JP2002039221A - One-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform rebound energization in a lock direction without skewing a roller through the force of a coil spring, in a one-way clutch. SOLUTION: In a one-way clutch, a coil spring 5 to be stored in such a form that a roller 4 is energized in a rebound manner in a lock direction by a free end part 5b is provided in a pocket 3a of a holder 3 with the base end side 5a locked in a state to be externally fitted in a peripheral groove 3e of a protrusion 3c. Protrusion parts 3g and 3g to regulate displacement in an axial direction of the coil spring are formed on a pair of inner surfaces 3f and 3f positioned opposite to each other in the axial direction of each pocket.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a one-way clutch. The one-way clutch is built in a feed mechanism of various functional devices, a pulley mounted on an auxiliary machine driven via a belt from a crankshaft of an engine of an automobile or the like, and the like. Examples of the aforementioned auxiliary equipment include a compressor for an air conditioner of an automobile, a water pump, an alternator, a cooling fan, a crank pulley, and the like.

[0002]

2. Description of the Related Art A one-way clutch switches between a locked state in which rotational power is transmitted from one of two inner and outer rings to the other, and a free state in which power transmission is interrupted.

[0003] In this one-way clutch, wedge-shaped spaces are provided at several places on the circumference of a circumferentially opposed space between two inner and outer rings. This wedge-shaped space forms a wedge-shaped space that is provided at several places around one of the opposing peripheral surfaces of both rings and has a radial gap narrowed in the locking direction with the other opposing peripheral surface. And a cylindrical opposing peripheral surface of one of the rings.

The one-way clutch further includes a ring-shaped retainer having a plurality of circumferential pockets corresponding to the cam surface in a circumferentially opposed space between the two annular members, and each pocket of the retainer has: The coil spring accommodates the roller so that it can be displaced in the circumferential direction between the lock position and the free position, and also urges the side surface of the roller accommodated in the pocket of the retainer in a substantially parallel posture in the locking direction. To accommodate.

[0005] In this case, a coil spring is externally mounted on the inner surface of the pocket of the retainer, and a projection for preventing buckling of the coil spring is provided.
At the free end side, the roller is elastically urged in the direction of the lock position (lock direction), which is the narrow side of the wedge-shaped space, at the free end side.

[0006] In this one-way clutch,
Due to the relative rotation of the two rings, the coil spring resiliently biases the roller in the locking direction, and the rollers lock the two ring bodies to a power transmission state, and also resists the resilient bias of the coil spring. Rolling in the direction of the free position (free direction), which is the wide side of the wedge-shaped space, releases the lock of the two annular members by the rollers, and enters the power transmission cutoff state.

[0007]

In the case of the one-way clutch described above, setting both rings in the locked state in a state in which the rollers are displaced (skewed) in the parallel position may cause instability of locking and unlocking. Therefore, it is necessary for the clutch to smoothly roll between the lock position and the free position while maintaining a substantially parallel posture.

However, in the case of the conventional one-way clutch, the opposing distance between the side walls corresponding to the base end of the coil spring in the pocket of the retainer is larger than the outer diameter of the base end of the coil spring, and the base end of the coil spring has the shaft. The structure is such that there is room for displacement in the direction. Therefore, the base end side of the coil spring is largely displaced in the axial direction, and the roller is elastically urged in a state where a non-uniform state of force that is greatly deviated from the axial center from the free end side of the coil spring is applied to the roller. However, this may cause the rollers to roll in the locking direction in a skewed state.

Accordingly, an object of the present invention is to improve a pocket of a retainer so that a roller can be elastically urged in a locking direction by a coil spring without skew in a one-way clutch.

