JP2009079672A - Pulley unit - Google Patents

Abstract

A pulley unit capable of preventing a roller from being lifted by a centrifugal force when the roller is received in a torque limit recess and is in a torque limit state.
A pulley 11, a rolling bearing 20, and a one-way clutch 40 are assembled between a protruding cylinder portion 3 and a rotating shaft 4 of an engine accessory 1. The one-way clutch 40 is formed on an outer ring body 41 provided in a fixed state on the inner peripheral surface of the pulley 11, an inner ring body 42 provided in a fixed state on the outer peripheral surface of the rotary shaft 4, and an outer peripheral surface of the inner ring body 42. A cam surface 43 that forms a plurality of wedge-shaped spaces at predetermined intervals in the circumferential direction, and a roller 61 are provided. For a torque limit that interrupts torque transmission by receiving a roller 61 that rolls over the cam surface 43 when a torque greater than a predetermined value acts on one side in the circumferential direction of the cam surface 43 of the inner ring body 42. A recess 46 is formed.
[Selection] Figure 1

Description

  The present invention relates to a pulley unit used in an engine auxiliary machine (for example, an air conditioning compressor, an alternator, a water pump, a cooling fan, etc.).

Conventionally, as shown in FIG. 6 and FIG. 7, when the engine accessory of the vehicle-mounted engine is an air conditioning compressor (hereinafter simply referred to as a compressor), it is integrally projected from one side of the casing 102 of the compressor 101. A pulley unit 110 including a pulley 111, a double row rolling bearing 120, and a one-way clutch 140 is assembled between the protruding cylindrical portion 103 and the rotating shaft 104 disposed at the central portion of the protruding cylindrical portion 103. Structures are known.
In this case, an outer ring 121, an inner ring 122, and a double row ball 123 are arranged between the outer peripheral surface of the protruding cylindrical portion 103 and the inner peripheral surface of the cylindrical body 113 fixed integrally to the inner periphery of one end of the pulley 111. , 124 is assembled.
In addition, the one-way clutch 140 is configured to switch the outer ring body 141, the inner ring body 142, the outer ring body 142 and the inner ring body 142 in a locked state in which the outer ring body 141 and the inner ring body 142 are synchronously rotated and a free state in which the outer ring body 142 and the inner ring body 142 are relatively rotated. A cam surface 143 formed on the surface and forming a plurality of wedge-shaped spaces at predetermined intervals in the circumferential direction in cooperation with the inner peripheral surface of the outer ring body 141, and rollers respectively disposed in the plurality of wedge spaces 161, a coil spring 160 that individually urges the rollers 161 in the locking direction, and a cage 150 that holds the plurality of rollers 161 and the coil springs 160.
Further, the inner ring body 142 of the one-way clutch 140 is press-fitted and fixed to the outer peripheral surface of the tubular body 113 on the pulley 111 side.
On the other hand, an annular member 130 is fitted on the outer peripheral surface near the end of the rotating shaft 104 so that torque can be transmitted, and is tightened by a nut 135. The outer ring body 141 of the one-way clutch 140 is connected to the outer peripheral portion of the annular member 130 by an appropriate connecting member so that torque can be transmitted.
As a result, the torque of the crankshaft of the in-vehicle engine is transmitted to the pulley 111 via the transmission belt 118. Torque from the pulley 111 side is transmitted to the rotating shaft 104 of the compressor 101 via the one-way clutch 140 and the annular member 130.
In addition, the cam of the inner ring body 142 is used to shut off torque transmission when the rotating shaft 104 of the compressor 101 is locked by seizure or the like and a torque (load torque) of a predetermined value or more is applied from the pulley 111 to the rotating shaft 4. A torque limit recess 146 is formed on one side of the surface 143 in the circumferential direction. When a torque greater than a predetermined value acts between the inner ring body 142 on the pulley 111 side and the outer ring body 141 on the rotating shaft 104 side, the roller 161 rolls over one side of the cam surface 143 and is used for torque limit. Received within the recess 146. As a result, the inner ring body 142 is idled together with the pulley 111, and torque transmission from the pulley 111 side to the rotating shaft 104 is cut off.
For example, Patent Document 1 discloses a one-way clutch in which a torque limit recess is formed on one side in the circumferential direction of the cam surface of the inner ring body.
JP 2002-106608 A

