One-way clutch

Abstract

To provide a one-way clutch capable of reducing its weight while actualizing stable operation.SOLUTION: A cage 9 includes a plurality of bearing parts 31 for supporting an outer ring inner peripheral face, and cam member holding parts 23 being the same in number as the bearing parts 31 for holding two or more prescribed-number cam members 7 at a predetermined peripheral space, the plurality of bearing parts 31 being arranged at equal-angle diagonal positions over the peripheral direction with respect to a center axis C, the plurality of cam member holding parts 23 being arranged at equal-angle angular positions over the peripheral direction with respect to the center axis C, the plurality of bearing parts 31 and the plurality of cam member holding parts 23 being alternately arranged in the peripheral direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a one-way clutch used for transmitting torque in vehicles and industrial machines. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in one-way clutches equipped with a mechanism for transmitting rotational power in one direction and locking the rotational power in the opposite direction, there are some in which a cage, which is one of the components, has a bearing function (see, for example, Patent Document 1). The retainer (retainer ring) of the one-way clutch of Patent Document 1 is made of a bearing material such as an alloy, and has a shape that improves the effect of suppressing wear of the cam member, which is a torque transmission member housed in the retainer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-208506 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a stricter demand for weight reduction in devices or equipment mounted on vehicles, etc. As a result, in devices such as automatic transmissions that use one-way clutches, the use of resin for the cage, which is a component of the one-way clutch, has been considered as one method of weight reduction. In the one-way clutch of Patent Document 1, the cam member accommodating portion of the cage is shaped to conform to the circumferential surface of the accommodated cam member. Therefore, if the cage is made of resin, unless stable operation of the outer and inner rings of the one-way clutch is ensured, there is a concern that the cam member may become caught in the cam member accommodating portion, making it impossible to release the fixed state and causing the one-way clutch to malfunction. Therefore, in order to prevent such cam member from becoming caught, it is necessary to realize stable operation of the outer and inner rings of the one-way clutch.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a one-way clutch that can be made lighter while achieving stable operation. [Means for solving the problem]

[0006] In order to solve the above problems, the one-way clutch according to the present invention comprises: With the inner circle, an outer ring arranged concentrically on a central axis of the inner ring; a plurality of cam members interposed between the inner ring and the outer ring and used for transmitting torque between the inner ring and the outer ring; a holding member for holding a plurality of the cam members; a spring member that biases the plurality of cam members to a torque non-transmitting position, the retaining member includes a plurality of bearing portions for supporting an inner peripheral surface of the outer ring, and a number of retaining portions for retaining a predetermined number (two or more) of the cam members at predetermined intervals in a circumferential direction equal to the number of the bearing portions; the bearing portions are disposed at diagonal positions of equal angles in a circumferential direction with respect to the central axis, and the holding portions are disposed at angular positions of equal angles in a circumferential direction with respect to the central axis, The bearing portions and the holding portions are arranged alternately in the circumferential direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide a one-way clutch that can achieve stable operation while being lightweight. [Brief description of the drawings]

[0008] [Figure 1] 1 is a front view showing a state in which a one-way clutch according to an embodiment is viewed from one axial side. FIG. [Diagram 2] FIG. 2 is a side view showing the one-way clutch according to the embodiment as viewed from a radial direction. [Diagram 3] 1 is a perspective view showing an appearance of a one-way clutch according to an embodiment; [Figure 4] 4A and 4B are enlarged cross-sectional views of essential parts showing the state of a cam member of the one-way clutch according to the embodiment, with FIG. 4A showing an unloaded state and FIG. 4B showing a torque loaded state. [Diagram 5] FIG. 5(a) is a perspective view of the cage, and FIG. 5(b) is a side view of the cage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of a one-way clutch according to the present invention will be described with reference to the drawings. In this embodiment, a one-way clutch of a type in which an inner ring is a driving ring and torque is transmitted from the inner ring to an outer ring will be described as an example.

[0010] First, the directions related to the one-way clutch in this embodiment are defined. In this embodiment, the "center axis C" refers to the center axis of the one-way clutch, i.e., the center axis of the outer ring and the inner ring, and the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction with respect to the center axis C. In addition, regarding the axial direction, in each of Figs. 1 and 4, the front direction of the paper is defined as one axial direction, and the back direction of the paper is defined as the other axial direction, and in Figs. 2 and 5(b), the left side of the paper is defined as one axial direction, and the right side of the paper is defined as the other axial direction. Regarding the circumferential direction, in each of Figs. 1 and 4, the clockwise rotation direction toward the paper is defined as one circumferential direction, and the counterclockwise rotation direction toward the paper is defined as the other circumferential direction.

