JP2001003961A - One-way clutch and pulley unit therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure which can reduce manufacturing costs while securing sufficient strength for positioning of a cage in a one-way clutch. SOLUTION: In this one-way clutch 3 of the type using a roller 13 and having a cam face 10a provided on the outer peripheral surface of an inner ring 10, a cage 12 is kept from rotating while in a configuration such that the cage 12 is circumferentially hooked on the cam face 10a of the inner ring 10, and the cage 12 is positioned while in a configuration such that it is axially hooked by both a small-diameter cylinder part 10a provided at the inner ring 10 and a flange part 12c provided at the cage 12. In such a structure, processes for manufacturing the cage 12 and for providing the inner ring 10 with the small- diameter cylinder part 10b can be performed easily and post-processes that are needed in one-way clutches of the prior art are not required. The small- diameter cylinder part 10b of the inner ring 10 avoids stress concentration since it differs from slits in one-way clutches of the prior art in that it is circumferentially continuous.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-way clutch and a pulley unit having the same. The pulley unit can be mounted on an accessory driven via a belt from a crankshaft of an engine of an automobile or the like, for example. Examples of the accessory 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 An example of such a conventional pulley unit is shown in FIGS. In the figure, 81 is a pulley, 82 is a shaft, 83 is a one-way clutch, and 84 is a rolling bearing.
The one-way clutch 83 has an inner ring 85, an outer ring 86, a plurality of rollers 87, a retainer 88, and a coil spring 89.

In this one-way clutch 83, a cage 88
If the outer ring 86 rattles in the circumferential or axial direction with respect to the inner ring 86, the locking and free operation of the one-way clutch 83 become unstable. Convex portions 90 provided inward in the radial direction
And two slits 91, 91 provided at two circumferential positions at one axial end of the inner ring 86, so as to be fitted in the axial direction.
Positioning is performed in the circumferential direction and the axial direction.

[0004]

In the above conventional example, there is room for improvement in the form of positioning the retainer 88 of the one-way clutch 83.

[0005] This is because the inner ring 85 is press-fitted and fitted to the shaft body 82 to prevent it from rotating. The circumferential tensile stress acting on the inner ring 85 due to the press-fitting is,
Since it concentrates on the inner corners of the slits 91, 91 of the inner ring 85, there is a possibility that the inner ring 85 will be broken starting from there.

In addition, the processing for forming the slits 91, 91 is costly, for example, the work efficiency is poor and post-processing is required because burrs are generated.

[0007] In view of such circumstances, an object of the present invention is to provide a structure that can suppress the manufacturing cost while securing sufficient strength for positioning of a retainer in a one-way clutch.

[0008]

A one-way clutch according to the present invention is disposed in a concentrically disposed annular space between inner and outer rings, and is in a locked state in which the inner and outer rings are rotated synchronously. A cam surface that forms a wedge-shaped space with the inner peripheral surface of the outer ring is provided at several places around the outer peripheral surface of the inner ring, and the wedge-shaped space The rollers are arranged one by one in a state where the circumferential rolling range is regulated by an annular cage,
By providing a small-diameter cylindrical portion on one axial end side of the inner ring, the one axial end side has a stepped shape, and the retainer is provided on at least a part of at least one cam surface with respect to the inner ring. While being prevented from rotating in the circumferential direction by being externally fitted while being hooked in the circumferential direction,
In the state where a flange portion projecting radially inward at one axial end is fitted to the small-diameter cylindrical portion of the inner ring and abuts against the stepped wall surface at the base side of the small-diameter cylindrical portion, the flange portion is axially formed. Positioned.

