JP4940995B2 - 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.

This type of one-way clutch may be assembled to a pulley unit used in, for example, engine accessories (alternator, compressor for air conditioner, water pump, cooling fan, etc.).
Further, as shown in FIGS. 7 and 8, the pulley 121 on which the transmission belt 108 to which the torque of the engine crankshaft is transmitted is stretched, and the rotor (rotor shaft) of the alternator as an auxiliary machine can be integrally rotated. There is a structure in which a one-way clutch 130 is disposed between the shaft body 111 and the shaft body 111 to be coupled to transmit or block torque from the pulley 121 to the shaft body 111.
Further, the one-way clutch 130 is between the opposing peripheral surfaces of the inner ring body (which may be configured by the shaft body 111 itself corresponding to the rotor) and the outer ring body (which may be configured by the pulley 121 itself). In addition, a plurality of wedge-shaped spaces are formed at predetermined intervals in the circumferential direction. In the plurality of wedge spaces, the same number of rollers 140 and coil springs 145 for individually urging each roller 140 toward the narrow side of the wedge-shaped space are held in a state where they are held by the cage 131. The thing of the provided structure is known (for example, refer patent document 1).
Further, as shown in FIGS. 7 and 8, the retainer 131 is configured so that the outer peripheral surface of the shaft body 111 serving as the inner ring body (or the inner periphery of the pulley 121 serving as the outer ring body) is maintained at a distance approaching both end faces of the roller 140. A pair of end plates 132 fixed to the surface), and a plurality of column portions 133 that define a plurality of pockets between the pair of end plates 132, and each column portion 133 is provided with a coil spring 145. A protrusion 134 that holds and guides expansion and contraction is provided.
JP 2003-214462 A

Incidentally, in the conventional cage 131 of the one-way clutch 130 shown in FIGS. 7 and 8, the coil spring 145, the column portion 133, and the protrusion 134 must be arranged in the circumferential direction with respect to each one roller 140. In some cases, it may be difficult to reduce the arrangement interval (arrangement pitch) between the adjacent rollers 140.
In other words, it may be difficult to increase the torque capacity by increasing the number of rollers 140 or to reduce the size.

  In view of the above problems, an object of the present invention is to easily reduce the arrangement interval (arrangement pitch) between adjacent rollers, and increase the number of rollers to increase the torque capacity or reduce the size. It is to provide a one-way clutch that can.

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. A one-way clutch that switches between
A plurality of wedge-shaped spaces are formed at predetermined intervals in the circumferential direction between the opposed peripheral surfaces of the inner ring body and the outer ring body,
In the plurality of wedge spaces, the same number of rollers and coil springs for individually urging each of the rollers toward the narrow side of the wedge-shaped space are respectively disposed in a state of being held by a cage,
The coil spring is wound long in the axial direction of the roller and has a longer diameter dimension larger than a length dimension of the roller,
The retainer has a pair of end plates that are fixed to the outer peripheral surface of the inner ring body or the inner peripheral surface of the outer ring body with a distance approaching both end faces of the roller.
The pair of end plates are formed with openings through which both sides of the coil spring in the major axis direction are inserted ,
The openings of the pair of end plates are formed with protrusions that hold both sides of the coil spring in the long diameter direction .

  According to the above configuration, by forming the major axis dimension of the coil spring larger than the length dimension of the roller, and by forming the pair of end plates in the openings through which the both sides in the major axis direction of the coil spring are inserted, A plurality of pillar portions can be deleted, and the roller storage space can be increased by this amount, and the arrangement interval (arrangement pitch) between adjacent rollers can be easily reduced. As a result, the torque capacity can be increased by increasing the number of rollers, or the size can be reduced.

Further, by forming a projection for holding the major axis direction on both sides of the coil spring into the opening formed in the pair of end plates of the hold control and the coil spring is effectively prevented a problem that positional deviation unforeseen it can.

The one-way clutch according to claim 2 is the one-way clutch according to claim 1 ,
The outer diameter side wall surfaces of the openings of the pair of end plates are characterized as guide surfaces that approach the coil spring and guide the coil spring to extend and contract.
According to the above configuration, the coil spring can be extended and contracted favorably by using the outer diameter side wall surface of the opening of the pair of end plates as the guide surface of the coil spring, and the coil spring is removed by the action of centrifugal force. It is possible to suppress deformation in the radial direction (that is, the inner peripheral surface of the outer ring body).
As a result, the coil spring can be prevented from coming into contact with the inner peripheral surface of the outer ring body, the wear due to the contact between the coil spring and the inner peripheral surface of the outer ring body can be prevented, and durability can be improved. Can do.

  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 based on the line II-II in FIG. FIG. 3 is a perspective view showing a state in which a pair of end plates, rollers, and coil springs of the cage are separated. FIG. 4 is a perspective view showing a state in which a pair of end plates, rollers, and coil springs of the cage are assembled. FIG. 5 is a front view showing the cage. 6 is a cross-sectional view based on the line VI-VI in FIG.
As shown in FIG. 1, the pulley unit including the one-way clutch according to the first embodiment exemplifies a case where the pulley unit is used for an alternator that is one of auxiliary components of an in-vehicle engine. 11, a pulley 21, a one-way clutch 30, a ball bearing 50, a roller bearing 55, and seal members 58 and 59.