[0011] For the sake of convenience, the direction of rotation of the one-way clutch will be described as the direction of rotation of the inner ring relative to the outer ring, but the rotation of the outer ring and the rotation of the inner ring are relative to each other. For example, if the inner ring can rotate clockwise, the outer ring can also rotate counterclockwise. Even if the inner ring and the outer ring rotate in the same direction, if the rotation speeds of the outer ring and the inner ring are different, it can be said that the outer ring and the inner ring rotate in one direction relative to each other.

[0012] FIG. 1 is a front view showing a one-way clutch 1 according to an embodiment as viewed from one axial side. FIG. 2 is a side view showing the one-way clutch 1 according to the embodiment as viewed from the radial direction. FIG. 3 is a perspective view showing the appearance of the one-way clutch 1 according to the embodiment. In addition, the inner ring 3 and the outer ring 5 are shown by virtual lines in FIG. 2, and are omitted in FIGS. 4A and 4B are enlarged cross-sectional views of essential parts showing the state of the cam member 7 of the one-way clutch 1 according to the embodiment, with FIG. 4(a) showing the no-load state and FIG. 4(b) showing the torque-loaded state.

[0013] 1 to 4, one-way clutch 1 according to this embodiment includes inner ring 3 and outer ring 5 arranged concentrically on central axis C, a plurality of cam members 7 arranged between inner ring 3 and outer ring 5, ring-shaped retainer 9 for holding the plurality of cam members 7, and spring member 15 for biasing the plurality of cam members 7 in a direction in which they come into contact with inner ring outer peripheral surface 11 (see FIG. 4) and outer ring inner peripheral surface 13 (see FIG. 4) in a torque non-transmitting state. In this embodiment, spring member 15 is a garter spring.

[0014] The multiple cam members 7 are torque transmission members that transmit torque from the inner ring 3 to the outer ring 5 by engaging with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13. The cam members 7 are columnar members with curved peripheral surfaces. As shown in Figs. 4(a) and (b), the cross-sectional shape of the cam members 7 is a combination of a semicircular portion 17 and a bulging portion 19 that bulges outward from a straight line connecting both ends of the arc of the semicircular portion 17. The bulging portion 19 has a gentle mountain shape with a rounded top, and one end of the contour of the bulging portion 19 and one end of the arc of the semicircular portion 17, and the other end of the contour of the bulging portion 19 and the other end of the arc of the semicircular portion 17 are smoothly continuous with each other. The cam members 7 are formed so that the length of the straight line connecting the top of the bulging portion 19 and the bottom of the arc of the semicircular portion 17 is shorter than the length of the straight line connecting the vicinity of both ends of the arc of the semicircular portion 17.

[0015] FIG. 5(a) is a perspective view showing the appearance of the cage 9, and FIG. 5(b) is a side view of the cage 9. As shown in FIG. In this embodiment, the cage 9 is entirely made of resin. The cage 9 includes an annular plate 21 that is disposed on the other axial side of the inner ring 3 and the outer ring 5 on the central axis C, and a plurality of cam member holding portions 23 that protrude in one axial direction from a surface on one axial side of the annular plate 21. In this embodiment, four cam member holding portions 23 are formed.

[0016] Next, the configuration of one cam member holding portion 23 will be described, but the other cam member holding portions 23 have the same configuration. The cam member holding portion 23 is composed of a plurality of pillar portions 25 that protrude in one axial direction from the surface on one axial side of the annular plate 21 and are arranged at equal intervals in the circumferential direction, and an arc-shaped flange portion 27 that connects one axial end of the plurality of pillar portions 25. Therefore, the cam member holding portion 23 is formed in a partially cylindrical shape. In this embodiment, four pillar portions 25 are formed. The cross-sectional shape of the pillar portions 25 is a rectangle consisting of sides extending in the radial direction and sides extending in the circumferential direction, as shown in each drawing of FIG. 4, and in this embodiment, it is a rectangle consisting of long sides extending in the radial direction and short sides extending in the circumferential direction. The inner peripheral surface of each pillar portion 25 and the inner peripheral surface of the flange portion 27 are smoothly continuous and are arranged on one imaginary cylindrical surface centered on the central axis C.

[0017] In the cam member holding portion 23, three radially penetrating window portions 29 are formed at equal intervals in the circumferential direction by the four pillar portions 25, the flange portion 27, and a portion of the annular plate 21. In detail, each window portion 29 is defined by a pair of circumferentially adjacent pillar portions 25, and a portion of the flange portion 27 and a portion of the annular plate 21 that face each other in the axial direction between the pair of pillar portions 25. As described later, one cam member 7 is held in each window portion 29 so as to be able to swing.

