JP6716284B2 - One-way clutch and one-way clutch built-in rotation transmission device - Google Patents

Description

The present invention relates to a one-way clutch using a sprag as an engaging element, and a one-way clutch built-in rotation transmission device incorporating the one-way clutch.

A one-way clutch using a sprag as an engaging element changes the posture of a sprag arranged between the inner ring and the outer ring depending on the relative rotation direction of the coaxially arranged inner ring and outer ring around the axis. , Has a function of switching between a state in which relative rotation between the inner ring and the outer ring is allowed and a state in which relative rotation is blocked.

This type of one-way clutch is provided with a cage having pocket portions for inserting sprags at regular intervals along the circumferential direction between an inner ring and an outer ring, and each of the pocket portions has a so-called gourd-shaped cross section. A sprag having a shape is arranged.

Each sprag has an outer ring side cam surface and an inner ring side cam surface formed by a curved surface having one or more radii of curvature. The outer ring side cam surface engages with the inner peripheral raceway surface of the outer ring, and the inner ring side cam surface engages with the outer peripheral raceway surface of the inner ring.

For example, Patent Document 1 discloses a technique of a one-way clutch built-in rotation transmission device (one-way clutch built-in pulley) that contains a sprag type one-way clutch. This pulley with a built-in one-way clutch is attached to the rotating shaft of an accessory of an automobile engine and transmits the rotation transmitted from the accessory belt in one direction around the rotating shaft and in the opposite direction around the rotating shaft. The rotation of the one-way clutch is prevented from being transmitted to the rotary shaft of the auxiliary machine by idling of the one-way clutch.

JP, 2009-299864, A

In the conventional sprag type one-way clutch, when some abnormal torque that is not normally assumed is input in the input direction indicated by an arrow in FIG. 5A, or an abnormal impact torque is input. At this time, the sprag may roll over (fall over to the torque load side) as shown in FIG. 5(b), or the sprag may pop out (fall over to the idling side) as shown in FIG. 5(c). There is. If the sprag rolls over or pops out, the one-way clutch can become slippery or disengageable.

Therefore, an object of the present invention is to prevent the sprag from tipping over when an abnormal torque or an abnormal impact torque is input to the sprag type one-way clutch.

In order to solve the above-mentioned problems, the present invention provides an outer ring and an inner ring that are relatively rotatable about an axis, and an outer ring and an inner ring that are arranged along the circumferential direction between the outer ring and the inner ring. A plurality of sprags that engage with the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring to couple the outer ring and the inner ring when relatively rotated in one direction, and release the engagement when relatively rotated in the other direction; A retainer for holding the sprag along the circumferential direction, an elastic member for urging the sprag in a direction to engage the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, and the disengagement of the sprag. In addition, the one-way clutch is provided with a fall prevention mechanism for preventing tilting in the engaging direction or the opposite direction with respect to the neutral state by a certain angle or more.

Here, the fall prevention mechanism is a groove formed along the circumferential direction on the end surface of the sprag, a slit formed along the circumferential direction on the end surface of the cage, and inserted into the slit and the groove. And a fall prevention member extending in the circumferential direction, and when the sprag tilts by a certain angle or more with respect to the neutral state, the fall prevention member comes into contact with the inner side surface of the groove to regulate the tilt of the sprag. can do.

An annular member can be adopted as the fall prevention member. Further, the fall prevention member may adopt a configuration in which the inner diameter side surface and the outer diameter side surface of the slit are in press-contact with each other, that is, the fall prevention member is press-fitted and fixed in the slit. ..

Further, the cage is configured to include a caulking portion protruding at the edge of the slit to hold the fall prevention member, that is, the fall prevention member is caulked and fixed in the slit. You can The caulked part is formed by plastically deforming a part of the metal when the cage material is metal, and by melting and deforming a part of the resin by heating etc. when the cage material is resin. can do.

As yet another form, the retainer may employ a configuration in which a snap fit portion that holds the fall prevention member is provided on an edge of the slit.

A one-way clutch built-in rotation transmission device including a pulley, a gear, or a sprocket that rotates integrally with the outer ring on the outer diameter side of the outer ring can be employed by using the one-way clutch having each of these configurations.

