JP2000310314A - Pulley device with built-in one-way clutch for alternator, and assembly thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To be resistant to seizing in a one-way clutch, sufficiently ensure torque capacity thereof, and prevent fatigue life thereof from shortening. SOLUTION: This device determines outer diameters of rollers 36a, 36b forming respective support bearing 17a, 17b and being assembled to a fitting part of a driven pulley 7b and a sleeve 8a partitioned by an inner or outer diameter dimension and rigidity. Dispersion of a radial gap in each support bearing 17a, 17b is kept to be small by adequately selecting the rollers 36a, 36b to be assembled to an assemblage of the driven pulley 7b and the sleeve 8a of each part.

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 for an alternator and a method of assembling the pulley device. The pulley device with a built-in one-way clutch for an alternator is provided at an end of a rotating shaft of an alternator which is a generator for an automobile. The alternator is used to drive the alternator by fixing an endless belt between a drive pulley fixed to the end of the engine crankshaft.

[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. 5 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 of the rotating shaft 3 (the right end in FIG. 5) 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
Nos. 17807 and 8-61443, Tokuhei 7
No. 72585, French Patent Publication FR 27260
59A1 and the like describe a pulley device with a built-in one-way clutch for an alternator having the above-described functions.
In addition, such a pulley device with a built-in one-way clutch for an alternator is actually used.

FIG. 6 shows a pulley device with a built-in one-way clutch for an alternator described in Japanese Patent Application Laid-Open No. Hei 8-61443. This one-way clutch built-in pulley device for an alternator has a sleeve 8 that can be externally fitted and fixed to the rotating shaft 3. And this sleeve 8
And a driven pulley 7a is arranged concentrically with the sleeve 8. A pair of support bearings 9 is provided between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a.
9 and a one-way clutch 10 are provided. The support bearings 9, 9 support the radial load applied to the driven pulley 7a while supporting the sleeve 8 and the driven pulley 7a.
The rotation relative to a can be freely performed. Only when the driven pulley 7a tends to rotate relative to the sleeve 8 in a predetermined direction, the one-way clutch 10 can freely transmit the rotational force from the driven pulley 7a to the sleeve 8. .

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. 5) driven to rotate by the endless belt 11 via the driven pulley 7 a includes the rotating shaft 3, the rotor 5 fixed to the rotating shaft 3, and the commutator 6 (FIG. 5). ) Does not fluctuate so rapidly. Therefore, when the driven pulley 7a is simply fixed to the rotating shaft 3, the endless belt 11 and the driven pulley 7a tend to rub in both directions with a change in the rotational angular speed of the crankshaft. As a result, the endless belt 11 rubbing against the driven pulley 7a
Stresses in different directions are repeatedly applied to cause slippage between the endless belt 11 and the driven pulley 7a, or shorten the life of the endless belt 11.

The endless belt 1 based on the friction between the outer peripheral surface of the driven pulley 7a and the inner peripheral surface of the endless belt 11 as described above.
The reduction in the service life of 1 also occurs by repeating acceleration and deceleration during traveling. That is, the driving force is transmitted from the endless belt 11 side to the driven pulley 7a side during acceleration, while the driven pulley 7a that continues to rotate based on inertia as described above during deceleration is transmitted from the endless belt 11 to the driven pulley 7a side. A braking force acts. The braking force and the driving force are the same as those of the endless belt 11.
Acts as a friction force in the opposite direction to the inner peripheral surface of
Again, this causes a reduction in the life of the endless belt 11. 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 pulley device with a built-in one-way clutch for the alternator as the driven pulley 7a as described above, if the running speed of the endless belt 11 is constant or tends to increase, the driven The transmission of the rotational force from the pulley 7a to the rotary shaft 3 is made freely, and conversely, when the running speed of the endless belt 11 tends to decrease, the relative rotation between the driven pulley 7a and the rotary shaft 3 becomes free. . That is, when the running speed of the endless belt 11 tends to decrease, the rotational angular speed of the driven pulley 7a is made slower than the rotational angular speed of the rotary shaft 3 so that the contact between the endless belt 11 and the driven pulley 7a is reduced. Prevents the contact parts from rubbing strongly. In this manner, the direction of the stress acting on the rubbed portion between the driven pulley 7a and the endless belt 11 is made constant, and slippage occurs between the endless belt 11 and the driven pulley 7a, or 11 is prevented from being shortened.

[0008]

As the pair of support bearings 9 constituting the pulley device with a built-in one-way clutch for an alternator as described above, a ball bearing (in the case shown) or a roller has conventionally been used. Bearings are used. In any case, conventionally, as such support bearings 9, 9,
Prior to assembling with a pulley device with a built-in one-way clutch for alternators, a free state in which the internal clearance was a normal clearance was used.

However, because of the limited space in which the pulley device with a built-in one-way clutch for an alternator is to be installed, the above-mentioned support bearings 9 are assembled.
The thickness of the cylindrical space 12 existing between the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the sleeve 8 is limited to be small in the diameter direction. Therefore, the outer race 1 constituting each of the support bearings 9, 9 incorporated in the cylindrical space 12.
3, 13 and the inner rings 14, 14 are limited in their thickness dimensions to be considerably smaller. Thus, the outer rings 13, 13 and the inner ring 14,
When the thickness of the outer ring 14 is limited to a small value,
3, 13 and the inner races 14, 14 are press-fitted into the driven pulley 7a and the sleeve 8, respectively, and fitted by interference fit, the amount of elastic deformation of the races of the outer races 13, 13 and the inner races 14, 14 is fitted. The value may be 80% or more of the interference of the joint portion, and may be large to a degree that cannot be ignored. As the amount of elastic deformation of the outer rings 13 and the inner rings 14 increases, the amount of variation in the radial gap in each of the support bearings 9 may increase.

The outer races 13, 13 and the inner races 14, 1
The fitting surfaces of the driven pulley 7a and the sleeve 8 for fitting the respective 4 are generally finished by turning. For this reason, dimensional errors inevitably produced in the manufacturing process occur in the diametrical dimensions of these fitting surfaces after finishing. Therefore, the outer rings 13, 13 and the inner rings 15, 1
5, each of the support bearings 9 configured by fitting
The variation amount of the radial gap in 9 may still be large.

The rigidity of the driven pulley 7a and the rigidity of the sleeve 8 differ depending on the parts to which the support bearings 9 are to be assembled. For example, in the example shown in FIG.
Driven pulley 7 to which the left support bearing 9 should be attached
The rigidity of the fitting portion a is clearly higher than the rigidity of the fitting portion of the driven pulley 7a to which the right support bearing 9 in FIG. For this reason, the expansion rates of the inner rings 14 and 14 fitted on the outer peripheral surface of the sleeve 8 and the contraction rates of the outer rings 13 and 13 fitted on the inner peripheral surface of the driven pulley 7a are determined by the respective support bearings 9 and 9. It differs depending on the part to be assembled. Conventionally, no consideration has been given to such a difference in rigidity of the fitting portion, and this also causes a large amount of variation in the radial gap in each of the support bearings 9, 9.

