JP2000320650A - Pulley device with built-in one-way clutch for alternator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure to sufficiently reduce size in a radial direction even when a radial roller bearing and a radial ball bearing are used as a pair of support bearings and lives for the two bearings are equalized with each other. SOLUTION: A radial ball bearihg 10 is situated at the peripheral part of a fit-in hole part 13 being an end part on the side where the inside diameter of a sleeve 8 is small. A margin on thickness in the direction of diameter is left at the part on the outside side of the fit-in hole part 13 of the sleeve 8. Thereby, even when the sleeve 8 is decreased in an outside diameter, the thickness of the sleeve 8 is not decreased at a part where the radial ball bearing 10 is situated and the size in the direction of a diameter of a pulley device is sufficiently decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art The structure of an alternator for generating electric power necessary for an automobile 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 driven pulley 7 is provided at one end (right end in FIG. 4) of the rotating shaft 3 protruding outside the housing 2.
Is fixed. In an assembled state to the engine, an endless belt is stretched over the driven pulley 7, and the rotary shaft 3 is rotatably driven by the crankshaft of the engine.

Conventionally, the driven pulley 7 is generally
What was simply fixed to the rotating shaft 3 was 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 pulley devices with a built-in one-way clutch for alternators, which make the relative rotation between the driven pulley and the rotary shaft freely, have been proposed and used in part. For example, JP-A-56-101353, JP-A-7-3
No. 17807, No. 8-61443, No. 8-2
Japanese Patent Publication No. 26462, Japanese Patent Publication No. 7-72585, French Patent Publication FR2726059A1, and the like describe a pulley device with a built-in one-way clutch for an alternator having the above-described functions.

The one-way clutch-incorporated pulley devices described in these documents have a driven pulley having a sleeve which can be externally fitted and fixed to a rotating shaft of an alternator, and which has a cylindrical inner peripheral surface around the sleeve. Are arranged concentrically with this sleeve. A pair of support bearings and a one-way clutch are provided between the outer peripheral surface of the sleeve and the inner peripheral surface of the driven pulley. Of these, support bearings
While supporting the radial load applied to the driven pulley, the relative rotation between the sleeve and the driven pulley is made free.
In addition, the one-way clutch allows the transmission of rotational force from the driven pulley to the sleeve only when the driven pulley rotates in a predetermined direction with respect to the sleeve.

The reasons for using the pulley device with a built-in one-way clutch for an alternator as described above are 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 (not shown), which runs 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, which is rotationally driven by the endless belt via a driven pulley, is connected to the rotating shaft 3 and the inertial mass of the rotor 5 and the commutator 6 (FIG. 4) fixed to the rotating shaft 3. And does not fluctuate so rapidly. Therefore, when the driven pulley is simply fixed to the rotating shaft 3, the endless belt and the driven pulley tend to rub in both directions due to a change in the rotational angular velocity of the crankshaft. As a result, stresses in different directions are repeatedly applied to the endless belt that rubs against the driven pulley, so that slippage easily occurs between the endless belt and the driven pulley, or the life of the endless belt is shortened. Or cause The reduction in the life of the endless belt due to the friction between the outer peripheral surface of the driven pulley and the inner peripheral surface of the endless belt also occurs due to repeated acceleration and deceleration during traveling.

Therefore, by using the pulley device with a built-in one-way clutch for the alternator as the driven pulley as described above, when the running speed of the endless belt is constant or tends to increase, the driven pulley is driven from the driven pulley. The transmission of the rotational force to the rotating shaft 3 is made freely, and conversely, when the running speed of the endless belt tends to decrease, the relative rotation between the driven pulley and the rotating shaft 3 is made freely. That is, when the running speed of the endless belt tends to decrease, the rotational angular speed of the driven pulley is made slower than the rotational angular speed of the rotating shaft 3 so that the contact portion between the endless belt and the driven pulley is strong. Prevent rubbing. In this way, the direction of the stress acting on the rubbed portion between the driven pulley and the endless belt is kept constant, slippage occurs between the endless belt and the driven pulley, or the life of the endless belt is shortened. To prevent

