JP2001032911A - Pulley device for alternator with built-in roller clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize structure capable of efficiently attempting security of sufficient durability. SOLUTION: A diameter of an outer peripheral surface of a part to an outer end in the axial direction out of a pair of rim parts 39 provided on both ends in the axial direction of a holder 37 for a clutch constituting a roller clutch 10a is made smaller than a diameter of an outer peripheral surface of a part to the inside in the axial direction of this part. A comparatively large annular space 44 free to hold grease sufficient in quantity for lubrication of the roller clutch 10a between this outer peripheral surface of the small diametrical part and an inner peripheral surface of an outer ring 33 for the roller clutch internally fitted and fixed in the driven pulley 7b. Additionally, as it is possible to increase the diameter of the outer peripheral surface of the inside part in the axial direction of each of the rim parts 39, strength of a part said to require sufficient strength by the holder 37 for the clutch is never lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pulley device with a built-in roller clutch for an alternator, which is fixed to an end of a rotating shaft of an alternator which is a generator for an automobile and fixed to an end of a crankshaft of an engine. The alternator is used to drive the alternator by wrapping an endless belt between the 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 roller clutch for an alternator that allow the relative rotation between the pulley and the rotation shaft have been proposed and used in part. For example, JP-A-56-101353, JP-A-7-31
JP-A-7807, JP-A-8-61443, JP-A-8-22
Japanese Patent Publication No. 6462, Japanese Patent Publication No. 7-72585, French Patent Publication FR2726059A1, and the like describe a pulley device with a built-in roller clutch for an alternator having the above-described functions. In some cases, such a pulley device with a built-in roller clutch for an alternator is actually used.

[0004] FIG.
2 shows a pulley device with a built-in roller clutch for an alternator described in Japanese Patent Application Publication No. 2 (JP-A) No. 2 (1999). This pulley device with a built-in roller clutch for alternator is an alternator 1
It has a sleeve 8 that can be externally fitted and fixed to the rotating shaft 3 (FIG. 4). The driven pulley 7a around the sleeve 8
Are arranged concentrically with the sleeve 8. A pair of support bearings 9 and 9 and a roller clutch 10 are provided between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a.
Are provided. Among these, the support bearings 9, 9 support the radial load applied to the driven pulley 7a,
The relative rotation between the sleeve 8 and the driven pulley 7a is made free. Further, the roller clutch 10 allows the transmission of 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.

The outer peripheral surface of the intermediate portion of the inner ring 11 which constitutes the roller clutch 10 and is fitted and fixed to the sleeve 8 is
A plurality of concave portions 12, 12 called ramp portions are formed at equal intervals in the circumferential direction, and the outer peripheral surface of the intermediate portion is cam surface 1
It is set to 3. The outer peripheral surfaces of both ends of the inner ring 11 are inner ring raceways 14 for the support bearings 9. On the other hand, the inner peripheral surface of the outer ring 15 that is fitted and fixed to the driven pulley 7a, which constitutes the roller clutch 10, is a simple cylindrical surface over substantially the entire length. or,
The plurality of rollers 16, 16 constituting the roller clutch 10 together with the inner ring 11 and the outer ring 15 are supported on a clutch retainer 17 so as to freely roll and slightly displace in the circumferential direction. Then, the clutch retainer 17
A spring is provided between the pillar portion provided in the above and each of the rollers 16. Each of these springs is directed toward a portion of the cylindrical gap formed between the outer peripheral surface of the cam surface 13 and the inner peripheral surface of the outer ring 15 whose width in the diametrical direction is reduced. The rollers 16, 16 are elastically pressed.

The reason for using the pulley device with a built-in roller clutch for an alternator as described above is as follows. For example, when the running 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 driven pulley 7a is
The rotating shaft 3 of the alternator 1 driven to rotate via
Due to the inertial mass of the rotating shaft 3 and the rotor 5 and the commutator 6 (FIG. 4) fixed to the rotating shaft 3, it does not fluctuate so rapidly. Therefore, when the driven pulley 7a is simply fixed to the rotating shaft 3, the rotating speed of the rotating shaft 3 decreases as the running speed of the belt decreases,
The power generation efficiency of the alternator 1 decreases. At the same time, the endless belt and the driven pulley 7a tend to rub in both directions with a change in the rotational angular velocity of the crankshaft. As a result, the endless belt rubbing with the driven pulley 7a
The stress in the different directions is repeatedly applied, so that the slip is easily generated between the endless belt and the driven pulley 7a,
Alternatively, the life of the endless belt may be shortened.