On the other hand, conventionally, the driven pulley 7
A ring gauge having the same inner diameter as the inner diameter of a (not shown)
The outer raceway diameter of the outer race 13 when the outer race 13 is fitted and fitted is determined, and the inner race 14 is fitted into a plug gauge (not shown) having the same outer diameter as the outer diameter of the sleeve 8 by fitting. The inner ring raceway diameter of this inner ring 14 at the time of
The rolling elements 15, which constitute the support bearings 9, 9, while taking into account the amount of elastic deformation of the inner rings 3, 13 and the inner rings 14, 14.
It is conceivable to determine 15 outer diameters. However, even in this case, when the support bearings 9, 9 are actually assembled to the pulley device with a built-in one-way clutch for the alternator, the dimensional error in manufacture and the outer rings 13, 13 or the inner rings 14, 14 are fitted. There is a possibility that the amount of variation in the radial gap becomes large based on the difference in rigidity of the mating portions.

If the amount of variation in the radial gap in each of the support bearings 9 is increased due to various causes as described above, the following problem occurs. That is, when the variation amount of the radial gap becomes large as described above, the one-way clutch 1
0 is a roller clutch, the overrun state of the one-way clutch 10 (the driven pulley 7a and the sleeve 8
The radial gap in the state where the relative rotation with
There is a possibility that the diameter becomes smaller than the radial gap in each of the support bearings 9 and 9. When the one-way clutch 10 is of the sprag type, the radial existing between the sprags, the driven pulley and the sleeve under the condition that the plurality of sprags constituting the one-way clutch are not twisted is assumed. The gap may be smaller than the radial gap in each of the support bearings 9, 9. When the radial gap in the one-way clutch 10 becomes small in this way, in the overrun state, a radial load based on the belt tension is not applied to each of the support bearings 9, 9, and the driven pulley 7 a receives the radial load. The radial load is directly applied to the rollers or sprags constituting the directional clutch 10, the PV value of the one-way clutch 10 increases, and the roller or sprag and the member that comes into contact with the roller or sprag are contacted. , There is a possibility that image sticking is likely to occur.

If the amount of variation in the radial gap is large, it becomes difficult to obtain a radial gap having a substantially uniform size between the pair of support bearings 9.
If a radial gap having a substantially uniform size cannot be obtained between the pair of support bearings 9 and 9 in this manner, the trajectory of the pair of members that comes into contact with the rollers or sprags constituting the one-way clutch 10 will be described. The surfaces may be inclined, and the two raceway surfaces and the roller or sprag may have a one-sided contact. In addition, a uniform surface pressure distribution cannot be secured between these rollers or sprags and the two raceway surfaces, so that the torque load capacity of the one-way clutch 10 cannot be sufficiently secured. It can lead to a decline. The pulley device with a built-in one-way clutch for an alternator and the method of assembling the alternator according to the present invention, in view of the above-described circumstances, reduce the variation in the radial gap existing in the support bearing after manufacture, and provide a high-performance pulley device. It was invented in order to provide.

[0015]

SUMMARY OF THE INVENTION A pulley device with a built-in one-way clutch for an alternator and a method of assembling the pulley device with a built-in one-way clutch for an alternator according to the present invention are known in the art. Similarly to the pulley device, a sleeve that can be fitted and fixed on the rotating shaft of the alternator, a driven pulley disposed around the sleeve and concentric with the sleeve, and an axially intermediate portion of the outer peripheral surface of the sleeve and a driven pulley. It is provided between the peripheral pulley and the axial middle portion, and enables the transmission of rotational force 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, with the one-way clutch sandwiched from both axial sides. While supporting a radial load applied to the driven pulley and a support bearing for freely relative rotation between the sleeves and the driven pulley.

In particular, in the pulley device with a built-in one-way clutch for an alternator according to the present invention, the outer ring constituting each of the support bearings is provided on the inner peripheral surface of the driven pulley, and the inner ring constituting each of the support bearings is provided above. On the outer surface of the sleeve,
The driven pulley and the sleeve are respectively fitted and fixed, and the driven pulley and the sleeve are each provided in a plural number by at least one of a diametrical dimension and a rigidity of a fitting portion for fitting the outer ring and the inner ring constituting each of the support bearings. Each of the support bearings is divided into a plurality of types by an initial radial gap before the outer ring and the inner ring are fitted to the driven pulley and the sleeve. And
Each of the divided support bearings to be assembled to the divided driven pulley and sleeve is selected and assembled to the driven pulley and sleeve.

Further, in the method for assembling a pulley device with a built-in one-way clutch for an alternator according to the present invention, the driven pulley and the sleeve are moved in a diametrical direction of a fitting portion for fitting the outer ring and the inner ring constituting each of the support bearings. The support bearings are divided into a plurality of types according to at least one of the following dimensions and rigidity, and each of the support bearings is divided into a plurality of types by an initial radial gap before the outer ring and the inner ring are fitted to the driven pulley and the sleeve. Classify into. Then, each of the divided support bearings to be assembled to the divided driven pulley and the sleeve is selected, and an outer ring constituting each of the support bearings is provided on an inner peripheral surface of the driven pulley, and each of the respective outer bearings is provided on an outer peripheral surface of the sleeve. The inner rings constituting the support bearing are fitted and fixed respectively.

[0018]

According to the pulley device with a built-in one-way clutch for an alternator of the present invention and the pulley device with a built-in one-way clutch for an alternator obtained by the assembling method of the present invention, the outer race and the inner race constituting each support bearing are provided. Even when the thickness of the support bearing is limited to a small value, the amount of variation in the radial gap existing in each of the support bearings after manufacturing can be reduced. Therefore, when the one-way clutch is a roller clutch, the radial gap in the overrun state, or when the one-way clutch is a sprag type, the radial gap in a state where a plurality of sprags are assumed not to be twisted is as described above. It is possible to prevent the clearance from becoming smaller than the radial gap in the support bearing, and reduce the PV value in the one-way clutch, thereby making it difficult to cause seizure in the one-way clutch. Furthermore, a radial gap having a substantially uniform size is obtained between the pair of support bearings, and a roller or sprag constituting the one-way clutch and a raceway surface of a pair of members that come into contact with the roller or sprag. It is possible to prevent the one-way clutch from having a one-sided contact, sufficiently secure the torque load capacity of the one-way clutch, and prevent the fatigue life of the one-way clutch from being shortened.

[0019]

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 an end of the rotating shaft 3 (see FIGS. 5 and 6) 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 spline portion 16 is formed on the inner peripheral surface of the intermediate portion of the sleeve 8a, and a male spline portion (not shown) formed on the female spline portion 16 and the outer peripheral surface of the end of the rotary shaft 3 is omitted. And are freely engageable. The structure for preventing the relative rotation between the rotary shaft 3 and the sleeve 8a may be replaced with a screw, a fitting between non-cylindrical surfaces, a key engagement, or the like instead of the spline.

