JP2000291785A - Pulley device with built-in one-way clutch for alternator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of a grease enclosed in a space installed a roller clutch to the outside through the fitting part of a bearing outer race and a driven pulley and the fitting part of a bearing inner race and a sleeve. SOLUTION: Bearing outer races 22, 22 are internally fitted and fixed to both ends of the inner periphery surface of a driven pulley 7a by tighteningly fitting. Respective bearing inner races 24, 24 are externally fitted and fixed to the outer periphery surface both ends of a sleeve 8 by tighteningly fitting respectively. Thereby, the generation of a clearance by which the grease can be passed to respective fitted part is prevented. At the same time, the generation of a creep at the fitted part of respective bearing inner races 24, 24 with the sleeve can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

Conventionally, the driven pulley 7 is generally
What was simply fixed to the rotating shaft 3 was used. On the other hand, in recent years, when the traveling speed of the endless belt is constant or increasing, transmission of power from the endless belt to the rotating shaft is freely performed, and when the traveling speed of the endless belt tends to decrease, Various pulley devices with a built-in one-way clutch for alternators, which make the relative rotation between the driven pulley and the rotary shaft freely, have been proposed and used in part. For example, JP-A-56-101353, JP-A-7-3
No. 17807, No. 8-61443, No. 8-2
Japanese Patent Publication No. 26462, Japanese Patent Publication No. 7-72585, French Patent Publication FR2726059A1, and the like describe a pulley device with a built-in one-way clutch for an alternator having the above-described functions.

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

The reasons for using the pulley device with a built-in one-way clutch for an alternator as described above are as follows. For example, when the driving engine is a diesel engine, the rotation angular speed of the crankshaft greatly fluctuates during low rotation such as during idling. As a result, the running speed of the endless belt (not shown), which runs over the drive pulley fixed to the end of the crankshaft, also fluctuates finely. On the other hand, the rotating shaft 3 of the alternator 1, which is rotationally driven by the endless belt via a driven pulley, is connected to the rotating shaft 3 and the inertial mass of the rotor 5 and the commutator 6 (FIG. 4) fixed to the rotating shaft 3. And does not fluctuate so rapidly. Therefore, when the driven pulley is simply fixed to the rotating shaft 3, the inner peripheral surface of the endless belt and the outer peripheral surface of the driven pulley tend to rub in both directions due to a change in the rotational angular velocity of the crankshaft. As a result,
Stresses in different directions are repeatedly applied to the endless belt that rubs with the driven pulley, causing slippage between the endless belt and the driven pulley, or shortening the life of the endless belt. Becomes The reduction in the life of the endless belt due to the friction between the outer peripheral surface of the driven pulley and the inner peripheral surface of the endless belt also occurs due to repeated acceleration and deceleration during traveling.

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

Conventionally, as a pair of support bearings constituting a pulley device with a built-in one-way clutch for an alternator as described above, an outer ring and an inner ring are relatively rotatably combined via a plurality of rolling elements. The use of conventional radial rolling bearings has been practiced. When such a radial rolling bearing is assembled to a pulley device incorporating a one-way clutch for an alternator, the outer ring is fitted inside both ends of the inner peripheral surface of the driven pulley, and the inner ring is attached to the outer peripheral surface of the sleeve described above. Fit externally on both ends. In this case, conventionally, the inner ring was fitted and fixed to the outer peripheral surface of the sleeve by interference fit, and the outer ring was fitted to the inner peripheral surface of the driven pulley by a clearance fit. Or, conversely, the inner ring is fitted to the outer peripheral surface of the sleeve by a clearance fit, and the outer ring is fitted and fixed to the inner peripheral surface of the driven pulley by interference fit.

The reason for adopting such an assembling method is to reduce the amount of change in the internal clearance in the radial direction of the radial rolling bearing before and after assembling (the amount of decrease after assembling). That is, by adopting the above-described assembling method, a normal initial clearance (a radial internal clearance before assembling) is obtained as the pair of support bearings.
A general-purpose radial rolling bearing having the following characteristics can be used. In addition, as described above, one of the inner races and the outer race is an interference fit, and the other race is a clearance fit. This is because it is difficult to incorporate the support bearings without applying a load to a plurality of rolling elements of the support bearings so that the rolling elements do not make indentations on the raceway surfaces.

For example, in the case of the structure described in Japanese Patent Application Laid-Open No. 11-63026, radial ball bearings are used as a pair of support bearings, and the inner races forming these radial ball bearings are connected to the outer periphery of the sleeve. The outer ring is similarly fitted and fixed to both ends of the driven pulley by clearance fit at both ends of the driven pulley. Furthermore, in the case of the structure described in this publication, the inner peripheral surface of the driven pulley
By providing a pair of step surfaces that are close to and opposed to one end surface of each of the outer rings, one end surface of each of these outer rings can abut against each of the step surfaces when the outer rings try to displace in the axial direction during operation. This prevents the outer ring from being displaced in the axial direction.

On the other hand, Japanese Patent Application Laid-Open No. 8-317599 discloses an inner ring constituting each radial ball bearing which is a support bearing, contrary to the structure described in Japanese Patent Application Laid-Open No. 11-63026. A structure is described in which the outer ring is externally fitted to the outer peripheral surface of the sleeve with a clearance fit, and the outer ring is internally fitted and fixed to the inner peripheral surface of the driven pulley by interference fit. Further, Japanese Patent Application Laid-Open No. Hei 8-
In the case of the structure described in Japanese Patent Publication No. 317599, a flange provided at one end of the sleeve and a washer provided at the other end are used.
When the inner rings of the support bearings are to be displaced in the axial direction during operation, one end surface of each of the inner rings is abutted against the flange or the washer to prevent the inner rings from being displaced in the axial direction. .