In addition, the above-described reduction in the power generation efficiency of the alternator and the reduction in the life of the endless belt due to friction between the outer peripheral surface of the driven pulley 7a and the inner peripheral surface of the endless belt are caused by repeated acceleration and deceleration during traveling. Also occurs. That is, the driving force is transmitted from the endless belt side to the driven pulley 7a side during acceleration, whereas the braking force from the endless belt is applied to the driven pulley 7a that continues to rotate based on inertia as described above during deceleration. Works. Not only does the power generation efficiency decrease based on the braking force, but also the braking force and the driving force act as frictional forces in the opposite direction to the inner peripheral surface of the endless belt, so that the It may cause shortening of the service life. In particular, in the case of a vehicle equipped with an exhaust brake such as a truck, the deceleration of the decrease in rotation of the crankshaft when the accelerator is off is remarkable, and the frictional force applied to the inner peripheral surface of the endless belt based on the braking force As a result, the power generation efficiency and the life are significantly reduced.

Therefore, the pulley device with a built-in roller clutch for alternator is used as the driven pulley 7a as described above. Accordingly, when the traveling speed of the endless belt is constant or tends to increase, the rollers 16 constituting the roller clutch 10
Of the cylindrical gap formed between the outer peripheral surface of the outer ring 15 and the inner peripheral surface of the outer ring 15 in a portion having a narrow width in a diametric direction (locked state), and the driven pulley is locked. Transmission of rotational force from the rotation shaft 7a to the rotating shaft 3 is made free.
On the other hand, when the running speed of the endless belt tends to decrease, the rollers 16, 16 move to the wider portion of the cylindrical gap, and the rollers 16, 16 move.
The portion 16 is allowed to roll freely (in an overrun state) at that portion, and the relative rotation between the driven pulley 7a 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 7a 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 7a is reduced. To prevent strong rubbing. In this way, the power generation efficiency of the alternator is ensured, the direction of the stress acting on the rubbed portion between the driven pulley 7a and the endless belt is made constant, and slippage occurs between the endless belt and the driven pulley 7a. Or the life of the endless belt is prevented from being shortened.

[0009]

In the case of a conventional pulley device with a built-in roller clutch for an alternator which operates and operates as described above, there is a possibility that the lubricity of the roller clutch 10 cannot be sufficiently ensured. That is, in the case of the conventional structure, in order to ensure the lubricity of the roller clutch 10, the shape of the clutch retainer 17 constituting the roller clutch 10 is not particularly considered. Therefore, in the conventional structure, a sufficiently large space is provided between the outer peripheral surface of the clutch retainer 17 and the inner peripheral surface of the outer ring 15 to hold a sufficient amount of grease to lubricate the roller clutch 10. May not be formed. If a sufficiently large space cannot be formed as described above, the rolling surfaces of the rollers 16 and 16 constituting the roller clutch 10 and members (the outer ring 15 or the inner ring 11
And grease for lubricating the contact portion with the spring). For this reason, at the time of overrun, the frictional force acting between the rolling surfaces of the rollers 16, 16 and the members that make sliding contact increases, and there is a possibility that heat generation based on the frictional force becomes significant. In such a case, the originally small amount of grease is thermally degraded early and causes the durability of the pulley device with a built-in roller clutch for the alternator to be impaired. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances to effectively secure sufficient durability.

