JP2000240766A - Pulley device with built-in one-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent axial displacement of a clutch retainer constituting a one-way clutch with eliminating elements causing high cost, e.g. dispensing with troublesome machining. SOLUTION: In this device, ball bearings are used as support bearings 9a, 9a provided in both sides of one-way clutch 10a. Both axial end faces of a clutch retainers 20 and side faces of rim parts 18, 18 of respective bearing retainers 17, 17 installed in the respective support bearings 9a, 9a are closely faced each other. Both the rim parts 18, 18 prevent axial displacement of the clutch retainer 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley device with a built-in one-way clutch. The pulley device is fixed to an end of a rotating shaft of an alternator which is a generator for an automobile, and is fixed to an end of a crankshaft of an engine. It is used to drive the alternator by wrapping an endless belt between them.

[0002]

2. Description of the Related Art The structure of an alternator for generating electric power necessary for an automobile by using an engine for driving the automobile as a driving source is described in, for example, Japanese Patent Application Laid-Open No. 7-139550. FIG. 4 shows an alternator 1 described in this publication. The rotating shaft 3 is rotatably supported inside the housing 2 by a pair of rolling bearings 4, 4. A rotor 5 and a commutator 6 are provided at an intermediate portion of the rotating shaft 3. A pulley 7 is fixed to a portion of the rotating shaft 3 protruding outside the housing 2 at one end (the right end in FIG. 4). In an assembled state to the engine, an endless belt is wrapped around the pulley 7, and the rotary shaft 3 is rotatably driven by the crankshaft of the engine.

Conventionally, a pulley simply fixed to the rotary shaft 3 has been used. On the other hand, in recent years, when the traveling speed of the endless belt is constant or increasing, transmission of power from the endless belt to the rotating shaft is freely performed, and when the traveling speed of the endless belt tends to decrease, Various one-way clutch built-in pulley devices that allow relative rotation between a pulley and a rotating shaft have been proposed and used in part. For example, JP-A-56-10
Nos. 1353, 7-317807 and 8
JP-A-61443, JP-B-7-72585, French Patent Publication FR2726059A1, and the like describe a one-way clutch built-in pulley device having the above-described functions.

FIG. 5 shows a one-way clutch built-in pulley device described in Japanese Patent Application Laid-Open No. Hei 8-61443. This one-way clutch built-in type pulley device has a sleeve 8 which can be externally fitted and fixed to the rotating shaft 3. A pulley 7 a is arranged around the sleeve 8 concentrically with the sleeve 8. A pair of support bearings 9 and 9 and a one-way clutch 10 are provided between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the pulley 7a. Of these, the support bearings 9, 9 are
a while supporting the radial load applied to the sleeve 8.
And the pulley 7a can rotate freely. The one-way clutch 10 is used only when the pulley 7a tends to rotate relative to the sleeve 8 in a predetermined direction.
Transmission of the rotational force from the pulley 7a to the sleeve 8 is made free.

The reason for using such a pulley device with a built-in one-way clutch for an alternator is as follows. For example, when the driving engine is a diesel engine, the rotation angular speed of the crankshaft greatly fluctuates during low rotation, such as during idling. As a result, the running speed of the endless belt 11 stretched over the drive pulley fixed to the end of the crankshaft also fluctuates finely. On the other hand, the rotating shaft 3 of the alternator 1 (FIG. 4) driven to rotate by the endless belt 11 via the pulley 7a
Does not fluctuate so rapidly based on the inertial mass of the rotating shaft 3, the rotor 5 fixed to the rotating shaft 3, and the commutator 6 (FIG. 4). Therefore, if the pulley 7a is simply fixed to the rotating shaft 3, the endless belt 11 and the pulley 7
a tends to rub in both directions. As a result, stresses in different directions repeatedly act on the endless belt 11 that rubs against the pulley 7a, and the endless belt 11 and the pulley 7
The endless belt 11 may easily slip or may have a shorter service life.

