JP2001032910A - Pulley device for alternator with built-in one-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent pressure in a space from becoming excessive and to prevent a seal lip of each of seal rings adjacent to this space by reducing compression quantity of air in the space sandwiched between each of support bearings to be compressed in accordance with assembly work of a pair of the support bearings. SOLUTION: A step part 15 to recessively enter from an inner peripheral surface is provided on a part adjacent to a fitting part of an outer ring 24 for a bearing to constitute one support bearing 9 on one end part in the axial direction of an inner peripheral surface of a driven pulley 7a. A part of air in a space 31 is discharged to an outer space through a part between an outer peripheral surface of the outer ring 24 for the bearing at the time of pushing the one support bearing 9 in it from one end opening part of the space existing between the inner peripheral surface of the aforementioned driven pulley 7a and the outer peripheral surface of the sleeve 8.

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. 2 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 (the right end in FIG. 2) 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 inertia masses of the rotor 5 and the commutator 6 (FIG. 2) 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, when the running speed of the endless belt is reduced, the rotating speed of the rotating shaft 3 is directly reduced, and the power generation amount of the alternator 1 is reduced. At the same time, the inner peripheral surface of the endless belt and the outer peripheral surface of the driven pulley tend to rub in both directions with the fluctuation of the rotational angular velocity of the crankshaft. As a result, stress is repeatedly applied to the endless belt that rubs with the driven pulley in different directions, so that slippage easily occurs between the endless belt and the driven pulley,
Alternatively, the life of the endless belt may be shortened. 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 At the same time, even when the rotational speed of the engine is reduced, the rotational speed of the rotor 5 of the alternator is prevented from being directly reduced, so that good power generation efficiency can be maintained.

By the way, the one-way clutch and the pair of support bearings constituting the alternator-built-in one-way clutch type pulley device are provided between the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve, respectively. In the case where the one-way clutch is arranged in an axially intermediate portion of the space, and the two support bearings are generally arranged at a position sandwiching the one-way clutch from both sides in the axial direction. It is. Conventionally, as the pair of support bearings, a general radial rolling bearing in which an outer ring and an inner ring are relatively rotatably combined via a plurality of rolling elements has been used. When such a radial rolling bearing is incorporated as a pair of support bearings, each of the radial rolling bearings is pushed into the space between the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve at both ends. . As a result, the outer ring constituting each of the radial rolling bearings is fitted and fixed to the inner peripheral surface of the driven pulley, and the inner ring is similarly fixed to the outer peripheral surface of the sleeve.

[0008]

In the case of the conventional structure as described above, the outer ring and the inner ring constituting each of the radial rolling bearings and the inner peripheral surface of the driven sleeve and the outer peripheral surface of the sleeve are fitted to each other. It is preferable that each has an interference. The reason for this is to prevent the occurrence of creep (slipping) at these fitting portions and to prevent the lubricating grease sealed in the internal space from leaking to the outside through these fitting portions. . However, in the case where each of the fitting portions has an interference, when the radial rolling bearings are pushed in, the air in the space sandwiched between the two bearings passes through the fitting portions to form an external space. Can not move to. For this reason, the air in the space sandwiched between the two bearings is compressed with the pushing operation of the two bearings, and the pressure in this space increases.

When the pressure in this space rises excessively, the pressure causes the peripheral edge of the seal ring mounted at the open end of the space where the rolling elements of the radial rolling bearing are installed to be turned up. The grease sealed in the space between the bearings or the space in which the rolling elements are installed may leak out of the spaces. When the grease leaks in this way, a predetermined portion in each of the above-mentioned spaces (for example, a sliding contact portion between the members constituting the one-way clutch, a rolling surface of each rolling element and the outer race and the inner race track) Rolling contact portion) cannot be sufficiently lubricated, and as a result, there is a possibility that the inconvenience of shortening the life of the pulley device with a built-in one-way clutch for the alternator may occur. 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.