By the way, in the conventional pulley unit 110 as shown in FIGS. 6 and 7, when the roller 161 is received in the torque limit recess 146 and enters the torque limit state, the inner ring body 142 is idled together with the pulley 111. .
When the inner ring body 142 together with the pulley 111 is in an idling state, the roller 161 may be lifted from the torque limit recess 146 by centrifugal force, and may be inadvertently caught between the inner ring body 142 and the outer ring body 141 to be locked. is there.

  In view of the above problems, an object of the present invention is to provide a pulley unit that can prevent the roller from being lifted by centrifugal force when the roller is received in the torque limit recess and is in the torque limit state. is there.

In order to achieve the above object, a pulley unit according to claim 1 of the present invention includes a projecting cylinder portion projecting to one side of a casing of an engine accessory, and a rotating shaft disposed at a central portion of the projecting cylinder portion. A pulley unit comprising a pulley, a rolling bearing, and a one-way clutch,
The one-way clutch includes an outer ring body provided in a fixed state on the inner peripheral surface of the pulley;
An inner ring body that is concentric with the outer ring body and provided in a fixed state on the outer peripheral surface of the rotating shaft;
In order to switch between a locked state in which the inner ring body and the outer ring body are rotated synchronously and a free state in which the inner ring body and the outer ring body are rotated relative to each other, a plurality of inner ring bodies are formed in cooperation with the inner circumferential surface of the outer ring body. A cam surface that forms a wedge-shaped space at a predetermined interval in the circumferential direction;
Rollers respectively disposed in the plurality of wedge spaces;
With
The outer ring body, the inner ring body, and the inner ring body are received on one side in the circumferential direction of the cam surface of the inner ring body by receiving the roller that rolls over the cam surface when a torque greater than a predetermined value is applied. A torque limit recess for blocking the torque transmission is formed.

According to the above configuration, when the rotating shaft of the engine auxiliary machine is locked due to seizure or the like and a torque of a predetermined value or more acts between the outer ring body on the pulley side and the inner ring body on the rotating shaft side of the engine auxiliary machine, the roller Gets over one side of the cam surface of the inner ring body and is received in the torque limit recess. As a result, the outer ring body is idled together with the pulley, and torque transmission from the pulley side to the rotating shaft is interrupted.
At this time, the inner ring body is in a stationary state together with the rotating shaft in the locked state. For this reason, the roller received in the recess for torque limit of the inner ring body does not receive the action of centrifugal force.
As a result, it is possible to prevent the roller from being lifted from the torque limit recess, and it is possible to suppress a problem that the roller unexpectedly bites between the inner ring body and the outer ring body.

  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 compressor including a pulley unit according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing the one-way clutch of the pulley unit. FIG. 3 is an enlarged plan view showing a state where a roller and a coil spring are housed in a pocket of a cage of a one-way clutch. FIG. 4 is an enlarged cross-sectional view showing a state where a roller and a coil spring are housed in a pocket of a cage of a one-way clutch. FIG. 5 is an explanatory view showing a state in which the roller of the one-way clutch is received in the recess for torque limit.

  As shown in FIG. 1, the pulley unit 10 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, and a casing 2 of the compressor 1. Assembling between the projecting cylinder part 3 integrally projecting from one side and the rotating shaft 4 of the compressor 1 assembled concentrically with the central part of the projecting cylinder part 3 In addition, a pulley 11, a double row rolling bearing 20, and a 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 a belt groove 12 having a corrugated cross section 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.
A double row rolling bearing 20 and a one-way clutch 40 are arranged in parallel in an annular space between the inner peripheral surface of the pulley 11 and the outer peripheral surface of the protruding cylindrical portion 3.