[0011]

As described above, in the case of a conventional pulley device with a built-in one-way clutch for an alternator, the outer races constituting each pair of support bearings and the radial rolling bearings are connected to the driven pulleys. Since the inner peripheral surface is fitted with a clearance fit, a minute clearance is generated at this fitting portion. One end in the axial direction of each of the minute gaps communicates with a space in which a one-way clutch is installed, and the other end in the axial direction communicates with an external space. For this reason, there is a possibility that the lubricating grease sealed in the space where the one-way clutch is installed leaks outside through each of the minute gaps.

In particular, the rotation speed of the pulley device with a built-in one-way clutch for an alternator, which is an object of the present invention, reaches a maximum of about 20,000 rpm. For this reason, a large centrifugal force is applied to the grease sealed in the space in which the one-way clutch is installed, and this grease is gathered to the outer diameter side portion in the space, and the pressure tends to increase in this portion. . On the other hand, one end of the minute gap generated between the outer peripheral surface of the outer ring and the inner peripheral surface of the driven pulley among the minute gaps generated in each of the fitting portions is an outer diameter of a space in which the one-way clutch is installed. Lead to the side. Therefore, the above-mentioned Japanese Patent Application Laid-Open No.
In the case of a structure in which the outer ring is internally fitted to the inner peripheral surface of the driven pulley with a clearance fit as in the structure described in JP-A-63026, the outer ring is gathered at the outer diameter side portion of the space as described above. The possibility that the grease whose pressure has increased in this portion leaks outside through the fitting portion between the outer ring and the driven pulley increases.

When the grease in the space in which the one-way clutch is installed leaks to the outside as described above, the amount of grease in this space decreases, and the sliding contact between the members constituting the one-way clutch is sufficiently reduced. Cannot be lubricated. Because of this,
At the time of overrun (unlocked) for relatively rotating the driven pulley and the sleeve, frictional heat generated in a sliding contact portion between the members constituting the one-way clutch increases,
The grease may be thermally degraded early and the durability of the one-way clutch may be impaired.

On the other hand, in the case of the structure described in the above-mentioned Japanese Patent Application Laid-Open No. 8-317599, a small diameter portion is formed as a gap by fitting the inner race to the outer peripheral surface of the sleeve with a gap. In addition, the centrifugal force acting on the grease is reduced, and the leakage of the grease is small as compared with the structure described in JP-A-11-63026, in which the outer peripheral surface of the outer ring and the inner peripheral surface of the sleeve are fitted with a gap. Is improved,
It is not yet possible to sufficiently prevent leakage. Further, in the case of the structure described in Japanese Patent Application Laid-Open No. 8-317599, the fitting surface between the inner peripheral surface of each inner ring and the outer peripheral surface of the sleeve may be abnormally worn. That is, when the engine is stopped, the pulley stops instantaneously, while the sleeve tries to continue rotation due to the inertia of the alternator.
As a result, creep (relative sliding) occurs at the fitting portion between the inner peripheral surface of each inner ring and the outer peripheral surface of the sleeve. If such creep is repeated every time the engine is stopped, the fitting surface is abnormally worn. For this reason, Japanese Patent Application Laid-Open
In the case of the structure described in JP-A-317599, not only the durability of the one-way clutch may be impaired due to the leakage of grease, but also the inner peripheral surface of each of the inner rings and the outer peripheral surface of the sleeve may be damaged. Due to the creep of the fitting surface, the durability of each of the support bearings may be impaired at an early stage. The pulley device with a built-in one-way clutch for an alternator of the present invention was invented in view of the above-mentioned circumstances.

[0015]

The pulley apparatus with a built-in one-way clutch for an alternator according to the present invention has a sleeve which can be externally fitted and fixed to the rotating shaft of the alternator, and has a sleeve around the sleeve. A driven pulley concentric with the sleeve is provided between an axially intermediate portion of the outer peripheral surface of the sleeve and an axially intermediate portion of the inner peripheral surface of the driven pulley, and the driven pulley is positioned relative to the sleeve in a predetermined direction. A one-way clutch that allows the transmission of rotational force between these driven pulleys and the sleeve only when it tends to rotate, and an outer circumferential surface of the sleeve at a position sandwiching the one-way clutch from both axial sides. A pair of support members provided between the inner peripheral surface of the driven pulley and supporting the radial load applied to the driven pulley and allowing relative rotation between the sleeve and the driven pulley. And a door bearing. Each of these support bearings has an outer raceway on the inner peripheral surface, and is fitted inside the inner peripheral surface of the driven pulley. The outer race for bearing is separate from the outer race of the one-way clutch. The bearing includes a bearing inner race having a raceway and externally fitted on the outer peripheral surface of the sleeve, and a plurality of rolling elements rotatably provided between the outer raceway and the inner raceway. In particular, in the pulley device with a built-in one-way clutch for an alternator of the present invention, each of the bearing inner rings is externally fitted and fixed to the outer peripheral surface of the sleeve by interference fit, and each of the bearing outer rings is fixed to the driven pulley by the driven pulley. It is internally fitted and fixed to the inner peripheral surface by interference fit. More preferably, as described in claim 2, the force required for fitting each bearing outer ring to the driven pulley is equal to or less than the force required for fitting the outer ring of the one-way clutch to the driven pulley. .