[0010]

A pulley device with a built-in roller clutch for an alternator according to the present invention is, like a conventionally known pulley device with a built-in roller clutch for an alternator, capable of being externally fixed to the rotating shaft of the alternator. A driven pulley disposed concentrically with the sleeve around the sleeve; and a driven pulley provided between an axially intermediate portion of an outer peripheral surface of the sleeve and an axially intermediate portion of an inner peripheral surface of the driven pulley. A roller clutch capable of freely transmitting rotational force between the driven pulley and the sleeve only when the roller clutch tends to rotate relative to the sleeve in a predetermined direction, and a state in which the roller clutch is sandwiched from both axial sides. Between the outer peripheral surface of the sleeve and the inner peripheral surface of the driven pulley to support the radial load applied to the driven pulley. And and a support bearing for freely relative rotation between the driven pulley.

In particular, in the alternator roller clutch built-in type pulley device of the present invention, a pair of rim portions provided at both axial ends of the clutch retainer constituting the roller clutch are closer to the axial outer end. The diameter of the outer peripheral surface of the portion is smaller than the diameter of the outer peripheral surface of the portion axially inside the portion.

[0012]

In the case of the pulley device with a built-in roller clutch for an alternator of the present invention constructed as described above, the outer peripheral surface of the clutch retainer near the both ends in the axial direction is fixed to the driven pulley or the inside of the driven pulley. A relatively large annular space capable of holding a sufficient amount of grease can be formed between the inner ring and the inner peripheral surface of the outer ring. Therefore, this grease suppresses heat generation due to friction generated at the time of overrun in which the sleeve and the driven pulley rotate relative to each other, prevents thermal deterioration of the grease, and ensures sufficient durability.

That is, in the case of the pulley device with a built-in roller clutch for an alternator, which is the object of the present invention, the rotation speed at the time of locking becomes close to 20,000 rpm at maximum, and the relative rotation between the sleeve and the driven pulley during overrun. Speeds can reach up to several thousand rpm. In such an application state, heat generation which is not a problem in the conventional roller clutch application becomes a problem. That is, the PV value (the product of the contact pressure and the sliding speed), which indicates the degree of the sliding friction and greatly affects the calorific value, becomes so large that it cannot be compared with the application of the conventional roller clutch. On the other hand, in the case of the present invention, a sufficient amount of grease for lubricating the roller clutch can be held in the annular space, and the grease allows the rolling surface of each roller to make sliding contact with each roller. The heat generation can be suppressed by sufficiently lubricating the contact portion with the member to be heated. In particular, in the case of the present invention, based on the centrifugal force generated when the pulley device is used, the grease held in the annular space is shaken off the inner peripheral surface of the driven pulley or the outer ring, and The inner peripheral surface and the rolling surface of each of the rollers, which spread uniformly and move to a portion that becomes a trajectory that comes into contact with each of the rollers, have a high sliding speed, and heat generation due to friction is particularly a problem. Can be lubricated sufficiently.

Further, in the case of the present invention, the diameter of the outer peripheral surface of the axially inner portion of the pair of rims constituting the clutch retainer is larger than the diameter of the outer peripheral surface of the portion closer to the axially outer end. Since each is large, the strength of the joint between the above-mentioned rims and the pillar connecting these two rims, which is a part of the clutch retainer where sufficient strength is required, is required. It does not decline. As a result, according to the present invention,
The life of the grease can be extended without impairing the durability of the clutch retainer, and sufficient durability of the pulley device can be ensured.

[0015]

1 and 2 show a first embodiment of the present invention. The one-way clutch built-in pulley device for the alternator of the present example is formed in a cylindrical shape as a whole,
The alternator includes a sleeve 8a externally fitted and fixed to the end of the rotating shaft 3 (see FIGS. 4 and 5) of the alternator, and a driven pulley 7b disposed around the sleeve 8a and concentrically with the sleeve 8a. The sleeve 8a is rotatable with the rotation shaft 3. For this reason, in the illustrated example, a female screw portion 18 is formed on the inner peripheral surface of the intermediate portion of the sleeve 8a, and the female screw portion 18 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. The structure for preventing the relative rotation between the rotary shaft 3 and the sleeve 8a may be a spline, a fitting between non-cylindrical surfaces, a key engagement, or the like instead of the screw. Further, in order to facilitate the screwing operation between the female screw portion 18 and the male screw portion, a tip of a tool such as a hexagon wrench is engaged with one end (left end in FIG. 1) of the sleeve 8a. A hexagonal hole 19 that can be stopped is formed.