[0007] As a pair of support bearings constituting a pulley device with a built-in one-way clutch for an alternator as described above, a radial roller bearing or a radial ball bearing has generally been used conventionally. When a pair of radial roller bearings is used as the pair of support bearings, the radial load applied to the driven pulley can be sufficiently supported. However, in the case of the radial roller bearing, since a thrust load applied to the driven pulley cannot be supported, it is necessary to provide a separate member such as a thrust washer to support the thrust load. However, providing such a separate member not only causes trouble in assembling work and parts management, but also ensures durability of the grease regardless of heat generated in the sliding friction portion. Expensive grease having excellent heat resistance must be used. In order to avoid an increase in cost due to such factors, it is preferable that one of the pair of support bearings is a radial ball bearing capable of supporting both a radial load and a thrust load.

In view of such circumstances, Japanese Unexamined Patent Application Publication No. Hei 8-226462 among the above-mentioned documents discloses that a pair of support bearings each including one radial roller bearing and one radial ball bearing are used. Is described. In the case of the pulley device incorporating a one-way clutch for an alternator described in this publication, a radial roller bearing is used as one of the support bearings, so that a relatively large radial load can be supported as a whole. In addition, since a radial ball bearing is used as the other support bearing, a thrust load applied to the driven pulley can be freely supported. Therefore, there is no need to provide a separate member for supporting the thrust load as described above.

[0009]

In the case of the conventional structure described in the above publication, a well-balanced design in which the rolling fatigue life of a pair of support bearings, a radial roller bearing and a radial ball bearing, is substantially equal. Is required, the diameter of each ball (rolling element) forming the radial ball bearing needs to be larger than the diameter of each roller (rolling element) forming the radial roller bearing. The reason for this is to make the surface pressures at the contact portions between the inner ring and outer ring raceways constituting these two bearings and the rolling surfaces of the rolling elements substantially equal. On the other hand, in order to reduce the diameter of the alternator one-way clutch built-in pulley device as described above in the diameter direction and increase the rotation speed of the alternator to increase the power generation efficiency,
It is necessary to reduce the outer diameter of the driven pulley. However,
Even in this case, it is necessary to reduce the inner diameter of the driven pulley in order to ensure a sufficient thickness in the diameter direction of the driven pulley and to secure the rigidity of the driven pulley. Further, in this case, it is necessary to reduce the outer diameter of the sleeve disposed on the inner diameter side of the driven pulley in order to secure the installation space for the pair of support bearings.

However, in the case of the conventional structure described in the above publication, the rolling fatigue life of the pair of support bearings, that is, the radial roller bearing and the radial ball bearing, is almost equal, and the diameter of the bearing is reduced as described above. It is difficult to reduce the diameter. The reason is as follows. That is, in order to make the rolling fatigue life of the radial roller bearing and that of the radial ball bearing substantially equal, as described above, the diameter of each ball constituting the radial ball bearing is changed to the diameter of each roller constituting the radial roller bearing. Must be larger than the diameter of As a result, the radial ball bearing requires more installation space in the diameter direction than the radial roller bearing.

On the other hand, in the case of the conventional structure described in the above-mentioned publication, the radial ball bearing is disposed in a portion having a large inner diameter of the sleeve, and the radial roller bearing is disposed in a portion having a small internal diameter of the sleeve. ing. For this reason, as described above, it is attempted to reduce the diameter of the pulley device with built-in one-way clutch for the alternator in the diametrical direction while making the rolling fatigue life of the radial roller bearing and the radial ball bearing substantially equal (the outer diameter of the sleeve). ), The diameter of the portion of the sleeve where the radial ball bearing is arranged becomes excessively small in the diameter direction. For this reason, it is difficult to ensure the rigidity of the sleeve at the inner diameter side portion of the radial ball bearing. Therefore, in the case of the conventional structure described in the above-mentioned publication, the rolling fatigue life of the pair of support bearings, that is, the radial roller bearing and the radial ball bearing, is almost equal, and the size is reduced in the diameter direction. Difficult to design. In consideration of the above-described circumstances, the one-way clutch built-in pulley device for an alternator of the present invention can be used even when the rolling fatigue lives of the radial roller bearing and the radial ball bearing, which are a pair of support bearings, are substantially equal. The present invention has been invented to realize a structure capable of sufficiently reducing the size in the diameter direction at a low cost.