[0016]

In the pulley device with a built-in one-way clutch for an alternator of the present invention constructed as described above, between the inner peripheral surface of each bearing inner race and the outer peripheral surface of the sleeve, and the outer periphery of each bearing outer race. There is no gap between the surface and the inner peripheral surface of the driven pulley such that grease can pass therethrough. In particular, even during operation, a large centrifugal force is applied to the grease sealed in the space where the one-way clutch is installed, and this grease is gathered at the outer diameter side portion of this space and the pressure increases in this portion. This grease does not leak outside through the space between the outer peripheral surface of each bearing outer ring and the inner peripheral surface of the driven pulley. Therefore, the amount of grease in the space where the one-way clutch is installed does not decrease, and the sliding contact between the members constituting the one-way clutch can be sufficiently lubricated. For this reason, the frictional heat generated in the sliding contact portion at the time of overrun is suppressed to a small extent, thereby preventing the grease from being thermally deteriorated at an early stage, and sufficiently ensuring the durability of the one-way clutch.

Further, since each of the bearing inner rings is fitted and fixed to the outer peripheral surface of the sleeve by interference fit, when the engine is stopped, the inner peripheral surface of each of the bearing inner rings and the outer peripheral surface of the sleeve are connected. No creep occurs at the fitting part. For this reason, abnormal wear is prevented from occurring at each of these fitting parts,
The durability of each of the above support bearings can be sufficiently ensured. Furthermore, as described in claim 2, if the force required to fit each outer ring for bearing into the driven pulley is set to be equal to or less than the force required to fit the outer ring of the one-way clutch to this driven pulley,
When incorporating each support bearing between the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve, without applying an excessive load to the rolling elements of these support bearings, the driven pulley and the sleeve While regulating the axial position of
Each of the above support bearings can be incorporated. Therefore, at the time of assembling, the rolling elements of these support bearings can prevent the support bearings from being damaged, such as making an indentation on each raceway surface.

[0018]

FIG. 1 shows a first embodiment of the present invention. The pulley device with a built-in one-way clutch for an alternator of the present embodiment has a sleeve 8 which can be fitted and fixed to the rotating shaft 3 of the alternator 1 (see FIG. 4). Further, a driven pulley 7 a is arranged around the sleeve 8 concentrically with the sleeve 8. A pair of support bearings 9, 9 and a roller clutch 10, which is a one-way clutch, are provided between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a.

The sleeve 8 is formed in a cylindrical shape as a whole. The sleeve 8 is externally fitted and fixed to an end of the rotating shaft 3 of the alternator 1 and is rotatable together with the rotating shaft 3. For this reason, in the illustrated example, a screw hole 11 is formed in the inner peripheral surface of the intermediate portion of the sleeve 8, and the screw hole 11 and a male screw portion provided on the outer peripheral surface of the tip of the rotating shaft 3 can be screwed freely. And
A locking hole 12 having a hexagonal cross section is formed on the inner peripheral surface of the distal end portion of the sleeve 8.
The tip of a tool such as a hexagon wrench can be freely locked. Further, the inner peripheral surface of the base end portion of the sleeve 8 is a cylindrical surface 33 that can be fitted to the middle portion of the rotary shaft 3 near the front end without rattling. Note that the structure in which the sleeve 8 and the rotating shaft 3 are combined so as not to rotate relative to each other may employ other structures such as spline engagement, non-circular engagement, and key engagement. At the center of the outer peripheral surface of the sleeve 8, a convex portion 13 projecting diametrically outward from the outer peripheral surface is formed over the entire periphery.

On the other hand, one half of the driven pulley 7a (FIG. 1)
The outer peripheral surface has a cross-sectional shape extending in the width direction as a waveform, and a part of an endless belt called a poly-V belt can be freely passed over. The inner peripheral surface of the driven pulley 7a is a simple cylindrical surface. Then, the sleeve 8
The roller clutch 10 is provided at an axially intermediate portion of a space existing between the outer peripheral surface of the driven pulley 7a and the inner peripheral surface of the driven pulley 7a.
The roller clutch 1 is also provided at both axial ends of this space.
0 at the position sandwiching the support bearing 9 from both sides in the axial direction.
9 are arranged respectively.

The roller clutch 10 transmits the rotational force between the driven pulley 7a and the sleeve 8 only when the driven pulley 7a tends to rotate relative to the sleeve 8 in a predetermined direction. Be free. In order to constitute such a roller clutch 10, the roller clutch inner ring 14 is externally fitted and fixed to the convex portion 13 formed on the outer peripheral surface of the sleeve 8 by interference fitting. The inner ring 14 for the roller clutch is formed entirely into a cylindrical shape by subjecting a steel plate such as carburized steel to plastic working such as press working, and has a cam surface 15 formed on the outer peripheral surface. That is, a plurality of concave portions 16 called ramps are formed on the outer peripheral surface of the roller clutch inner ring 14 at equal intervals in the circumferential direction, so that the outer peripheral surface is the cam surface 15.