According to a second aspect of the present invention, a one-way clutch includes a wedge formed between an outer ring having an inner peripheral surface formed in a cylindrical shape and an inner peripheral surface of the outer ring which is inserted through the inner periphery of the outer ring at several locations around the circumference. An inner ring provided with a cam surface forming a ring-shaped space, rollers disposed one by one in each of the wedge-shaped spaces, and rollers interposed in opposed annular spaces of the inner and outer rings, and each of the rollers rotates in a circumferential direction. An annular retainer having a pocket accommodated in a state where the movement range is regulated, and an elastic member disposed in the pocket of the retainer and elastically urging the rollers toward the narrow side of the wedge-shaped space. The inner ring is provided with a small-diameter cylindrical portion on one axial end side so that the one axial end side has a stepped shape, and the retainer is at least a part of at least one cam surface with respect to the inner ring. Circumferentially hooked against In the state in which the flange is prevented from rotating in the circumferential direction by being externally fitted, and a flange portion protruding radially inward at one axial end is externally fitted to the small-diameter cylindrical portion of the inner ring, Is positioned in the axial direction by abutting against the stepped wall on the base side.

According to a third aspect of the present invention, there is provided a pulley unit, wherein the one-way clutch according to the first or second aspect and at least one of the one-way clutch are provided in an annular space opposed to a shaft inserted through an inner periphery of the pulley. A rolling bearing disposed on one side in the axial direction is interposed.

According to a fourth aspect of the present invention, in the pulley unit, the rolling bearing of the third aspect is disposed adjacent to a side of the one-way clutch on which the flange of the retainer exists, and the retainer is axially moved. It is supposed to be restrained.

In summary, the present invention presupposes a one-way clutch of the type that uses rollers and has a cam surface on the outer peripheral surface of an inner ring, and devises a form of detent and axial positioning of the retainer with respect to the inner ring. are doing.

First, as for the detent, the retainer is positioned so as to be hooked in the circumferential direction on the cam surface of the inner race. In this case, if the cage is made of a resin molded product, it can be manufactured without increasing the number of extra steps.

In the axial positioning, the small-diameter cylindrical portion provided on the inner ring and the flange provided on the retainer are positioned so as to be hooked in the axial direction. In this case, processing for providing the small-diameter cylindrical portion on the inner ring is simple, and post-processing as in the conventional example is unnecessary. If the collar of the cage is made of a synthetic resin material, it can be manufactured without increasing the number of extra steps.

In the pulley unit of the fourth aspect, the retainer of the one-way clutch is restrained in the axial direction by the rolling bearing which is one of the constituent elements, so that no extra member is used. Thus, the positioning of the retainer in the axial direction can be reliably performed.

[0016]

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

1 to 3 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a pulley unit, and FIG.
1 is a sectional view taken along the line (2)-(2) of FIG. 1, and FIG. 3 is a perspective view showing an inner race and a retainer in the one-way clutch.

The illustrated pulley unit A has a pulley 1, a hollow shaft 2, a one-way clutch 3, and two rolling bearings 4, 4.

The pulley 1 is rotatably driven via a belt B by, for example, a crankshaft of an automobile engine, and has a wavy groove formed around the belt B around which the belt B is wound.

The hollow shaft 2 is inserted through the inner periphery of the pulley 1 and is fixed to an input shaft of an auxiliary machine of an automobile engine (for example, a rotor of an alternator), not shown.

The one-way clutch 3 comprises a pulley 1 and a hollow shaft 2
The inner ring 10, the outer ring 11, an annular retainer 12 made of a synthetic resin,
A plurality of rollers 13, an elliptical coil spring 1 as an elastic member
4 is provided.

The two rolling bearings 4 and 4 are provided one by one on both sides in the axial direction of the opposed annular space between the pulley 1 and the hollow shaft 2, and each is a general deep groove ball bearing or the like. ing. Seals 5 and 5 are attached to the axially outer ends of these rolling bearings 4 and 4.

The components of the one-way clutch 3 will be described.

The inner ring 10 is externally fitted to the hollow shaft 2 by press-fitting, and is provided with a flat key-shaped cam surface 10a at several places on the outer peripheral surface thereof. In this example, the number of the cam surfaces 10a is eight.
The outer diameter of 0 is octagonal.

