JP5040555B2 - One-way clutch - Google Patents

Description

  The present invention relates to a one-way clutch that switches between a locked state in which an inner ring body and an outer ring body that are concentrically arranged inside and outside in a radial direction are synchronously rotated and a free state in which the inner ring body is relatively rotated.

Conventionally, a one-way clutch may be assembled to a pulley unit used in, for example, an engine auxiliary machine (air conditioning compressor, alternator, water pump, cooling fan, etc.).
For example, when the auxiliary machine is an air-conditioning compressor, a one-way clutch is disposed between a pulley around which a transmission belt to which the torque of a crankshaft of an in-vehicle engine is transmitted and a rotating shaft of the compressor. The engine is designed to absorb fluctuations in engine rotation by transmitting or blocking torque from the pulley to the rotating shaft.
In this type of one-way clutch, as shown in FIG. 7, one of the opposing peripheral surfaces of the outer ring body 141 and the inner ring body 142, for example, the outer ring surface of the inner ring body 142, A cam surface 143 that forms a plurality of wedge-shaped spaces at predetermined intervals in the circumferential direction in cooperation with the peripheral surface is formed.
In the plurality of wedge spaces, the same number of rollers 161 and coil springs 160 individually energizing the rollers 161 in the locking direction to engage the rollers 161 are accommodated in the pocket 151 of the cage 150. It is arranged in the state.
An engaging portion 155 that engages with the cam surface 143 is formed at a position facing the cam surface 143 on the inner peripheral surface of the cage 150. And what was comprised so that the reaction force of the coil spring 160 might be received by stopping rotation of the holder | retainer 150 with respect to the inner ring body 142 by engagement with the cam surface 143 and the engaging part 155 is known.

Further, for example, a one-way clutch as disclosed in Patent Document 1 is known in order to cut off torque transmission when a torque of a predetermined value or more acts on the rotation shaft of the compressor from the pulley.
In this case, a torque limit recess is formed adjacent to one side in the circumferential direction of the cam surface, and when a torque of a predetermined value or more is applied between the outer ring body and the inner ring body, the roller is on one side of the cam surface. , The torque is transferred between the outer ring body and the inner ring body.
JP 2002-106608 A

By the way, in the conventional one-way clutch as shown in FIG. 7, when the displacement angle of the roller 161 is large when the roller moves toward the narrow side of the wedge space when torque is applied, the pocket 151 of the cage 150 is partitioned. It is assumed that the roller 161 moves in a state in which the roller 161 hits one side surface 152a of the pillar portion 152 that is in contact.
On the other hand, since the engaging portion 155 on the inner peripheral surface of the retainer 150 is engaged with the cam surface 143, when the roller 161 moves in a state where the roller 161 hits one side surface of the pillar portion 152, the retainer 150 may be deformed and damaged.
In particular, in a one-way clutch in which a torque limit recess is formed adjacent to one side of the cam surface in the circumferential direction, the displacement angle of the roller while the roller is received and arranged in the torque limit recess from the cam surface Therefore, it is assumed that the cage 150 is significantly deformed or damaged.

  In view of the above problems, an object of the present invention is to permit rotation of the cage in the lock direction at an angle corresponding to the displacement angle of the roller with respect to the narrow side of the wedge space during torque load. It is to provide a one-way clutch that can prevent deformation.

In order to achieve the object, the one-way clutch according to claim 1 of the present invention is a free state in which the inner ring body and the outer ring body, which are concentrically disposed inside and outside in the radial direction, are synchronously rotated with the locked state. In order to switch to each other, among the opposing peripheral surfaces of the inner ring body and the outer ring body, one peripheral surface cooperates with the other peripheral surface, and a plurality of wedge-shaped spaces are spaced apart at a predetermined interval in the circumferential direction. Forming cam surface,
In the plurality of wedge spaces, the same number of rollers and coil springs individually energizing the rollers in the locking direction for engaging each of the rollers in the wedge-shaped spaces are arranged in a state of being accommodated in the pockets of the cage. A one way clutch,
Between the cage and the member on which the cam surface is formed, an engagement portion that prevents the cage from rotating in the free direction and receives the reaction force of the coil spring is formed, respectively. A contact avoiding portion that allows rotation of the cage in the locking direction within a range of a predetermined angle is formed,
The allowable rotation angle of the cage in the locking direction is set to the revolution angle of the roller with respect to the inner ring body when torque is applied.