The driven pulley 7b provided around the sleeve 8a has a pair of support bearings 20, 20 and a roller clutch 10a described below mounted inside the driven pulley 7b. or,
The outer peripheral surface of one half (the left half in FIG. 1) of the driven 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 freely passed over.

In this embodiment, a pair of support bearings 20, each of which is a deep groove type ball bearing, is provided between the outer peripheral surface of the sleeve 8a and the inner peripheral surface of the driven pulley 7b.
20 and one roller clutch 10a.
Each of the support bearings 20, 20 includes an inner ring 22 having a deep groove type inner raceway 21 on an outer peripheral surface, an outer ring 24 having a deep groove type outer raceway 23 on an inner peripheral surface, and the inner raceway 21 and the outer raceway. 23 and a plurality of rolling elements (balls) 25 which are provided to be able to roll freely. And the outer ring 2
4 is fitted to and fixed to inner peripheral surfaces of both ends of the driven pulley 7b and stepped portions 26, 26 having the inner ring 22 formed on the outer peripheral surfaces of both ends of the sleeve 8a. are doing. In this state, each of the inner races 22 has one end in the axial direction having a step surface 27, 2 between the step portions 26, 26 and the outer peripheral surface of the main body portion of the sleeve 8a.
7, the support bearings 20, 20 are prevented from slipping over the sleeve 8a in the axial direction.

Each of the rolling elements 25 is accommodated in a plurality of pockets 29 provided in a retainer 28 formed in an annular shape as a whole.
It is held so that it can roll freely. Seal rings 30, 30 are provided between the outer peripheral surfaces of both ends of each inner ring 22 and the inner peripheral surfaces of both ends of the outer ring 24, respectively. The seal rings 30 prevent the foreign matter from entering the space in which the plurality of rolling elements 25 exist from the outside, and the grease existing in the support bearings 20 is externally provided. Prevents leakage.

Further, in order to constitute the roller clutch 10a, an inner ring 31 for the roller clutch is externally fitted and fixed to the outer peripheral surface of the sleeve 8a in the axially intermediate portion by interference fit. The inner ring 31 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 into a cylindrical shape, and the outer peripheral surface is a cam surface 32.

On the other hand, an outer ring 33 for a roller clutch is fixedly fitted to the inner peripheral surface of the intermediate portion of the driven pulley 7b by interference fit. The outer ring 33 for the roller clutch, which is formed into a cylindrical shape as a whole by pressing a hard metal plate material such as bearing steel or a carburized steel plate material such as SCM415, is provided with inward flanges at both axial ends. Are formed. In addition, these both collar parts 3
4a, 34b, one (left side in FIG. 1) flange 34a
Is formed before combining with other components,
It has the same thickness dimension as the main body of the roller clutch outer ring 33. On the other hand, the other (right side in FIG. 1) flange portion 34b is formed to be thin after being combined with other components. Each such flange 34a, 34b
The outer surface in the axial direction is in close proximity to the inner end surfaces of the outer races 24, 24 constituting the support bearings 20, 20, respectively, through abutment or minute gaps.

At a plurality of locations on the outer peripheral surface of the roller clutch inner ring 31, recesses 35, 35, called ramps, whose depth increases as going in a predetermined direction with respect to the circumferential direction.
Are formed at equal intervals in the axial direction of the inner race 31 for the roller clutch and in the circumferential direction, and the outer peripheral surface of the inner race 31 for the roller clutch is the cam surface 32. A cylindrical gap 45 is formed between the outer peripheral surface of the roller clutch inner race 31 and the inner peripheral surface of the roller clutch outer race 33. Of the dimensions of the cylindrical gap 45, The width dimension of the outer ring 33 in the diametric direction is larger than the outer diameter of the plurality of rollers 36 provided in the cylindrical gap 45 at a portion corresponding to each of the recesses 35, and at each portion deviating from each of the recesses 35. It is smaller than the outer diameter of the roller 36.