The reduction in the life of the endless belt 11 due to the friction between the outer peripheral surface of the pulley 7a and the inner peripheral surface of the endless belt 11 as described above also occurs due to repeated acceleration and deceleration during traveling. That is, during acceleration, the pulley 7 is moved from the endless belt 11 side.
While the driving force is transmitted to the side a, the pulley 7a tries to keep rotating based on the inertia as described above during deceleration.
Then, a braking force acts from the endless belt 11. Since the braking force and the driving force act as frictional forces on the inner peripheral surface of the endless belt 11 in the opposite direction, the life of the endless belt 11 is also reduced. In particular, in the case of a vehicle equipped with an exhaust brake like a truck, the deceleration of the decrease in the rotation of the crankshaft when the accelerator is off is remarkable, and the friction applied to the inner peripheral surface of the endless belt 11 based on the braking force As a result of an increase in force, the above-mentioned life is significantly reduced.

Therefore, by using the one-way clutch built-in pulley device as the pulley 7a as described above, when the running speed of the endless belt 11 is constant or tends to increase, the pulley 7a rotates. When the running speed of the endless belt 11 tends to decrease, the pulley 7a
And the rotating shaft 3 can be freely rotated. That is, when the running speed of the endless belt 11 tends to decrease, the rotational angular speed of the pulley 7a is made slower than the rotational angular speed of the rotary shaft 3 so that the contact portion between the endless belt 11 and the pulley 7a To prevent strong rubbing. In this way, the direction of the stress acting on the rubbed portion between the pulley 7a and the endless belt 11 is made constant, and slippage occurs between the endless belt 11 and the pulley 7a, or the endless belt 11 Prevents shortening of service life.

When a pulley device with a built-in one-way clutch as described above is constructed, the one-way clutch may be a sprag-type one-way clutch using sprags as a plurality of lock members, all of which are conventionally known. Alternatively, a roller clutch using a roller as a plurality of lock members is used. Any one-way clutch requires a retainer for retaining the lock member. When such a one-way clutch is incorporated in a pulley device with a built-in one-way clutch, it is necessary to prevent the retainer from moving in the axial direction. For this reason, conventionally, Japanese Patent Laid-Open No. 7-3
As described in Japanese Patent No. 17807, it has been considered to provide an engaging portion between a pulley having a built-in one-way clutch and a retainer to prevent the retainer from moving in the axial direction.

[0009]

In order to prevent the retainer from moving in the axial direction, it is troublesome to provide an engaging portion between the pulley and the retainer, which increases the cost of the one-way clutch built-in pulley device. Cause. In view of such circumstances, the present invention can prevent a cage constituting a one-way clutch from being displaced in the axial direction without performing extra processing on a pulley or a cage, and a pulley device with a built-in one-way clutch. It was invented in order to realize.

[0010]

A pulley device with a built-in one-way clutch according to the present invention has a sleeve which can be externally fitted and fixed to a rotating shaft, like a pulley device with a built-in one-way clutch. A pulley is arranged around the sleeve and concentrically with the sleeve, and is provided between a part of the outer peripheral surface of the sleeve in the axial direction and a part of the inner peripheral surface of the pulley in the axial direction. A one-way clutch that allows the transmission of rotational force only between the pulley and the sleeve only when it tends to rotate relative to the other, an axial other portion of the outer peripheral surface of the sleeve, and a shaft of the inner peripheral surface of the pulley. And a support bearing provided between the sleeve and the pulley and supporting the radial load applied to the pulley while allowing relative rotation between the sleeve and the pulley.

In particular, in the pulley apparatus with a built-in one-way clutch of the present invention, the one-way clutch includes a plurality of lock members and a clutch retainer for holding each of the lock members. . Each of the support bearings is rotatably provided between an outer raceway having an arc-shaped cross section provided on the outer peripheral surface of the pulley and an inner raceway having an arc-shaped cross section provided on the outer peripheral surface of the sleeve. The vehicle includes a plurality of balls and a bearing retainer that holds each of the balls in a freely rolling manner, and is capable of supporting a thrust load. Then, at least one end face of the both ends in the axial direction of the clutch retainer is opposed to the axial end face of the bearing retainer so as to prevent displacement in the axial direction.