As shown in FIGS. 1 and 2, the shaft body 11 is formed in a cylindrical shaft shape that is attached around a tip end shaft of a rotor shaft of an alternator rotor (not shown). A female screw 12 that is fastened to a male screw portion formed on the tip end side of the rotor shaft is formed at a substantially central portion in the axial direction of the inner hole of the shaft body 11, and an opening on one end side of the inner hole of the shaft body 11 is formed. A hexagonal hole-shaped fastening recess 13 into which a fastening tool such as a hexagonal bar can be fitted is formed.
In the first embodiment, the shaft body 11 constitutes the inner ring bodies of the one-way clutch 30, the ball bearing 50, and the roller bearing 55.

  As shown in FIGS. 1 and 2, the pulley 21 is concentrically disposed on the outer periphery of the shaft body 11 and constitutes the outer ring bodies of the one-way clutch 30, the ball bearing 50, and the roller bearing 55, and the outer periphery thereof. On the surface, a belt groove 22 having a corrugated cross section is formed on which the transmission belt 8 is stretched. The transmission belt 8 is stretched around the pulley of the crankshaft of the engine and transmits the torque of the crankshaft to the pulley 21.

As shown in FIGS. 2 to 6, the one-way clutch 30 includes a shaft body 11 as an inner ring body, a pulley 21 as an outer ring body, and an axial center of an annular space between the shaft body 11 and the pulley 21. In the region, a plurality of rollers 40 arranged at predetermined intervals in the circumferential direction, a coil spring 45 for individually urging these rollers 40 toward the narrow side of the wedge-shaped space described below, and a plurality of rollers 40 And a cage 31 for holding the coil spring 45.
That is, a plurality (10 in FIG. 2) of wedge-shaped spaces are formed at predetermined intervals in the circumferential direction between the opposed peripheral surfaces of the shaft body 11 and the pulley 21. The same number of rollers 40 and coil springs 45 for individually urging each of the rollers 40 toward the narrow side of the wedge-shaped space are disposed in a state of being held by the cage 31.
In the first embodiment, on the outer peripheral surface of the shaft body 11, in order to form a plurality of wedge spaces, the same number of flat cam surfaces 15 (or curved surfaces) as the plurality of wedge spaces are formed in the circumferential direction. As a result, the outer peripheral surface of the shaft 11 forms a regular polygon (a regular decagon in FIG. 2), while the inner peripheral surface of the pulley 21 is circular.

  As shown in FIGS. 3 to 6, the coil spring 45 is formed by winding a spring wire in an elliptical shape that is long in the axial direction of the roller 40, and the major axis dimension is larger than the length dimension of the roller 40. ing.

As shown in FIGS. 3 to 5, the retainer 31 has a polygonal inner hole that is fitted and fixed (for example, press-fitted and fixed) to the outer peripheral surface of the shaft body 11 while maintaining an interval close to both end surfaces of the roller 40. It has a pair of end plates 32 penetrating in the center.
The pair of end plates 32 are formed with a plurality of notched openings 34 at predetermined intervals through which the both sides of the plurality of coil springs 45 in the major axis direction are respectively inserted.
On one wall surface of each opening 34 of the pair of end plates 32, projections 36 are formed that hold both sides in the major axis direction of the proximal winding portion of the coil spring 45.
The coil spring 45 is in a state in which both sides in the major axis direction of the proximal winding portion are held by the projections 36 of the opening 34 of the pair of end plates 32 and one wall surface of the opening 34 is supported as a spring seat. Thus, the tip winding portion comes into contact with the outer peripheral surface of the roller 40. As a result, the roller 40 is elastically biased toward the narrow side (the side in the locked state) of the wedge-shaped space formed by the cam surface 15 of the shaft body 11 and the inner peripheral surface of the pulley 21.
Further, the outer diameter side wall surface of the opening of the pair of end plates 32 is a guide surface 35 that approaches the coil spring 45 and guides the coil spring 45 to extend and contract.

As shown in FIG. 1, in an annular space between the shaft body 11 and the pulley 21, a ball bearing 51 serving as a rolling bearing is formed on one of both sides of the pair of end plates 32 of the one-way clutch 30. A plurality of balls 52 are arranged to be able to roll while being held by a cage 53. Further, a plurality of rollers 57 constituting a roller bearing 56 as a rolling bearing are arranged on the other of both sides of the pair of end plates 32 so as to be able to roll while being held by a cage 58.
Further, seal rings 60 and 61 for sealing the annular space are mounted in the vicinity of both openings of the annular space.