[0010]

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 enables the transmission of rotational force between these driven pulleys and the sleeve only when they tend to rotate, a position sandwiching the one-way clutch from both axial sides, and the driven pulley and the sleeve. A portion closer to the center in the axial direction than both ends in the axial direction is provided between the outer peripheral surface of the sleeve and the inner peripheral surface of the driven pulley, and the radial applied to the driven pulley While supporting the heavy and a pair of support bearings to freely relative rotation between the sleeves and the driven pulley. In addition, each of these support bearings has an outer raceway on an inner peripheral surface, an outer race for a bearing that is internally fixed to the inner peripheral surface of the driven pulley by interference fit, and an inner raceway on an outer peripheral surface, and An inner ring for a bearing, which is externally fitted and fixed to the outer peripheral surface by interference fit, and a plurality of rolling elements rotatably provided between the outer raceway and the inner raceway, and an inner peripheral surface of the outer race for a bearing. A seal ring is provided for closing at least one of the openings at both ends of a space in which the rolling elements are installed between the outer peripheral surface of the bearing inner ring and the outer peripheral surface.

In particular, in the pulley device with a built-in one-way clutch for an alternator according to the present invention, at least one of the inner circumferential surface of the driven pulley and the outer circumferential surface of the sleeve has at least one axial direction. At the end, a stepped portion diametrically recessed from the peripheral surface to a portion axially deviated from the portion for fitting and fixing the outer ring for bearing or the inner ring for bearing to the open end side of the peripheral surface. A concave groove extending in the axial direction is formed. The shape of the stepped portion may be a cylindrical surface that is recessed in a crank shape from each of the peripheral surfaces, or a tapered surface that is inclined in a direction that is diametrically concave toward the axial end of each of the peripheral surfaces. (Chamfer) can be adopted.

[0012]

In the pulley apparatus with a built-in one-way clutch for an alternator according to the present invention constructed as described above, at least one of the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve is provided. The amount of air compressed in the portion between the two support bearings can be reduced by the axial dimension of the step or the concave groove formed at the axial end. That is, in the case of the present invention, in order to assemble a pair of support bearings into the space between the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve, when each of these support bearings is pushed through both ends of the space, at least, A gap is formed between the outer peripheral surface of the bearing outer race or the inner peripheral surface of the bearing inner race that constitutes one of the support bearings, and the step or the concave groove, through which air can pass. Further, the gap is provided until the amount of pushing of the support bearing from the opening edge reaches the axial dimension of the step portion or the groove. In other words, the outer peripheral surface of the bearing outer ring or the bearing The leading edge of the inner peripheral surface of the inner ring in the pushing direction is the base edge of the step or the concave groove (the edge near the center in the axial direction of the driven pulley and the sleeve).
During this period, the space between the two support bearings communicates with the external space.

Therefore, when the support bearing is pushed in,
Until the pushing amount of the support bearing from the opening edge reaches the axial dimension of the step portion or the concave groove, the outer peripheral surface of the bearing outer race or the inner periphery of the bearing inner race constituting the support bearing. The air in the space sandwiched between the two support bearings can be discharged to the outside through the portion between the surface and the step or the concave groove. Therefore, in the case of the present invention, the amount of air compression in the space sandwiched between the two support bearings can be reduced by the axial dimension of the step portion or the concave groove, and the pressure in this space can be reduced. The rise can be suppressed. Accordingly, it is possible to prevent the peripheral edge of the seal ring mounted on each support bearing from being turned up by the pressure in this space, and to prevent the grease sealed in this space from leaking to the outside. According to the result of the evaluation test, when the temperature in the space is constant, it is confirmed that the grease deteriorates earlier in a state where the pressure in the space is higher. For this reason, in the case of the present invention, it is possible not only to prevent the peripheral edge of the seal ring from being turned up as described above, but also to suppress the pressure increase in the space (even when the peripheral edge of the seal ring is not turned up). The life of the grease can be improved.