The roller clutch 10a is provided between the inner peripheral surface of the outer ring 33 for roller clutch and the outer peripheral surface of the inner ring 31 for roller clutch. And a plurality of the rollers 36 and springs 38, 38, respectively.
The clutch retainer 37 includes a pair of rim portions 39, 39 each having an annular shape, and both rim portions 3 and 39.
9 and 39 are connected to each other. Then, the portion surrounded by the inner side surface of each of the rim portions 39, 39 and the side surface of each of the pillar portions 40, 40 is held so that each roller 36 can be rolled and slightly displaced in the circumferential direction. In order to do so, a plurality of pockets 41 are provided. By engaging the convex portions 42, 42 formed at a plurality of positions on the inner peripheral surface of each rim portion with the concave portions 35, 35 formed on the outer peripheral surface of the roller clutch inner ring 31,
The roller clutch inner ring 31 is mounted so as not to rotate relative to the inner ring 31. Note that both axial end surfaces of the clutch retainer 37 are respectively close to and axially opposed to the axial inner side surfaces of the flange portions 34a and 34b. Each of the above springs 3
8, 38 are provided between the pillars 40, 40 constituting the above-described clutch retainer 37 and the rollers 36,
These rollers 36 are elastically pressed in the same direction (left direction in FIG. 2) with respect to the circumferential direction.

Particularly, in the case of the present invention, a pair of rim portions 39, 3 provided at both axial ends of the clutch retainer 37 are provided.
9, the diameter of the outer peripheral surface of the portion near the outer end in the axial direction is smaller than the diameter of the outer peripheral surface of the inner portion in the axial direction. Accordingly, a relatively large annular space 44 is provided between the outer peripheral surface of the outer end portion of each of the rim portions 39, 39 and the inner peripheral surface of both end portions of the roller clutch outer ring 33 constituting the roller clutch 10a. 44 are formed.

In the pulley device with a built-in roller clutch for an alternator of the present invention constructed as described above, the roller clutch 10a has a driven pulley 7b in which a roller clutch outer ring 33 is fixedly fitted and a rotary shaft in which a sleeve 8a is fixedly fitted externally. 3, and transmits only a rotational force in a predetermined direction. For example, assuming that the roller clutch inner race 31 is fixed and only the roller clutch outer race 33 rotates in FIG. 2, if the roller clutch outer race 33 rotates clockwise in FIG. Based on the force received from the inner peripheral surface of the roller clutch outer ring 33, the recesses 35, 35, as shown by solid lines in FIG.
Tends to be displaced toward the deeper side. Then, the respective rollers 36 are in a state of being able to roll within the cylindrical gap 45, so that transmission of rotational force between the roller clutch outer ring 33 and the roller clutch inner ring 31 is stopped, so-called. An overrun occurs. Conversely, when the roller clutch outer ring 33 rotates in the counterclockwise direction in FIG.
As shown by a chain line in FIG. 2, based on the force received from the inner peripheral surface of the inner peripheral surface 3 and the elasticity of each of the springs 38, 38,
35 is wedge-shaped into the shallow side, and the roller clutch outer ring 33 and the roller clutch inner ring 31 are integrally connected to each other, and the rotational force is applied between the roller clutch outer ring 33 and the roller clutch inner ring 31. In a so-called locked state in which the transmission of light is freely performed.

By repeating these operations, the endless belt stretched over the driven pulley 7b and the driven pulley 7b
With the direction of the stress acting on the rubbing part with b constant,
It is possible to prevent the occurrence of slippage between the endless belt and the driven pulley 7b or to reduce the life of the endless belt. Further, when the rotation speed of the engine decreases and the running speed of the endless belt tends to decrease, the relative rotation between the sleeve 8a and the driven pulley 7b becomes free (overrun state). Regardless of the fluctuation, the rotating shaft 3 of the alternator is rotated at a certain high speed based on the rotating inertia force of the rotating shaft 3 itself and the rotor 5 and the commutator 6 (FIG. 4) fixed to the rotating shaft 3. The rotation can be continued, and the power generation efficiency of the alternator can be improved.