The pulley unit including the one-way clutch according to the first embodiment is configured as described above.
Therefore, when the rotational speed of the pulley 21 becomes higher than the rotational speed of the shaft body 11, the roller 40 of the one-way clutch 30 bites into the narrow side of the wedge-shaped space and is locked, so that the shaft body 11 is integrated with the pulley 21. Rotate.
When the rotational speed of the pulley 21 becomes slower than the rotational speed of the shaft body 11, the roller 40 of the one-way clutch 30 moves out of the lock position and moves to the wider side of the wedge-shaped space to switch to the free state. As a result, the shaft body 11 is blocked from transmitting the rotational power from the pulley 21, but the shaft body 11 continues to rotate after the interruption because the rotor of the alternator has a large rotational inertia.

Now, in the cage 31 of the one-way clutch 30, projections 36 are formed in the notched openings 34 formed in the pair of end plates 32, and the major axis of the proximal winding portion of the coil spring 45 is formed on these projections 36. Because it is configured to hold both sides in the direction, multiple pillars are not required compared to the conventional type in which a plurality of pillars are formed in the cage and projections are formed on each pillar to hold the coil spring. Can be deleted.
For this reason, the roller storage space between the pair of end plates 32 can be increased by deleting the plurality of column portions, and the arrangement interval (arrangement pitch) of the adjacent rollers 40 can be easily reduced. It becomes. As a result, the number of rollers 40 can be increased, and it becomes easy to increase the torque capacity or reduce the size.

Further, in the cage 31 of the one-way clutch 30, the coil spring 45 can be extended and contracted satisfactorily by using the outer diameter side wall surface of the opening 34 of the pair of end plates 32 as the guide surface 35 of the coil spring 45. In addition, the coil spring 45 can be prevented from being deformed toward the outer diameter direction, that is, the inner peripheral surface of the pulley 21 by the action of the centrifugal force.
As a result, the coil spring 45 can be prevented from coming into contact with the inner peripheral surface of the pulley 21 and wear due to contact between the coil spring 45 and the inner peripheral surface of the pulley 21 can be prevented, thereby improving durability. Can be planned.

The present invention is not limited to the first embodiment.
For example, in the first embodiment, the cam surface 15 is formed on the outer peripheral surface of the shaft body 11, and the wedge-shaped space is formed by the inner peripheral surface of the pulley 21 and the cam surface 15, but the cam is formed on the inner peripheral surface of the pulley 21. A surface may be formed, and a wedge-shaped space may be formed by the outer peripheral surface of the shaft body 11 and the cam surface.
However, in this case, the pair of end plates 32 of the cage 31 are fixed (for example, press-fitted and fixed) to the inner peripheral surface of the pulley 21 with a distance approaching both end surfaces of the roller 40.

In the first embodiment, the case where the inner ring body of the one-way clutch 30 is the shaft body 11 and the outer ring body is the pulley 21 is illustrated. However, the inner ring body is formed separately from the shaft body 11. You may comprise so that it may assemble | attach to the outer peripheral surface of the shaft body 11, and you may comprise so that an outer ring body may be formed separately from the pulley 21, and may be assembled | attached to the inner peripheral surface of the pulley 21. FIG.
Further, in the first embodiment, the case where the pulley unit is provided with a one-way clutch corresponding to an alternator which is one of engine auxiliary machines is exemplified. However, the compressor for the air conditioner, the water pump, and the cooling fan are exemplified. It can be used as a pulley unit having a one-way clutch corresponding to an engine accessory such as a one-way clutch assembled to the pulley unit.
Further, the one-way clutch of the present invention can be adopted even with gears or sprockets other than the 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 sectional drawing based on the II-II line of FIG. It is a perspective view which shows the shape which similarly separated a pair of end plate, roller, and coil spring of a holder | retainer. It is a perspective view which shows the state which similarly assembled | attached the pair of end plate, roller, and coil spring of the holder | retainer. It is a front view showing a cage similarly. It is sectional drawing based on the VI-VI line of FIG. 5 similarly. It is a side cross section which shows the pulley unit provided with the conventional one-way clutch. It is sectional drawing based on the VIII-VIII line of FIG. 7 similarly.

Explanation of symbols

11 Shaft (Inner ring)
21 Pulley (outer ring body)
30 One-way clutch 31 Cage 32 Pair of end plates 34 Opening 35 Guide surface 36 Projection 40 Roller 45 Coil spring

Claims (2)

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,
A plurality of wedge-shaped spaces are formed at predetermined intervals in the circumferential direction between the opposed peripheral surfaces of the inner ring body and the outer ring body,
In the plurality of wedge spaces, the same number of rollers and coil springs for individually urging each of the rollers toward the narrow side of the wedge-shaped space are respectively disposed in a state of being held by a cage,
The coil spring is wound long in the axial direction of the roller and has a longer diameter dimension larger than a length dimension of the roller,
The retainer has a pair of end plates that are fixed to the outer peripheral surface of the inner ring body or the inner peripheral surface of the outer ring body with a distance approaching both end faces of the roller.
The pair of end plates are formed with openings through which both sides of the coil spring in the major axis direction are inserted ,
The one-way clutch characterized in that protrusions are formed in the openings of the pair of end plates to hold both sides of the coil spring in the long diameter direction . The one-way clutch according to claim 1 ,
The one-way clutch characterized in that the outer diameter side wall surface of the opening of the pair of end plates is a guide surface that approaches the coil spring to extend and guide the coil spring.

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