In the case of the present invention, the stepped portion or the concave groove fits and fixes the bearing outer ring or the bearing inner ring between the inner peripheral surface both ends of the driven pulley and the outer peripheral surface both ends of the sleeve, respectively. It can be formed in a portion that is deviated in the axial direction from the portion to be opened toward the opening end of the peripheral surface. Therefore, the axial dimension or area of the fitting portion between the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve and the outer peripheral surface of the outer ring for bearing and the inner peripheral surface of the inner ring for bearing does not decrease. For this reason, it is possible to sufficiently secure the fitting strength at each of these fitting portions, and suppress an increase in pressure without creep (slipping) occurring at each of these fitting portions.

[0015]

FIG. 1 shows a first embodiment of the present invention.
An example is shown. The pulley device with a built-in one-way clutch for an alternator according to the present embodiment includes a rotating shaft 3 (see FIG.
) Has a sleeve 8 which can be externally fitted and fixed. Further, the driven pulley 7a around the sleeve 8 is
And are arranged concentrically. 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 fixed to the end of the rotating shaft 3 of the alternator 1 and is rotatable together with the rotating shaft 3. For this reason, in the illustrated example, a screw hole 11 is formed in the middle of the inner peripheral surface of the sleeve 8, and the screw hole 11 is screwed into a male screw portion provided on the outer peripheral surface of the tip of the rotary shaft 3. It is free.
Also, the tip of the inner peripheral surface of the sleeve 8 (the left end in FIG. 1).
In addition, a locking hole portion 12 having a hexagonal cross section is formed,
The tip of a tool such as a hexagon wrench can be freely locked in the locking hole 12. Further, a base end (the right end in FIG. 1) of the inner peripheral surface of the sleeve 8 is a circular hole portion 13 which can be freely fitted to the middle portion of the rotary shaft 3 near the front end.
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 14 projecting diametrically outward from the outer peripheral surface is formed over the entire circumference.

On the other hand, the first half of the outer peripheral surface of the driven pulley 7a has a cross-sectional shape extending in the width direction, and a part of an endless belt called a poly-V belt can be freely passed over. Further, at the tip of the inner peripheral surface of the driven pulley 7a, a portion axially adjacent to a portion for fitting and fixing the bearing outer ring 24 described later (from the portion for fitting and fixing the bearing outer ring 24 to the driven pulley A step 15 is formed over the entire circumference of the inner peripheral surface of the inner peripheral surface of the inner peripheral surface 7a. The roller clutch 10 is provided at an axially intermediate portion of a space existing between the outer peripheral surface of the sleeve 8 and the inner peripheral surface of the driven pulley 7a. The support bearings 9 and 9 are located at a position sandwiching the shaft 10 from both sides in the axial direction and at a position closer to the center in the axial direction than both ends of the driven pulley 7a and the sleeve 8 in the axial direction.
Each is arranged.

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 1 is provided on the convex portion 14 formed on the outer peripheral surface of the sleeve 8.
6 are externally fitted and fixed by interference fit. The inner ring 16 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 17 formed on the outer peripheral surface. That is, a plurality of recesses 18 called ramps are formed on the outer peripheral surface of the roller clutch inner ring 16 at equal intervals in the circumferential direction, so that the outer peripheral surface is the cam surface 17.

On the other hand, of the inner peripheral surface of the outer ring 19 for the roller clutch, which is fixedly fitted to the intermediate portion of the inner peripheral surface of the driven pulley 7a by interference fit, at least the axially intermediate portion which comes into contact with the roller 21 described below. The part is simply a cylindrical surface. The outer ring 19 for such a roller clutch is also formed into a cylindrical shape as a whole by subjecting a steel plate such as carburized steel to plastic working such as press working, and has inward flange-like flanges 20a and 20b at both axial ends. Is formed. It should be noted that one (left side in FIG. 1) of the flange portions 20a and 20b is one of the flange portions 20a and 20b.
Since a is formed in advance at the time of manufacturing the roller clutch outer ring 19, the thickness a is equal to the thickness of the cylindrical portion of the roller clutch outer ring 19. On the other hand, the other (right side in FIG. 1) flange portion 20b is connected to the outer ring 19 for the roller clutch.
The roller 21 and the clutch retainer 22 described below are assembled on the inside in the diametrical direction, so that the thickness is reduced.