According to the above configuration, the cage is prevented from rotating in the free direction by the engagement of the engaging portions formed between the cage and the member (outer ring body or inner ring body) on which the cam surface is formed. Can receive the reaction force of the coil spring.
When the roller is moved toward the narrow side of the wedge space when the torque is applied, the roller is in contact with one side surface of the pillar section defining the cage pocket. Rolls. Then, since the cage is rotated in the locking direction at an angle corresponding to the displacement angle of the roller, deformation and damage of the cage can be prevented.

The one-way clutch according to claim 2 is the one-way clutch according to claim 1,
A torque limit recess is formed on one side in the circumferential direction of the cam surface. When a torque exceeding a predetermined value acts between the inner ring body and the outer ring body, the roller rolls over the cam surface and rolls the torque. It is configured so that torque transmission between the inner ring body and the outer ring body is cut off by being received in the recess for limit,
The allowable rotation angle of the cage in the locking direction is set to an angle corresponding to the displacement angle of the roller while the roller is received and arranged in the torque limit recess from the cam surface. It is characterized by being.

  According to the above configuration, when a torque exceeding a predetermined value acts between the outer ring body and the inner ring body, the roller rolls over one side of the cam surface and is received and disposed in the torque limit recess. Thus, torque transmission is interrupted. At this time, after the roller hits one side surface of the pillar portion of the cage, the cage is rotated in the same direction together with the roller, so that deformation and damage of the cage can be prevented.

The one-way clutch according to claim 3 is the one-way clutch according to claim 2,
The cam surface is formed on the outer peripheral surface of the inner ring body,
On the outer peripheral surface of the inner ring body, a flat surface is formed at a position displaced in the axial direction with the cam surface,
The engaging portion that receives the reaction force of the coil spring by preventing the cage from rotating in the free direction is formed to be able to engage with the flat surface at the inner peripheral surface portion of the cage facing the flat surface. Formed by the engagement piece and the flat surface,
The contact avoiding portion that allows the retainer to rotate in the locking direction within a predetermined angle range is formed in the engagement piece in a cutout shape.

  According to the said structure, the engaging part which receives the reaction force of a coil spring can be easily comprised with the flat surface formed in the outer peripheral surface of an inner ring body, and the engagement piece formed in the inner peripheral surface of a holder | retainer. In addition, the contact avoiding portion that allows the retainer to rotate in the locking direction within a predetermined angle range can be easily configured by cutting out the engaging piece of the retainer.

  Next, the best mode for carrying out the present invention will be described with reference to examples.

Example 1
A first embodiment of the present invention will be described with reference to FIGS.
1 is a side sectional view showing a pulley unit including a one-way clutch according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the one-way clutch. FIG. 3 is an enlarged plan view showing a state where rollers and coil springs are housed in the pockets of the cage. FIG. 4 is an enlarged cross-sectional view showing a state where a roller and a coil spring are stored in a pocket of the cage. FIG. 5 is an explanatory diagram showing the relationship between the flat outer peripheral surface of the inner ring body, the engagement piece of the cage and the contact avoiding portion. FIG. 6 is an explanatory view showing a state in which the cage is rotated in the locking direction at an allowable rotation angle.

  As illustrated in FIG. 1, the pulley unit 10 including the one-way clutch 40 according to the first embodiment exemplifies a case where the pulley unit 10 is used in a compressor 1 that is one of engine auxiliary machines of an in-vehicle engine. A projecting cylindrical portion 3 that is integrally projected from one side of the casing 2 of the compressor 1 and a rotating shaft 4 of the compressor 1 that is concentrically and rotatably assembled to the center of the projecting cylindrical portion 3. The pulley 11, the double row rolling bearing 20, the annular member 30, and the one-way clutch 40 are provided.

The pulley 11 is formed in a cylindrical shape concentrically disposed on the outer periphery of the protruding cylinder portion 3, and an annular end plate 11 a is integrally formed on the inner periphery of one end portion thereof. A one-way clutch 40 is provided on the inner side surface of the annular end plate 11 a between the first annular space for assembling the rolling bearing 20 between the outer peripheral surface of the protruding cylindrical portion 3 and the inner peripheral surface of the pulley 11. A cylindrical body 13 constituting a second annular space for assembling is integrally formed.
In addition, a belt groove 12 having a cross-sectional wave shape, on which the transmission belt 18 is stretched, is formed on the outer peripheral surface of the pulley 11. The transmission belt 18 is stretched around the pulley of the crankshaft of the vehicle-mounted engine, and transmits the torque of the crankshaft to the pulley 11.