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.
In the double row rolling bearing 20, the inner ring 22 is press-fitted and fixed to the projecting cylindrical portion 3 on the compressor 1 side, and the outer ring 21 is press-fitted and fixed to the inner peripheral surface of the pulley 11.

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 one-way clutch 40 has its inner ring body 42 fixed to the clutch mounting shaft portion 4 a at the tip of the rotating shaft 4 of the compressor 1 so that torque can be transmitted, and the outer ring body 41 is press-fitted and fixed to the inner peripheral surface of the pulley 11. Has been.

  That is, as shown in FIGS. 2 and 4, a plurality (six in FIG. 2) of wedge-shaped spaces between the outer ring body 41 of the one-way clutch 40 and the inner ring body 42 are predetermined in the circumferential direction. A flat surface (or curved surface) cam surface 43 is formed at a predetermined interval 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. ing. In the plurality of wedge spaces, the same number of rollers 61 and coil springs 60 that individually bias these rollers 61 in the locking direction (the narrow side of the wedge space) are accommodated in the respective pockets 51 of the cage 50. Each is arranged in the state.

As shown in FIG. 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 the rotary shaft 4 of the compressor 1 is locked by seizure or the like, and a torque (load torque) of a predetermined value or more is applied from the outer ring body 41 on the pulley 11 side to the inner ring body 42 on the rotary shaft 4 side, FIG. As shown, the roller 61 rolls over the cam surface 43 and is received in the torque limit recess 46, so that the roller 61 cannot be caught between the outer ring body 41 and the inner ring body 42. Torque transmission between the outer ring body 41 on the pulley 11 side and the inner ring body 42 on the rotating shaft 4 side is cut off.

Further, the cage 50 of the one-way clutch 40 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 arranged in the circumferential direction. Is formed. The cage 50 is fitted to the outer peripheral surface of the inner ring body 42.
A protrusion 53 into which the proximal winding portion of the coil spring 45 is inserted is provided on one side surface (a surface facing the narrow side of the wedge space) of both side wall surfaces of each pillar portion 52 of the cage 50. Yes. In addition, on the other side of the column 52 of the cage 50 that faces the roller 61, when the roller 61 is received in the torque limit recess 46, the roller 61 is clamped in cooperation with the torque limit recess 46. It is desirable to form a roller holding portion 55 that holds the shape. Furthermore, the roller holding part 55 is more preferably formed in an arc shape along the outer peripheral surface of the roller 61.
In the first embodiment, the reaction force of the coil spring 60 is received between the outer peripheral surface of the inner ring body 42 and the inner peripheral surface of the cage 50 while preventing the cage 50 from rotating in the free direction. An engagement portion (not shown) is provided that allows the retainer 50 to rotate in the locking direction in accordance with the displacement angle of the roller 61 when it is disposed in the torque limit recess 46 from the cam surface 43. ing.

The coil spring 60 is formed by winding a spring wire into an elliptical shape, a rectangular shape or the like, and the base end winding portion of the coil spring 60 is fitted into the projection 53 with the base portion of the projection 53 of the column portion 52 as a spring seat. 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).
Note that engaging portions (not shown) that engage with each other and receive a reaction force of the coil spring 60 are formed on the inner peripheral surface of the cage 50 and the outer peripheral surface of the inner ring body 42.