On the other hand, of the inner peripheral surface of the outer ring 17 for the roller clutch fixed to the inner peripheral surface of the intermediate portion of the driven pulley 7a by interference fit, at least the axial intermediate portion which comes into contact with the roller 19 described below. Is simply a cylindrical surface. The outer ring 17 for such a roller clutch is also formed in a cylindrical shape by subjecting a steel plate such as carburized steel to plastic working such as press working, and has inward flange-like flanges 18a and 18b at both axial ends. Is formed. In addition, the above both flange portions 1
8a, 18b, one (left side in FIG. 1) flange 18a
Is formed in advance at the time of manufacturing the roller clutch outer ring 17, so that it has a thickness equivalent to the cylindrical portion of the roller clutch outer ring 17. On the other hand, the other (rightward in FIG. 1) flange portion 18b is formed by incorporating a roller 19 and a clutch retainer 20, which will be described later, inside the roller clutch outer ring 17 in the diameter direction. It is thin.

A plurality of rollers 19 constituting the roller clutch 10 together with the roller clutch inner ring 14 and the roller clutch outer ring 17 cause the roller clutch inner ring 14 to rotate with respect to the roller clutch inner ring 14. It is supported by a synthetic resin clutch retainer 20 fitted externally as being impossible so as to be able to freely roll and slightly displace in the circumferential direction. A spring such as a leaf spring or a synthetic resin spring integrated with the clutch retainer 19 is provided between the column provided on the clutch retainer 20 and each of the rollers 19. 19 is elastically pressed in the same direction with respect to the circumferential direction. Further, in the state shown in the drawing, both axial end surfaces of the clutch retainer 20 are brought into close proximity to the inner side surfaces of both flange portions 18a and 18b constituting the roller clutch outer ring 17, and the clutch retainer 20 is formed. Prevents axial displacement. Since the basic structure and operation of such a roller clutch 10 are well known in the related art, further detailed illustration and description will be omitted.

The support bearings 9, 9 support the radial load applied to the driven pulley 7a, and allow the driven pulley 7a and the sleeve 8 to rotate relative to each other. In the case of this example, as each of the above support bearings 9,
Uses deep groove ball bearings. That is, each of these support bearings 9, 9 has a deep groove type outer raceway 2 on its inner peripheral surface.
Bearing outer races 22 and 22 having bearings 1 and 21, bearing inner races 24 and 24 having deep groove type inner races 23 and 23 on the respective outer peripheral surfaces, and the outer races 21 and 21 and the inner race 2
3 and 23, each of which is provided with a plurality of rolling elements, each of which is provided with a plurality of rolling elements. Further, locking grooves 2 formed on the inner peripheral surfaces of both ends of the outer rings 22 for bearings.
By attaching seal rings 27, 27 to 6, 26, respectively, spaces 28, in which the respective balls 25, 25 are installed,
28 are closed at both ends.

When assembling such support bearings 9, 9 between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a, the roller clutch 10 is sandwiched from both axial sides. The bearing inner rings 24, 24 are externally fitted and fixed to the both ends of the outer peripheral surface of the sleeve 8 by interference fitting, and the respective bearing outer rings 22, 22 are located at both ends of the inner peripheral surface of the driven pulley 7a. Then, the inner fitting is fixed by interference fitting. In the case of this example, the dimensional tolerance of the outer peripheral surface of the sleeve 8 is set to n6 specified in JIS, and the interference of each of the bearing inner rings 24, 24 with respect to this outer peripheral surface is set to about 15 to 30 μm. And the dimensional tolerance of the inner peripheral surface of the driven pulley 7a
, And the interference of the bearing outer rings 22, 22 with respect to the inner peripheral surface is set to about 5 to 30 μm.

The lower limit of the interference between the bearing inner rings 24, 24 and the sleeve 8 is determined by the bearing outer ring 2
The lower limit of the interference between the driven pulleys 2 and 22 and the driven pulley 7a is set to be larger than the lower limit. The reason is that when the engine is stopped, the driven pulley 7a, which has an endless belt stretched between the driven pulley fixed to the end of the crankshaft of the engine and the driven pulley, stops instantaneously, whereas the sleeve 8 This is because the rotation of the alternator is intended to continue due to inertia. That is, in such a state, each of the bearing inner rings 24,
Since there is a high possibility that creep will occur at the fitting surface between the inner peripheral surface of the sleeve 24 and the outer peripheral surface of the sleeve 8, the lower limit of the interference of this fitting surface portion is set to a large value to reduce the occurrence of the creep. This is to prevent it. In the assembled state shown in the figure, the internal clearance in the radial direction of each of the support bearings 9 is set to an appropriate value (about 5 to 30 μm). That is, in consideration of the amount of change (decrease) in the radial internal gap of each of the support bearings 9 before and after the assembling, the radial internal gap of each of the support bearings 9 before the assembling is considered. The initial gap is set to a relatively large value of about 50 μm (40 to 60 μm).
Further, in the illustrated example, one end surfaces of the bearing inner rings 24, 24 abut against step surfaces existing at both axial ends of the projection 13, respectively.