The driven pulley 7b provided around the sleeve 8a has a support bearing 17 described below inside thereof.
a, 17b and the one-way clutch 18 are mounted. In the outer peripheral surface of the driven pulley 7b, a plurality of (four in this example) concave grooves 19, 19 each having a V-shaped cross section, are provided.
Are formed in parallel with each other and over the entire circumference. Between the driven pulley 7b and a driving pulley (not shown), an endless end having a plurality of ribs (four in the present example) formed on the inner peripheral surface and having a V-shaped cross-section and continuous over the entire periphery. Hang the belt.

A pair of support bearings 17a and 17b, each of which is a radial roller bearing, is provided between the outer peripheral surface of the sleeve 8a configured as described above and the inner peripheral surface of the driven pulley 7b configured as described above. And one one-way clutch 18 which is a roller clutch. In order to configure the one-way clutch 18, the one-way clutch inner ring 20 is externally fixed to the outer peripheral surface of the intermediate portion of the sleeve 8a by interference fit. This one-way clutch inner ring 20 is
The whole is formed in a cylindrical shape from a plate material made of hard metal such as bearing steel or a plate material of carburized steel such as SCM415, and the outer peripheral surface is a cam surface 21 described later.

To form the support bearings 17a and 17b, inner rings 22 and 22 are externally fitted to outer peripheral surfaces of both ends of the sleeve 8a by interference fitting. Again, hard metal plate material such as bearing steel or SC
Each of these inner rings 22, 22 made of a carburized steel plate material such as M415 has an L-shaped cross section by forming an inner ring side flange portion 24 having an outward flange shape at one end edge of a cylindrical portion 23, respectively. Is formed. In addition, each of these inner rings 2
2, 22 have the same inner diameter and thickness dimensions as each other.

Each of the inner races 22 is externally fitted to the sleeve 8a with the inner race side flanges 24 located on the opposite sides, and the leading edge of each of the inner races is formed on the inner race 20 for the one-way clutch. It abuts against both axial edges. In the case of this example, the outer diameter of the cylindrical portion 23 of the inner races 22 is larger than the diameter of an inscribed circle related to the bottom of the plurality of recesses 25 formed on the outer peripheral surface of the one-way clutch inner race 20. are doing.

On the other hand, the driven pulley 7b has an outer ring 26
Are internally fixed by interference fit. This outer ring 26
Is not only an outer ring of the one-way clutch 18 but also
It also functions as an outer ring of each of the support bearings 17a and 17b, and is also a plate made of hard metal such as bearing steel or S
The entire body is formed into a cylindrical shape by performing press working on a plate material of carburized steel such as CM415. Outer ring 26 like this
Are formed with outer ring side flanges 27a and 27b in the form of inward flanges at both ends in the axial direction. It should be noted that one of the outer ring side flange portions 27a and 27b (left side in FIG. 1) is formed before being combined with the other constituent members, so that the outer ring side flange portion 27a and the main body portion of the outer ring 26 are not formed. It has similar thickness dimensions. On the other hand, the other outer ring side flange portion 27b (right side in FIG. 1) is formed to be thin after being combined with other components.

The one-way clutch 18 is provided between the inner peripheral surface of the intermediate portion of the outer race 26 and the inner race 2 for the one-way clutch.
0 outer peripheral surface. That is, at a plurality of locations on the outer peripheral surface of the one-way clutch inner ring 20, concave portions 25, 25 called a ramp portion, whose depth increases toward one end in the circumferential direction (the right side in FIG. 2), are respectively formed. The one-way clutch inner race 20 is formed at regular intervals in the circumferential direction along the axial direction of the one-way clutch inner race 20.
Is the cam surface 21. A cylindrical gap 28 is formed between the outer peripheral surface of the one-way clutch inner race 20 and the inner peripheral surface of the outer race 26. The cross-sectional height dimension is larger than the outer diameter of the plurality of rollers 29 provided in the cylindrical gap 28 at a portion corresponding to each of the recesses 25, 25, and at a portion outside the respective recesses 25, 25 at the portion corresponding to each of the recesses 25, 25. It is smaller than the outer diameter of each roller 29.

The one-way clutch 18 has a cage-shaped cylindrical cage made of synthetic resin between the inner peripheral surface of the intermediate portion of the outer race 26 and the outer peripheral surface of the inner race 20 for the one-way clutch. 30 and a plurality of rollers 29 and springs 31, 31, each of which is provided. The clutch retainer 30 engages the convex portions 32 formed on the inner peripheral surface with the concave portions 25 formed on the outer peripheral surface of the one-way clutch inner ring 20 on the inner side of the outer ring 26. By doing so, the one-way clutch inner ring 20 is mounted so as not to rotate relative to the inner ring 20. Further, each of the convex portions 32, 3
The one side in the axial direction of 2 is opposed to the edge of each of the inner rings 23, 23 to prevent the clutch retainer 30 from shifting in the axial direction. The plurality of rollers 29 are held inside the pockets 33, 33 formed in the clutch retainer 30 so as to be able to roll and slightly displace in the circumferential direction.

The springs 31, 31 are provided between the pillars 34, 34 constituting the clutch retainer 30 as described above and the rollers 29, and these rollers 29 are arranged in the circumferential direction. Are elastically pressed in the same direction (left direction in FIG. 2). Generally, each of the springs 31, 31
It is a leaf spring made of stainless steel formed by pushing a band-shaped spring plate back into a U-shape or a M-shape, or a synthetic resin spring formed integrally with the retainer.

The support bearings 17a, 17b
Are configured to include each of the inner rings 23, 23 and portions of the outer ring 26 near both ends in the axial direction. That is, between the outer peripheral surfaces of the inner rings 23, 23 and the inner peripheral surfaces of the outer ring 26 near the axial ends, bearing cages 35, 35 each formed of a synthetic resin in a cage type cylindrical shape. And a plurality of rollers 36a, 36b that are rotatably held by the bearing retainers 35, 35 to form a radial roller bearing.

Floating washers 37 are provided between the outer surfaces of the outer ring flanges 27a, 27b and the inner surfaces of the inner ring flanges 24, 24, respectively. 27a, 27b and inner ring side flanges 24, 2
4 and relative rotation. The floating washers 37 are made of a metal having self-lubricating properties such as copper, a metal treated with tuftride, or a metal material impregnated with a lubricating oil such as an oil-impregnated metal, or a polyamide resin, a polyacetal resin, or a polytetrafluoride. It is formed in a ring shape from a synthetic resin having a low friction coefficient such as an ethylene resin. Such floating washers 37, 37
Each of the outer ring side flanges 27a, 27b and the inner ring side flanges 24, 2
4 and loosely clamped. The floating washers 37, 37 guide (prevent radial displacement) by the outer peripheral surfaces of the inner rings 22, 22 or the inner peripheral surfaces of the driven pulleys 7b.