A plurality of rollers 21 constituting the roller clutch 10 together with the roller clutch inner ring 16 and the roller clutch outer ring 19 cause the roller clutch inner ring 16 to rotate with respect to the roller clutch inner ring 16. It is supported by a synthetic resin clutch retainer 22 fitted externally as impossible to allow rolling and slight displacement 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 22 and each of the rollers 21. 21 is elastically pressed in the same direction with respect to the circumferential direction. In the state shown in the figure, both axial end surfaces of the clutch retainer 22 are closely opposed to the inner side surfaces of both flange portions 20a and 20b constituting the outer ring 19 for the roller clutch. 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 and 9 allow the driven pulley 7a and the sleeve 8 to rotate relative to each other while supporting the radial load applied to the driven pulley 7a. In the case of this example, a deep groove type ball bearing is used as each of the support bearings 9 and 9. That is, each of these support bearings 9, 9 has a deep groove type outer raceway 2 on its inner peripheral surface.
Outer races 24, 24 having bearings 3, 23, inner races 26, 26 having a deep groove inner raceway 25, 25 on the outer peripheral surface thereof, the outer raceways 23, 23 and the inner raceway 2
5 and 25, each of which comprises a plurality of balls 27, 27 which are provided so as to freely roll. Also, the bearing outer rings 24, 2
Sealing rings 29, 29 are respectively fitted to the locking grooves 28, 28 formed on the inner peripheral surfaces of both ends of No. 4, thereby closing the openings at both ends of the spaces 30, 30 in which the balls 27, 27 are installed. .

When assembling such support bearings 9 between the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the sleeve 8, the roller clutch 10 is sandwiched from both sides in the axial direction. The respective bearing outer races 24, 24 are internally fitted to the driven pulley 7a near the opposite ends of the inner peripheral surface thereof by interference fitting, and the respective bearing inner rings 26, 26 are positioned near the opposite ends of the outer peripheral surface of the sleeve 8. Then, it is externally fitted and fixed by interference fit. In order to perform such assembling work, specifically, each of the support bearings 9,
9 are pushed (press-fitted) from openings at both ends of the space between the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the sleeve 8, respectively. In the illustrated example, each of the bearing inner rings 2 is used.
One end surfaces of the protrusions 6 and 26 are respectively abutted on step surfaces existing at both ends in the axial direction of the projection 14.

In the case of this embodiment, with the support bearings 9, 9 assembled as described above, a space 31 in which the roller clutch 10 is interposed between the support bearings 9, 9 is provided. The spaces 30, 30 in which the balls 27, 27 are installed are separated by the seal rings 29, 29 arranged on the roller clutch 10 side among the seal rings 29, 29. Thus, in the case of the present example, an appropriate amount of grease can be freely filled in each of the spaces 30 and 31.

In the case of the pulley device with a built-in one-way clutch for an alternator of the present embodiment as described above, a pair of support bearings 9 and 9 are respectively mounted on the driven pulley 7a in the same manner as in the conventional structure described above. The space 31 sandwiched between the two support bearings 9 and 9 is pushed into the space between the peripheral surface and the outer peripheral surface of the sleeve 8 through the openings at both ends of the space.
The air inside is compressed. However, in the case of this example, this space 3
The amount of compression of the air in 1 can be reduced by the formation of the step portion 15 at the tip of the inner peripheral surface of the driven pulley 7a. The reason will be described below.

In the case of this embodiment, when assembling the support bearings 9, 9, the support bearings 9, 9 are connected to the inner peripheral surface of the driven pulley 7 a and the outer peripheral surface of the sleeve 8. It is pushed one by one from the openings at both ends of the space existing between them. In particular, in the case of this example, the support bearing 9 to be pushed in later is pushed in from the opening (the left side in FIG. 1) on which the step 15 is formed, of the openings at both ends of the space. When the support bearing 9 to be pushed in later is pushed in from the opening on the side where the step 15 is formed, in the initial stage of pushing, the outer peripheral surface of the bearing outer ring 24 constituting the support bearing 9 and the step 15 And a gap through which air can pass freely is generated. Also, this gap is maintained until the pushing amount of the support bearing 9 from the opening edge reaches the dimension of the step portion 15 in the axial direction. In other words,
Inner edge of the outer peripheral surface of the bearing outer ring 24 (right edge in FIG. 1)
Until と reaches the base edge (the right edge in FIG. 1) of the step portion 15, the space 31 communicates with the external space.