Further, with the support bearings 9 and 9 assembled as described above, the roller clutch 10 is engaged with the intermediate portion of the inner peripheral surface of the driven pulley 7a and the intermediate portion of the outer peripheral surface of the sleeve 8. Openings at both ends of the installed space 29 are formed by a pair of seal rings 2 attached to the support bearings 9 and 9 described above.
Of the seals 7, 27, the seal rings 27, 27 on the roller clutch 10 side are densely closed. Lubricating grease is sealed in the spaces 28, 28 in which the balls 25, 25 constituting the support bearings 9, 9 are installed, and in the space 29 in which the roller clutch 10 is installed. In particular, in the case of this example, the amount of grease sealed in the space 29 in which the roller clutch 10 is installed is determined by the lower limit grease amount for sufficiently lubricating the roller clutch 10 and suppressing the heat generation during operation, and The upper limit grease amount for preventing the seal rings 27 of the ball bearing from turning over due to an increase in internal pressure at the time of the above-mentioned operation.
60-80% of the volume of the hollow part.

The outer surfaces of the flanges 18a, 18b formed at both ends of the outer ring 17 for the roller clutch, and the outer rings 22 for the bearings of the support bearings 9, 9 are opposed to each other. Of the gap between the end face in the axial direction,
The thickness in the axial direction is restricted to 1 mm or less. The reason for this is to suppress a decrease in the amount of grease in the roller clutch 10. That is, according to an experiment conducted by the inventor, when the roller clutch 10 is overrun, the grease sealed in the roller clutch 10 is agitated by the roller 19 and the like, and a part of the grease is formed by the roller clutch outer ring 17. Flange portions 18a formed at both ends,
It scatters to the outside of 18b. In this way, each flange 18
The grease scattered to the outside of a and 18b enters each of the gaps due to centrifugal force acting during operation and does not return into the roller clutch 10. For this reason, if the volume of each of these gaps is large (thickness in the axial direction exceeds 1 mm), the amount of grease in the roller clutch 10 significantly decreases due to long-term operation, resulting in insufficient lubrication. The roller clutch 10 may be easily seized due to heat generation.
It is difficult to ensure the durability of the tire. On the other hand, if the thickness of the gap in the axial direction is 1 mm or less, the flange 1
There is no place for receiving the grease scattered outside of the roller clutches 8a and 18b, and the grease is easily returned to the inside of the roller clutch 10 (furthermore, it becomes difficult to scatter the grease outside the flange portions 18a and 18b). The durability of the clutch 10 can be easily secured.

As described above, in the case of the pulley device with a built-in one-way clutch for the alternator of the present embodiment, the bearing inner rings 24, 24 constituting the pair of support bearings 9, 9 are fastened to the outer peripheral surface of the sleeve 8. The outer rings 22 and 22 for bearings are similarly fixed to the inner peripheral surface of the driven pulley 7a by interference fit. Therefore, between the inner peripheral surfaces of the bearing inner rings 24, 24 and the outer peripheral surface of the sleeve 8, and between the outer peripheral surfaces of the bearing outer rings 22, 22 and the inner peripheral surface of the driven pulley 7a. In addition, there is no gap that allows grease to pass through.

In particular, during operation, a large centrifugal force is applied to the grease sealed in the space 29 in which the roller clutch 10 is installed, and this grease is gathered on the outer diameter side of the space 29 to increase the pressure. However, the grease does not leak to the outside from between the outer peripheral surfaces of the bearing outer rings 22 and 22 and the inner peripheral surface of the driven pulley 7a. Therefore, the grease in the space 29 does not decrease,
The sliding portion between the members constituting the roller clutch 10 can be sufficiently lubricated. For this reason, the frictional heat generated in the sliding contact portion at the time of overrun is suppressed to a small extent, so that the grease is prevented from being thermally deteriorated at an early stage, and sufficient durability of the roller clutch 10 can be ensured.

When the roller clutch outer ring 17 and the bearing outer rings 22 and 22 are press-fitted into the driven pulley 7a so as to be fitted and fixed in the driven pulley 7a, each of the peripheral rings fitted to each other is fitted. It is important that the surface be free from incorporation flaws (axial scratches). What happens
If such a built-in flaw occurs, a minute gap is formed in the fitting portion in the axial direction, and the grease may leak through the gap. Therefore, in order to prevent the above-mentioned incorporation flaws from occurring, the peripheral edges of both ends of the inner peripheral surface of the driven pulley 7a, or both ends of the outer peripheral surfaces of the outer ring 17 for the roller clutch and the outer rings 22, 22 for the bearings. It is preferable to provide sufficient chamfers and guides on the periphery. At the same time, of the inner peripheral surface of the driven pulley 7a, in particular, the roller clutch outer ring 17 and each bearing outer ring 2
It is preferable that the surface hardness of the fitting portion between the fitting portions 2 and 22 is Hv250 or more (more preferably, Hv350 or more) so that the fitting portion withstands the stress based on the tight allowance.
Further, at the same time, the driven pulley 7 including the fitting portion
It is preferable that the arithmetic average roughness (at least of the fitting portion) of the inner peripheral surface of a is 1.6 Ra or less. Therefore, if it is difficult to reduce the arithmetic average roughness to 1.6 Ra or less by simple turning, the inner peripheral surface of the driven pulley 7a is subjected to finishing by grinding as necessary.

The driven pulley 7a and the sleeve 8
In order to regulate the position in the axial direction with respect to the arrangement conditions of the engine and the alternator, the constituent members must be incorporated. The reason is that the driven pulley 7a and the sleeve 8
If the axial position of the endless belt is deviated from an appropriate position determined by the arrangement conditions of the engine and the alternator and the endless belt bridged between the driven pulley 7a and the driving pulley becomes oblique, a uniform load is applied in the width direction of the endless belt. Is not loaded, and the endurance life of the endless belt is significantly reduced. Normally, in order to ensure the durability of the endless belt, it is necessary to limit the axial tolerance of the mounting position of the driven pulley 7a and the sleeve 8 to about 0.2 mm.