The gaps between the inner peripheral surfaces of both ends of the outer race 26 in the axial direction and the outer peripheral surfaces of the inner races 22, 22 are closed by seal rings 38a, 38b, respectively. Each of these seal rings 38a and 38b is
And an elastic member 40, which is internally fitted to the inner peripheral surfaces of both ends of the outer ring 26 in a state where the outer diameter of the elastic member 40 is elastically reduced. And each elastic member 40, 4
The end edges of a plurality of seal lips provided on the inner ring 22 are in contact with the outer peripheral surfaces of the intermediate portions of the inner rings 22 and 22 and the inner surfaces of the outer ring side flange portions 27a and 27b.
In the case of this example, each of the above-mentioned seal rings 38a, 38b
One end of one (left side in FIG. 1) seal ring 38a is slid or abutted against the inner surface of one outer ring side flange 27a, so that the one seal ring with respect to the outer ring 26 is formed. 38a is positioned in the axial direction. On the other hand, the seal rings 38a, 3a
8b, the other (right side in FIG. 1) seal ring 38b
Of the outer ring 26 with the other outer ring side flange 27b.
Abutting against the step surface between the main body and the main body. At the same time, the other end edge of the other seal ring 38b is brought into contact with the inner surface of the other outer ring side flange 27b, thereby positioning the other seal ring 38b with respect to the outer ring 26 in the axial direction. I'm trying.

Also, one side of each of the metal cores 39, 39 of each of the seal rings 38a, 38b,
The portions facing the end faces of the bearing retainers 35, 35 constituting the a, 17b are not covered with the elastic members 40, 40, and the end faces of the bearing retainers 35, 35 and the core metal 39 are temporarily assumed. , 39, the sliding resistance can be kept low even when it comes into sliding contact with one side surface.

In particular, in the case of the pulley device with a built-in one-way clutch for an alternator of the present invention and the method of assembling the same, the pair of support bearings 17a and 17b are divided into a plurality of types (for example, two types) according to the initial radial clearance. are doing. At the same time, the driven pulley 7b and the sleeve 8a
Are divided into a plurality of types (for example, two types) according to the diametrical size and rigidity of a fitting portion for fitting the outer race 26 and the inner races 22 constituting the support bearings 17a and 17b, respectively. I have. That is, in the case of this example, the driven pulley 7b after manufacture is divided into two sections, a large diameter side and a small diameter side, according to the inner diameter of the fitting portion into which the outer ring 26 is fitted. In the case where the inner diameter is divided into two sections in this way, the inner diameter as a boundary value is arbitrarily set. For example, the boundary value is a value when the dimensional error of the inner diameter is zero, and the inner diameter is equal to or larger than this value. (Small diameter section) or whether the inner diameter is smaller than this value (small diameter section). or,
For each of the large-diameter side and small-diameter side sections, the median inner diameter dimension is selected as a representative example of each section.

Then, using the driven pulley 7b of the representative example of each section selected in this manner, one end (the left end in FIG. 1) and the other end (the left end in FIG. 1) of the driven pulley 7b having different fitting stiffnesses. The outer ring 26 is press-fitted to the right end of FIG. 1). That is, the fitting portion of the driven pulley 7b is divided at one end and the other end by rigidity. The outer ring raceway diameter D ₂₆ of the outer ring 26 when press-fitted as described above,
D ₂₆ ′ and the contraction rate of the outer ring 26 are obtained by measurement at one end and the other end of the driven pulley 7b for each of the representative driven pulleys 7b in each section.

The manufactured sleeve 8a is divided into two sections, a large-diameter side and a small-diameter side, according to the outer diameter, as in the case of the driven pulley 7b. Further, for each section of the fitting portion to which the inner rings 22 on the large diameter side and the small diameter side are fitted,
The median inner diameter is selected as a representative example of each section. Then, using the sleeve 8a of the representative example of each section selected in this manner, the inner rings 22 and 22 are attached to one end and the other end of the sleeve 8 having different rigidities of the fitting portions.
, Respectively. That is, the fitting portion of the sleeve 8a is also divided by the rigidity at one end and the other end (the rigidity at one end is smaller than the rigidity at the other end). The inner ring raceway diameters d ₂₂ , d ₂₂ ′ of the inner rings 22, 22 at the time of press-fitting as described above, and the expansion rates of the inner rings 22, 22 are determined by using one end and the other end of the sleeve 8 a. Is obtained by measurement for each representative sleeve 8a in each section.

Then, the outer ring raceway diameters D ₂₆ , D ₂₆ ′ of the outer ring 26 when the outer ring 26 is press-fitted and the respective driven pulleys 7 b of the representative example of each section obtained by the measurement as described above and The contraction rate of the outer ring 26, the range of the inner diameter of the driven pulley 7b in each section, and the outer ring 26
The range of the outer ring raceway diameter of the outer ring 26 after press-fitting into one end and the other end of the driven pulley 7b is determined by the inner diameter size from the inevitable manufacturing amount of the outer ring raceway diameter obtained by press-fitting. It is determined for each of the divided driven pulleys 7b.

Similarly, the inner ring raceway diameters d ₂₂ , d ₂₂ ′ of the inner ring 22 when the inner ring 22 is press-fitted into each of the sleeves 8 a as a representative example of each section, and the expansion rate of the inner ring 22, One end and the other end of the sleeve 8a are obtained from the range of the outer diameter of the sleeve 8a and the inevitable variation in the inner ring raceway diameter obtained by press-fitting the inner ring 22 into a plug gauge (not shown). The range of the inner ring raceway diameter of the inner ring 22 after the press-fitting is determined for each of the sleeves 8a divided by the outer diameter.

Then, the one support bearing 17a, which is to be assembled with a combination of the driven pulley 7b and the sleeve 8a, which is classified according to either the inner diameter or the outer diameter, is appropriately selected. Therefore, the range of the outer ring raceway diameter of the outer ring 26 after press-fitting into one end of the driven pulley 7b, which was obtained for the driven pulley 7b of each section, and the sleeve 8a of each section, also obtained. The inner ring 2 after being press-fitted into one end of the sleeve 8a.
The appropriate outer diameter of the roller 36a constituting the one support bearing 17a to be assembled to one end of the driven pulley 7b and the sleeve 8a is determined in consideration of the respective ranges of the inner ring raceway diameters. Then, the one support bearing 17a is divided by an initial radial gap before the outer ring 26 and the inner ring 22 are fitted to the driven pulley 7b and the sleeve 8a. As a combination of the driven pulley 7b and the sleeve 8a, each of which is classified by the inner diameter or the outer diameter, four sets are considered in total, so that the outer diameter of the roller 36a which is different for each set is determined.
The rollers 36a having different outer diameters are prepared in advance.