The outer race 11 is fitted inside the pulley 1 by press fitting, and has an inner peripheral surface formed in a cylindrical shape.

The retainer 12 is provided in an annular space facing the inner and outer rings 10 and 11 and is externally positioned while being positioned in the circumferential direction and the axial direction with respect to the inner ring 10.
The pockets 12 penetratingly formed inward and outward in the radial direction are provided at several places around the circumference, that is, in a region corresponding to the cam surface 10a of the inner ring 10.
a is provided.

The rollers 13 are provided in the respective pockets 12 of the cage 12.
a is stored in a state in which the circumferential rolling range is regulated one by one.

The coil spring 14 is mounted on a projection 12b projecting from the inner wall surface of each pocket 12a of the retainer 12, and forms a wedge-shaped space that forms the rollers 13 with the cam surface 10a and the inner peripheral surface of the outer ring 11. To the narrow side (lock side).

Next, the operation of the pulley unit A will be described. In short, when the rotation speed of the pulley 1 becomes relatively higher than that of the hollow shaft 2, the roller 13 of the one-way clutch 3 is rolled toward the narrow side of the wedge-shaped space to be in a locked state. 2 and rotate synchronously. However, when the rotation speed of the pulley 1 becomes relatively slower than that of the hollow shaft 2, the roller 13 of the one-way clutch 3 is rolled to the wide side of the wedge-shaped space to be in a free state. As a result, the transmission of the rotational power to the hollow shaft 2 is interrupted, and the hollow shaft 2 continues to rotate only by the rotational inertia force.

By the way, when the pulley unit A is used as an alternator for an automobile engine, the belt B
Irrespective of fluctuations in the rotation of the crankshaft of the engine, which is the driving source of the motor, the rotation of the rotor of the alternator can be maintained at a high frequency to increase the power generation efficiency. That is, when the rotational speed of the crankshaft increases, the one-way clutch 3 is locked to rotate the inner ring 2 synchronously with the outer ring 1, while when the rotational speed of the crankshaft decreases, The one-way clutch 3 is brought into the free state, and the hollow shaft 2 may be continuously rotated by its own rotational inertia regardless of the speed reduction of the pulley 1.

In this embodiment, the one-way clutch 3 is characterized by the manner in which the retainer 12 is attached to the inner race 10 and will be described in detail below.

First, the retainer 12 is prevented from rotating in the circumferential direction with respect to the inner ring 10 by forming the inner peripheral surface of the retainer 12 into a shape that matches and fits the polygonal outer peripheral surface shape of the inner ring 10. Like that.

A flange 12c extending radially inward is provided on one axial end side of the retainer 12, while the inner ring 1
By providing a small-diameter cylindrical portion 10b on one axial end of the inner ring 10, the one axial end has a stepped shape, and the small-diameter cylindrical portion 10c of the retainer 12 is fitted to the small-diameter cylindrical portion 10b of the inner ring 10. By making contact with the stepped wall surface 10c on the base side of the cylindrical portion 10b, the movement of the retainer 12 in one axial direction (left side in the figure) is blocked.

The movement of the retainer 12 in the axial direction to the other side (right side in the figure) is caused by the one-way clutch 3
Is sealed by the inner ring 20 of one of the rolling bearings 4 disposed adjacent to the side where the flange portion 12c is located, so that the cage 12 is axially positioned with respect to the inner ring 10. I have.

As described above, first, the retainer 12 is prevented from rotating in such a manner that the retainer 12 is hooked in the circumferential direction with respect to the cam surface 10a of the inner race 10, so that the shape of the inner peripheral surface of the retainer 12 made of synthetic resin is many. Since it is only necessary to form a square shape, it can be manufactured without increasing the number of extra steps, thereby preventing an increase in manufacturing cost.

