JP3668856B2 - One-way clutch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a sprag disposed in an annular space formed between the outer ring and the inner ring, and allows the rotation in one direction and the locked state in the other direction when the outer ring and the inner ring are relatively rotated. Related to the one-way clutch.
[0002]
[Prior art]
A one-way clutch is used for an automatic transmission mechanism or the like of an automobile to transmit rotational torque only in one direction. For example, as shown in FIG. 6, such a one-way clutch includes a plurality of engagement members (an outer ring 11, an inner ring 12, and a plurality of engagement members arranged at a constant pitch in an annular space 14 formed between the outer and inner rings. Sprags) 15, an outer retainer 13a and an inner retainer 13b for holding the sprags 15, and a ribbon spring 16 for urging the sprags 15 toward the lock side. In this case, the ribbon spring 16 is also provided with an insertion hole 16P for inserting and holding the sprag 15. In the one-way clutch, as shown in FIG. 7, the sprag 15 disposed in the annular space 14 formed between the outer and inner rings is held by one cage 13 and the sprag 15 is held by the ribbon spring 16. Some are designed to be energized. In any case, the one-way clutch is mainly constituted by the sprag 15, the cage 13 (13a, 13b), and the ribbon spring 16. In these one-way clutches, the ribbon spring is devised so as to suppress the unstable movement of the sprag that repeatedly swings or to prevent the wear caused by the swinging movement of the sprag as much as possible (Japanese Patent Laid-Open No. 63). No. -266222, JP-A 63-259225).
[0003]
[Problems to be solved by the invention]
Since the one-way clutch repeats rotation (idling) and locking, it is desirable that the sprag is made to swing (rotate) at a constant angle around the center of curvature of the inner or outer cam surface. However, in reality, the sprag does not move around the center of curvature of the cam surface due to the relationship with the contact surface with the outer ring or inner ring. For example, when the rotation operation between the rotation and the lock is fast, it is smooth. In some cases, the sprags may jump greatly due to popping during idling, etc. without operating, resulting in damage. Furthermore, there is a problem that the shape of the sprag holding of the ribbon spring and the cage is limited.
[0004]
The present invention has been made by paying attention to the above-mentioned problems. It is possible to stabilize the operation even when popping occurs when the sprag swings, and the design flexibility of the cage is high, and the sprag is held on the lock side. It is an object to provide a one-way clutch with a spring that is easy to do.
[0005]
[Means for Solving the Problems]
That is, in order to solve the above-described problems, the invention according to claim 1 is a holding device that holds the sprags at a constant interval in the circumferential direction in an annular space formed between the outer ring and the inner ring. And a spring for urging the sprag in the locking direction. The sprag includes a cam surface that contacts the inner peripheral surface of the outer ring when swinging on the outer peripheral side, and an outer peripheral surface of the inner ring on the inner peripheral side. The cam surface that is in contact with the cylindrical surface and the cylindrical convex portion or the concave portion are formed on the side surface, and the cam surface that is in contact with the inner peripheral surface of the outer ring or the outer peripheral surface of the inner ring and the cylindrical convex portion or the concave portion have the same center of curvature. It is formed so as to rotate at the center, and the center of curvature of the cam surface opposite to the cam surface having the center of curvature located at the same center is formed so as to rotate in the vicinity of the same center. In the one-way clutch
On the side surface of the sprag is formed a curved stepped portion that is higher than the side moving in the idling direction to the side in which the sprag moves in the locking direction, and in the direction in which the sprag is locked in the stepping portion. Lock the garter spring to urge it,
Further, the retainer is formed with a concave or convex portion that fits with a cylindrical convex portion or concave portion provided on the side surface of the sprag.
Further, the retainer is formed with a concave portion or a convex portion that fits with a cylindrical convex portion or a concave portion provided on the side surface of the sprag.
[0006]
The invention described in claim 2 is characterized in that the cage is a cage that also serves as an end bearing for sealing an annular space between the outer ring and the inner ring.
[0007]
Alternatively, the invention according to claim 3 is characterized in that a projection that collides with the inner peripheral surface of the outer ring or the outer peripheral surface of the inner ring during idling is formed on the outer peripheral side or the inner peripheral side of the sprag.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial perspective view of a one-way clutch of the present invention, and FIG. 2 is a diagram showing a part of a cross section of the one-way clutch of the present invention.
An outer ring 1 is fixed to the inner diameter side of the stator boss portion of the torque converter, for example. An inner ring 2 is fixed to, for example, a fixed shaft of a torque converter. In the annular space 4 formed between the outer ring 1 and the inner ring 2, sprags 5 are arranged at regular intervals in the circumferential direction, and these sprags are held by cages 3 and 3 arranged on both sides.
[0009]
The sprag 5 includes a cam surface 5a that is in contact with the inner peripheral surface 1a of the outer ring 1 on the outer peripheral side, a cam surface 5b that is in contact with the outer peripheral surface 2a of the inner ring 2 on the inner peripheral side, and a cylindrical convex portion 5c on the side surface. And are formed. In this case, the cylindrical projecting portion 5c of the cage 3 and the cam surface 5a contacting the inner circumferential surface 1a of the outer ring 1, the curvature radius r _p of the radius of curvature of each cam surface 5a is r _o and cylindrical projecting portion 5c These cam centers 5b are formed so as to rotate at the same center O _o when the sprag 5 swings, and the cam surface 5b in contact with the outer peripheral surface 2a of the inner ring 2 is: The radius of curvature is r _i , and the center of curvature O _i is formed to rotate in the vicinity of the center O _o .
[0010]
Further, on both sides of the sprag 5 , stepped portions 5d and 5d are formed which are higher than the side moving in the idling direction to the side moving in the locking direction. Gutter springs 6 and 6 are engaged with the step portions 5d and 5d, and the sprags 5 are biased in the locking direction.
[0011]
One-way clutch with the sprags 5 was the shape, when the outer ring 1 and inner ring 2 rotates relatively, the inner circumferential surface 1a of the sprag 5 is the outer ring 1 cam face 5a of the outer around the O _o The upper cam surface 5b rolls on the outer peripheral surface 2a of the inner ring 2 around O _i . Even if the rotation and locking of the one-way clutch are frequently repeated, the sprags 5 do not pop and the movement does not become unstable.
[0012]
The radius of curvature r _p of the cylindrical convex portion 5c and the radius of curvature r _i of the other cam surface 5b are formed so as to rotate at the same center O _o when the sprag 5 is swung. Even if the center of curvature of the cam surface 5a is positioned so as to rotate in the vicinity of the same center O _o , the same effect as described above can be obtained.
[0013]
3 is a cross-sectional view taken along line AA in FIG. The cages 3, 3 are provided with recesses 3 a, 3 a for loosely fitting cylindrical protrusions 5 c, 5 c provided on the side surface of the sprag 5. An end bearing or the like (not shown) is disposed outside the retainers 3 and 3 to hold the annular space 4 in a sealed manner. However, the retainers 3 and 3 themselves may be used as a retainer serving as an end bearing. Thus, when the sprag 5 is formed with the cylindrical convex portion 5c and the retainer 3 is formed with the concave portion 3a into which the cylindrical convex portion 5c is fitted, the sprag 5 is formed by cold forging, etc. In the case of a synthetic resin, any of them can be manufactured at low cost because it is extremely easy to process by injection molding or the like. As shown in FIG. 4, the sprags 5 may be formed with recesses 5e and 5e, and the retainers 3 and 3 may be formed with cylindrical protrusions 3b and 3b so that they are loosely fitted. .
[0014]
FIG. 5 is a view showing a part of a cross section of a modification of the one-way clutch of the present invention. In this embodiment, a projection 5f is formed on the outer peripheral side of the sprag 5 so as to collide with the inner peripheral surface 1a of the outer ring when the sprag 5 is slightly rotated during idling. The protrusions 5f have a function of preventing the sprags 5 from rotating excessively when popping occurs during idling when the sprags 5 repeatedly swing and move.
The protrusion 5f may be provided inside the sprag 5 so as to collide with the inner ring outer peripheral surface 2a during idling.
[0015]
【The invention's effect】
As described above in detail, according to the one-way clutch of the present invention, the movement of the sprag is almost the same as the theoretical movement, and the movement of the sprag is stabilized in the process of repeated swinging and locking. Further, since the movement of the sprag is restricted when popping occurs during idling, the sprag itself can be prevented from being damaged. Furthermore, the degree of freedom of design of the cage is increased, and the spring for biasing the sprag does not require a design ingenuity for stabilizing the sprag, so that a one-way clutch that is inexpensive in cost can be obtained.
[Brief description of the drawings]
FIG. 1 is a partial perspective view of a one-way clutch of the present invention.
FIG. 2 is a view showing a part of a cross section of the one-way clutch of the present invention.
3 is a cross-sectional view taken along the line AA in FIG. 2;
4 is a cross-sectional view taken along the line AA of FIG. 2 and shows an embodiment in which a concave portion is formed in a sprag and a cylindrical convex portion that fits into the concave portion is formed in a cage.
FIG. 5 is a view showing a part of a cross section of a modified example of the one-way clutch of the present invention.
FIG. 6 is a diagram showing a part of a cross section of a conventional one-way clutch, and is an example diagram in the case of using two cages.
FIG. 7 is a diagram showing a part of a cross section of a conventional one-way clutch, and is an example diagram in the case of using one cage.
[Explanation of symbols]
Reference Signs List 1 Outer ring 2 Inner ring 3 Cage 4 Annular space 5 Sprag 5a Cam surface (outside)
5b Cam surface (inner side)
5c Cylindrical convex part 5d Step part 5e Concave part 5f Protrusion 6 Gutter spring