In particular, in the case of the pulley device incorporating a roller clutch for an alternator according to the present invention, the clutch retainer 3 is used.
7, a relatively large amount of grease can be held between the outer peripheral surface of the portion near the both ends in the axial direction and the inner peripheral surface of the driven pulley 7b or the outer ring 33 for the roller clutch fixed inside the driven pulley 7b. Large annular spaces 44, 44 can be formed. Accordingly, the grease held in each of the annular spaces 44 causes the sleeve 8a and the driven pulley 7 to move.
Heat generation due to friction at the time of overrun in which b rotates relative to each other is suppressed, thereby preventing thermal deterioration of the grease and ensuring sufficient durability.

That is, in the case of the present invention, a sufficient amount of grease for lubricating the roller clutch 10a can be held in the annular spaces 44, 44.
The heat generation can be suppressed by sufficiently lubricating the contact portions between the rolling surfaces of the rollers 36 and the members that are in sliding contact with the rollers 36. In particular, in the case of the present invention, the grease held in each of the annular spaces 44, 44 is blown off to the inner peripheral surface of the roller clutch outer ring 33 based on the centrifugal force generated when the pulley device is used, The inner peripheral surface and each of the rollers, which spread uniformly on the inner peripheral surface and move to a portion that becomes a trajectory that comes into contact with each of the rollers, have a high sliding speed and are particularly problematic in that heat generation due to friction is a problem. The contact portion between the rolling surface and the rolling surface can be sufficiently lubricated.

Further, in the case of the present invention, the diameter of the outer peripheral surface of the pair of rim portions 39, 39 constituting the clutch retainer 37 in the axial direction is determined by changing the diameter of the outer peripheral surface of the portion closer to the axial outer end. Because it is larger than the diameter, this clutch retainer 3
7, the strength of the joints between the rims 39, 39, which are parts requiring sufficient strength, and the pillars 40, 40 connecting the rims 39, 39 to each other, is reduced. Nothing to do. That is, at the time of overrun, since each roller 36 moves against the elasticity of each spring 38, 38, a load based on the elasticity of each spring 38, 38 is applied to each of the column portions 40, 40. Therefore, each of these pillars 40, 40
It is necessary to secure a sufficient strength at the joint between the rims 39 and 39. On the other hand, in the case of the present invention, since the diameter of the outer peripheral surface of the axially inner portion of each of the rim portions 39, 39 is increased, the strength of the coupling portion does not decrease. As a result, according to the present invention, sufficient durability of the pulley device can be ensured without impairing the durability of the clutch retainer 37.

In the case of this embodiment, support bearings 20, 2 are provided on the inner peripheral surface of one end (left end in FIG. 1) of the driven pulley 7b.
A large-diameter portion 46 having a diameter larger than the outer diameter of the outer races 24, 24 constituting the outer ring 24 is formed. The outer ring 24 that constitutes one of the support bearings 20 (the left side in FIG. 1) of the pair of support bearings 20 is provided with the driven pulley 7.
The inner peripheral surface b is fitted and fixed to a portion shifted inward in the axial direction from the large diameter portion 46. The outer ring 24 constituting the one support bearing 20 is fixedly fitted to the inner peripheral surface of the driven pulley 7b, and the inner ring 22 is similarly fixed to the outer peripheral surface of the sleeve 8a by interference fit having a margin. In the case of the present embodiment in which the large diameter portion 46 is formed on the inner peripheral surface of the driven pulley 7b, when the outer ring 24 is fitted by interference fit, the outer ring 24 is fitted to the driven pulley 7b with a tight allowance. It is possible to shorten the length of movement while holding it. Therefore, between the pair of support bearings 20, 20, the seal ring 3 attached to the two support bearings 20, 20 is provided.
The pressure in the space where both ends are densely closed by 0 and 30 and in which the roller clutch 10a exists is prevented from becoming excessively high. Therefore, each of the support bearings 20, 20
It is possible to prevent the seal lip of each of the seal rings 30 and 30 mounted on the lip from being turned up.

FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of this example, the roller clutch 10
On the inner peripheral surface of one end (left end in FIG. 3) in the axial direction of the clutch retainer 37a constituting a, a locking projection 47 projecting inward in the diametrical direction is formed over the entire circumference. On the other hand, on the inner peripheral surface of the other end in the axial direction (the right end in FIG. 3) of the clutch retainer 37a, a plurality of hook-shaped engaging pieces 48 projecting inward in the diametrical direction are provided. It is formed intermittently in the circumferential direction.

When the clutch retainer 37a is mounted around the roller clutch inner ring 31, the plurality of locking pieces 48 constituting the clutch retainer 37a are elastically moved outward in the diameter direction. While being deformed, the clutch retainer 37a is externally fitted to the roller clutch inner race 31 from the side where the locking pieces 48 are provided. Then, the inner side surface of the locking projection 47 abuts against one edge (the left edge in FIG. 3) of the roller clutch inner race 31. In this state, the locking pieces 48 are elastically restored, and the locking pieces 4 are restored.
8 and the other end of the roller clutch inner race 31 (the right end in FIG. 3) are engaged. For this reason, in the case of the present example, the axial length of the roller clutch inner race 31 is set between the locking projection 47 and each locking piece 48 in the free state of the clutch retainer 37a. It is almost the same as or slightly smaller than the distance between the side surfaces.

As described above, the clutch retainer 37
a is externally fitted to the roller clutch inner race 31, the clutch retainer 37a is
No displacement in the axial direction with respect to 1. Since the roller clutch inner race 31 is externally fitted and fixed to the outer peripheral surface of the intermediate portion of the sleeve 8a, the clutch retainer 37a does not move in the axial direction relative to the sleeve 8a. As a result, it is possible to prevent the axial end surfaces of the clutch retainer 37a and the axial inner surface of the roller clutch outer ring 33 fitted and fixed on the driven pulley 7b from slidingly contacting each other during overrun. Heat generation due to sliding contact and thermal deformation of the clutch holder 37a due to this heat generation can be prevented. Other configurations and operations are the same as those of the first example described above, and therefore, the same parts are denoted by the same reference numerals, and redundant description will be omitted.

[0033]

The pulley device with a built-in roller clutch for an alternator according to the present invention is constructed and operates as described above, so that sufficient durability can be ensured.

[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 sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing a second example of the embodiment of the present invention.

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

FIG. 5 is a cross-sectional view showing one example of a conventionally known pulley device with a built-in roller clutch for an alternator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alternator 2 Housing 3 Rotating shaft 4 Rolling bearing 5 Rotor 6 Commutator 7, 7a, 7b Followed pulley 8, 8a Sleeve 9 Support bearing 10, 10a Roller clutch 11 Inner ring 12 Depression 13 Cam surface 14 Inner ring raceway 15 Outer ring 16 Roller 17 Clutch Retainer 18 female screw part 19 hexagon hole 20 support bearing 21 inner raceway 22 inner raceway 23 outer raceway 24 outer raceway 25 rolling element 26 stepped part 27 stepped surface 28 retainer 29 pocket 30 seal ring 31 roller clutch inner race 32 cam surface 33 roller Clutch outer ring 34a, 34b Flange 35 Recess 36 Roller 37, 37a Clutch retainer 38 Spring 39 Rim 40 Column 41 Pocket 42 Convex 44 Annular space 45 Cylindrical gap 46 Large diameter portion 47 Engagement protrusion 48 Locking piece

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 roller clutch is provided between the outer peripheral surface of the sleeve and the inner peripheral surface of the driven pulley in a state where the roller clutch is sandwiched from both sides in the axial direction, and the roller clutch is driven while supporting the radial load applied to the driven pulley. In a pulley device with a built-in roller clutch for an alternator, the pulley device including a support bearing for allowing relative rotation with respect to the pulley, the clutch constituting the roller clutch is provided. That the diameter of the outer peripheral surface of the portion closer to the axial outer end of the pair of rim portions provided at both axial ends of the switch retainer is smaller than the diameter of the outer peripheral surface of the axially inner portion of this portion. A pulley device with a built-in roller clutch for alternators.