Therefore, each of the support bearings 9, between the inner peripheral surface of the driven pulley 7 a and the outer peripheral surface of the sleeve 8.
9 and the roller clutch 10 by regulating the axial position of the driven pulley 7a and the sleeve 8 without applying an excessive load to the balls 25, 25 constituting the support bearings 9, 9. The method of assembling will be described with reference to FIG. For the sake of explanation, it is assumed that there is a restriction of δ between one axial end surface of the driven pulley 7 a (right end surface in FIG. 1) and one axial end surface of the sleeve 8. I do.

First, the inner race 14 for the roller clutch constituting the roller clutch 10 is fitted to the convex portion 13 formed on the outer peripheral surface of the intermediate portion of the sleeve 8, and one end surface in the axial direction of the inner race 14 for the roller clutch {FIG. 2A, the upper end face of FIG. 2C and the lower end face の of FIG. The axial length of the roller clutch inner ring 14 is slightly shorter than the axial length of the projection 13. Accordingly, the roller clutch inner race 1
In the state where one axial end face of the roller 4 is assembled flush with the step of the projection 13, the other end face of the inner ring 14 for the roller clutch ク ラ ッ チ the lower end face in FIGS. 2 (A) and 2 (C) and the lower end face in FIG. The upper end surface｝ does not protrude from the other end surface of the convex portion 13.

Next, as shown in FIG. 2 (A), in order to regulate the axial position of the driven pulley 7a and the sleeve 8, the outer end of the driven pulley 7a is brought close to the outer diameter. The roller clutch 10 is constructed in a state in which the driven pulley 7a and the sleeve 8 are supported by the receiving jig 34 having a step of δ between the portion and the inner diameter portion where the axial end face of the sleeve 8 is brought into contact. The roller clutch outer ring 17 is pushed into the driven pulley 7 a by a jig 35. The pushing operation is performed by pressing the front end surface of the jig 35 against the flange portion 18a of the outer ring 17 for the roller clutch. There is a step on the tip surface of this jig 35,
In a state where the concave inner diameter side of the front end surface abuts the step surface of the convex portion 13, the roller clutch outer ring 1 is formed.
7 is press-fitted to a desired (designed) position. The press-fitting process of the roller clutch inner race 14 and the roller clutch outer race 17 may be performed simultaneously.

Next, as shown in FIG. 2B, a bearing outer ring 22 constituting one of the pair of support bearings 9, 9 is mounted on the pulley 7a, and similarly a bearing inner ring. 24 are simultaneously press-fitted into the sleeve 8 by a press-fitting jig 36 having a flat distal end surface. This press-fitting jig 3
Numeral 6 has a flat end face, and simultaneously presses the axial end face of the bearing outer race 22 and the axial end face of the bearing inner race 24.
No load is applied to 5. In addition, this press-fitting work
The process is performed until the inner end surface of the bearing inner ring 24 abuts on the step of the convex portion 13 formed on the outer peripheral surface of the intermediate portion of the sleeve 8. In this press-fitting operation, the jig 35 is turned over together with the pulley 7a and the sleeve 8 and used as a receiving jig. In this press-fitting operation, the jig 35 functioning as a receiving jig does not directly support the driven pulley 7a, but indirectly connects the driven pulley 7a with the flange portion 18a of the outer ring 17 for the roller clutch. I support it. The pressure input of the roller clutch outer ring 17 to the driven pulley 7a is about 200 to 500 kgf, while the pressure input of the bearing outer ring 22 to the driven pulley 7a is
It is about 0 kgf. Therefore, even if the driven pulley 7a is supported via the roller clutch outer ring 17 as described above, the driven pulley 7a does not move relative to the sleeve 8 in the axial direction. The deviation between the axial end surfaces of the sleeve 8 and the sleeve 8 is maintained at the value of δ.

When the present invention is practiced, preferably, the safety factor is twice or more ｛(条件) with respect to the condition in which the fitting portion of the roller clutch outer ring 17 to the driven pulley 7a does not move when the support bearing 9 is press-fitted. Force for fitting roller clutch outer ring 17 inside driven pulley 7a / (driven pulley 7a)
(The force for internally fitting the bearing outer ring 22) ≧ 2 °, and a design with a margin is adopted. In order to increase the pressure input of the roller clutch outer ring 17 to the driven pulley 7a for such a purpose, for example, the interference between the fitting portions of the two members 7a and 17 is set to 0.07 to 0. The value is about 14 mm. With such a firm fit, the driven pulley 7
When the outer ring 22 for bearing is press-fitted into the inside of the outer ring 17a, not only the fitting portion between the driven pulley 7a and the outer ring 17 for roller clutch does not move, but also the driven pulley 7a during operation.
Even if a large torque is applied between the driven pulley 7a and the outer ring 17 for the roller clutch, even when a large torque is applied between the driven pulley 7a and the outer ring 17 for the roller clutch, a large torque can be transmitted.