A rotation shaft for driving an auxiliary machine included in an automobile engine may be connected to an inner ring of the one-way clutch built-in rotation transmission device.

This invention is provided with a fall prevention mechanism for preventing the sprag from tilting in the engaging direction or the opposite direction by a certain angle or more with respect to the neutral state in which the engagement is released, so that the sprag is prevented from falling. can do.

1 shows an embodiment of the present invention, (a) is a sectional view taken along line AA of (b), and (b) is a sectional view. (A)-(c) is an enlarged view of a main part of FIG. 1(a). (A) is a perspective view of a cage, (b) is a perspective view of a fall prevention member, and (c) is a perspective view of a sprag. (A) and (b) are principal part enlarged sectional views showing a fixing structure of a fall prevention member to a cage. (A)-(c) is a principal part enlarged view which shows the fall example of a sprag.

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the sprag type one-way clutch 10 (hereinafter, simply referred to as “clutch 10”) of this embodiment includes an outer ring 1 having an inner peripheral raceway surface on an inner peripheral surface 1a thereof, and an inner ring 1 An inner race 2 having an outer raceway surface on its outer circumferential surface 2a, and a sprag 3 arranged between the outer race 1 and the inner race 2 for transmitting torque between the inner raceway surface and the outer raceway surface. It is a thing.

Further, the clutch 10 holds the sprags 3 at equal intervals along the circumferential direction, and the outer ring 1 in order to urge the sprags 3 in a direction to engage the outer circumferential raceway surface and the inner circumferential raceway surface. And an elastic member 5 arranged between the inner ring 2 and the inner ring 2.

The outer ring 1 and the inner ring 2 are rotatable relative to each other about an axis, and the sprag 3 is configured to rotate between the inner peripheral surface 1a of the outer ring 1 and the inner ring 2 when the outer ring 1 and the inner ring 2 relatively rotate about the axis of the clutch 10 in one direction. The outer ring 1 and the inner ring 2 are joined by engaging with the outer peripheral surface 2a. When the outer ring 1 and the inner ring 2 relatively rotate around the axis of the clutch 10 in the other direction, the engagement is released.

The cage 4 connects a pair of annular end portions 4c juxtaposed along the axial direction of the clutch 10 and a column portion connecting the annular end portions 4c, 4c at a constant interval along the circumferential direction around the axial center. 4b (see FIGS. 1 and 3).

The space between the pillar portions 4b, 4b adjacent to each other in the circumferential direction penetrates from the inner diameter side to the outer diameter side to form a pocket portion 4a for housing the sprag 3. A holding portion 4d for holding the elastic member 5 is formed in the central portion of the pillar portion 4b, that is, in the central portion of the pillar portion 4b in the axial direction of the clutch 10. In this embodiment, the elastic member 5 is a coil spring, but another elastic member 5 such as a leaf spring or a ribbon spring may be adopted (see FIGS. 1 and 3).

A fall prevention mechanism 20 for preventing the sprag 3 from falling is provided between the sprag 3 and the cage 4. The fall prevention mechanism 20 prevents the sprag 3 from tilting in the engaging direction or the opposite direction by a certain angle or more with respect to the neutral state in which the engagement is released.

As shown in FIGS. 3A to 3C, the configuration of the fall prevention mechanism 20 includes a groove 23 formed in the end surface of the sprag 3 along the circumferential direction and a groove 23 formed in the end surface of the cage 4 along the circumferential direction. It is provided with the formed slit 24 and the fall prevention member 22 which is inserted into the slit 24 and the groove 23 and extends in the circumferential direction.

As shown in FIG. 3( c ), the sprag 3 has an inner ring side cam surface 3 a and an outer ring side cam surface 3 b that are formed by curved surfaces, and the inner ring side cam surface 3 a is on the outer peripheral surface 2 a of the inner ring 2 and the outer ring side. The cam surface 3b engages with the inner peripheral surface 1a of the outer ring 1. The groove 23 of the end surface 3c of the sprag 3 is provided between the side surfaces connecting the inner ring side cam surface 3a and the outer ring side cam surface 3b, and has a width w2 slightly wider than the width w1 of the fall prevention mechanism 20 over the entire length thereof. It is formed in a straight line.