[0012]

According to the present invention, there is provided a pulley device with a built-in one-way clutch for an alternator according to the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-
As in the conventional structure described in Japanese Patent Application Publication No. 226462, a sleeve which can be externally fitted and fixed to the rotating shaft of the alternator, a driven pulley disposed around the sleeve and concentric with the sleeve, and an axially intermediate portion between the outer peripheral surfaces of these sleeves Between the driven pulley and the sleeve only when the driven pulley tends to rotate relative to the sleeve in a predetermined direction with respect to the axially intermediate portion of the inner peripheral surface of the driven pulley. A one-way clutch capable of transmitting force freely, and a radial load applied to the driven pulley provided between an outer peripheral surface of the sleeve and an inner peripheral surface of the driven pulley at a position sandwiching the one-way clutch from both axial sides. And a pair of support bearings that allow the sleeve and the driven pulley to rotate relative to each other. One of the pair of support bearings is a radial roller bearing, and the other support bearing is a deep groove type radial ball bearing capable of supporting a thrust load in addition to a radial load. In particular, in the pulley device with a built-in one-way clutch for an alternator according to the present invention, the inner peripheral surface of the driven pulley is formed into a single cylindrical surface with no step in the middle, and the radial ball bearing is connected to the one-way clutch. One of the axially opposite side portions of the directional clutch, the inner diameter of a circular hole provided at the center of the sleeve or the diameter of a circumscribed circle of one or more holes provided at the inner diameter side of the sleeve. Is disposed in a portion smaller than the other portion, and further, by providing a step surface on the outer peripheral surface of the sleeve, the outer diameter of one side of the outer peripheral surface of the sleeve where the radial ball bearing is disposed is reduced. , Also smaller than the outside diameter on the other side.

[0013]

In the pulley apparatus with a built-in one-way clutch for an alternator according to the present invention, the diameter of each ball constituting the radial ball bearing is made larger than the diameter of each roller constituting the radial roller bearing. As a result, even when the durability performance of these two bearings is made equal, the size reduction in the diameter direction can be sufficiently achieved. That is, in the case of the present invention, the radial ball bearing, in which the installation space in the diameter direction is increased,
The inner diameter of the sleeve (or the diameter of the circumscribed circle of one or more holes) in both axial parts of the one-way clutch.
Is located in the small part. In the portion of the sleeve having a small inner diameter, there is a margin in the thickness in the diameter direction. Therefore, even if the outer diameter of the sleeve is reduced in order to reduce the size in the diameter direction,
By sufficiently securing the wall pressure at the portion where the radial ball bearing is arranged, the rigidity of the sleeve can be sufficiently secured. Therefore, in the case of the present invention, the rolling fatigue life of the pair of support bearings, the radial roller bearing and the radial ball bearing, can be made substantially equal, and the size in the diameter direction can be sufficiently reduced. In the case of the present invention, the inner peripheral surface of the driven pulley is formed as a single cylindrical surface, and the outer peripheral surface of the sleeve is formed as a stepped but relatively simple two-stage cylindrical surface. And the cost can be reduced.

[0014]

FIG. 1 shows a first embodiment of the present invention. The pulley device with a built-in one-way clutch for an alternator of the present embodiment has a sleeve 8 which can be fitted and fixed to the rotating shaft 3 of the alternator 1 (see FIG. 4). A driven pulley 7 a is arranged around the sleeve 8 concentrically with the sleeve 8. A radial roller bearing 9 and a radial ball bearing 10 as a pair of support bearings and a roller clutch 1 as a one-way clutch are provided between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a.
1 is provided. Of these, the radial roller bearing 9 and the radial ball bearing 10 are provided at least in the driven pulley 7a.
The relative rotation between the sleeve 8 and the driven pulley 7a is made free while supporting the radial load applied to the armature. In particular, the radial ball bearing 10 is a deep groove type, and the driven pulley 7
The thrust load applied to a is also freely supported. The roller clutch 11 can freely transmit the rotational force from the driven pulley 7a to the sleeve 8 only when the driven pulley 7a tends to rotate relative to the sleeve 8 in a predetermined direction.

