JPH0814279A - One-way clutch - Google Patents

Abstract

PURPOSE:To smooth the operation of a sprag, enhance the durability of the sprag and a retainer, and facilitate the assembling. CONSTITUTION:In a one-way clutch having a number of sprags 12 between an outer race 10 and an inner race 11, a retainer 15 for circumferentially arranging each sprag at a prescribed pitch and a ring spring 20 for rotating and energizing each sprag in the engaging direction, the sprag has a groove 13 for fitting the spring on the one circumferential part forming the outer circumferential part or inner circumferential part, and the one circumferential part having the groove is protruded axially outward to the other circumferential part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-way clutch in which a large number of sprags are interposed between an outer race and an inner race, and the operation of the sprags transmits torque in one direction.

[0002]

2. Description of the Related Art As a conventional technique, there is one shown in FIGS. In FIG. 4, 1 is an outer race mounted on the rotating side of a stator boss or the like, 2 is an inner race mounted on the fixed side of a case or the like, and a large number of them are arranged by a retainer 3 between them at a predetermined pitch in the circumferential direction. The sprag 4 is inserted. The retainer 3 is formed by punching and drawing a sheet metal material with a press machine to form rectangular window holes 3a in a short tubular main body at a predetermined pitch in the circumferential direction, and radially outward on both sides. A bent flange 3b is formed, and the outer peripheral end portion of the sprag 4 is rotatably fitted and held by the window hole 3a, and the flange 3b is brought into contact with the inner peripheral surface 1a of the outer race 1 to be frictionally engaged.

The sprags 4 are formed, for example, by forging a steel material. As shown in FIG. 5, the sprags 4 are circumferentially formed on the inner peripheral portion of the main body 4a having the same width W1 in the axial direction. An outer peripheral surface 4b and an inner peripheral surface 4c of the main body 4a that are in contact with the outer race 1 and the inner race 2
Is formed in a predetermined arcuate surface, and a ring-shaped coil spring 6 is fitted in the groove 5 to urge each sprag 4 outward in the radial direction.

[0004]

In the above-mentioned conventional one, the groove 5 into which the coil spring 6 is fitted is formed in the inner peripheral portion of the main body 4a formed to have the same width in the axial direction.
The inner peripheral surface 4c is divided by the groove 5, and the sum of the axial widths W2 and W2 becomes smaller than the axial width W1 of the outer peripheral surface 4b. For this reason, the contact area between the inner peripheral surface 4c of the sprag 4 and the outer peripheral surface 2a of the inner race 2 becomes smaller than the contact area between the outer peripheral surface 4b of the sprag 4 and the inner peripheral surface 1a of the outer race 1, The stress of the contact portion on the surface 4c side becomes high.

Further, since the ring-shaped coil spring 6 is fitted into the groove 5 formed in the inner peripheral portion of each sprag 4, the sprag 4 is inadvertently moved in the axial direction at the time of assembling so as to be smooth. It is difficult to assemble the retainer 3 or the retainer 3 is located on the outer peripheral side of the sprag 4 about its rotation center, so the outer race 1 rotates to the left in FIG. When the specific sprag 4, for example, the central sprag 4-1 in FIG. 1 rotates to the left earlier than the other sprags 4-2 due to a processing error or the like, the central sprag 4-1 is rotated. The forward end of the retainer 3, that is, the left end 4d is the edge 3 of the window hole 3a of the retainer 3.
There was a defect that the retainer 3 was damaged by colliding with a-1 (rear end). It is an object of the present invention to obtain a novel one-way clutch that overcomes the above drawbacks.

[0006]

The present invention is configured as follows to achieve the above object. That is, one direction in which a large number of sprags are provided between the outer race and the inner race, a retainer arranging each sprag at a predetermined pitch in the circumferential direction and a ring-shaped spring for biasing each sprag to rotate in the engaging direction are provided. In the clutch, the sprag has a groove into which the spring fits, which is formed on one peripheral portion that forms an outer peripheral portion or an inner peripheral portion, and one peripheral portion where the groove is formed with respect to the other peripheral portion. It is configured to project outward in the axial direction. In this case, it is preferable that the front and rear surfaces of the body of the sprag are formed into arcuate surfaces centered on the center of rotation of the sprag, and the retainer is fitted to the center of rotation of the sprag. In addition, the sprag has a groove in which the spring fits in the outer peripheral portion, and the outer peripheral portion in which the groove is formed is protruded axially outward in a stepwise manner with respect to the inner peripheral portion, and It is preferable that the retainer is fitted to the peripheral portion.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part of a one-way clutch showing an embodiment of the present invention. In FIG. 1, A is a one-way clutch, in which a large number of sprags 12 are interposed between an outer race 10 attached to a rotating side such as a stator boss and an inner race 11 attached to a fixed side such as a case. The retainers 15 hold the splines 12 at a predetermined pitch in the circumferential direction, and the ring-shaped springs 20 actuate and urge each sprag 12 in the engaging direction.

As shown in FIGS. 2 and 3, each of the sprags 12 has an outer peripheral portion stepwise protruding outward in the left-right direction (outward in the axial direction) with respect to the inner peripheral portion so as to surround the outer peripheral portion. A groove 13 extending in the direction is formed. The bottom surface of this groove 13 is left end 13
It is tilted so that a (counterclockwise side) is radially outward from the right end 13b (clockwise side) (FIG. 1). The sprag 12
The amount of outward protrusion of the outer peripheral surface of the outer peripheral surface 12c is such that the sum of the axial widths W4 and W4 of the outer peripheral surface 12c is substantially equal to the axial width W3 of the inner peripheral surface 12d. As shown in FIG. 3, the lower surface of the protruding portion, that is, the step portion 14 is inclined in a V-shape from the rotation center portion of the sprag 12 toward the outer peripheral side, and the sprag 1
The circumferential front and rear ends of the stepped portion 14 are prevented from colliding with the retainer 15 when 2 rotates on its axis.