[0012]

In the case of the pulley device with a built-in one-way clutch of the present invention constructed as described above, the retainer for the clutch constituting the one-way clutch is displaced in the axial direction by the retainer for the support bearing. To block. Therefore, it is not necessary to perform troublesome processing on the raceway made of hard metal, which constitutes the one-way clutch, and the cost of the pulley device with a built-in one-way clutch can be reduced.

[0013]

FIG. 1 shows a first embodiment of the present invention. The sleeve 8a is formed in a cylindrical shape as a whole, and the rotating shaft 3 of the alternator (see FIGS. 4 and 5).
And is rotatable together with the rotating shaft 3. For this purpose, in the illustrated example, a female screw portion 12 is formed on the inner peripheral surface of the intermediate portion of the sleeve 8a, and the female screw portion 12 and a male screw portion (not shown) formed on the outer peripheral surface of the end of the rotary shaft 3 are screwed. It is free to fit. In order to lock a tool such as a hexagon wrench when screwing these two screw portions together, a locking hole 1 having a hexagonal cross section is formed in the inner peripheral surface of the end of the sleeve 8a.
3 is formed. The structure for preventing the relative rotation between the rotating shaft 3 and the sleeve 8a may be replaced by a spline engagement, a fitting of non-cylindrical surfaces, a key engagement or the like instead of the screw.

A pulley 7b is disposed concentrically with the sleeve 8a around the sleeve 8a as described above. The pulley 7b has a support bearing 9a described below inside thereof,
9a and the sprag type one-way clutch 10a are mounted. Further, the outer peripheral surface of the pulley 7b has a cross-sectional shape extending in the width direction and has a waveform, so that a part of an endless belt called a poly-V belt can be passed around.

Between the outer peripheral surface of the sleeve 8a configured as described above and the inner peripheral surface of the pulley 7b configured as described above,
A pair of support bearings 9a, 9a and one one-way clutch 10a are provided. Support bearing 9 of these
a and 9a allow the relative rotation between the sleeve 8a and the pulley 7b while supporting the radial load applied to the pulley 7b. In the illustrated example, each of the support bearings 9a,
As 9a, a deep groove ball bearing is used. That is, each of these support bearings 9a, 9a is provided with a deep groove type outer raceway 14, formed on the inner peripheral surface of both ends of the pulley 7b,
Deep-groove type inner raceways 15, 15 formed on the outer peripheral surfaces of both ends of the sleeve 8aa, and a plurality of balls each provided between the outer raceways 14, 14 and the inner raceways 15, 15 so as to freely roll. 16, 16 and bearing retainers 17, 17 for rollingly holding the balls 16, 16 respectively.

In the case of this embodiment, since the outer raceways 14, 14 are formed directly on the pulley 7b and the inner raceways 15, 15 are formed directly on the sleeve 8a, the pulley 7b and the sleeve 8a are formed respectively. It is made of hard metal such as bearing steel such as SUJ2 or carburized steel such as SCM415. Then, as the surface hardness of the outer ring raceway 14, 14 and the inner ring raceways 15, 15 portion is about H _R C60~64, and subjected to hot curing treatment such as carburizing hardening.
On the other hand, each of the bearing retainers 17 and 17 uses a crown-shaped retainer made of synthetic resin. The crown type retainer is provided with an elastic piece on one axial side of the annular rim portions 18, 18.
A space between a pair of elastic pieces adjacent in the circumferential direction is formed as a pocket for holding the balls 16. In the case of the present example, the rims 18 of each of the bearing retainers 17 and 17 are connected to the pulley 7b and the sleeve 8 respectively.
a is directed toward the center in the axial direction.