That is, in the driven pulley device with a built-in one-way clutch for an alternator of the present embodiment as described above, the entire sleeve 8 is formed in a cylindrical shape, and the end of the rotating shaft 3 of the alternator 1 And is rotatable together with the rotating shaft 3. For this reason, in the illustrated example, a screw hole 12 is formed in the inner peripheral surface of the middle portion of the sleeve 8 near the tip (the portion near the left end in FIG. 1), and the screw hole 12 and the tip of the rotating shaft 3 are formed. An external thread portion provided on the outer peripheral surface of the portion can be screwed freely. A cylindrical fitting hole 13 is formed in the inner peripheral surface of the base half (the right half in FIG. 1) of the sleeve 8. Can be freely fitted inside without rattling. Further, the distal end inner peripheral surface of the sleeve 8, a hexagonal cross-sectional shape, the diameter D ₁₄ of the circumscribed circle is larger than the inner diameter d ₁₃ of the fitting hole portion 13 (D
_14> d ₁₃₎ to form a locking hole portion 14. The tip of a tool such as a hexagon wrench can be freely locked in the locking hole 14. Incidentally, the structure in which the sleeve 8 and the rotating shaft 3 are combined so as not to rotate relatively is a spline engagement,
Other structures such as non-circular fitting and key engagement may be employed.

On the other hand, the outer peripheral surface of the driven pulley 7a has a cross-sectional shape extending in the width direction and has a corrugated shape so that a part of an endless belt called a poly-V belt can be passed around. or,
The inner peripheral surface of the driven pulley 7a is formed in a simple cylindrical shape over the entire length. The roller clutch 11 is provided at an axially intermediate portion of a space existing between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a. The radial roller bearing 9 and the radial ball bearing 10 are arranged at positions sandwiching the roller bearings from both sides in the axial direction. In particular, in the case of the present example, the radial ball bearing 10 in which the installation space in the diametrical direction is increased, is formed by inserting the radial hole bearing 10 into the fitting hole, which is the end on the side where the inner diameter of the sleeve 8 is smaller, of the axial ends of the space. It is arranged around the part 13.

In the illustrated example, the roller clutch 1 is used.
In order to form the roller 1, the roller clutch inner ring 15 is externally fixed to the outer peripheral surface of the intermediate portion of the sleeve 8 by interference fit. The inner ring 15 for the roller clutch is formed entirely of a hard metal plate material such as bearing steel or a carburized steel plate material such as SCM415 in a cylindrical shape. A plurality of recesses 20 called ramps are formed on the outer peripheral surface of the roller clutch inner ring 15 at regular intervals in the circumferential direction, so that the outer peripheral surface is used as the cam surface 16. Further, in order to constitute the radial roller bearing 9, a roller bearing inner ring 17 is externally fixed to the outer peripheral surface of the distal end portion of the sleeve 8 by interference fitting. Again, it was made of a hard metal plate such as bearing steel or carburized steel plate such as SCM415.
The inner race 17 for roller bearings is formed in a cylindrical shape with an L-shaped cross section by forming an inner flange portion 19 having an outward flange shape at one end edge of a cylindrical portion 18.