Actually, the driven pulley 7b and the sleeve 8
In the case where a is combined with one of the support bearings 17a, the inside diameter of the driven pulley 7b after manufacture and the outside diameter of the sleeve 8a after manufacture are measured, and it is determined which category each belongs to. And the driven pulley 7
b and one of the support bearings 17a to be assembled to one end of the sleeve 8a. When the driven pulley 7b and the sleeve 8a are combined with one of the support bearings 17a in this manner, the outer ring 26 and the inner ring 22 are combined.
Are generated by fitting the driven pulley 7b and the sleeve 8a, respectively, the amount of elastic deformation of the outer ring 26 and the inner ring 22, the dimensional error inevitable in manufacturing the driven pulley 7b and the sleeve 8a, and the In consideration of the difference in rigidity, the amount of variation in the radial gap in the one support bearing 17a can be reduced.

In the case of this embodiment, one end of the driven pulley 7b and one end of the sleeve 8a is attached to one of the support bearings 17a.
After assembling a, the radial gap in the one support bearing 17a is restricted to a range of 0 to 50 μm. At the same time, the radial gap of the one-way clutch 18 in an overrun state described later is restricted to 50 μm or more. Therefore, in the overrun state of the one-way clutch 18, the belt load can be prevented from being applied from the driven pulley 7b to the plurality of rollers 29 constituting the one-way clutch 18 without passing through the one support bearing 17a. .

The pair of support bearings 17a, 17
As for the other support bearing 17b, the driven pulley 7b and the sleeve 8a, which are divided by either the inner diameter or the outer diameter, in the same manner as the one support bearing 17a described above. The above-mentioned other support bearing 17b to be assembled into the combination is appropriately selected. However, the rigidity of the fitting portion of the driven pulley 7b and the sleeve 8a to which the other support bearing 17b is to be assembled is different from the rigidity of the fitting portion of the driven pulley 7b and the sleeve 8a to which the one support bearing 17a is to be assembled. . Therefore, based on this difference in rigidity, the contraction amount of the outer ring 26 and the expansion amount of the inner ring 22 constituting the other support bearing 17b are also changed by the one support bearing 17a.
It is different from the case. For this reason, a plurality of rollers 36a, 36b forming a pair of support bearings 17a, 17b to be assembled to the driven pulley 7b and the sleeve 8a having the same inner diameter or outer diameter are combined with the pair of support bearings 17a, 17a.
In order to obtain a substantially uniform radial gap between the 17b
Use different outer diameters. The size of the radial gap existing after the assembling of the other support bearing 17b is also limited to a range of about 0 to 50 μm. Further, even if the plurality of rollers 36a, 36b constituting the pair of support bearings 17a, 17b have the same outer diameter, if the interference of the fitting portions of the outer ring 26 and the inner rings 22, 22 is the same, Since the mutual difference in the radial gap between the pair of support bearings 17a and 17b is caused only by the difference in the amount of contraction of the outer ring 26 and the amount of expansion of the inner ring 22 that constitute the respective bearings, it can be suppressed to about 10 μm or less. it can.

According to the pulley device with a built-in one-way clutch for an alternator of the present invention and the pulley device with a built-in one-way clutch for an alternator obtained by the method of assembling the same, the one-way clutch 18 is formed by the outer ring 26. Is transmitted between the driven pulley 7b and the rotating shaft 3 in which only the rotational force in a predetermined direction is transmitted. For example, assuming that the inner race is fixed and only the outer race 26 rotates in FIG. 2, if the outer race 26 rotates clockwise in FIG.
Based on the force received by the inner ring 9 from the inner peripheral surface of the outer ring 26, the concave portions 25 tend to be displaced toward the deeper side against the elasticity of the springs 31. And each of the rollers 2
9 becomes rotatable in the cylindrical gap 28, and a so-called overrun state occurs in which transmission of rotational force between the outer ring 26 and the one-way clutch inner ring 20 is stopped. Conversely, when the outer ring 26 rotates in the counterclockwise direction in FIG. 2, the respective recesses are formed by the respective rollers 29 based on the force received from the inner peripheral surface of the outer ring 26 and the elasticity of the respective springs 31. 25, 25 bites into the shallow side in a wedge-like manner, and the outer ring 26 and the one-way clutch inner ring 20 are integrally connected to each other, and the rotational force between the outer ring 26 and the one-way clutch inner ring 20 is reduced. It becomes a so-called locked state in which transmission is free. And, irrespective of the fluctuation of the rotational angular velocity of the crankshaft of the engine, the direction of the stress acting on the frictional portion between the driven pulley 7b and the endless belt is made 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.

In particular, according to the pulley device with built-in one-way clutch for alternator of the present invention and the pulley device with built-in one-way clutch for alternator obtained by the method of assembling the same,
The thickness of the outer race 26 and the inner races 22, 22 constituting each of the support bearings 17 a, 17 b is limited to a small value.
And the interference between the fitting portions of the inner races 22
Even when the diameter of the raceway of the inner races 22, 22 is greatly affected, the amount of variation in the radial gap existing in each of the support bearings 17a, 17b after manufacturing can be reduced. Therefore, the radial gaps in the overrun state of the one-way clutch 18 are limited to the above-described support bearings 17a and 17a.
It can be prevented from becoming smaller than the radial gap in b, and the PV value in the one-way clutch 18 can be reduced, so that seizure in the one-way clutch 18 can be made hard to occur. Further, a radial gap having a substantially uniform size is obtained between the pair of support bearings 17a and 17b, and a roller 29 constituting the one-way clutch 18 and an inner ring for the one-way clutch constituting the one-way clutch 20 and outer ring 2
6 can prevent one-sided contact between the two raceway surfaces, sufficiently secure the torque load capacity of the one-way clutch 18, and prevent the fatigue life of the one-way clutch 18 from being shortened.

In the present invention, each of the support bearings 17
a, 17b by reducing the amount of variation in the radial gap in the support bearings 17a, 17b.
Is smaller than the radial gap when the one-way clutch 18 is in the overrun state. On the other hand, by making the radial gap in the overrun state of the one-way clutch 18 sufficiently large, the radial gap in the pair of support bearings 17a and 17b is reduced in the radial direction in the overrun state of the one-way clutch 18. It is also conceivable to make it smaller than the gap. However, if the radial clearance in the overrun state of the one-way clutch 18 is made sufficiently large, it may be difficult to secure a sufficient torque capacity when the one-way clutch 18 is a roller clutch. is there. Next, the reason will be described with reference to FIG.

First, when each of the rollers 29 constituting the one-way clutch 18 bites into the side where each of the recesses 25, 25 becomes shallow, when viewed in a cross section perpendicular to the axial direction of each of the rollers 29, A tangent line P at the point where the rolling surface of each roller 29 contacts the inner peripheral surface of the outer ring 26, and at the point where the rolling surface of each roller 29 contacts the bottom surface of each of the recesses 25, 25. The angle at which the tangent Q intersects is defined as the wedge angle α. The wedge angle α is generally set to a small value of about 9 ° because the roller 29 needs to be securely locked. On the other hand, the outer diameter of the one-way clutch inner ring 20 after manufacturing may vary due to dimensional errors inevitable in manufacturing. Therefore, this one-way clutch inner race 2
Assume that the outer diameter of 0 has increased slightly, as indicated by the dashed line in FIG. In this case, since the wedge angle α is a very small value, the position where each roller 29 locks is
The position is greatly shifted rightward in FIG. 2 from the normal position, and becomes the position indicated by the two-dot chain line in FIG. However, each roller 29
In the case where the roller 29 is largely displaced from the normal position to be locked, as shown in FIG.
There is a possibility that the recesses 25 will come into contact with one end existing on the deepened side of each of the recesses 25. In this case, there is no radial gap in the overrun state, and the one-way clutch 18 cannot realize the overrun state.