The positioning of the retainer 12 in the axial direction is such that the small-diameter cylindrical portion 10b provided on the inner ring 10 and the flange portion 12c provided on the retainer 12 are fitted to each other. Since it can be formed by a simple process, the manufacturing cost itself can be reduced, and post-processing as in the conventional example is unnecessary, which can also contribute to a reduction in the manufacturing cost. The collar 12 of the retainer 12
Since c can also be formed by resin molding, it can be manufactured without increasing extra steps. The small-diameter cylindrical portion 10b of the inner ring 10 is continuous in the circumferential direction, unlike the slit of the conventional example, so that the circumferential tensile stress generated by press-fitting the inner ring 10 to the hollow shaft 2 causes local tensile stress. It is excellent in strength, such as no longer being concentrated.

It should be noted that the present invention is not limited to the above-described embodiment, and various applications and modifications are conceivable.

(1) The cam surface 10a formed on the inner race 10 of the one-way clutch 3 in the above embodiment can be shaped as shown in FIGS.

In the embodiment shown in FIGS. 4 and 5, the cam surface 10a is a flat surface as in the above-described embodiment. However, the cam surface 10a has a radial direction at one end in the circumferential direction where the coil spring 14 is disposed. Outward bulging part 10d
Is different from the above embodiment. In the case of the inner ring 10 having such an outer peripheral surface shape, the inner peripheral surface shape of the retainer 12 is not
The shape is set so that it fits and fits in the area excluding 0d.

In the embodiment shown in FIGS. 6 and 7, the cam surface 10a is provided in a depressed shape within the rolling range of the roller 13, and the bottom surface thereof is formed as a convex curved surface bulging radially outward. And a receiving seat 15 for the coil spring 14 having a flat surface adjacent to the cam surface 10a in the circumferential direction.
Is provided. In the case of such an inner ring 10, the shape of the inner peripheral surface of the retainer 12
5 is set to a shape that fits into each of them.

As described above, with respect to the positioning of the cage 12 in the circumferential direction, the inner ring 1 does not have to have the shape of the inner circumferential surface of the cage 12 almost completely conforming to the shape of the outer circumferential surface of the inner ring 10.
It is sufficient to adopt a form in which the outer surface is fitted to at least a part of the zero cam surface 10a in a state of being hooked in the circumferential direction.

(2) In the above embodiment, the one-way clutch 3 is exemplified by the type having the inner and outer rings 10 and 11, but the inner ring 10 is integrated with the hollow shaft 2 of the pulley unit A, and the outer ring 11 is Pulley 1 of pulley unit A
The present invention also includes those formed integrally with the present invention.

(3) In the above embodiment, the coil spring 14 is taken as an example of the elastic member of the one-way clutch 3. However, various types of leaf springs and elastic pieces can be used instead.

[0044]

According to the first and second aspects of the present invention, the retainer is prevented from rotating with respect to the inner ring in which the cam surface is provided at several places on the outer circumferential surface. In order to cope with the problem by providing a portion that is hooked in the circumferential direction with respect to the inner ring, the axial positioning of the retainer with respect to the inner ring is configured to be hooked in the axial direction by a small-diameter cylindrical portion provided on the inner ring and a flange provided on the retainer. In this case, the processing of the cage and the inner ring can be simplified, and the post-processing as in the conventional example is not required. In particular, if the collar portion of the retainer is made of a synthetic resin material, it can be manufactured without increasing an extra step. As described above, it is possible to provide a one-way clutch having a configuration in which manufacturing costs can be suppressed and operation stability is excellent. In addition,
Unlike the conventional slit, the small-diameter cylindrical portion provided on the inner ring is continuous in the circumferential direction, so that even in a situation where the inner ring is press-fitted to the shaft body or the like, the circumferential tensile stress acting on the inner ring is localized. It is excellent in strength, such as no longer being concentrated.