As shown in FIG. 3A, the slit 24 of the retainer 4 is a circular groove portion formed in the circumferential direction along the end surface 4e of the annular end portion 4c of the retainer 4. The slit 24 is formed to have the same width w1 as the fall prevention mechanism 20 or a width w3 slightly smaller than the width w1.

As the fall prevention member 22, in this embodiment, as shown in FIG. 3B, a metal annular member (fixing ring) is adopted. The fall prevention member 22 is in pressure contact with both the inner diameter side surface 24a and the outer diameter side surface 24b of the slit 24. That is, the fall prevention member 22 is press-fitted and fixed in the slit 24. The fall prevention member 22 is inserted into the slit 24 of the cage 4 from the end surface 4e after inserting the sprag 3 into the pocket 4a of the cage 4.

As shown in FIG. 4A, the retainer 4 may be provided with a caulking portion 26 protruding at the edge of the slit 24 for holding the fall prevention member 22. The caulking portion 26 is formed by plastically deforming a part of the resin cage 4 or by melting it with heat to deform it. The crimp portion 26 is formed after the fall prevention member 22 is inserted into the slit 24 of the cage 4, and holds the fall prevention member 22 so as not to jump out from the slit 24.

Instead of the crimp portion 26, a snap fit portion 27 may be provided as shown in FIG. The snap-fit portion 27 is a pair of protruding claws provided on the edge of the slit 24, and when the fall prevention member 22 is inserted into the slit 24, the snap fit portion 27 is elastically deformed to open the gap between the pair of protruding claws and to fall. The prevention member 22 is allowed to pass. After the fall prevention member 22 is inserted into the slit 24, the elastic deformation is released, the distance between the pair of protruding claws returns to the original state, and the fall prevention member 22 is held so as not to jump out from the slit 24. ..

The crimp portion 26 and the snap fit portion 27 can be provided as needed. When such an assembling method and a manufacturing method of the one-way clutch 10 using the crimp portion 26 and the snap fit portion 27 are not adopted, the crimp portion 26 and the snap fit portion 27 may be omitted.

The operation of the fall prevention mechanism 20 will be described. The state shown in FIG. 2A is the neutral state of the sprag 3. In this neutral state, no torque is input to the outer ring 1, which is the input side bearing ring.

Conventionally, when some abnormal torque is input to the outer ring 1, the sprag 3 may try to roll over (fall over to the torque load side) as shown in FIG. 5B. According to this invention, when an abnormal torque is input, the overturn preventing member 22 contacts the side surfaces 23a, 23b of the groove 23 of the sprag 3 at the contact points 21a, 21b as shown in FIG. 2(b). To do. As a result, the tilt of the sprag 3 toward the engaging side, that is, the tilt in the clockwise direction in the drawing is restricted. As a result, the fall of the sprag 3 is prevented.

Further, when some abnormal impact torque is input to the outer ring 1, conventionally, as shown in FIG. 5C, the sprag 3 may try to pop out (fall over to the idling side). According to the present invention, when the abnormal impact torque is input, the overturn preventing member 22 is attached to the side surfaces 23a and 23b of the groove 23 of the sprag 3 at the contact points 21c and 21d, as shown in FIG. 2C. Contact. As a result, the tilt of the sprag 3 to the opposite side of the engaging side, that is, the counterclockwise tilt in the drawing is restricted. As a result, the fall of the sprag 3 is prevented.

As described above, when the sprag 3 tilts by a certain angle or more with respect to the neutral state, the side surfaces 23a and 23b of the groove 23 of the sprag 3 come into contact with the overturn preventing member 22 to regulate the tilt of the sprag 3, so that the sprag 3 moves. A situation in which the vehicle falls and is caught between the outer ring 1 and the inner ring 2 is prevented.

It should be noted that in a normal torque load state, the fall prevention member 22 and the side surfaces 23a and 23b of the groove 23 do not come into contact with each other, or even if they come into contact with each other, they are in slight contact with each other. It does not affect the tilting of. When the sprag 3 tilts toward the engagement side or the anti-engagement side with respect to the neutral state by a certain amount or more, as described above, the inner diameter surface or the outer diameter surface of the fall prevention member 22 and the side surface 23a of the groove 23, The contact with 23b can prevent the sprag 3 from falling.