Claims (3)

In the annular space formed between the outer ring and the inner ring, a sprag, a retainer that holds the sprag at a constant circumferential interval, and a spring that biases the sprag in the locking direction are disposed . A cam surface that is in contact with the inner peripheral surface of the outer ring when swinging on the outer peripheral side, a cam surface that is in contact with the outer peripheral surface of the inner ring on the inner peripheral side, and a columnar convex portion or a concave portion are formed on the side surface, and the inner periphery of the outer ring The cam surface in contact with the outer surface of the surface or the inner ring and the columnar convex portion or the concave portion are formed such that the respective centers of curvature are located at the same center and rotate, and the cam has the center of curvature located at the same center. In the one-way clutch formed so that the center of curvature of the cam surface opposite to the surface is rotated in the vicinity of the same center,
On the side surface of the sprag is formed a curved stepped portion that is higher than the side moving in the idling direction to the side in which the sprag moves in the locking direction, and in the direction in which the sprag is locked in the stepping portion. Lock the garter spring to urge it,
Further, the retainer is formed with a concave or convex portion that fits with a cylindrical convex portion or concave portion provided on the side surface of the sprag.   The one-way clutch according to claim 1, wherein the cage is a cage that also serves as an end bearing for sealing an annular space between the outer ring and the inner ring.   The one-way clutch according to claim 1 or 2, wherein a protrusion that collides with the inner peripheral surface of the outer ring or the outer peripheral surface of the inner ring during idling is formed on the outer peripheral side or inner peripheral side of the sprag.

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