As described above, the reason that the driven pulley 7a is not directly supported by the receiving jig is irrespective of the difference between the driven pulley 7a and the sleeve 8 in the axial direction. This is for restricting the positional relationship between the shafts 8 in the axial direction with sufficient accuracy. That is, these two members 7
The axial dimensions of a and 8 are slightly different for each product even with the same model number due to unavoidable errors in manufacturing. Therefore, a pair of support bearings 9 on both sides of the roller clutch 10 are provided.
When the driven pulley 7a and the sleeve 8 are turned over to assemble the shaft 9, the axial end faces of the two members 7a and 8 are brought into contact at the same time (in the axial direction of the two members 7a and 8). Jigs that support the end face)
This is because it cannot actually be built.

When the support bearing 9 is press-fitted by using a receiving jig that does not simultaneously contact the axial end surfaces of the two members 7a and 8 such as the receiving jig that only contacts the axial end surface of the driven pulley 7a. , The bearing inner ring 24 of the support bearing 9
When the inner end surface of the sleeve 8 comes into contact with the stepped surface of the convex portion 13 formed on the outer peripheral surface of the intermediate portion of the sleeve 8, the sleeve 8 is subjected to an axial load by the excessively large load applied to the sleeve 8. Move until it hits the tool. As a result, the deviation between the axial end face of the driven pulley 7a and the axial end face of the sleeve 8 regulated in the first step described above deviates from the desired value δ. Even if the displacement is corrected in the next step, the relative position between the driven pulley 7a and the sleeve 8 cannot be shifted without applying a load to the balls 25, 25 of the support bearing 9. For this reason, there is a possibility that indentations are made on the outer raceway 21 and the inner raceway 23 by the balls 25, 25. Thus, as described above, the driven pulley 7a is not directly supported by the receiving jig. When the outer ring 22 for bearing is press-fitted into the driven pulley 7a, the outer ring 22 for bearing is press-fitted so that the press-fitting operation can be performed smoothly and smoothly without excessive force input. Driven pulley 7a serving as an entrance to
It is preferable that a sufficient chamfer or a guide portion is provided at the edge of the inner peripheral surface.

If one of the support bearings 9 is press-fitted between the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the sleeve 8 as described above, then, as shown in FIG. Then, after the driven sleeve 7a and the sleeve 8 are inverted, the driven pulley 7 is again
a and the sleeve 8 are supported. Since the shift amount δ between the axial end surface of the driven pulley 7a and the axial end surface of the sleeve 8 is maintained in the previous process, the receiving jig 34 is also used in the process shown in FIG. 7a and the axial end surface of the sleeve 8 simultaneously. Therefore, the press-fitting jig 36 used in the previous step shown in FIG.
The inner ring for the bearing that constitutes the other support bearing 9 so as not to apply a load to the balls 25, 25 in the same manner as when the one support bearing 9 is press-fitted. The outer race 22 for bearing and the inner race 24 for bearing are simultaneously pushed until the inner end face of 24 abuts the step of the convex portion 13 formed on the outer peripheral surface of the intermediate portion of the sleeve 8. In this step, since the press-fitting operation is performed without relatively displacing the driven pulley 7a and the sleeve 8 relative to each other, the balls 25, 2 of one of the support bearings 9 previously press-fitted in the previous step.
No excessive load is applied to 5.

As described above, each of the support bearings 9, 9
When the axial ends of the bearing outer ring 22 and the bearing inner ring 24 are flush with each other and press-fitted into the driven pulley 7a and the sleeve 8 simultaneously with an interference, the bearing outer ring 22 The width of the bearing inner ring 24 is not the same as that of the bearing outer ring 22 and the bearing inner ring 24.
Depending on the size of the interference between the fitting and the driven pulley 7a and the sleeve 8, and the size of the radial gap between the support bearings 9, 9, a preload may be applied to the support bearings 9, 9. . Therefore, it is necessary to study in detail to set a condition in which no preload is applied to each of the support bearings 9 or a condition in which even if the preload is applied, a large preload is not applied. In the above process,
Although a pair of support bearings 9 and 9 were sequentially pressed one by one,
With the driven pulley 7a and the sleeve 8 fixed,
It is also possible to press-fit a pair of support bearings 9 between the driven pulley 7a and the sleeve 8 at the same time.

FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of the present example, a female spline portion 30 is formed at a portion of the inner peripheral surface of the sleeve 8a closer to one side (a portion closer to the left in FIG. 3). The female spline portion 30 and a male spline portion (not shown) formed on the outer peripheral surface of the end of the rotating shaft 3 (FIG. 4) are freely engageable. The outer peripheral surface of the sleeve 8a is a simple cylindrical surface over the entire length. The roller clutch inner race 14 is externally fixed to the outer peripheral surface of the intermediate portion of the sleeve 8a by interference fit.
Further, an outer sleeve 31 is provided on the inner peripheral surface of the driven pulley 7b.
Are internally fitted and fixed by interference fit. The outer diameter side sleeve 31 is formed entirely of a hard metal such as bearing steel into a cylindrical shape, and has a convex portion 3 projecting inward in the diameter direction on the inner peripheral surface of the intermediate portion.
2 is formed over the entire circumference. And this convex part 32
Is a cylindrical surface that forms a roller clutch mechanism together with a cam surface 15 formed on the outer peripheral surface of the roller clutch inner ring 14. That is, when the roller clutch 10a is locked, the plurality of rollers 19 constituting the roller clutch 10a are configured to project between the cam surface 15 and the inner peripheral surface of the convex portion 32.