The inner ring 17 for such a roller bearing is mounted on the sleeve 8 with the inner ring side flange portion 19 positioned at the distal end side.
, And the other end of the cylindrical portion 18 abuts against the axial end of the inner race 15 for roller clutch (the left end in FIG. 1). In the case of the present example, the outer diameter of the cylindrical portion 18 constituting the roller bearing inner ring 17 is set to the roller clutch inner ring 15.
Is larger than the diameter of an inscribed circle related to the bottom of the plurality of recesses 20 formed on the outer peripheral surface of. Further, a clutch retainer 21 to be described later, which constitutes the roller clutch 11,
Each protruding piece 2 formed on the inner peripheral surface of the
2 and 22, one side (left side in FIG. 1) of the protrusion 22 on the radial roller bearing 9 side (left side in FIG. 1) faces the other end of the inner ring 17 for each roller bearing. The clutch retainer 21 is prevented from moving toward the radial roller bearing 9. The displacement of the clutch retainer 21 toward the radial ball bearing 10 (to the right in FIG. 1) is prevented by an outer ring side flange portion 24 provided on the outer ring 23 described below.

On the other hand, an outer ring 23 is provided on the inner peripheral surface of the driven pulley 7a near the front end of the intermediate portion (the portion near the left end in FIG. 1).
The inner fit is fixed by interference fit. This outer ring 23
It functions not only as an outer ring of the roller clutch 11 but also as an outer ring of the radial roller bearing 9, and is also formed by pressing a hard metal plate such as bearing steel or a carburized steel plate such as SCM415. Are formed in a cylindrical shape as a whole. The inner peripheral surface of such an outer ring 23 is a mere cylindrical surface over substantially the entire length except for the outer ring side flanges 24 formed at both ends. Also, this outer ring 23
Are formed on both ends in the axial direction at the outer ring side flange portions 24, 24 in the form of inward flanges.

The roller clutch 11 includes a base half (the right half in FIG. 1) of the outer race 23 and the roller clutch inner race 15. That is, between the inner peripheral surface of the base half portion of the outer race 23 and the outer peripheral surface of the inner race 15 for the roller clutch, a clutch retainer 21 formed of a synthetic resin into a basket-like cylindrical shape, and a plurality of rollers 25 each of which is formed. And a spring (not shown). Further, as described above, the clutch retainer 21 is configured such that the protruding pieces 22 formed on the inner peripheral surface thereof are connected to the roller clutch inner race 15.
Is engaged with the concave portion 20 constituting the cam surface 16 of the roller clutch to prevent the relative rotation with respect to the roller clutch inner ring 15. Since the basic structure and operation of the roller clutch 11 are well known in the art, detailed illustration and description are omitted.

The radial roller bearing 9 comprises a first half (left half in FIG. 1) of the outer ring 23 and the inner ring 1 for the roller bearing.
7 is included. That is, between the inner peripheral surface of the first half of the outer race 23 and the outer peripheral surface of the inner race 17 for roller bearings,
A cage for roller bearing 26 formed of a synthetic resin in a cage shape is provided, and a plurality of rollers 27 (rolling elements) rotatably held by the cage for roller bearing 26.
The gap between the inner peripheral surface of the outer ring 23 and the outer peripheral surface of the roller bearing inner ring 17 is closed by a seal ring 28. The seal ring 28 is composed of a cored bar 29 and an elastic member 30. The seal ring 28 is internally fitted to the inner peripheral surface of the outer ring 23 while the outer diameter of the elastic member 30 is elastically reduced. are doing. The tip edges of the plurality of seal lips provided on the elastic member 30 are slid or abutted on the outer peripheral surface of the intermediate portion of the inner race 17 for roller bearings and the inner surface of the flange portion 24 on the outer ring side. . In the illustrated example, the inner ring-side flange portion 19 is arranged outside the outer ring-side flange portion 24, and a labyrinth gap is formed between the two flange portions 19 and 24.

The radial ball bearing 10 includes a ball bearing outer ring 32 having a deep groove type outer ring raceway 31 locked on an inner peripheral surface thereof;
A ball bearing inner ring 34 having a deep groove type inner ring raceway 33 formed on the outer peripheral surface; a plurality of balls 35 (rolling elements) rotatably provided between the outer ring raceway 31 and the inner ring raceway 33; A synthetic resin ball bearing retainer 36 that holds the ball 35 in a freely rolling manner. In such a radial ball bearing 10, the ball bearing outer ring 32 is internally fitted and fixed to the inner peripheral surface of the base end (the right end in FIG. 1) of the driven pulley 7a by interference fit. The outer peripheral surface of the sleeve 8 is fixed between the inner peripheral surface of the proximal end portion of the driven pulley 7a and the outer peripheral surface of the proximal end portion of the sleeve 8 by being externally fitted and fixed.

