JPH11247902A - One-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a fixed torque to be maintained so that in particular the fixed torque does not decrease even under high temperature, and the fixed torque can be enforced even if heat deformation develops. SOLUTION: An outer holder 2 which holds the outside of a sprag is formed with an amorphous synthetic resin material. On both sides, a ring-shaped part 2a is formed. Pillar parts 2b, which link these ring-shaped parts in a circumferential direction in fixed intervals, are formed. A pocket 2c is formed for holding a sprag between a pillar part and another pillar part. On the outside of the pillar part 2b, a smooth arc-shaped projection 2d is formed which is press-fitted to the inner circumferential surface of the outer wheel.

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 for use in, for example, a speed change mechanism of an automobile, and more particularly to a one-way clutch provided with a retainer which is fixed to the inner peripheral surface of an outer ring, maintains a fixed torque and has excellent heat resistance. For directional clutches.

[0002]

2. Description of the Related Art A one-way clutch as shown in FIGS. 10A and 10B is used in a torque converter of an automobile or the like. The one-way clutch includes sprags 21 arranged at regular intervals in a circumferential direction, an outer cage 22 for holding an outer portion 21a of the sprag 21,
An inner retainer 23 for holding the inner part 21b of the first spring 21 and an annular ribbon spring 24 for urging the sprag 21 in one circumferential direction (for example, clockwise). The one-way clutch having such a configuration is disposed in an annular space (not shown) between the outer ring and the inner ring.

As shown in FIG. 11, the outer retainer made of synthetic resin in a conventional one-way clutch is formed with angular projections 22d, 22d,. Are press-fitted and fixed to the inner peripheral surface 5a of the outer race 5 so as to secure a predetermined fixing torque. Conventionally, for the outer cage 22 and the inner cage 23, a crystalline synthetic resin such as a nylon resin is selected for weight reduction.

[0004]

In the conventional one-way clutch, as the crystalline synthetic resin used for the outer cage 22 and the inner cage 23 for holding the sprags 21, for example, glass fiber-reinforced nylon 66 is used. Used. However, the strength and rigidity of such a crystalline synthetic resin decrease at high temperatures. That is, there is a problem that the physical strength is reduced because the glass transition point exists at about 90 ° C. Also, since the projection 22d of the outer cage 22 is angular, once it is deformed by heat or the like (especially, creep deformation), the fixed torque cannot be maintained, and the phase between the outer cage and the inner cage is advanced and delayed. This causes a problem that the sprags 21 do not function smoothly.

SUMMARY OF THE INVENTION The present invention has been made to address the above-described problems, and is capable of maintaining a fixed torque. In particular, the fixed torque does not decrease even at high temperatures, and thermal deformation occurs. It is an object of the present invention to provide a one-way clutch that can maintain a fixed torque.

[0006]

That is, in order to solve the above-mentioned problems, the present invention provides sprags (1) arranged at regular intervals in a circumferential direction, and an outer holding member for holding an outer portion of the sprag (1). A container (2), an inner retainer (3) for holding an inner portion of the sprag (1), an annular ribbon spring (4) for urging the sprag (1) in one circumferential direction,
The outer cage (2) is made of an amorphous synthetic resin material, and has annular portions (2a, 2a) on both sides and these annular portions (2a, 2).
(a) a pillar portion (2b) that connects the spaces between (a) at regular intervals in the circumferential direction;
A pocket (2c) for holding the sprag (1) is formed between the pillar (2b) and the pillar (2b),
Further, on the outer side of the pillar portion (2b), a projection (2) whose outer peripheral surface to be press-fitted to the inner peripheral surface of the outer ring has an arc shape in the circumferential direction.
d) is formed.

Further, the pillar (2) of the outer cage (2)
On the outer side of b), smooth curved projections (2d) which are press-fitted to the inner peripheral surface of the outer ring are formed on all the pillars (2b).

Further, the above-mentioned or the above-mentioned protrusion (2)
d) is characterized in that it is formed by a part of a cylinder extending in the axial direction.

Further, the projection (2d) or the projection (2d) is characterized in that the outer peripheral surface of the projection (2d) is formed as a projection (2f) having an arc shape in the axial direction.

[0010] Alternatively, in any of the above (1) to (3), glass fiber is added to an amorphous synthetic resin material.
It is characterized in that 0 to 40% by weight is added.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 (A)
1 is an overall side view of a one-way clutch of the present invention, and FIG.
FIG. 2B is a sectional view taken along the line AA in FIG. Also,
FIG. 2 is a partially enlarged view of the inside of the one-way clutch of the present invention viewed from the same direction as FIG. 1A. The one-way clutch includes sprags 1 arranged at regular intervals in a circumferential direction, an outer cage 2 for holding an outer portion 1a of the sprag 1, an inner cage 3 for holding an inner portion 1b of the sprag 1, An annular ribbon spring 4 for urging the sprag 1 in one circumferential direction (for example, clockwise). The outer retainer 2 is press-fitted and fixed to the inner peripheral surface 5a of the outer race 5 to secure a predetermined fixing torque.