The double row rolling bearing 20 is arranged to be able to roll in a double row in a state where it is held by the outer ring 21, the inner ring 22, and the retainers 25 and 26 between the outer ring 21 and the inner ring 22, respectively. A plurality of balls 23 and 24 are provided.
The double-row rolling bearing 20 has an inner ring 22 that is press-fitted into the outer peripheral surface of the protruding cylindrical portion 3 on the compressor 1 side and is prevented from coming off by a retaining ring 27, while the outer ring 21 is a cylindrical shape on the pulley 11 side. It is press-fitted and attached to the inner peripheral surface of the body 13.

As shown in FIGS. 1 and 2, the one-way clutch 40 includes an outer ring body 41, an inner ring body 42, a plurality of rollers 61, a coil spring 60, and a cage 50.
The inner ring body 42 of the one-way clutch 40 is press-fitted into the outer peripheral surface of the tubular body 13 on the pulley 11 side, and is prevented from coming off by a retaining ring 28.
On the other hand, on the outer peripheral surface near the end of the rotating shaft 4 on the compressor 1 side, an annular member 30 is fitted and inserted in a boss portion 31 formed at the center thereof so as to be able to transmit torque, and from the shaft end portion of the rotating shaft 4. The boss portion 31 of the annular member 30 is fixed by tightening the nut 5 to the male screw portion protruding integrally concentrically. And the outer ring | wheel body 41 of the one-way clutch 40 is connected with the outer peripheral part of the annular member 30 so that torque transmission is possible by a suitable connection member. Thus, torque from the pulley 11 side is transmitted to the rotary shaft 4 on the compressor 1 side via the one-way clutch 40 and the annular member 30.

That is, as shown in FIGS. 2 to 4, a plurality of (six in FIG. 2) wedge-shaped spaces are provided in the circumferential direction between the outer circumferential surfaces of the outer ring body 41 and the inner ring body 42 of the one-way clutch 40. The plurality of wedge spaces are formed at predetermined intervals, and the same number of rollers 61 and coil springs 60 for individually urging the rollers 61 in the locking direction (the narrow side of the wedge space) are held in the plurality of wedge spaces. They are arranged in a state of being accommodated in the respective pockets 51 of the container 50.
In the first embodiment, a flat surface for forming a plurality (six in FIG. 2) of wedge-shaped spaces at predetermined intervals in the circumferential direction between the outer circumferential surfaces of the outer ring body 41 and the inner ring body 42 (see FIG. 2). (Or curved surface) cam surfaces 43 are formed at predetermined intervals in the circumferential direction of the outer peripheral surface of the inner ring body 42, while the inner peripheral surface of the outer ring body 41 is circular.

  As shown in FIGS. 2 and 4, a torque limit recess 46 such as a concave arc shape or a concave curve shape is formed with a required depth on one side in the circumferential direction of each cam surface 43 of the inner ring body 42. . When a torque greater than a predetermined value acts between the outer ring body 41 and the inner ring body 42, the roller 61 rolls over the cam surface 43 and is received and disposed in the torque limit recess 46. The roller 61 cannot be engaged with the outer ring body 41 and the inner ring body 42, and torque transmission between the outer ring body 41 and the inner ring body 42 is interrupted.

The cage 50 is integrally formed into a cylindrical shape by injection molding of a synthetic resin material, and a plurality of pockets 51 and column portions 52 that partition the pockets 51 are alternately formed in the circumferential direction. The cage 50 is fitted to the outer peripheral surface of the inner ring body 42.
On one side surface (the surface facing the narrow side of the wedge space) of each column portion 52 of the cage 50, a protrusion 53 into which the proximal end winding portion of the coil spring 45 is fitted is projected.

  The coil spring 60 is formed by winding a spring wire into an elliptical shape, a rectangular shape, or the like. In this state, the tip winding portion is in contact with the outer peripheral surface of the roller 61. The coil spring 60 elastically urges the roller 61 toward the narrow side of the wedge-shaped space (the side in the locked state) (see FIG. 4).

As shown in FIG. 5, a flat surface between the cage 50 and the inner ring body 42 as an engaging portion that prevents the cage 50 from rotating in the free direction and receives the reaction force of the coil spring 60. 47 and the engagement piece 55 are formed, respectively, and the contact avoiding portion 56 that allows the retainer 50 to rotate in the locking direction by a predetermined rotation angle θ is formed in the engagement piece 55 in a cutout shape. Has been.
Further, the allowable rotation angle θ of the cage 50 in the locking direction is set to the revolution angle of the roller 61 with respect to the inner ring body 42 at the time of torque load. This revolution angle corresponds to an angle corresponding to the roller displacement angle α at which the roller 61 is displaced from the cam surface 43 into the torque limit recess 46.