In the case of the illustrated example, the inner ring 34 for the ball bearing is used.
The small-diameter step portion 37 provided at the base end of the sleeve 8
For example, after being externally fitted with a clearance fit, it is fixed to the sleeve 8 by being sandwiched between a step surface 38 of the small-diameter step portion 37 and a caulking portion 39 provided on the outer peripheral edge portion of the base end of the sleeve 8. are doing. In the case of this example, the caulking section 39
A plurality of (for example, 4 to 8) circumferential portions of the outer peripheral edge portion of the base end portion of the sleeve 8 are formed by plastically deforming diametrically outward toward the end surface of the ball bearing inner ring 34. In the illustrated example, a relief groove 40 is formed on the inner diameter side portion of the caulking portion 39 over the entire circumference. The relief groove 40 is for preventing the inner diameter of the fitting hole 13 and the like provided at the center of the sleeve 8 from changing when the caulking portion 39 is formed. In this case,
The sleeve 8 is made of S which is easy to perform the plastic deformation.
It is preferable to use a steel material of about 25C to S50C.
Also, in order to improve the fixing force of the caulking portion 39,
The caulking portion 39 may be formed by plastically deforming the outer peripheral edge of the base end of the sleeve 8 over the entire circumference.

Further, in the state where the radial ball bearing 10 is assembled as described above, the outer end of the space existing between the inner peripheral surface of the ball bearing outer ring 32 and the outer peripheral surface of the ball bearing inner ring 34 ( The opening (right end in FIG. 1) is sealed by a seal ring 42 locked on the inner peripheral surface of the outer end of the outer race 32 for the ball bearing. That is, in the case of the present example, the roller clutch 11, the radial roller bearing 9, and the radial ball bearing 1 are formed by the seal ring 42 and the seal ring 28 described above.
In addition to preventing intrusion of foreign matter such as muddy water into the internal space, the grease sealed in the internal space is prevented from leaking to the outside.

In the case of the pulley apparatus with a built-in one-way clutch for an alternator of the present embodiment constructed as described above, the rotation speed of the driven pulley 7a over which the endless belt is stretched is reduced by the action of the low clutch 11. The torque is transmitted from the driven pulley 7a to the rotation shaft 3 only when the rotation speed is equal to or higher than the rotation speed of the sleeve 8 fixed to the first rotation shaft 3 (see FIG. 4). Conversely, when the rotation speed of the driven pulley 7a is lower than the rotation speed of the sleeve 8,
The connection between the driven pulley 7a and the sleeve 8 is disconnected to prevent an unnecessary (braking direction) force from being applied to the endless belt. Further, in the case of this example, one radial roller bearing 9 and one radial ball bearing 10 are used as a pair of support bearings. Therefore, not only the relatively large radial load applied to the driven pulley 7a can be sufficiently supported by the radial roller bearing 9, but also the thrust load applied to the driven pulley 7a can be supported by the radial ball bearing 10. Therefore, there is no need to provide a separate member such as a thrust washer.