Therefore, when the support bearing 9 is pushed in, until the pushing amount of the support bearing 9 from the opening edge reaches the dimension of the step portion 15 in the axial direction, the bearing outer ring 24 is The air in the space 31 can be discharged to an external space through a portion between the outer peripheral surface and the step portion 15. Therefore, in the case of this example, the step portion 1
The amount of compression of the air in the space 31 can be reduced by an amount corresponding to the dimension 5 in the axial direction, so that a pressure increase in the space 31 can be suppressed. Accordingly, the pressure in the space 31 causes the roller clutch 1 mounted on the support bearings 9 and 9 to rotate.
By preventing the seal lips of the zero-side seal rings 29, 29 from being turned up, the grease sealed in the space 31 can be prevented from leaking into the spaces 30, 30 in which the balls 27, 27 are installed.

In the case of the present embodiment, the step 15 is formed at one end of the inner peripheral surface of the driven pulley 7a in a portion axially displaced from a portion to which the bearing outer ring 24 is fitted and fixed. are doing. Accordingly, the axial dimension of the fitting portion between the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the bearing outer ring 24 does not decrease. For this reason, it is possible to sufficiently secure the fitting strength of the fitting portion and prevent the occurrence of creep (slipping) at the fitting portion. However, when the load applied to the driven pulley 7a is small and the width of the bearing outer ring 24 (support bearing 9) in the axial direction is large, and there is no possibility that creep occurs in the fitting portion. In this case, the base end of the step portion 15 is extended to the fitting portion, and the axial dimension of the fitting portion is slightly sacrificed (to the extent that creep does not occur at the fitting portion), thereby reducing the space 31. Pressure rise in the inside can be further suppressed.

As shown in this embodiment, the space 31 in which the roller clutch 10 is installed and the space 30 in which the balls 27, 27 are installed,
When the support bearings 9 and 9 are separated from each other by seal rings 29 and 29 mounted on the support bearings 9 and 9, respectively, the compression ratio of the air in the space 31 after assembling the support bearings 9 and 9 is a certain degree. growing. As a result, the pressure in the space 31 increases, and each of the seal rings 2
The seal lips 9 and 29 are turned up, and the grease sealed in the space 31 may leak into the spaces 30 and 30. Therefore, when the spaces 31 and 30 are separated from each other by the seal rings 29 and 29 as described above, the seal ring 2 attached to at least one of the support bearings 9 is used.
At least one through hole or notch for communicating the two spaces 31 and 30 with each other can be formed in a part of the space 9.

By forming such a through hole or notch, when the pressure in the space 31 tends to increase, a part of the air in the space 31 is made to pass through the through hole or notch. It can be moved into the space 30. Thereby, the compression ratio of the air in the space 31 can be further reduced, and the pressure in the space 31 can be prevented from excessively increasing. At the same time, the pressure difference between the spaces 30 and 31 can be eliminated. As a result, the disadvantage that the seal lip is turned up and the grease leaks as described above can be prevented. On the other hand, in the present invention, the seal rings 29 on the roller clutch 10 side are omitted, and the roller clutch 1 is omitted.
The present invention can also be applied to a pulley device with a built-in one-way clutch for an alternator having a structure in which a space 31 in which 0 is installed and spaces 30 in which the balls 27 are communicated.