[0010]

SUMMARY OF THE INVENTION A one-way clutch according to the present invention switches between a locked state in which two rings concentrically arranged inside and outside facing each other are synchronously rotated and a free state in which the rings are relatively rotated. A cam, which is provided at several positions on the circumference of one of the opposed peripheral surfaces of the two ring bodies and forms a wedge-shaped space in which a radial gap is narrowed toward the locking direction between the two opposed annular surfaces. Surface, a retainer interposed between the two annular bodies and having a roller and a coil spring receiving pocket at several places corresponding to the cam surface, and a lock position and a free position in the retainer pocket. And a coil spring accommodated one by one so as to be displaceable in the circumferential direction between the rollers, and a coil spring housed adjacent to the roller in the circumferential direction and resiliently urges the roller in the locking direction in the pocket of the retainer. In each pocket of the cage, a pair of opposed inner surfaces in the axial direction, in which projecting portion for restricting the axial displacement of the coil spring is provided.

According to the present invention, the coil spring skews the roller when the roller is resiliently urged in the locking direction and rolls, because the axial displacement is regulated by the overhanging portion on the axially opposed inner surface of the pocket. It can be rolled in the lock direction without the need.

[0012] In the present invention, preferably, the both protruding portions are tapered so that the axial space between them becomes narrower from the locking direction toward the free direction in the accommodation space on the base end side of the coil spring. . In such a case, there is an effect that the coil spring can be easily inserted, and the axial position of the coil spring can be stabilized.

[0013] In the present invention, preferably, a projection is provided on an inner surface of the pillar portion between the pockets of the retainer, the projection of the base end of the coil spring being externally fitted to prevent buckling, and a side surface at the base of the projection. However, a taper angle is provided so that the accommodation space on the base end side of the coil spring together with the overhanging portion is narrowed from the locking direction toward the free direction. In such a case, there is an effect that the coil spring can be easily inserted, and the axial position of the coil spring can be stabilized.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings.

1 to 6 relate to an embodiment of the present invention. FIG. 1 is a longitudinal side view of a one-way clutch, FIG. 2 is a sectional view taken along line (2)-(2) of FIG. 3 is a cross-sectional view around the pocket of the cage in FIG. 1, FIG. 4 is a developed plan view around the pocket of the cage, FIG. 5 is a perspective view around the pocket of the cage, and FIG. FIG.
In FIG. 3, illustration of the outer ring is omitted.

In FIG. 1, A indicates the entire one-way clutch. The one-way clutch A includes an inner ring 1 as an inner ring, an outer ring 2 as an outer ring, a retainer 3, rollers 4 as rolling elements, and a coil spring 5. As the operation, the roller 4 rolls in accordance with the rotation difference between the inner ring 1 and the outer ring 2 and switches between a state in which the inner and outer rings 1 and 2 are rotated relative to each other and a state in which the inner and outer rings 1 and 2 are synchronously rotated. The rotational power is cut off or transmitted between the two.

The inner ring 1 is provided with a flat key-shaped cam surface 1a at several locations on the outer peripheral surface, whereby the outer peripheral surface is formed in a polygonal shape (for example, an octagon).

The outer race 2 is fitted concentrically to the outer periphery of the inner race 1 via a required facing space, and both inner and outer peripheral surfaces are formed in a cylindrical shape. The inner peripheral surface of the outer ring 2 and the inner ring 1
A wedge-shaped space is formed with the cam surface 1a.

The retainer 3 is interposed between the inner and outer rings 1 and 2 and is press-fitted onto the outer peripheral surface of the inner ring 1. The retainer 3 is positioned radially inward and outward at a position corresponding to each cam surface 1 b of the inner ring 1. A penetrating pocket 3a is provided.

Each of the pockets 3a of the retainer 3 has a base end 5a of the coil spring 5 fitted around the center of the inner surface 3b of the pillar portion on one side (free side) in the circumferential direction. A projection 3c for preventing bending is integrally formed.

The base of the projection 3c is cut out in the axial direction,
A circumferential groove 3e is formed between the cutout wall surface 3d and the circumferential inner surface 3b on one side.

The projection 3c has a trapezoidal shape in a plan view in which the outer diameter in the axial direction increases from the lock direction toward the free direction and is tapered.

The roller 4 is attached to the pocket 3a of the cage 3 by one.
Each of them is housed in a wedge-shaped space formed between the cam surface 1a of the inner ring 1 and the outer ring 2 in a state of being stored so as to be capable of rolling in the circumferential direction.