The one-way clutch 10a can freely transmit the rotational force between the pulley 7b and the sleeve 8a only when the pulley 7b tends to rotate in a predetermined direction with respect to the sleeve 8a. I do. In the case of this example, a sprag type clutch is used as such a one-way clutch 10a. In order to constitute such a sprag type one-way clutch, the inner peripheral surface of the intermediate portion in the axial direction of the pulley 7b and the outer peripheral surface of the axially intermediate portion of the sleeve 8a are straight cylindrical surfaces which are not stepped. And A plurality of sprags 19 each of which is a lock member and has a non-circular cross-sectional shape are provided between these two peripheral surfaces.
Is provided in a state of being held by the clutch retainer 20. The clutch retainer 20 may be made of a metal made by subjecting a metal plate such as a steel plate to plastic working such as press working. However, in the case of the present embodiment, the clutch retainer 20 is made of a synthetic resin, and when the clutch retainer 20 and each of the bearing retainers 17, 17 are rubbed, friction is generated. The friction acting between the surfaces is reduced, and heat generated inside the one-way clutch built-in pulley device is suppressed. As the synthetic resin used for constituting the clutch retainer 20 for such a purpose, polyamide 66 or polyamide 46 reinforced with glass fiber can be preferably used.

The clutch retainer 20 and each sprag 1
An elastic material such as a spring is provided between the pulley 7b and the inner peripheral surface of the pulley 7b and the outer peripheral surface of the sleeve 8a in the axial direction. It has elasticity. When the pulley 7b and the sleeve 8a relatively rotate in a predetermined direction, the sprags 19 project between the inner peripheral surface of the axially intermediate portion of the pulley 7b and the outer peripheral surface of the axially intermediate portion of the sleeve 8a. The torque is transmitted between the pulley 7b and the sleeve 8a. On the other hand, when the pulley 7b and the sleeve 8a rotate relative to each other in the opposite direction, the sprags 19 are formed between the inner peripheral surface of the axially intermediate portion of the pulley 7b and the outer peripheral surface of the axially intermediate portion of the sleeve 8a. On the other hand, it does not transmit the torque between the pulley 7b and the sleeve 8a. The structure and operation of such a sprag-type one-way clutch 10a are well known in the related art, and a detailed description thereof will be omitted. The sprags 19 may have various shapes depending on the magnitude of torque to be transmitted and the like.

Further, in the case of the pulley device with a built-in one-way clutch according to the present invention, both end faces in the axial direction of the clutch retainer 20 are connected to the rim portions 18, 18 constituting the bearing retainers 17, 17, respectively. And is closely opposed to the inner side surface. Each of the bearing retainers 17, 17 is prevented from being displaced in the axial direction (the left-right direction in FIG. 1) of the pulley 7b and the sleeve 8a based on the engagement with the balls 16, 16.
The balls 16 are also prevented from being displaced in the axial direction based on the engagement between the outer raceways 14, 14 each having a deep groove shape and the inner raceways 15, 15, respectively. Therefore, the clutch retainer 20 is prevented from being displaced in the axial direction. For this reason, the clutch retainer 20
The sprags 19 held on the inner surface of the pulley 7b and the outer peripheral surface of the sleeve 8a in the axial direction do not come off. The outer peripheral edges of the annularly formed seal rings 21 and 21 are engaged with the inner peripheral surfaces of both ends in the axial direction of the pulley 7b, respectively, so that the outer space, the support bearings 9a and 9a, and the one-way clutch are secured. 10a is blocked from the internal space. Therefore, foreign matter such as dust existing in the external space does not enter the internal space, or the grease sealed in the external space does not leak to the external space. The grease used is one that can achieve both the lubrication of the support bearings 9a and 9a and the lubrication and traction transmission of the one-way clutch 10a.