Therefore, even if the outer diameter of the one-way clutch inner race 20 varies due to dimensional errors, in order to sufficiently increase the radial clearance in the overrun state of the one-way clutch 18, the one-way clutch inner race 20 must be mounted. It is necessary to make the length of each of the recesses 25, 25 formed on the outer peripheral surface in the circumferential direction sufficiently large. However, in this case, the number of rollers 29 constituting the one-way clutch 20 decreases, which causes a reduction in the torque capacity of the one-way clutch 18. Therefore, in the case of the present invention, by assuming that the radial gap in the overrun state of the one-way clutch 18 cannot be made sufficiently large, the variation amount of the radial gap in the pair of support bearings 17a and 17b is reduced. The radial gap in each of the support bearings 17a and 17b is made smaller than the radial gap in the overrun state of the one-way clutch 18. That is, according to the present invention, the size of the radial gap in the pair of support bearings 17a, 17b can be reduced without reducing the torque capacity of the one-way clutch 18 in the overrun state of the one-way clutch 18. It is possible to solve the above-mentioned inconvenience caused by the increase in the size.

Next, FIGS. 3 and 4 show a second example of the embodiment of the present invention. In the case of this example, a pair of support bearings 41a, 41 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 7c.
b and a sprag-type one-way clutch 18a. Among these, the support bearings 41a and 41b are each provided with an outer race 43 having a deep groove type outer raceway 42 on the inner peripheral surface thereof.
And an inner ring 45 having a deep groove type inner ring raceway 44 on each outer peripheral surface thereof, and balls 46a, 46b each provided between the outer ring raceway 42 and the inner ring raceway 44 so as to freely roll.
Consisting of Each such support bearing 41a, 41b
The inner rings 4 are fixedly fitted to both ends of the inner peripheral surface of the driven pulley 7c by interference fitting.
The outer peripheral surface of the sleeve 8a is tightly fitted to the outer peripheral surface of the sleeve 8a so as to be provided between the outer peripheral surface of the sleeve 8a and the inner peripheral surface of the driven pulley 7c. Then, the radial load applied to the driven pulley 7c is
It is supported by the pair of support bearings 41a and 41b. In this embodiment, the positioning of these support bearings 41a and 41b in the axial direction is achieved only by fitting the driven pulley 7c and the sleeve 8a by interference fit. Therefore, it is necessary to consider that the inner wheel 45 and the outer wheel 43 do not creep during operation of the pulley device. That is, when a radial load due to belt tension is applied to each of the support bearings 41a and 41b, the interference of the fitting portions of the inner ring 45 and the outer ring 43 on the non-load side decreases. It is necessary to set an interference in consideration of the amount of reduction so that a predetermined interference exists on the side.
In the case of this example, the effective interference of the fitting portion between the outer ring 43 and the driven pulley 7c is set in a range of 20 to 45 μm,
The effective interference of the fitting portion between the inner ring 45 and the sleeve 8a is set in a range of 15 to 35 μm.

The one-way clutch 18a can be used to move the driven pulley 7c and the sleeve 8 only when the driven pulley 7c tends to rotate in a predetermined direction with respect to the sleeve 8a.
The transmission of the rotational force between the first and the second a is free. In order to constitute such a one-way clutch 18a, in the case of this example, the driven pulley 7c and the sleeve 8a are made of a hard metal such as bearing steel, and the inner peripheral surface of the intermediate portion of the driven pulley 7c and the sleeve 8a. Are formed as cylindrical surfaces. A plurality of sprags 47 each having a non-circular cross-sectional shape, each of which is a lock member, are provided between the two peripheral surfaces while being held by the clutch retainer 30a. In the case of this example, both ends in the axial direction of the clutch retainer 30a are supported by the support bearings 4 described above.
The end faces of the inner races 45, 45 constituting the first and the first races 41a, 41b are brought into contact with or close to each other to prevent the inner races 45 from shifting in the axial direction.

Each of the sprags 47 is shown in FIG.
The engagement type is used, as detailed in Fig. The sprag 47 of this type has a positional relationship between a point of contact with the outer peripheral surface of the sleeve 8a, which is a cylindrical surface, and the center of gravity.
The centrifugal force associated with the orbital movement is such that the sprag 4 is a cylindrical surface.
7 and the inner peripheral surface of the driven pulley 7c and the sleeve 8a.
Act in a direction in which the outer peripheral surface of the first member comes into contact with the outer peripheral surface. Sprags 4 each having a shape as detailed in FIG.
7 is one in the pocket 48 of the clutch holder 30a.
Each is held so as to be freely displaceable. A garter spring 50 is inserted into an engagement groove 49 formed in an intermediate portion in the thickness direction (the left-right direction in FIG. 3) of each sprag 47. The garter spring 50 has elasticity in a direction of shortening the entire length, and a contact portion between the garter spring 50 and the bottom surface of each of the engagement grooves 49 is formed by an outer peripheral surface of the sprag 47 and an outer peripheral surface of the sleeve 8a. With respect to point C where
The part where the outer peripheral surface of the sprag 47 abuts on the inner peripheral surface of the driven pulley 7c is on the opposite side in the circumferential direction. Therefore, the garter spring 50 elastically urges the sprags 47 in a direction in which the outer peripheral surface of each sprag 47 and the inner peripheral surface of the driven pulley 7c abut.

The pulley device with a built-in one-way clutch for an alternator and the pulley device with a built-in one-way clutch for an alternator obtained by the method of assembling the driven pulley 7c by the one-way clutch 18a are constructed as described above. Only the rotational force in a predetermined direction from the shaft to the sleeve 8a can be transmitted. Specifically, the transmission of the rotational force is performed by frictionally engaging the outer peripheral surfaces of the plurality of sprags 47 with the inner peripheral surface of the driven pulley 7c and the outer peripheral surface of the sleeve 8a, each of which is a cylindrical surface. Do. When the angular speed of the engine crankshaft fluctuates greatly, the outer peripheral surface of each sprag 47 and the driven pulley
The frictional force between the inner peripheral surface of the sleeve 8a and the outer peripheral surface of the sleeve 8a is reduced or lost, so that the sleeve 8a idles and releases the inertial mass of the alternator 1 (FIG. 5). The endless belt stretched over the driven pulley 7c and the driven pulley 7
c prevents the contact portion of the endless belt with the outer peripheral surface from strongly rubbing against each other, thereby preventing slippage between the endless belt and the driven pulley 7c or shortening of the life of the endless belt. . On the other hand, when the angular velocity increases again and the relative rotational speed between the sleeve 8a and the driven pulley 7c becomes zero, the outer peripheral surface of each sprag 47 becomes the inner peripheral surface of the driven pulley 7c and the sleeve. The outer peripheral surface of the endless belt 8a is frictionally engaged with the outer peripheral surface of the sleeve 8a (meshing with both peripheral surfaces), and the power of the endless belt is transmitted to the sleeve 8a again. The sprags 47 constituting the one-way clutch 18a may have various shapes depending on the magnitude of the torque to be transmitted.