The coil spring 5 is provided in each pocket 3 of the holder 3.
a, the roller 4 is housed in a compressed state one by one adjacent to the roller 4 in the circumferential direction.
Is elastically urged toward the narrow side (lock side) of the wedge-shaped space formed by the cam surface 1a of the inner ring 1 and the outer ring 2. The coil spring 5 is a rectangular spring formed by winding a spring wire in a rectangular shape, and is attached to the projection 3 c in the pocket 3 a of the retainer 3 so as to be substantially parallel to the cam surface 1 a of the inner ring 1. And the base end 5a is engaged with the circumferential groove 3e of the projection 3c so as to be attached to the retainer 3 in a non-separable manner.

Therefore, the coil spring 5 resiliently urges the roller 4 in the locking direction at its free end 5b with its base end 5a locked in the circumferential groove 3e of the projection 3c. .

The characteristic configuration of the present embodiment will be described.

The present embodiment is characterized in that the inner surfaces 3f, 3f of the pocket 3a in the axial direction are provided with protrusions 3g, 3g for regulating the axial displacement of the coil spring 5.

Both overhangs 3g. 3g is pocket 3a
In the axial inner surface 3b, at the position axially opposed to the proximal end 5a of the coil spring 5, the accommodation space of the proximal end 5a of the coil spring 5 is narrowed from the lock direction toward the free direction. Are tapered.

The projection 3c has a taper angle on its side surface so that the axial width decreases from the locking direction to the free direction from the tip to the base.
Both overhangs 3g. 3g and outer surface 3 in both axial directions of protrusion 3c
h, 3h, the two coil spring base end side accommodation spaces 3i, 3i are narrowed from the locking direction toward the free direction.

In this case, the minimum axial distance between the protrusions 3g, 3g on one side in the circumferential direction is equal to the protrusion 3
c is approximately equal to or slightly larger than the outer diameter of the coil spring 5 fitted externally.

In the one-way clutch having the above structure, the roller 4 is elastically urged in the lock direction by the coil spring 5 by the relative rotation of the inner and outer rings 1 and 2, and the inner and outer rings 1 and 2 are pressed by the roller 4. The inner and outer rings 1 and 2 are locked in the power transmission state, and are rolled in the free position direction (free direction) on the wide side of the wedge-shaped space against the elastic bias of the coil spring 5 to lock the inner and outer rings 1 and 2. Release to set the power transmission cutoff state.

In this case, the axial displacement of the base end 5a of the coil spring 5 in the axial direction is restricted by the projecting portions 3g, 3g of the pocket 3a of the retainer 3, so that the lock of the inner and outer rings 1, 2 is released. Therefore, when the roller 4 is rolled in the locking direction by the coil spring 5, the free end side 5b of the coil spring 5 can be elastically biased to the side surface of the roller 4 at a substantially equal distance from the axial direction thereof. The roller 4 can roll without skew.

Thus, the locking operation of the one-way clutch according to the embodiment is stabilized.

In this case, the free end 5b of the coil spring 5
If the roller 4 does not skew, the roller 4 may be resiliently urged at a position slightly shifted in the axial direction from the center in the axial direction. The regulation of the axial displacement for 5a may have some tolerance.

It should be noted that the present invention is not limited to only the above embodiment, and various applications and modifications are conceivable. (1) In the case of the above embodiment, the pocket 3 of the retainer 3
a, both overhanging portions 3g on the axial inner surfaces 3f, 3f,
Although 3g has a tapered chamfer, as shown in FIG. 7, the overhangs 3g, 3g are connected to the circumferentially straight overhangs 3g1, 3g1 and the circumferential overhangs 3g1, 3g1. 3g of tapered overhang
2, 3g3. In this case, the axially opposed interval between the straight projections 3g1 and 3g1 is slightly larger than the outer diameter of the coil spring 5. (2) In the case of the above embodiment, the pocket 3 of the retainer 3
Both overhang portions 3g, 3 on the inner surfaces 3f, 3f in the a-axis direction
g regulates the axial displacement of the coil spring 5 relative to the proximal end 5a, as shown in FIG.
Projections 3g, 3g for regulating the axial displacement of the intermediate portions 5c, 5c may be provided. The projecting portions 3g, 3g in FIG. 8 bulge in the directions of each other, and their axially opposed intervals are substantially equal to or slightly larger than the outer diameter of the coil spring 5. (3) The one-way clutch A of the above-described embodiment can be built in pulleys of various auxiliary machines mounted on an engine such as an automobile. 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 a deep groove ball bearing are disposed on both axial sides of the one-way clutch A. In this case, according to the rotation difference between the pulley 20 and the rotor 21, the one-way clutch A switches between the free state and the locked state,
The rotation power is transmitted from 0 to the rotor 21 or cut off.