In the first embodiment, a flat surface 47 as one engaging portion is formed on the outer peripheral surface of the inner ring body 42 at a portion that is appropriately displaced in the axial direction and the circumferential direction with respect to the cam surface 43.
On the other hand, a portion of the inner peripheral surface of the retainer 50 facing the flat surface 47 of the inner ring body 42 has a flat engagement surface 55a as the other engagement portion formed to be engageable with the flat surface 47. An engagement piece 55 is formed.
Furthermore, the contact avoiding portion 56 is formed by cutting away the engagement piece 55 of the retainer 50 by leaving only the dimension a.
That is, as shown in FIG. 5, the center line of the flat surface 47 passing through the center O of the inner ring body 42 is L, the distance from the center O of the inner ring body 42 to the flat surface 47 is C / 2, and the inner ring body 42 The contact angle portion of the engagement piece 55 that contacts and engages with the flat surface 47 is P, the allowable rotation angle in the locking direction of the cage 50 is θ, and the flatness based on the allowable rotation angle θ. The displacement distance of the contact angle portion P of the engagement piece 55 with respect to the surface 47 is d, and the length dimension of the flat surface 47 of the inner ring body 42 (the length of the engagement piece 55 of the cage 50 without the contact avoidance portion 56). (Corresponding to the dimension) is b,
“D = Ctan (θ / 2)”
“2a = b−d”
The contact avoiding portion 56 is formed so as to satisfy the following relationship.

Further, in the first embodiment, as shown in FIG. 1, in the annular space between the outer ring body 41 and the inner ring body 42 of the one-way clutch 40, the roller 61 is positioned on one side of the cage 50 and rolls. A plurality of balls 71 constituting the bearing 70 are arranged to be able to roll while being held by a cage 72.
When the roller 61 is disposed in the torque limit recess 46, the outer ring body 41 and the inner ring body 42 are concentrically held by the rolling bearing 70.

The pulley unit 10 including the one-way clutch 40 according to the first embodiment is configured as described above.
Therefore, when the torque of the crankshaft is transmitted to the pulley 11 by the transmission belt 18 during the operation of the on-vehicle engine, the inner ring body 42 of the one-way clutch 40 is rotated together with the cylindrical body 13 that rotates integrally with the pulley 11. The The torque of the inner ring body 42 is transmitted to the outer ring body 41 by the roller 61, and the torque is transmitted to the rotating shaft 4 of the compressor 1 by the annular member 30 that rotates integrally with the outer ring body 41, thereby rotating the rotating shaft 4.
That is, when the rotation speed of the pulley 11 is higher than the rotation speed of the rotary shaft 4 during the operation of the engine, the one-way clutch 40 is locked, so that the rotary shaft 4 rotates together with the pulley 11.
Further, when the rotation speed of the pulley 11 becomes slower than the rotation speed of the rotating shaft 4, the roller 61 of the one-way clutch 40 moves out of the lock position and moves to the wider side of the wedge-shaped space to switch to the free state. Thereby, the rotation fluctuation of the pulley 11 is absorbed.

When seizure or the like occurs on the rotating shaft 4 of the compressor 1 and the rotating shaft 4 is locked, a torque (load torque) of a predetermined value or more acts between the outer ring body 41 and the inner ring body 42.
In this case, the roller 61 rolls over one side of the cam surface 43 and is received and disposed in the torque limit recess 46. By disposing the roller 61 in the torque limit recess 46, torque transmission from the pulley 11 side to the rotating shaft 4 is interrupted.

On the other hand, when the roller 61 is disposed in the torque limit recess 46, after the roller 61 hits one side surface of the column portion 52 of the cage 50, the cage 50 is rotated in the same direction together with the roller 61. (See FIG. 6).
That is, as shown in FIG. 5, the contact avoiding portion 56 is formed by cutting away the engagement piece 55 of the retainer 50 by leaving only the dimension a. As a result, as shown in FIG. 4, at the rotation angle θ corresponding to the roller displacement angle α at which the roller 61 is displaced from the cam surface 43 into the torque limit recess 46, as shown in FIG. Is rotated in the locking direction. For this reason, the malfunction which the holder | retainer 50 deform | transforms or is damaged by the displacement of the roller 61 can be eliminated.