Further, in the first embodiment, as shown in FIG. 1, a rolling bearing 70 is located on one side of the cage 50 in the annular space between the outer ring body 41 and the inner ring body 42 of the one-way clutch 40. A plurality of balls 71 that are configured are arranged so as to be able to roll while being held by a holder 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 used in the compressor 1 as an engine accessory 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 in-vehicle engine, the outer ring body 41 of the one-way clutch 40 is rotated together with the pulley 11. The torque of the outer ring body 41 is transmitted to the inner ring body 42 and the rotating shaft 4 of the compressor 1 by the roller 61, and the rotating shaft 4 is rotated.
That is, when the on-board engine is operated, when the rotation speed of the pulley 11 is higher than the rotation speed of the rotation shaft 4, the one-way clutch 40 is locked, so that the rotation 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 in the torque limit recess 46. When the roller 61 is received in the torque limit recess 46, the pulley 11 is idled together with the outer ring body 41, and torque transmission from the pulley 11 side to the rotating shaft 4 is interrupted.
At this time, as shown in FIG. 5, the inner ring body 42 is in a stationary state together with the rotating shaft 4 in a locked state of the compressor 1. For this reason, the roller 61 received in the torque limit recess 46 of the inner ring body 42 is not affected by the centrifugal force.
As a result, it is possible to prevent the roller 61 from floating from the torque limit recess 46 on the outer peripheral surface of the inner ring body 42, and to suppress the problem that the roller 61 bites between the inner ring body 42 and the outer ring body 41 unexpectedly. Can do.

Further, in the first embodiment, as shown in FIG. 5, when the roller 61 is received in the torque limit recess 46 and the pulley 11 is idled together with the outer ring body 41, the torque limit recess 46 and the holding The roller 61 can be held in a sandwiched manner by cooperation with the roller holding portion 55 of the column portion 52 of the container 50.
For this reason, it is possible to prevent the roller 61 from floating or rattling from the torque limit recess 46 due to vibration or the like during vehicle travel. As a result, it is possible to prevent the roller 61 from accidentally biting between the inner ring body 42 and the outer ring body 41, and to keep the pulley 11 in the idling state together with the outer ring body 41.

The present invention is not limited to the first embodiment.
For example, in the first embodiment, the case where the arc-shaped roller holding portion 55 along the outer peripheral surface of the roller 61 is formed on the other side surface of the column portion 52 of the cage 50 is illustrated. The present invention can be implemented even if the portion 55 is not necessarily provided.
Moreover, in the said Example 1, although the case where it was a pulley unit employ | adopted as the compressor as an engine auxiliary machine was illustrated, it uses as a pulley unit corresponding to engine auxiliary machines, such as an alternator, a water pump, and a cooling fan. Is possible.

It is a sectional side view which shows the compressor provided with the pulley unit which concerns on Example 1 of this invention. It is a cross-sectional view which similarly shows the one-way clutch of a pulley unit. 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 of a one-way clutch. 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 cage | basket of a one-way clutch. Similarly, it is explanatory drawing which shows the state in which the roller of the one-way clutch was received in the recessed part for torque limits. It is a sectional side view which shows the compressor provided with the conventional pulley unit. It is a cross-sectional view which similarly shows the one-way clutch of a pulley unit.

Explanation of symbols

1 Compressor (engine accessory)
DESCRIPTION OF SYMBOLS 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 50 Cage 52 Pillar part 55 Roller holding part 60 Coil Spring 61 Roller

Claims (1)

A pulley, a rolling bearing, and a one-way clutch are assembled between a protruding cylindrical portion protruding from one side of the casing of the engine accessory and a rotating shaft disposed at the center of the protruding cylindrical portion. A pulley unit comprising:
The one-way clutch includes an outer ring body provided in a fixed state on the inner peripheral surface of the pulley;
An inner ring body that is concentric with the outer ring body and provided in a fixed state on the outer peripheral surface of the rotating shaft;
In order to switch between a locked state in which the inner ring body and the outer ring body are rotated synchronously and a free state in which the inner ring body and the outer ring body are rotated relative to each other, a plurality of inner ring bodies are formed in cooperation with the inner circumferential surface of the outer ring body. A cam surface that forms a wedge-shaped space at a predetermined interval in the circumferential direction;
Rollers respectively disposed in the plurality of wedge spaces;
With
The outer ring body, the inner ring body, and the inner ring body are received on one side in the circumferential direction of the cam surface of the inner ring body by receiving the roller that rolls over the cam surface when a torque greater than a predetermined value is applied. A pulley unit having a torque limit recess for interrupting torque transmission.

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