In the case of the pulley device with a built-in one-way clutch constructed as described above, the one-way clutch 10 is used.
a, the pulley 7 having an endless belt
b only when the rotation speed of b is higher than the rotation speed of the sleeve 8a fixed to the rotating shaft 3 of the alternator.
b transmits the torque to the rotating shaft 3. Conversely,
When the rotation speed of the pulley 7b is lower than the rotation speed of the sleeve 8a, the connection between the pulley 7b and the sleeve 8a is cut off, thereby preventing an excessive force from being applied to the endless belt. In particular, in the case of the pulley device with a built-in one-way clutch of this embodiment, the one-way clutch 10 is formed by the bearing retainers 17 and 17 constituting the support bearings 9a and 9a.
This prevents the clutch retainer 20 constituting a from being displaced in the axial direction. Therefore, this one-way clutch 10a
The pulley 7b and the sleeve 8a, each of which is made of a hard metal such as bearing steel, need not be subjected to troublesome processing, and the cost of the one-way clutch built-in pulley device can be reduced.

FIG. 2 shows a second embodiment of the present invention.
An example is shown. In the case of the present example, the bearing outer rings 22, 22 for forming the pair of support bearings 9b, 9b are fixedly fitted to the inner peripheral surfaces of both ends of the pulley 7b by interference fitting, and similarly, the bearing inner ring 23, 23 is externally fitted and fixed to the outer peripheral surfaces of both ends of the sleeve 8b by interference fit. Also, a clutch outer ring 24 for constituting the sprag type one-way clutch 10b is fixedly fitted inside the inner peripheral surface of the intermediate portion of the pulley 7b by interference fitting, and the clutch inner ring 25 is similarly fixed to the outer peripheral portion of the intermediate portion of the sleeve 8b. The outer surface is fixed to the surface by interference fit. The outer peripheral edges of the seal rings 21, 21 for blocking the internal space from the external space are locked to the inner peripheral surfaces of the end portions of the bearing outer rings 22, 22. In the case of this example,
Each of the above bearing outer rings 22, 22, each of the above bearing inner rings 23,
23, the clutch outer race 24, the clutch inner race 2
5 is made of a hard metal such as bearing steel such as SUJ2, but the pulley 7b and the sleeve 8b are not necessarily made of hard metal. In the case of this example, the outer peripheral surface of the clutch inner race 25 and the inner peripheral surface of the clutch outer race 24, which constitute the one-way clutch 10b, are both straight cylindrical surfaces that are not stepped and are troublesome. Therefore, the processing cost of the pulley device with a built-in one-way clutch can be reduced. Other configurations and operations are the same as those of the above-described first example, and thus redundant description will be omitted.

Next, FIG. 3 shows a third embodiment of the present invention.
An example is shown. In the case of this example, a single-row support bearing 9c and a sprag-type one-way clutch 10c
The pulley device has a built-in one-way clutch. When the assembling of the one-way clutch built-in type pulley device is completed, the outer race 26 is internally fitted and fixed to a pulley (not shown) by interference fit. On the other hand, the inner ring 27 corresponding to the sleeve described in the claims,
Externally fixed to the rotating shaft 3 of the alternator 1 (see FIG. 4). A deep groove type outer raceway 14 is formed on an inner peripheral surface of one end (left end in FIG. 3) of the outer race 26, and a deep groove type inner raceway 15 is formed on an outer peripheral surface of one end of the inner race 27.
A plurality of balls 16, 16 are provided between the outer raceway 14 and the inner raceway 15 to constitute the above-described support bearing 9c, which is a single-row ball bearing of a deep groove type. Each ball 1 above
A bearing retainer 17, which is a synthetic resin crown retainer that holds the rollers 6 and 16 in a freely rolling manner, is mounted on each of the balls 16 and 16 with the rim portion 18 facing the center in the axial direction. are doing.