Further, the sprag 12 has a front surface 12a (left surface in FIG. 1), a rear surface 12b (right surface in FIG. 1) and an outer peripheral surface 12c of the body portion of the sprag 12, which is the center O of rotation of the sprag.
It is formed in an arcuate surface having radii r1, r2 and r3 centered at 1, and this body is fitted into the window hole 15a of the retainer 15. Due to the counterclockwise rotation of the outer race 10, the sprags 12 increase in height in the radial direction when rotated in the counterclockwise direction (a) about the rotation center O1 and the outer peripheral surface 12c and the inner peripheral surface thereof. 12d press-engages with the inner peripheral surface 10a of the outer race 10 and the outer peripheral surface 11a of the inner race 11, and the outer race 10 rotates clockwise (idle direction) to rotate clockwise about the rotation center O1.
When it is rotated, the height in the radial direction is lowered and the pressure contact engagement with the outer race 10 and the inner race 11 is released.

The retainer 15 is, as shown in FIG.
A sheet metal material is punched and drawn by a press machine to form rectangular window holes 15a at a predetermined pitch in the circumferential direction in a short tubular main body, and flanges 15b that are bent outward in the radial direction are formed on both sides. The window hole 15a is formed on the locus circle C passing through the rotation center O1 of the sprag 12, and the body of each sprag 12 is fitted and held so as to be rotatable, and the flange 15b is formed on the inner circumference of the outer race 10. The surface 10a is brought into contact with and frictionally engaged. In addition, the groove 13 of each sprag 12
2 a coil spring with a ring shape
0 is fitted and is pressed against the left end 13a of the groove 13 and the sprags 12 are rotated counterclockwise (a) about the rotation center O1 by the reaction force of the spring 20 at the initial stage.
That is, it is rotated in the engagement direction.

According to the above embodiment, the outer peripheral portion of the sprag 12 in which the groove 13 for fitting the spring 20 is formed is formed wider than the inner peripheral portion, and the outer peripheral surfaces 12c, 12c have axial widths W4, W4. And the width W3 of the inner peripheral surface 12d in the axial direction are made substantially equal, so that each sprag 12 comes into contact with the outer race 10 and the inner race 11 in substantially the same area. Therefore, the stresses at the contact portions of the sprags 12 with the outer race 10 and the inner race 11 become substantially equal, which makes the operation smooth and increases the durability.

The front surface 12a of the body of each sprag 12
And the rear surface 12b is formed into an arc surface having the rotation center O1 of the sprag 12 as a center, and the window hole 15a of the retainer 15 passes through the rotation circle C passing through the rotation center O1 of each sprag 12.
Therefore, even if the sprags 12 rotate irregularly relative to each other due to a processing error or the like, the sprags 12 do not attack the retainer 15 and the durability of the retainer 15 increases. Further, the retainer 15 having high strength is attached to the inner peripheral portion of each sprag 12.
Hold each sprag 12 from the outer peripheral side with the spring 2
Since it is pressed in the direction of the retainer 15 (axial direction) by 0, each sprag 12 does not move carelessly in the axial direction during assembly, which facilitates assembly to the outer race 10 and the inner race 11. Become.

As is apparent from the above description, the present invention is
The operation of the sprag becomes smooth, and the durability of the sprag and the retainer becomes high. Further, there are effects such as easy assembling.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a one-way clutch according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a sprag according to the present invention.

FIG. 4 is a sectional view of a main part of a one-way clutch showing a conventional example.

5 is a sectional view taken along line VV of FIG.

[Explanation of symbols]

 A one-way clutch 10 outer race 10a inner peripheral surface 11 inner race 11a outer peripheral surface 12 sprag 12a front surface 12b rear surface 12c outer peripheral surface 12d inner peripheral surface 13 groove 13a left end 13b right end 14 step 15 retainer 15a window hole 15b flange W3 plug W3 Axial width of the surface W4 Axial width of the outer peripheral surface of the sprag

Claims (3)

[Claims] 1. A plurality of sprags are provided between the outer race and the inner race, and retainers for arranging the sprags at a predetermined pitch in the circumferential direction and a ring-shaped spring for urging the sprags to rotate in the engaging direction are provided. In the one-way clutch described above, the sprag has a groove into which the spring fits, formed in one peripheral portion that forms an outer peripheral portion or an inner peripheral portion, and one peripheral portion where the groove is formed is formed in the other peripheral portion. A one-way clutch characterized by being projected outward in the axial direction with respect to. 2. The sprag is characterized in that the front and rear surfaces of its body are formed into arcuate surfaces centering on the center of rotation of the sprag, and the retainer is fitted in the center of rotation of the sprag. The one-way clutch according to Item 1. 3. The sprag has a groove into which the spring fits, is formed on an outer peripheral portion of the sprag, and the outer peripheral portion having the groove is axially outwardly protruded stepwise with respect to an inner peripheral portion, The one-way clutch according to claim 1 or 2, wherein a retainer is fitted to the inner peripheral portion of the sprag.