In particular, in the case of this embodiment, the diameter of each of the balls 35 constituting the radial ball bearing 10 is made larger than the diameter of each of the rollers 27 constituting the radial roller bearing 9 so that these two bearings are formed. Even in the case where the durability performances of the components 9 and 10 are made substantially equal, the size in the diameter direction can be sufficiently reduced. That is, in the case of the present example, the radial ball bearing 10 having a large installation space in the diameter direction between the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the sleeve 8 is mounted on the shaft of the roller clutch 11. The sleeve 8 is located at the end on the side where the inner diameter of the sleeve 8 is smaller, that is, at the peripheral portion of the fitting hole 13 in the both sides in the direction. In the portion of the sleeve 8 where the fitting hole 13 is formed, there is a margin in the thickness in the diameter direction. For this reason, even when the outer diameter of the sleeve 8 is reduced in order to reduce the size in the diametrical direction, a sufficient wall pressure is secured in a portion of the sleeve 8 where the radial ball bearing 10 is arranged. The rigidity of the sleeve 8 can be sufficiently ensured. Therefore, in the case of the present example, the rolling fatigue life of the pair of support bearings, that is, the radial roller bearing 9 and the radial ball bearing 10, can be substantially equalized, and the size in the diameter direction can be sufficiently reduced. In the case of this example, the inner peripheral surface of the driven pulley 7a is formed in a single cylindrical surface, and the outer peripheral surface of the sleeve 8a is formed in a stepped cylindrical surface, so that the machining cost 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 engagement as in the first example described above is carried out on the inner diameter side portion of the distal end (the left end in FIG. 2) of the sleeve 8a fixed to the end of the rotating shaft 3 (see FIG. 4) of the alternator 1. The hole 14 (FIG. 1) is not formed. Instead, in the case of the present example, a plurality of engaging holes 43, each of which is a hole described in the claims, are provided at equal intervals in the circumferential direction in a portion near the outer diameter of the distal end surface of the sleeve 8a. It is formed by. The tip of the assembling tool is freely engageable with each of the engagement holes 43. These diameter D ₄₃ of the circumscribed circle of each engagement hole 43 is larger than the inner diameter d ₁₃ of the fitting hole portion 13 provided in the base half portion inner peripheral surface of the sleeve 8a (D _43>
d _13). Therefore, also in the case of this example, the radial ball bearing 10 which is one of the pair of support bearings is used.
Are disposed on the outer diameter side portion of the fitting hole 13 which is the end on the side where the thickness of the sleeve 8a has a margin.

In this embodiment, the radial ball bearing 10 is used.
The outer end surfaces of the inner race 34 for ball bearings and the outer race 32 for ball bearings are located on substantially the same plane as the base end surface of the driven pulley 7a, and slightly project from the base end surface of the sleeve 8a. I have. In the case of this example, the sleeve 8a
In a state in which the outer member is fixed to the end of the rotary shaft 3, the end surface of the annular member externally fitted to the rotary shaft 3 abuts against the outer end surface of the inner ring 34 for the ball bearing, and the base end of the sleeve 8 a is closer to the base end. The ball bearing inner ring 34 is sandwiched between a stepped surface 38 provided on the outer peripheral surface of the ball bearing. In the case of this example, the driven pulley 7a is used to prevent the pulley device from being disassembled during transport.
The interference of the ball bearing outer ring 32 with respect to the inner peripheral surface is increased, and the ball bearing inner ring 34 also has a slight interference with the outer peripheral surface of the sleeve 8a. Other configurations and operations are the same as those of the above-described first example.

FIG. 3 shows a third embodiment of the present invention.
An example is shown. In the case of this example, a serration hole 41 is formed at the inner diameter side of the distal end of the sleeve 8b, and a serration shaft provided at the distal end of the assembling tool can be engaged with the serration hole 41. In the case of this example, since the engagement between the sleeve 8b and the assembling tool is serration engagement, a sufficient torque can be applied to the sleeve 8b even if the pitch circle diameter of the serration hole 41 is reduced. . Therefore, in the case of this example, the groove bottom diameter D ₄₁ of the circumscribed circle about the serration hole portion 41, smaller than the inner diameter d ₁₃ of the fitting hole portion 13 provided in the base half portion inner peripheral surface of the sleeve 8b (D ₄₁ <d ₁₃ ). For this reason, in the case of this example, the radial ball bearing 10, which is one of the pair of support bearings, is connected to the serration hole, which is the end of the sleeve 8b on the side of the sleeve 8b having a sufficient thickness. It is arranged around the part 41.