The bearing outer races 22, 22 constituting the pair of support bearings 9, 9 are fixedly fitted to both ends in the axial direction of the outer diameter side sleeve 31 by interference fitting. One end surfaces of the projections 22 are abutted on step surfaces existing at both ends in the axial direction of the projection 32. still,
In the case of this example, if the interference of the fitting portion between the outer diameter side sleeve 31 and each of the bearing outer rings 22 is sufficiently increased, it is possible to prevent the fitting portion from moving in the axial direction. ,
It is not necessary to abut one end surface of each of the bearing outer rings 22, 22 against each of the step surfaces. Therefore, in this case, forming the convex portion 32 on the inner peripheral surface of the intermediate portion of the outer diameter side sleeve 31 is omitted, and the processing cost can be reduced.

In the case of this embodiment, each of the support bearings 9
Space 2 in which a plurality of balls 25, 25 constituting 9 are installed
Of the openings at both ends in the axial direction of the roller clutches 8 and 28, no seal ring is provided at the opening facing the roller clutch 10a.
The space 29 in which a is installed is communicated. Each of these spaces 2 is placed in the spaces 28 and 29 thus communicated.
About 70% (60-80%) of the volume of the cavities 8 and 29
Grease is enclosed.

Also in the case of the present embodiment constructed as described above, the bearing inner races 24 and 24 and the bearing outer races 22 and 22 constituting the pair of support bearings 9 and 9 are respectively connected to the sleeve 8a.
Are fitted and fixed to both ends of the outer peripheral surface of the outer diameter side and both ends of the inner peripheral surface of the outer diameter side sleeve 31 by interference fit. For this reason, there is no gap in each of these fitting portions enough to allow grease to pass. Therefore, also in the case of this example, each of the spaces 28, 2
The grease sealed in 9 can be prevented from leaking outside through each of the fitting portions.

In each of the above-described examples, the case where the low clutch is used as the one-way clutch has been described. However, the present invention has been known as a one-way clutch such as a cam clutch such as a sprag clutch. The same effect can be obtained even when a one-way clutch having another structure is used. Further, the pair of support bearings is not limited to the case where one pair of ball bearings is used, and the same applies to the case where one pair of roller bearings or ball bearings is used. The effect of is obtained.

[0047]

The pulley device with a built-in one-way clutch for an alternator according to the present invention is constructed and operates as described above, so that the grease sealed in the space where the one-way clutch is installed can be prevented from leaking outside. . For this reason, the frictional heat generated at the time of overrun is reduced, the deterioration of the grease is prevented, and the durability of the one-way clutch can be sufficiently ensured. In addition, it is possible to prevent the occurrence of creep at the fitting portion between the inner peripheral surface of the bearing inner ring and the outer peripheral surface of the sleeve which constitute each support bearing, and to sufficiently secure the durability of each of the support bearings.

[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 showing a method of assembling the one-way clutch built-in pulley device for an alternator according to the present invention in the order of steps.

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Alternator 2 Housing 3 Rotating shaft 4 Rolling bearing 5 Rotor 6 Commutator 7, 7a, 7b Followed pulley 8, 8a Sleeve 9 Support bearing 10, 10a Roller clutch 11 Screw hole part 12 Locking hole part 13 Convex part 14 For roller clutch Inner ring 15 Cam surface 16 Recess 17 Roller clutch outer ring 18a, 18b Flange 19 Roller 20 Clutch retainer 21 Outer ring raceway 22 Bearing outer ring 23 Inner ring raceway 24 Bearing inner ring 25 Ball 26 Lock groove 27 Seal ring 28 Space 29 Space Reference Signs List 30 female spline part 31 outer diameter side sleeve 32 convex part 33 cylindrical surface 34 receiving jig 35 jig 36 press fitting jig

Claims (2)

[Claims] 1. A sleeve which can be externally fitted and fixed to a rotating shaft of an alternator, a driven pulley disposed around the sleeve and concentric with the sleeve, an axially intermediate portion of an outer peripheral surface of the sleeve, and an inner periphery of the driven pulley. Provided between the driven pulley and the sleeve only when the driven pulley tends to rotate relative to the sleeve in a predetermined direction. A one-way clutch, provided between the outer peripheral surface of the sleeve and the inner peripheral surface of the driven pulley at a position sandwiching the one-way clutch from both sides in the axial direction, and supporting the radial load applied to the driven pulley with these sleeves. A pair of support bearings that allow relative rotation with the driven pulley, and each of the support bearings has an outer raceway on an inner peripheral surface and is fitted inside the inner peripheral surface of the driven pulley. A bearing outer race separate from the outer race of the one-way clutch, an inner raceway on the outer peripheral surface, and a bearing inner race fitted on the outer peripheral surface of the sleeve; and between the outer raceway and the inner raceway. In a pulley device with a built-in one-way clutch for an alternator, comprising a plurality of rolling elements rotatably provided on the outer peripheral surface of the bearing, the inner rings for bearings are externally fitted and fixed to the outer peripheral surface of the sleeve by interference fit. A pulley device with a built-in one-way clutch for an alternator, wherein each of the bearing outer rings is internally fitted and fixed to the inner peripheral surface of the driven pulley by interference fit. 2. The alternator according to claim 1, wherein the force required to fit each outer race for bearing inside the driven pulley is equal to or less than the force required to fit the outer race of the one-way clutch to the driven pulley. Pulley device with built-in one-way clutch.