cage 3 so as to be able to roll in the circumferential direction. It is arranged in the shape space.

The coil spring 5 is provided in each pocket 3 of the holder 3.
a is stored one by one in the compressed state, and the roller 4 is elastically urged toward the narrow side (lock side) of the wedge-shaped space by the expansion restoring force. The coil spring 5 is formed of a square-wound spring wound in a rectangular tube shape having a substantially rectangular shape in a side view, and the direction of expansion and contraction is orthogonal to the center axis of the roller 4 and one end of the roller 4 In the axial intermediate region, the length is applied to a half or more, for example, こ of the axial length of the roller 4.

Next, the features of the present invention will be described. By interposing the pressing member 7 between the roller 4 and the coil spring 5, the urging force of the coil spring 5 is indirectly applied via the pressing member 7 without directly contacting the coil spring 5 with the roller 4. The roller 4 is provided. The pressing member 7 is held in the pocket 3a of the retainer 3 in a state that allows a required amount of movement in a direction orthogonal to the axial direction of the roller 4.

More specifically, as shown in FIG. 5, the holding member 7 has a band plate portion 7a having substantially the same size as the effective track area of the roller 4.
And a pair of left and right legs 7b integrally formed on the back side of the band plate portion 7a, and is manufactured by, for example, molding a synthetic resin material.

The strip portion 7a is formed in a rectangular shape having the same size as the effective track area of the roller 4, and its front surface has a shape along the outer peripheral surface of the roller 4, that is, the same curvature as the curvature of the roller 4 or more. The concave surface s has a slightly larger curvature. Thereby, the contact area of the pressing member 7 with the roller 4 becomes as large as possible.

The pair of legs 7b is provided in the pocket 3 of the retainer 3.
It engages with the guide projection 3c provided on the inner wall surface at one end in the circumferential direction of FIG. In a state where the leg portions 7b are engaged with the guide projections 3c, the coil springs 5 are provided so as to surround them, so that the coil springs 5 are compressed between the inner wall surface of the pocket 3a and the back surface of the band plate portion 7a. Will be retained. The pressing member 7 is resiliently urged toward the rollers 4 by the extension restoring force of the coil spring 5 in the compressed state, so that the concave curved surface s of the band plate portion 7a of the pressing member 7 presses against the outer peripheral surface of the rollers 4. Can be Further, according to this mode, the postures of the holding member 7 and the coil spring 5 are positioned in the up, down, left, and right directions.
The contact position of the pressing member 7 with respect to the roller 1 does not shift even when subjected to vibration or impact.

Further, a step 3d is provided on the left and right side surfaces of the guide projection 3c of the retainer 3 on the tip side, while a projection 7c is provided on the inner surface of the free end of the leg 7b of the pressing member 7.
When the protrusion 7c is hooked on the step 3d, the forward movement amount of the pressing member 7 is regulated. The backward movement of the holding member 7 is restricted by the contact between the free end of the leg 7b of the holding member 7 and the inner wall surface of the pocket 3a. By restricting the backward movement, the amount of compression of the coil spring 5 is restricted, so that the winding portions of the coil spring 5 are prevented from coming into close contact with each other.

If such a pressing member 7 is used,
Since the concave curved surface s of the band plate portion 7a in the pressing member 7 can be made to contact the roller 4 with a wide and large contact area in the axial direction, regardless of the shape of the coil spring 5,
The resilient urging force of the coil spring 5 can be uniformly distributed over substantially the entire axial direction of the roller 4. In other words, the roller 4 does not need to be given a skew force.

Further, as in this embodiment, if the coil spring 5 is a square-wound spring and presses both ends in the longitudinal direction of the strip 7a of the holding member 7, the elastic biasing force of the coil spring 5 is reduced. The roller 4 can be easily dispersed and applied to almost the entire area in the axial direction.

From these facts, since the elastic urging force of the coil spring 5 can always be applied to the rollers 4 in a well-balanced manner, the rollers 4 can easily roll smoothly while maintaining an appropriate posture. The skew of the roller 4 can be prevented, and the roller 4 can contribute to the stabilization of the lock and free operation.

The present invention is not limited only to the above embodiment, and various applications and modifications can be considered.

(1) As shown in FIGS. 6 and 7, the leg 7b of the holding member 7 shown in the above embodiment can be formed in a hollow prismatic shape or a substantially U-shape in side view. In this case, the guide projection 3c provided on the retainer 3 may be formed in a simple prismatic shape, and the leg 7b of the pressing member 7 may be fitted.

(2) The leg portion 7b of the holding member 7 and the guide projection 3c of the retainer 3 shown in the above embodiment may be provided in a relationship opposite to each other, for example, as shown in FIGS. . That is, in the illustrated example, a single hollow prismatic leg 7 b is formed on the holding member 7, and the pair of two guide projections 3 sandwiching the leg 7 b from the left and right are formed on the retainer 3.
c is formed. These engagement forms are the same as in the above-described embodiment.

(3) In the above embodiment, the example in which the cam surface 6 is formed on the inner ring 1 side is described. However, the present invention can be applied to the one provided on the outer ring 2 side. The cam surface 6 is not limited to a flat shape, but may be a curved surface.

(4) In the above embodiment, the coil spring 4
Is a square-wound spring, but a general one wound in an elliptical or circular shape can also be used.

(5) The front surface shape of the band plate portion 7a of the holding member 7 in the above-described embodiment may be formed in an uneven plane.
It may be formed in a V shape.