In the case of the present embodiment, the outer ring side flange is not formed at one end (the left end in FIG. 3) of the outer ring 23a which is fitted and fixed to the driven pulley 7a. In the axial direction. Further, with the omission of forming the outer ring side flange portion at one end portion of the outer ring 23a, one end surface (the left end surface in FIG. 3) of the clutch retainer 21 is connected to the inner end surface (the left end surface of the ball bearing outer ring 32). The clutch retainer 21 is opposed to the radial ball bearing 1 (the right end face in FIG. 3).
Displacement to the 0 side is prevented. If possible, it is preferable that one end face of the clutch retainer 21 be opposed to the inner end face of the ball bearing inner ring 34 constituting the radial ball bearing 10 if possible. Further, in the case of the present example, the serration hole portion 41 which engages with the assembling tool has a large dimensional tolerance. Therefore, when forming the caulked portion 39 for fixing the ball bearing inner ring 34, the serration hole portion 41 is used. There is no problem even if the pitch circle diameter of the hole 41 slightly changes. For this reason, in the case of this example, it is not necessary to provide the relief groove 40 (see FIG. 1) in the inner diameter side portion of the caulking portion 39. Other configurations and operations are the same as in the case of the above-described first example.

In each of the above-described examples, the case where the low clutch 11 is used as the one-way clutch has been described. However, the present invention relates to another known one-way clutch such as a sprag clutch. The same effect can be obtained even when a one-way clutch having a structure is used.

[0032]

The pulley device with a built-in one-way clutch for an alternator according to the present invention is constructed and operated as described above, so that one roller bearing and one ball bearing are used as a pair of support bearings. In addition, it is possible to sufficiently reduce the size in the diametrical direction while maintaining the same life for both bearings. As a result, the weight can be reduced. Further, the processing of each part is easy, and the production cost does not increase.

[Brief description of the drawings]

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

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alternator 2 Housing 3 Rotating shaft 4 Rolling bearing 5 Rotor 6 Commutator 7, 7a Driven pulley 8, 8a, 8b Sleeve 9 Radial roller bearing 10 Radial ball bearing 11 Roller clutch 12 Screw hole 13 Fitting hole 14 Locking hole Part 15 Inner ring for roller clutch 16 Cam surface 17 Inner ring for roller bearing 18 Cylindrical part 19 Inner ring side flange 20 Recess 21 Clutch retainer 22 Projection 23, 23a Outer ring 24 Outer ring side flange 25 Roller 26 Roller bearing retainer 27 Roller 28 Seal ring 29 Core metal 30 Elastic material 31 Outer raceway 32 Outer race for ball bearing 33 Inner raceway 34 Inner race for ball bearing 35 Ball 36 Ball bearing retainer 37 Small diameter step portion 38 Step surface 39 Caulking portion 40 Relief groove 41 Serration hole Part 42 Seal ring 43 Engagement hole

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Ouchi 1-50-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Japan Seiko Co., Ltd. F-term (reference) 3J031 AC06 AC10 BA08 BA09 CA03

Claims (1)

[Claims] 1. A sleeve which can be externally fitted and fixed to a rotating shaft of an alternator, a driven pulley disposed around the sleeve and concentric with the sleeve, an axially intermediate portion of an outer peripheral surface of the sleeve, and an inner periphery of the driven pulley. Provided between the driven pulley and the sleeve only when the driven pulley tends to rotate relative to the sleeve in a predetermined direction. A one-way clutch, provided between the outer peripheral surface of the sleeve and the inner peripheral surface of the driven pulley at a position sandwiching the one-way clutch from both sides in the axial direction, and supporting the radial load applied to the driven pulley with these sleeves. A pair of support bearings that allow relative rotation with respect to a driven pulley; one of the pair of support bearings is a radial roller bearing, and the other is a radial roller bearing; In a pulley device with a built-in one-way clutch for an alternator in which the support bearing is a radial ball bearing, the inner peripheral surface of the driven pulley is formed as a single cylindrical surface with no step in the middle, and the radial ball bearing is The inner diameter of a circular hole provided at the center of the sleeve or the circumcircle of one or a plurality of holes provided at the inner diameter side of the sleeve at one of the axially opposite side portions of the one-way clutch. The outer diameter of one side of the outer peripheral surface of the sleeve, on which the radial ball bearing is disposed, is disposed in a portion where the diameter of Characterized in that the outer diameter of the pulley is also smaller than the outer diameter of the other side.