Further, in the case of the present invention, the shape of the step portion 15 is not limited to the cylindrical surface as shown in FIG. May be formed as a tapered surface (chamfered) inclined in the direction in which the taper moves. As means for releasing the air in the space sandwiched between the pair of support bearings to the outside, in addition to the above-described stepped portion, a concave formed in the axial end of the peripheral surface in the axial direction. Grooves can also be used. In addition, such a concave groove is also displaced in the axial direction from the axial end of the peripheral surface to a portion where the bearing outer ring 24 or the bearing inner ring 26 is fitted and fixed to the opening end side of the peripheral surface. Form on the part.

Further, in the case of the present invention, the step portion or the concave groove as described above is formed between the both ends of the inner peripheral surface of the driven pulley 7a and the sleeve 8
It is sufficient if they are formed at least at one of the two ends of the outer peripheral surface of the driven pulley. However, the ends of the inner peripheral surface of the driven pulley 7a and the outer peripheral surface of the sleeve 8 which are opposite to each other in the axial direction are sufficient. If at least one support bearing is provided, it is not necessary to consider the order of assembling the support bearings 9 as in the above-described embodiment, and the efficiency of the assembling work can be improved.

In the above-described embodiment, the case where the low clutch is used as the one-way clutch has been described. However, the present invention is conventionally known as the one-way clutch, such as a cam clutch such as a sprag clutch. The same effect can be obtained 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.

[0033]

The pulley device with a built-in one-way clutch for an alternator of the present invention is constructed and operates as described above, so that the grease sealed in the space sandwiched between the pair of support bearings is externally provided. Leakage can be prevented. As a result, a highly reliable product in which poor lubrication due to the grease is prevented can be provided.

[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 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 Followed pulley 8 Sleeve 9 Support bearing 10 Roller clutch 11 Screw hole part 12 Locking hole part 13 Round hole part 14 Convex part 15 Step part 16 Roller clutch Inner ring 17 Cam surface 18 Recess 19 Roller clutch outer ring 20a, 20b Flange 21 Roller 22 Clutch retainer 23 Outer ring raceway 24 Bearing outer ring 25 Inner ring raceway 26 Bearing inner ring 27 Ball 28 Lock groove 29 Seal ring 30 Space 31 space

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J031 BA03 CA02 5H605 BB03 BB09 CC04 CC08 EB10 EB28 5H607 BB02 BB04 EE05 EE28 FF22 FF24 GG01 GG08

Claims (1)

[Claims] 1. A sleeve which can be externally fitted and fixed to a rotating shaft of an alternator, a driven pulley disposed around the sleeve and concentric with the sleeve, an axially intermediate portion of an outer peripheral surface of the sleeve, and an inner periphery of the driven pulley. Provided between the driven pulley and the sleeve only when the driven pulley tends to rotate relative to the sleeve in a predetermined direction. The one-way clutch and the portion sandwiching the one-way clutch from both sides in the axial direction, and a portion closer to the center in the axial direction than both ends in the axial direction of the driven pulley and the sleeve, the inner peripheral surface of the sleeve and the driven pulley. A pair of support bearings provided between the sleeve and the driven pulley to support a radial load applied to the driven pulley and to allow relative rotation between the sleeve and the driven pulley. Each support bearing has an outer ring raceway on the inner peripheral surface, an outer ring for a bearing that is internally fixed to the inner peripheral surface of the driven pulley by interference fit, and an inner raceway on the outer peripheral surface,
An inner ring for a bearing, which is externally fitted and fixed to the outer peripheral surface of the sleeve by interference fit, and a plurality of rolling elements rotatably provided between the outer ring raceway and the inner ring raceway, wherein A pulley with a built-in one-way clutch for an alternator, which has a seal ring for closing at least one of the openings at both ends of a space in which the rolling elements are installed between a peripheral surface and an outer peripheral surface of the bearing inner ring. In the device, the outer ring for bearing or the inner ring for bearing is fitted and fixed at at least one axial end of at least one of the inner peripheral surface of the driven pulley and the outer peripheral surface of the sleeve. A step portion or a groove extending in the axial direction diametrically recessed from the peripheral surface at a portion axially deviated from the portion to be opened to the opening end side of the peripheral surface. Built-in direction clutch Over Li equipment.