Further, the pulley unit of the third aspect is provided with the above-described one-way clutch which is inexpensive and has excellent operation stability, so that a structure capable of stably switching the power transmission state can be provided at low cost. become.

In particular, in the pulley unit according to the fourth aspect, the retainer in the one-way clutch is restrained in the axial direction by the rolling bearing which is one of the constituent elements, so that no extra member is used. In addition, the positioning of the retainer in the axial direction can be reliably performed, and waste can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an upper half of a pulley unit 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 perspective view showing an inner ring and a retainer in the one-way clutch.

FIG. 4 is a diagram corresponding to FIG. 1 according to another embodiment of the present invention.

FIG. 5 is a diagram corresponding to FIG. 3 according to the embodiment of FIG. 4;

FIG. 6 is a diagram corresponding to FIG. 1 according to another embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 3 according to the embodiment of FIG. 6;

FIG. 8 is a longitudinal sectional view of a pulley unit of a conventional example.

9 is a sectional view taken along line (9)-(9) of FIG.

[Explanation of symbols]

 Reference Signs List A pulley unit B belt 1 pulley 2 hollow shaft 3 one-way clutch 4 rolling bearing 10 inner ring of one-way clutch 10a inner cam surface 10b small-diameter cylindrical portion of inner ring 11 outer ring of one-way clutch 12 retainer of one-way clutch 12a retainer Pocket 12c Cage flange 13 Roller 14 Coil spring

Claims (4)

[Claims] 1. A one-way clutch which is interposed in concentrically opposed annular spaces of inner and outer races and switches between a locked state in which the inner and outer races are synchronously rotated and a free state in which the inner and outer races are relatively rotated, A cam surface is formed at several places on the outer peripheral surface of the inner ring to form a wedge-shaped space with the inner peripheral surface of the outer ring. In this wedge-shaped space, the rollers are circumferentially rolled by an annular retainer. One of the inner rings is arranged stepwise by providing a small-diameter cylindrical portion on one axial end side of the inner ring, and the retainer is provided on the inner ring. On the other hand, it is prevented from rotating in the circumferential direction by being externally fitted to at least a part of the at least one cam surface while being hooked in the circumferential direction, and protruding radially inward at one shaft end. The collar is the small inner ring A one-way clutch, wherein the one-way clutch is positioned in the axial direction by abutting on the stepped wall surface on the base side of the small-diameter cylindrical portion in a state of being externally fitted to the radial cylindrical portion. 2. An outer ring having an inner peripheral surface formed in a cylindrical shape, and a cam surface which is inserted through the inner periphery of the outer ring and forms a wedge-shaped space between the inner peripheral surface of the outer ring at several places around the circumference. An inner ring, a roller disposed in each of the wedge-shaped spaces, a roller interposed in the opposed annular space of the inner and outer rings, and each of the rollers housed in a state in which a rolling range in the circumferential direction is regulated. An annular retainer having a pocket formed therein, and an elastic member disposed in the pocket of the retainer to resiliently bias the rollers toward the narrow side of the wedge-shaped space. By providing a small-diameter cylindrical portion, the one shaft end side has a stepped shape, and the retainer is externally engaged with at least a part of at least one cam surface of the inner ring in a circumferential direction. Circumferential rotation by fitting While being stopped, a flange portion protruding radially inward at one axial end thereof is abutted on the stepped wall surface on the base side of the small-diameter cylindrical portion in a state of being fitted to the small-diameter cylindrical portion of the inner ring. A one-way clutch, wherein the one-way clutch is axially positioned. 3. A one-way clutch as claimed in claim 1 or 2 and an at least one axial side of said one-way clutch in an annular space opposed to a pulley and a shaft inserted through the inner periphery thereof. A pulley unit characterized by being provided with a rolling bearing. 4. The pulley unit according to claim 3, wherein the rolling bearing is disposed adjacent to a side of the one-way clutch where a flange portion of the cage exists, and restrains the cage in the axial direction. A pulley unit.