The present invention is not limited to the first embodiment.
For example, in the first embodiment, the cam surface 43 and the torque limit recess 46 are formed on the outer peripheral surface of the inner ring body 42 and the wedge-shaped space is formed by the inner peripheral surface of the outer ring body 41 and the cam surface 43. The present invention can be implemented even if a cam surface and a torque limit recess are formed on the inner peripheral surface of the body 41 and a wedge-shaped space is formed by the outer peripheral surface of the inner ring body 42 and the cam surface.
However, in this case, an engaging portion that receives the reaction force of the coil spring 60 against the roller 61 is provided between the inner peripheral surface of the outer ring body and the outer peripheral surface of the cage.
In the first embodiment, the torque limit recess 46 is formed on one side of the cam surface 43. However, the present invention is also applied to a one-way clutch in which the torque limit recess 46 is not provided. be able to.

  In the first embodiment, the case where the pulley unit is provided with a one-way clutch corresponding to the compressor for air conditioning, which is one of the engine auxiliary machines, is exemplified. However, the engine such as an alternator, a water pump, a cooling fan, It can be used as a pulley unit provided with a one-way clutch corresponding to an auxiliary machine, or a one-way clutch assembled to a pulley unit.

It is a sectional side view which shows the pulley unit provided with the one way clutch which concerns on Example 1 of this invention. It is a transverse cross section of a one way clutch similarly. It is a top view which expands and shows the state in which the roller and the coil spring were similarly accommodated in the pocket of the holder | retainer. It is a cross-sectional view which expands and shows the state in which the roller and the coil spring were similarly accommodated in the pocket of the holder | retainer. It is explanatory drawing which similarly shows the relationship between the flat surface of the outer peripheral surface of an inner ring body, the engagement piece of a cage | basket, and a contact avoidance part. It is explanatory drawing which shows the state rotated to the locking direction in the rotation angle which similarly accept | permitted. It is explanatory drawing which shows the relationship between the cam surface of the outer peripheral surface of the inner ring body of the conventional one-way clutch, and the engaging part of the inner peripheral surface of a holder | retainer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Casing 3 Projection cylinder part 4 Rotating shaft 10 Pulley unit 11 Pulley 20 Double row rolling bearing 40 One-way clutch 41 Outer ring body 42 Inner ring body 43 Cam surface 46 Torque limit recessed part 47 Flat surface (engagement part)
50 Cage 52 Column 55 Engagement piece (engagement part)
60 Coil spring 61 Roller

Claims (3)

In order to switch between a locked state in which the inner ring body and the outer ring body that are concentrically disposed radially inward and outer are synchronously rotated and a free state in which the inner ring body and the outer ring body are relatively rotated, of the opposed peripheral surfaces of the inner ring body and the outer ring body, A cam surface that forms a plurality of wedge-shaped spaces at predetermined intervals in the circumferential direction in cooperation with the other peripheral surface is formed on one peripheral surface,
In the plurality of wedge spaces, the same number of rollers and coil springs individually energizing the rollers in the locking direction for engaging each of the rollers in the wedge-shaped spaces are arranged in a state of being accommodated in the pockets of the cage. A one way clutch,
Between the cage and the member on which the cam surface is formed, an engagement portion that prevents the cage from rotating in the free direction and receives the reaction force of the coil spring is formed, respectively. A contact avoiding portion that allows rotation of the cage in the locking direction within a range of a predetermined angle is formed,
The one-way clutch characterized in that an allowable rotation angle of the cage in the locking direction is set to a revolution angle of the roller with respect to the inner ring body when torque is applied. The one-way clutch according to claim 1,
A torque limit recess is formed on one side in the circumferential direction of the cam surface. When a torque exceeding a predetermined value acts between the inner ring body and the outer ring body, the roller rolls over the cam surface and rolls the torque. It is configured so that torque transmission between the inner ring body and the outer ring body is cut off by being received in the recess for limit,
The allowable rotation angle of the cage in the locking direction is set to an angle corresponding to the displacement angle of the roller while the roller is received and arranged in the torque limit recess from the cam surface. One-way clutch characterized by The one-way clutch according to claim 2,
The cam surface is formed on the outer peripheral surface of the inner ring body,
On the outer peripheral surface of the inner ring body, a flat surface is formed at a position displaced in the axial direction with the cam surface,
The engaging portion that receives the reaction force of the coil spring by preventing the cage from rotating in the free direction is formed to be able to engage with the flat surface at the inner peripheral surface portion of the cage facing the flat surface. Formed by the engagement piece and the flat surface,
The one-way clutch characterized in that a contact avoiding portion that allows rotation of the cage in the locking direction within a predetermined angle range is formed in a cutout shape in the engagement piece.

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