The inner peripheral surface of the other half of the outer race 26 and the outer peripheral surface of the other half of the inner race 27 are simply cylindrical surfaces, respectively, and are sprags 19 constituting the one-way clutch 10c.
a and 19a can be frictionally engaged. Also, a clutch retainer 20 for holding these sprags 19a, 19a is provided.
“a” is provided between the inner peripheral surface of the other half of the outer ring 26 and the outer peripheral surface of the other half of the inner ring 27 in a state biased toward the inner peripheral surface of the outer ring 26. And the above-mentioned clutch retainer 2
0a in the axial direction of the rim 1 of the bearing holder 17
Similarly, the other end face in the axial direction is closely opposed to the inner side face of the seal ring 21 locked to the inner peripheral face at the end of the outer ring 26 on the side face 8. The clutch retainer 2
The inner diameter of the seal ring 21 is larger than the outer diameter of the seal lip 28 forming the inner peripheral edge of the seal ring 21.
8 so as not to rub against each other.
8 to ensure durability.

In the case of this embodiment constructed as described above, the displacement of the clutch retainer 20a to one axial end means that the bearing retainer 17 is also displaced to the other axial end. Are blocked by the seal rings 21 respectively. Accordingly, the sprags 19a, 19a do not deviate from the inner peripheral surface of the other half of the outer ring 26 and the outer peripheral surface of the other half of the inner ring 27. Although the sprag type one-way clutch is used in each of the above-described examples, a roller clutch may be used as the one-way clutch when the present invention is implemented. When the roller clutch is used as the one-way clutch in this manner, the one-way clutch is formed, either on the inner peripheral surface of the outer ring or on the outer peripheral surface of the inner ring,
It is necessary to form a cam surface, which is an uneven surface in the circumferential direction. However, according to the present invention, even when the cam surface is formed in this way, it is not necessary to perform stepping processing in which the diametrical dimension in the axial direction is different, and the processing cost of the one-way clutch built-in type pulley device is also eliminated. Can be reduced as in the case of using a sprag type one-way clutch.

[0025]

The pulley apparatus with a built-in one-way clutch according to the present invention is constructed and operated as described above, so that a highly reliable structure can be realized without particularly increasing the cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is a sectional view showing the second example.

FIG. 3 is a sectional view showing a third example.

FIG. 4 is a sectional view showing an example of a conventionally known alternator.

FIG. 5 is a partial cross-sectional view showing one example of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alternator 2 Housing 3 Rotating shaft 4 Rolling bearing 5 Rotor 6 Commutator 7, 7a, 7b Pulley 8, 8a, 8b Sleeve 9, 9a, 9b, 9c Support bearing 10, 10a, 10b, 10c One-way clutch 11 Endless belt 12 Female thread part 13 Locking hole part 14 Outer raceway 15 Inner raceway 16 Ball 17 Bearing retainer 18 Rim part 19, 19a Sprag 20, 20a Clutch retainer 21 Seal ring 22 Bearing outer race 23 Bearing inner race 24 Clutch outer race 25 Inner ring for clutch 26 Outer ring 27 Inner ring 28 Seal lip

Claims (1)

[Claims] 1. A sleeve which can be externally fitted and fixed to a rotating shaft, a pulley disposed around the sleeve and concentric with the sleeve, a part of an outer peripheral surface of the sleeve in an axial direction and an axial direction of an inner peripheral surface of the pulley. A one-way clutch provided between the pulley and the sleeve to freely transmit a rotational force between the pulley and the sleeve only when the pulley tends to rotate relative to the sleeve in a predetermined direction; Between the other part of the outer peripheral surface in the axial direction and the other part of the inner peripheral surface of the pulley in the axial direction,
In a pulley device with a built-in one-way clutch, which includes a support bearing that allows relative rotation between the sleeve and the pulley while supporting a radial load applied to the pulley,
The one-way clutch includes a plurality of lock members and a clutch retainer that holds each of the lock members. Each of the support bearings has an arc-shaped cross-section provided on an outer peripheral surface of the pulley. A plurality of balls rotatably provided between the outer ring raceway and the inner raceway having an arc-shaped cross section provided on the outer peripheral surface of the sleeve; and a bearing retainer for rollingably holding each of the balls. The thrust load can be freely supported, and at least one end face among the axial end faces of the clutch retainer is closely opposed to the axial end face of the bearing retainer, so that the A pulley device with a built-in one-way clutch, characterized in that displacement of the pulley is prevented.