The outer cage 2 uses an amorphous synthetic resin material, for example, polyethersulfone (PES). In this case, in order to strengthen the rigidity of the outer cage 2, P
ES with glass fiber (glass fiber, GF) 30-4
0% by weight is added. In this way, glass fiber is added to PES
Addition of 0 to 40% by weight can prevent a sharp decrease in rigidity even at high temperatures. However, when the fixing torque may be low, the amount of glass fiber added is 30.
% Or less.

FIG. 3A is a developed plan view of the outer retainer 2, FIG. 3B is a side view, FIG. 3C is a cross-sectional view taken along the line AA of FIG. FIG. 4 is a perspective view of the outer cage 2. The outer retainer 2 has annular portions 2a, 2a, and pillar portions 2b, 2 connecting the annular portions at regular intervals in the circumferential direction.
, and pockets 2c for holding the outer portion 1a of the sprag 1 between the pillars 2b and 2b.
2c,... Are formed. And the column 2b,
Projections 2d, 2d,... Are formed outside the outer surfaces of 2b,. The projections 2d provided on the pillars 2b, 2b,.
a, 2a so as to uniformly protrude outside, that is, by a single column extending in the axial direction. Since the protrusion 2d is a part of a cylinder, it can be easily formed.

As described above, the outer cage 2 provided with the pillar portions 2b, 2b,... Formed with the smooth arc-shaped projections 2d on the outside has an inner periphery of the outer race 5 in order to secure a fixed fixing torque. It is press-fitted to the surface 5a. As described above, when the curved protrusions 2d are formed outside the pillar portions 2b of the outer cage 2, it is possible to prevent the fixing torque from decreasing. That is, as shown in FIG. 6, in the outer cage 2, the outer peripheral surface of the projection 2 d of the column 2 b is in contact with the inner peripheral surface 5 a of the outer ring 5 at one point, but the stress applied to the outer cage 2 Are dispersed from the contact portion of the projection 2d in the direction of the root of the pillar 2b. When the stress of each column 2b provided with the curved projections 2d in the circumferential direction is dispersed in this way, the entire outer retainer 2 receives a force,
The deformation of the outer cage 2 can be reduced.

In the conventional outer cage, as shown in FIG. 7, a force is applied to the projection 22d provided outside the outer cage 22 from the inner peripheral surface 5a of the outer race 5, and the outer cage 22 has two points. It is easy to deform as shown by the chain line. In addition, in the angular projection 22d of the outer cage 22, since the contact in the vicinity of both ends 22a and 22b is strong, when the wear of this portion increases, the reaction force from the outer ring 5 side decreases as a whole. Therefore, the fixed torque is also likely to be small, and a phase difference with the inner cage is likely to occur, and the behavior of the sprag 21 (see FIG. 10) does not become the intended predetermined movement, which causes the function of the one-way clutch to deteriorate. .

Further, in the outer cage 2 of the one-way clutch of the present invention, if an arc-shaped projection 2d is formed outside the column portion 2b, the area of contact with the inner peripheral surface 5a of the outer ring 5 even when thermally deformed. Can be increased. That is, as shown in FIG. 8A, the contact area with the inner peripheral surface 5a of the outer ring 5 is relatively small at the beginning of the press-fitting, but expands due to thermal deformation during use and the contact area increases. Therefore, as shown in FIG. 8 (B), the contact area of the protrusion 2d provided on the column portion 2b with the inner peripheral surface 5a of the outer ring 5 also increases. Therefore, even if the outer surface of the projection 2d of the pillar portion 2b of the outer cage 2 is worn, the fixed torque can be maintained. The smooth curved (round) projections 2d are preferably provided on all the pillars 2b, but may be provided at several places in the circumferential direction.

FIG. 4 shows another embodiment.
b is a drum-shaped projection 2 whose outer peripheral surface is formed in an arc shape in a circumferential direction and in an arc direction in an axial direction.
f, 2f,... The projections 2f, 2f,.
By adopting such a shape, the effect of maintaining the fixed torque in FIG. 8 described above is greater, and the one-way clutch can be smoothly incorporated into the inner peripheral surface 5a of the outer race 5 from the axial direction. .