(6) The cage 2 and the holding member 7
The material is not particularly limited, but can be easily and inexpensively manufactured by molding with a synthetic resin. In particular, the holding member 7 is made of a resin having excellent lubricity or a resin mixed with a lubricating material.
When the roller is formed, the rolling of the roller 4 is smoothed and the roller 4 is further effectively prevented from being damaged.

(7) The one-way clutch A can be built in pulleys of various auxiliary machines mounted on engines such as automobiles. Specifically, a case where an alternator is used as an auxiliary machine will be described with reference to FIG. In this case, between the pulley 20 and the rotor 21 of the alternator,
The one-way clutch A of the above-described embodiment is interposed, and rolling bearings 22, such as deep groove ball bearings are disposed on both axial sides of the one-way clutch A. In this case, pulley 2
The one-way clutch A is switched between a free state and a locked state in accordance with the rotational speed difference between 0 and the rotor 21, and the rotational power is transmitted from the pulley 20 to the rotor 21 or cut off. In the alternator, the pulley 20 is connected to a belt 23 by an engine crankshaft.
Conventionally, for example, when the rotational speed of the crankshaft decreases, the power generation efficiency of the alternator decreases, but when the one-way clutch A is built in, the rotational speed of the pulley 20 decreases. At this time, the one-way clutch A can be caused to function so that the rotational speed of the rotor 21 is maintained in a high range by its own inertial force, so that it is possible to contribute to improvement in power generation efficiency.

[0042]

According to the first to fifth aspects of the present invention, the roller can be smoothly rolled while keeping the roller in an appropriate posture, and the roller can contribute to the stabilization of locking and free operation. It can contribute to the improvement of performance. Also,
Since the roller can be prevented from being damaged by the coil spring, it is possible to contribute to improving the durability of the roller.

In particular, when the roller rolls to the free state side to compress the coil spring, the leg of the pressing member abuts against the inner wall surface of the retainer pocket, so that the compression amount of the coil spring is reduced. It will be regulated. This makes it possible to avoid collision of each of the winding portions of the coil spring, thereby contributing to an improvement in the durability of the coil spring.

According to the third aspect of the present invention, since the slide of the holding member is guided by the guide projection, the movement of the holding member can be stabilized, and a more stable elastic biasing force can be applied to the rollers. become.

According to the fourth aspect, since the displacement of the coil spring in the up-down and left-right directions can be prevented by the pressing member and the guide projection, the buckling of the coil spring can be prevented, so that the lock in the event of an emergency. It becomes possible to prevent detachment.

According to the fifth aspect of the present invention, the contact area with the holding member is further increased, so that the contact pressure can be reduced as much as possible, and the durability can be improved. Become.

[Brief description of the drawings]

FIG. 1 is a side view showing a cross section of an upper half of a one-way clutch according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line (2)-(2) of FIG.

FIG. 3 is an expanded plan view of a pocket portion of the cage.

FIG. 4 is an exploded perspective view showing a retainer, a coil spring, and the like.

FIG. 5 is a perspective view of a single holding member.

FIG. 6 is a view corresponding to FIG. 5 in another embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 5 in another embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 3 in another embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 5 in another embodiment of the present invention.

FIG. 10 is a sectional view showing the upper half of the pulley unit incorporating the one-way clutch of FIG. 1;

[Explanation of symbols]

 A One-way clutch 1 Inner ring 2 Outer ring 3 Cage 3a Cage pocket 3c Cage guide projection 4 Roller 5 Coil spring 7 Pressing member 7a Pressing member strip 7b Pressing member leg

Claims (5)

[Claims] 1. A one-way clutch for switching between a locked state in which two inner and outer rings arranged concentrically are synchronously rotated and a free state in which the two rings are relatively rotated, wherein the two inner and outer rings are radially opposed to each other. A retainer having pockets penetrating in and out in the radial direction at a plurality of circumferential positions corresponding to the wedge-shaped spaces provided in the space and provided at several circumferential positions of the radially opposed space; A plurality of rollers movably housed, a plurality of coil springs housed in a compressed state in respective pockets of the retainer and elastically urge each roller toward the lock side by an extension restoring force; and each roller and each coil spring. And a plurality of pressing members interposed between the pressing members to apply the resilient biasing force of the coil spring substantially uniformly in the axial direction of the rollers. 2. The one-way clutch according to claim 1, wherein the pressing member is formed integrally with a band plate portion that abuts widely along the axial direction of the roller, and is integrally formed on a back side of the band plate portion. A one-way clutch having a leg fitted into the periphery. 3. The one-way clutch according to claim 2, wherein a guide protrusion is provided on an inner wall surface on one side in a circumferential direction of the pocket of the retainer, the guide protrusion protruding in a direction in which the coil spring expands and contracts. On the other hand, the one-way clutch is characterized in that the one-way clutch is engaged in a state where the legs of the holding member are slid and guided and the amount of sliding to the roller side is regulated. 4. The one-way clutch according to claim 3, wherein the coil spring is provided so as to surround the guide projection and the leg, and both ends of the coil spring in the direction of expansion and contraction are provided.
A one-way clutch, wherein the one-way clutch is in contact with a back surface of the band plate portion and an inner wall surface on which a guide projection is formed in a retainer. 5. The one-way clutch according to claim 1, wherein a roller contact surface of the pressing member is formed as a concave curved surface along an outer peripheral surface of the roller. One-way clutch to do.