In particular, in the case of the pulley device with a built-in one-way clutch for an alternator of the present invention of this invention and the pulley device with a built-in one-way clutch for an alternator obtained by the method of assembling the same, as in the case of the first embodiment described above. And a pair of support bearings 41a and 41b to be assembled are selected.
In other words, the driven pulley 7c and the sleeve 8a are divided into two parts according to the size of the fitting part into which the outer ring 43 and the inner ring 45 constituting the support bearings 41a and 41b are fitted. The representative driven pulley 7c and sleeve 8a are selected. Then, using the selected representative example of the driven pulley 7c and the sleeve 8a, the outer ring 43 and the inner ring 45 constituting the support bearings 41a and 41b are press-fitted into one end and the other end, respectively. Then, the outer raceway diameter of the outer race 43 and the inner raceway diameter of the inner race 45, and the contraction rate of the outer race 43 and the expansion rate of the inner race 45 at the time of press fitting are determined by measurement. In the illustrated example, since the thickness of the driven pulley 7c and the sleeve 8a is greater at one end than at the other end, the rigidity is greater at one end than at the other end. Therefore, when the outer race 43 and the inner race 45 are pressed into the driven pulley 7c and the sleeve 8a, respectively, the contraction rate of the outer race 43 and the expansion rate of the inner race 45 are larger at one end than at the other end.

The diameter of the outer raceway of the outer race 43 and the contraction rate of the outer race 43 when the outer race 43 is pressed into each driven pulley 7c of the representative example of each section, obtained by measuring as described above, From the range of the inner diameter of the driven pulley 7c in each section, the range of the outer ring raceway diameter of the outer ring 43 after press-fitting into one end and the other end of the driven pulley 7c is divided by the inner diameter. It is determined for each of the driven pulleys 7c.

Similarly, for each representative sleeve 8a in each section, the inner ring raceway diameter of the inner ring 45 when the inner ring 45 is press-fitted and the expansion rate of the inner ring 45, and the sleeve 8a in each section. From the outer diameter of the sleeve 8
The range of the inner ring raceway diameter of the inner ring 45 after press-fitting into one end and the other end of a is obtained for each of the sleeves 8a divided by the outer diameter.

The above-mentioned 1 to be assembled into a combination of the driven pulley 7c and the sleeve 8a, which are classified according to either the inner diameter or the outer diameter.
The pair of support bearings 41a and 41b are appropriately selected. Therefore, the range of the outer ring raceway diameter of the outer ring 43 after press-fitting into one end and the other end of the driven pulley 7c, which is obtained for the driven pulley 7c of each section, and the sleeve 8a of each section, I found this sleeve 8a
Considering the range of the inner ring raceway diameter of the inner ring 45 after press-fitting into the one end and the other end of the driven pulley 7c and the sleeve 8a, the one pair should be assembled to the one end and the other end of the driven pulley 7c and the sleeve 8a. The appropriate outer diameter of the balls 46a, 46b constituting the support bearings 41a, 41b is determined. However,
When using the support bearings 41a and 41b in which the inner ring 45, the outer ring 43, and the balls 46a and 46b are assembled in a separate process in advance, as described above, the balls 46a and 46b are set depending on the dimensions of the fitting portions of the driven pulley 7c and the sleeve 8a. It is not possible to determine an appropriate outer diameter of 46b. Therefore, in such a case, the outer ring 43 and the inner ring 45 are divided by the initial radial gap before the outer ring 43 and the inner ring 45 are fitted to the driven pulley 7c and the sleeve 8a. Driven pulleys 7 separated by size
c and the sleeve 8a are appropriately selected and combined. However, even in this case, it is necessary to know in advance the amount of decrease in the internal clearance in each of the support bearings 41a and 41b due to the fitting.

As described above, the contraction rate of the outer ring 43 and the expansion rate of the inner ring 45 are determined by the driven pulley 7c and the sleeve 8a.
At one end thereof is larger than the other end thereof.
In order to make the radial gap in a, 41b almost uniform,
By making the outer diameter of the ball 46a constituting one support bearing 41a smaller than the outer diameter of the other support bearing 41b, the radial gap in the one support bearing 41a in the free state can be reduced. It must be larger than the radial gap. After being assembled in the pulley device in this way, a pair of support bearings 41a, 4a
The radial gap in 1b is, for example, in the range of 0 to 25 μm, and the mutual difference between the radial gaps in the pair of support bearings 41a, 41b is in the range of 0 to 20 μm.

According to the pulley device with a built-in one-way clutch for the alternator ball bearing and the pulley device with the built-in one-way clutch for the alternator obtained by the method of assembling the alternator ball bearing and the pulley device with the built-in one-way clutch according to the present embodiment, a pair of pulley devices is manufactured after the production. Support bearing 4
The variation amount of the radial gap existing in 1a and 41b can be reduced. Therefore, the radial gap in these support bearings 41a, 41b is
8a, it is easy to make smaller than the radial gap in a state where it is assumed that the sprags 47 are not twisted, and it is difficult to cause seizure in the one-way clutch 18a.
The torque load capacity of the one-way clutch 18a can be sufficiently ensured, and the fatigue life of the one-way clutch 18a can be prevented from being shortened.

In the case of this example, each of the support bearings 4
By reducing the amount of variation in the radial gap in the pair of support bearings 41a, 41b, 41a, 41b.
The radial gap in b is made smaller than the radial gap in a state where each sprag 47 of the one-way clutch 18a is not twisted. On the other hand, by making the radial gap in the one-way clutch 18a sufficiently large, the radial gap in the pair of support bearings 41a and 41b can be made smaller than the radial gap in the one-way clutch 18a. Conceivable. However, if the radial gap in the one-way clutch 18a is made sufficiently large,
The torsion angle of each sprag 47 becomes large, and there is a possibility that seizure may occur easily in the one-way clutch 18a. This reason will be described next with reference to FIG.