[0018]

FIG. 9 is a diagram showing a comparison test result of a change in tensile modulus of the outer cage 2 used in the one-way clutch of the present invention and a conventional outer cage 22 with a rise in temperature. That is, the outer cage 2 of the one-way clutch of the present invention was an outer cage formed by injection molding using amorphous PES of synthetic resin as a material to be used and adding 30% by weight of glass fiber. Further, the conventional outer cage 22 was an outer cage obtained by adding 30% by weight of glass fiber to nylon 66 of a crystalline material and injection molding. As is clear from the test results,
The outer cage using the crystalline material nylon 66 is 50 °
While the rate of decrease is large in the range of C to 80 ° C, the outer retainer using the amorphous material PES is 160 ° C to 17 ° C.
It was found that the strength was uniformly reduced to 0 ° C. That is, it is understood that the rigidity of the amorphous resin is hardly affected by the temperature change. In addition, as an amorphous synthetic resin material other than PES, you may use polyamideide (PAI), polyetherimide (PEI), polysulfone (PSU), etc.

[0019]

As described in detail above, according to the one-way clutch of the present invention, the fixing torque of the outer cage can be stably maintained without lowering. Therefore,
A one-way clutch having a stable function by preventing advance and delay of the phase between the outer cage and the inner cage can be provided. Further, the one-way clutch of the present invention can be a one-way clutch that is thermally strong and hardly deforms.

[Brief description of the drawings]

FIG. 1A is an overall side view of a one-way clutch of the present invention, and FIG. 1B is a sectional view taken along the line AA of FIG. 1A.

FIG. 2 is a partially enlarged view of the inside of the one-way clutch of the present invention viewed from the same direction as FIG. 1 (A).

3A is a developed plan view of an outer retainer of the one-way clutch of the present invention, FIG. 3B is a side view, and FIG.
FIG. 3C is a cross-sectional view taken along the line BB of FIG.

FIG. 4 (A) is a developed plan view of an outer retainer of a one-way clutch according to a modified embodiment of the present invention, and FIG. 4 (B).
FIG. 4C is a cross-sectional view taken along the line CC of FIG. 4B.

FIG. 5 is a perspective view of an outer retainer of the one-way clutch of the present invention.

FIG. 6 is a view showing a state in which the outer retainer of the one-way clutch of the present invention is fitted to the inner peripheral surface of the outer race.

FIG. 7 is a view showing a state in which an outer retainer of a conventional one-way clutch is fitted to an inner peripheral surface of an outer race.

FIG. 8A shows a state in which the outer retainer of the one-way clutch of the present invention is fitted to the inner peripheral surface of the outer ring, and FIG. 8A shows the state in which the outer retainer is fitted to the inner peripheral surface of the outer ring. FIG. 8 shows the initial state.
(B) is a figure which shows the state which expanded by thermal deformation during use and the contact area expanded.

FIG. 9 is a graph showing a comparison test result of a change in tensile modulus of the outer cage used for the one-way clutch of the present invention and a conventional outer cage with a rise in temperature.

10 (A) is a side view of a conventional one-way clutch, and FIG. 10 (B) is a cross-sectional view taken along the line DD in FIG. 10 (A).

FIG. 11 is a partially enlarged cross-sectional view of the conventional one-way clutch as viewed from the same direction as FIG. 10 (A).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sprag 2 Outer retainer 2a Annular part 2b Pocket 2c Column part 2d Projection 2f Projection 3 Inner retainer 4 Ribbon spring 5 Outer ring 5a Inner ring inner peripheral surface

Claims (5)

[Claims] 1. A sprag arranged at regular intervals in a circumferential direction, an outer cage for holding an outer portion of the sprag, an inner cage for holding an inner portion of the sprag, and the sprag in one circumferential direction. The outer retainer is formed of an amorphous synthetic resin material, and has an annular portion on both sides and a circumferential portion between the annular portions. A pillar portion that is connected at regular intervals in the direction and a pocket for holding the sprag are formed between the pillar portions, and further, on the outside of the pillar portion, a press-fitting is performed on an inner peripheral surface of an outer ring. A one-way clutch, wherein a formed outer peripheral surface has a projection formed into an arc shape in a circumferential direction. 2. A smooth curved projection, which is press-fitted to the inner peripheral surface of the outer race, is formed on all the pillars outside the pillars of the outer retainer. The one-way clutch according to claim 1. 3. The projection according to claim 1, wherein the projection is formed as a part of a column extending in an axial direction.
The one-way clutch according to claim 1. 4. The one-way clutch according to claim 1, wherein an outer peripheral surface of the projection is formed in an arc shape in an axial direction. 5. The outer cage according to claim 1, wherein glass fiber is added to the amorphous synthetic resin material in an amount of 30 to 40% by weight. One-way clutch.