In this embodiment, the clutch 10 as described above is used, and as shown in FIG. 1, a pulley 11 which rotates integrally with the outer ring 1 is provided on the outer diameter side of the outer ring 1, and an inner ring 2 is a supplementary component of an automobile engine. A one-way clutch built-in rotation transmission device (one-way clutch built-in pulley) connected to a rotating shaft 28 for driving the machine is adopted. An endless belt is wound between the pulley 11 and a crank pulley provided on the crankshaft of the engine, and rotation is transmitted via the belt.

Instead of the pulley 11, a one-way clutch built-in rotation transmission device having a gear or a sprocket on the outer diameter side of the outer ring 1 may be used.

As described above, in the present invention, since the sprag 3 which is the engaging element between the outer race 1 and the inner race 2 is provided with the fall prevention mechanism 20 for preventing the sprag 3 from being inclined at a certain angle or more with respect to the neutral state, It is possible to prevent roll-over and pop-out of the sprag 3.

In the above embodiment, a metal member is used as the fall prevention member 22, but the fall prevention member 22 is not limited to a metal, and the material thereof may be hard resin. Further, in the above-described embodiment, the annular member is adopted as the fall prevention member 22, but the fall prevention member 22 is not limited to the annular member, and its shape may be used as a shaft member, particularly as a shaft member curved in an arc shape. Good.

Further, in the above-described embodiment, the outer ring 1 is the input-side race ring and the inner ring 2 is the output-side race ring, but the outer ring 1 may be the output-side race ring and the inner ring 2 may be the input-side race ring.

1 Outer ring 2 Inner ring 3 Sprag 4 Retainer 5 Elastic member 10 One-way clutch 11 Pulley 12 One-way clutch built-in pulley 20 Fall prevention mechanism 21a, 21b, 21c, 21d Contact point 22 Fall prevention member 23 Groove 24 Slit 28 Rotation shaft

Claims (7)

An outer ring (1) and an inner ring (2) that are relatively rotatable about an axis;
It is arranged along the circumferential direction between the outer ring (1) and the inner ring (2), and when the outer ring (1) and the inner ring (2) relatively rotate in one direction, the inner peripheral surface of the outer ring (1). (1a) is engaged with the outer peripheral surface (2a) of the inner ring (2) to couple the outer ring (1) with the inner ring (2) and relatively rotate in the other direction to release the engagement. With a sprag (3),
A retainer (4) for retaining the sprag (3) in the circumferential direction,
An elastic member (5) for urging the sprag (3) in a direction to engage the inner peripheral surface (1a) of the outer ring (1) and the outer peripheral surface (2a) of the inner ring (2);
A fall prevention mechanism (20) for preventing the sprag (3) from tilting in the engaging direction or the opposite direction with respect to the disengaged neutral state by a certain angle or more ;
The fall prevention mechanism (20) has a groove (23) formed along the circumferential direction on the end surface (3c) of the sprag (3) and a circumferential direction along the end surface (4e) of the cage (4). A slit (24) formed by: and a fall prevention member (22) inserted in the slit (24) and the groove (23) and extending in the circumferential direction,
When the sprag (3) tilts by a certain angle or more with respect to the neutral state, the fall prevention members (22) come into contact with the side surfaces (23a, 23b) of the groove (23) to restrict the tilt of the sprag (3). One way clutch. The one-way clutch according to claim 1 , wherein the fall prevention member (22) is an annular member. The one-way clutch according to claim 1 or 2, wherein the fall prevention member (22) is in pressure contact with the inner diameter side surface (24a) and the outer diameter side surface (24b) of the slit (24). The one-way clutch according to claim 1 or 2 , wherein the retainer (4) includes a caulking portion (26) protruding at an edge of the slit (24) for retaining the fall prevention member (22). The one-way clutch according to claim 1 or 2 , wherein the retainer (4) includes a snap fit portion (27) that holds the fall prevention member (22) on an edge of the slit (24). Using one-way clutch according to claim 1 to 5, a pulley (11) rotating said with integrally outer ring (1) on the outer diameter side of the outer ring (1), a gear, or provided with a sprocket Rotation transmission device with built-in one-way clutch. The rotation transmitting device with a built-in one-way clutch according to claim 6 , wherein a rotary shaft (28) for driving an auxiliary machine included in an automobile engine is connected to the inner ring (2).

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