[0057] That is, when the one-way clutch 18a is in overrun condition, the force acting on the sprags 47 from the garter spring 50 and P _50, the force of the P _8a acting on each sprag 47 from the outer peripheral surface of the sleeve 8a and then, a force acting from the inner peripheral surface of the driven pulley 7c to the sprags 47 and P _7c. Moreover, between the point C of the working point and the force P _8a of the force P _50, the distance over the tangential direction of the outer peripheral surface of the sleeve 8a in the action point C is set to L _1, the force P _7c The distance between the point of action and the point of action C of the force P _8a over the tangential direction of the outer peripheral surface of the sleeve 8a at the point of action C is represented by L _2.
And Balance between the force P ₅₀ and the force P _8a and the force P _7c, and from the moment balance at point C around the following two equations are obtained. P _8a = P ₅₀ + P _7c --- (1) P ₅₀ · L ₁ = P _7c · L _2- (2) Then, by eliminating P _7c from these equations (1) and (2), An expression is obtained. P _8a = (1 + L ₁ / L ₂ ) P ₅₀ --- (3)

Here, if the radial gaps are made sufficiently large on the assumption that the sprags 47 of the one-way clutch 18a are not twisted, the torsion angles of the sprags 47 become large, and as shown in FIG. to, the distance L ₁ is large, the distance L ₂ is decreased. However, even in this case, since the circumferential length of the garter spring 50 is hardly changed, the magnitude of the force P ₅₀ is considered to be substantially constant.

Therefore, as is apparent from the above equation (3),
The higher the radial clearance in the one direction clutch 18a, the force P _8a acting on each sprag 47 from the outer peripheral surface of the sleeve 8a is increased. In this case, the sprags 4 from the inner peripheral surface of the driven pulley 7c
The force P _7c acting on the pressure ₇ also increases. Therefore, when the radial clearance in the one-way clutch 18a is sufficiently increased, the force applied to each sprag 47 from the driven pulley 7c and the sleeve 8a increases, and the driven pulley 7c and the sleeve 8a Seizure is likely to occur between each sprag 47. For this reason, in the case of the present example, the dispersion of the radial gap in each of the support bearings 41a and 41b is suppressed to be small, so that the radial gap in the one-way clutch 18a is not increased and the support bearings 41a and 41b are not increased. Is made smaller than the radial gap in the one-way clutch 18a to prevent seizure in the one-way clutch 18a. Other configurations and operations are the same as those in the above-described first example, and therefore, the same parts are denoted by the same reference numerals and overlapping description will be omitted.

[0060]

The pulley apparatus with a built-in one-way clutch for an alternator and the method of assembling the same according to the present invention are constructed and operated as described above, so that the amount of variation in the radial gap existing in the support bearing after manufacture is reduced. Thus, seizure in the one-way clutch is less likely to occur, the torque load capacity of the one-way clutch can be sufficiently ensured, and the fatigue life of the one-way clutch can be prevented from being reduced.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

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

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a sectional view showing an example of a conventionally known alternator.

FIG. 6 is a cross-sectional view showing an example of a conventionally known pulley device with a built-in one-way 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, 7c Followed pulley 8, 8a Sleeve 9 Support bearing 10 One-way clutch 11 Endless belt 12 Cylindrical space 13 Outer ring 14 Inner ring 15 Rolling element 16 Female spline portion 17a, 17b Support bearing 18, 18a One-way clutch 19 Depressed groove 20 Inner ring for one-way clutch 21 Cam surface 22 Inner ring 23 Cylindrical portion 24 Inner ring side flange 25 Recess 26 Outer ring 27a, 27b Outer ring side flange 28 Cylindrical Gap 29 Roller 30, 30a Clutch retainer 31 Spring 32 Convex portion 33 Pocket 34 Column 35 Bearing retainer 36a, 36b Roller 37 Floating washer 38a, 38b Seal ring 39 Core metal 40 Elastic material 41a, 41b Support bearing 42 Outer ring Orbit 4 Outer 44 inner raceway 45 inner ring 46a, 46b ball 47 sprag 48 pocket 49 engaging groove 50 garter spring

Claims (4)

[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. Between the driven pulley and the sleeve only when the driven pulley tends to rotate relative to the sleeve in a predetermined direction. The one-way 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 one-way clutch is sandwiched from both sides in the axial direction, and is driven by these sleeves while supporting the radial load applied to the driven pulley. In a pulley device with a built-in one-way clutch for an alternator, the pulley device having a one-way clutch for an alternator having a support bearing capable of rotating relative to a pulley. On the inner peripheral surface of the moving pulley, an inner ring constituting each of the support bearings is fitted and fixed to an outer peripheral surface of the sleeve, respectively.The driven pulley and the sleeve form an outer ring and an inner ring constituting each of the support bearings. Each of the support bearings is divided into a plurality of types according to at least one of a diametrical dimension and rigidity of a fitting portion to be fitted, and each of the support bearings fits the outer ring and the inner ring with the driven pulley and the sleeve. It is divided into a plurality of types by the radial gap at the initial stage before the above, and each of the above-mentioned support bearings to be assembled to the divided driven pulley and the sleeve is selected and assembled to these driven pulleys and the sleeve. A one-way clutch built-in pulley device for alternators. 2. The degree of contraction of the outer ring in the diameter direction when an outer ring constituting each support bearing is fitted to a fitting portion of a driven pulley, and the inner ring constituting each support bearing is fitted to a fitting portion of a sleeve. By measuring the degree to which the inner ring expands in the diameter direction when fitted, the outer diameters of the plurality of rolling elements constituting each of the support bearings are determined based on the measured results, so that at least fitting is performed. The pulley device with a built-in one-way clutch for an alternator according to claim 1, wherein each of the divided support bearings to be assembled to the driven pulley and the sleeve, which is divided according to the rigidity of the portion, is selected. 3. A sleeve which can be externally fitted to and fixed to the rotating shaft of the 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. Between the driven pulley and the sleeve only when the driven pulley tends to rotate relative to the sleeve in a predetermined direction. The one-way 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 one-way clutch is sandwiched from both sides in the axial direction, and is driven by these sleeves while supporting the radial load applied to the driven pulley. A method of assembling a pulley device with a built-in one-way clutch for an alternator comprising a support bearing that allows relative rotation with a pulley, wherein the driven pulley and the sleeve are Each of the support bearings is divided into a plurality of types according to at least one of a diametrical dimension and a rigidity of a fitting portion for fitting the outer ring and the inner ring constituting each of the support bearings, and each of the support bearings is divided into the outer ring and the inner ring. Are divided into a plurality of types by an initial radial gap before being fitted to the driven pulley and the sleeve, and each of the divided support bearings to be assembled to the divided driven pulley and the sleeve is selected, and the driven pulley is selected. The outer ring that constitutes each of these support bearings on the inner peripheral surface of the inner ring that constitutes each of these support bearings on the outer peripheral surface of the sleeve,
A method for assembling a pulley device with a built-in one-way clutch for an alternator, wherein the pulley devices are fitted and fixed. 4. The degree of diametric contraction of the outer ring when the outer ring forming each support bearing is fitted to the fitting portion of the driven pulley, and the inner ring forming each support bearing is fitted to the fitting portion of the sleeve. By measuring the degree to which the inner ring expands in the diameter direction when fitted, the outer diameters of the plurality of rolling elements constituting each of the support bearings are determined based on the measured results, so that at least fitting is performed. The method for assembling a one-way clutch with built-in one-way clutch for an alternator according to claim 3, wherein each of the divided support bearings to be assembled to the driven pulley and the sleeve divided according to the rigidity of the portion is selected.