In the alternator, the pulley 20 is
Conventionally, for example, when the rotation speed of the crankshaft decreases, the power generation efficiency of the alternator decreases because the engine is driven to rotate by the crankshaft via the belt 23. When the rotation speed of the motor 20 decreases, the one-way clutch A can function so that the rotation speed of the rotor 21 is maintained at a high range by its own inertial force, so that the power generation efficiency can be improved. Also, due to the rotation fluctuation from the crankshaft and the inertia force of the alternator rotor shaft,
It is possible to prevent the stress on the belt 23 from shortening the service life of the belt 23 and preventing noise due to slippage.

[0037]

In the one-way clutch of the present invention, the axial displacement of the coil spring is regulated by the axial displacement projections provided on both side walls defining the pockets of the retainer. The roller can be rolled in a substantially parallel posture by the uniform elastic biasing of the wedge-shaped space between the inner and outer rings in the locking direction, thereby preventing the occurrence of skew.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view 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 a cross-sectional view around the pocket of the cage in FIG. 1;

FIG. 4 is a plan view around the pocket of the cage of FIG. 1;

FIG. 5 is a perspective view of a pocket of the cage of FIG. 1;

FIG. 6 is a perspective view of the inner race of FIG. 1;

FIG. 7 is a plan view showing another modification of the cage.

FIG. 8 is a plan view showing still another modification of the cage.

9 is a sectional view of the upper half showing a pulley unit including the one-way clutch shown in FIG. 1;

[Explanation of symbols]

 A One-way clutch 1 Inner ring 1a Inner ring cam surface 2 Outer ring 3 Cage 3a Cage pocket 3b Circumferential inner surface 3c Projection 3d Projection notch 3e Circumferential groove 3f Cage axial inner surface 3g Overhang on retainer Part 4 Roller 5 Coil spring

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadahiro Terada 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Inside Koyo Seiko Co., Ltd. (72) Inventor Mitsuru Ueda 3-58-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Inside the corporation

Claims (3)

[Claims] 1. A one-way clutch for switching between a locked state in which two rings disposed concentrically inside and outside facing each other and a free state in which the rings are relatively rotated, wherein one of the two rings is A cam surface which is provided at several places on the circumference of the opposing peripheral surface and forms a wedge-shaped space in which a radial gap is narrowed in the locking direction with the other opposing peripheral surface; And a retainer having rollers and coil spring receiving pockets at several circumferential positions corresponding to the cam surface, and one retainer is accommodated in the pocket of the retainer so as to be circumferentially displaceable between a locked position and a free position. And a coil spring, which is housed adjacent to the roller in the circumferential direction and resiliently biases the roller in the locking direction, in a pocket of the retainer, and in each pocket of the retainer, One-way clutch, wherein the pair of opposed inner surfaces to direction, projecting portion for restricting the axial displacement of the coil spring is provided, that. 2. The one-way clutch according to claim 1, wherein the two projecting portions have a taper angle such that an axial space between the projecting portions is narrowed from a locking direction toward a free direction in a housing space at a base end side of the coil spring. A one-way clutch, which is attached. 3. The one-way clutch according to claim 2, wherein a base end side of the coil spring is externally fitted to an inner surface of the pillar portion between the pockets of the retainer to prevent buckling of the coil spring. A one-way clutch, wherein a side surface of a base has a taper angle so as to narrow the accommodation space on the base end side of the coil spring together with the overhang from the locking direction toward the free direction.