[0018] The four cam member holding portions 23 each having such a configuration are arranged, as viewed in the axial direction, at equal intervals in the circumferential direction on the circumference of one imaginary circle centered on the central axis C. Therefore, the inner peripheral surfaces of the pillar portions 25 of the four cam member holding portions 23 and the inner peripheral surfaces of the flange portions 27 are arranged on one imaginary cylindrical surface centered on the central axis C.

[0019] The cage 9 further includes a plurality of quadrangular prism-shaped bearings 31 protruding from one axial surface of the annular plate 21 toward one axial direction. The number of bearings 31 is the same as the number of cam member holders 23. Therefore, in this embodiment, four bearings 31 are formed. The bearings 31 and the cam member holders 23 are alternately arranged in the circumferential direction. Specifically, one bearing 31 is arranged between the cam member holders 23 adjacent to each other in the circumferential direction. Therefore, the plurality of cam member holders 23 and the plurality of bearings 31 are alternately arranged on the circumference of one imaginary circle centered on the central axis C as viewed from the axial direction. With this configuration, the four bearings 31 are arranged at diagonal positions with equal angles in the circumferential direction with respect to the central axis C as viewed from the axial direction, that is, at angular positions of 90° in the circumferential direction in this embodiment. Similarly, the four cam member holding portions 23 are arranged at equal angular positions circumferentially relative to the central axis C when viewed from the axial direction, that is, at angular positions of 90° circumferentially in this embodiment.

[0020] The inner peripheral surface of bearing portion 31 is disposed on an imaginary cylindrical surface different from the inner peripheral surface of cam member holding portion 23, i.e., the inner peripheral surfaces of each pillar portion 25 and the inner peripheral surface of flange portion 27. These multiple cam member holding portions 23 and multiple bearing portions 31 are disposed between the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13. The inner ring 3 is disposed on the inner diameter side of the bearing portion 31 and cam member holding portion 23, as shown in FIG.

[0021] The bearing portion 31 supports the outer ring 5 at an outer peripheral surface 33. The outer peripheral surface 33 of the bearing portion 31 may be a curved surface having a radius of curvature different from that of the inner peripheral surface 13 of the outer ring 5. A flange portion 35 protruding radially outward is formed at one axial end of the bearing portion 31. In addition, a portion of the annular plate 21 extending radially outward from a portion where the multiple cam member holding portions 23 and the multiple bearing portions 31 are formed forms a flange portion 22. The cage 9 is arranged such that the flange portion 22 of the annular plate 21 fits into a circumferential groove 37 formed in the inner peripheral surface 13 of the outer ring, and the flange portion 35 of the bearing portion 31 faces the end face of the outer ring 5 in the axial direction. As a result, the cage 9 is fixed to the inner peripheral side of the outer ring 5 so as to be immovable in the axial direction and imrotatable relative to the outer ring 5 in the circumferential direction.

[0022] The multiple cam members 7 are fitted from the outer diameter side in one-to-one correspondence into the window portions 29 of the cage 9, with their axial direction aligned with the axial direction of the one-way clutch 1. In this way, the multiple cam members 7 are held in the circumferential direction by the cage 9. The multiple cam members 7 are held in one cam member holding portion 23 at equal intervals in the circumferential direction. In this embodiment, three cam members 7 are held in one cam member holding portion 23 at equal intervals in the circumferential direction. Both axial end faces of the cam members 7 are located inside the portion of the flange portion 27 and the portion of the annular plate 21 that axially face the window portions 29 of the cage 9. In other words, the axial dimension of the cam members 7 is formed to be smaller than the axial dimension of the window portions 29. As shown in Figure 4(a), in an unloaded state, the cam member 7 has a semicircular portion 17 facing the inner ring 3, with the bottom of the semicircular portion 17 in contact with the inner ring outer surface 11, and a bulge portion 19 facing the outer ring 5, with the top of the bulge portion 19 in contact with the outer ring inner surface 13.

[0023] The peripheral surface of the semicircular portion 17 of the cam member 7 contacts a pair of pillar portions 25 that form the window portion 29 of the cage 9, and a portion of the semicircular portion 17 penetrates the window portion 29 of the cage 9 and protrudes further inward than the pair of pillar portions 25. In this manner, the pair of pillar portions 25 of the cage 9 are disposed in contact with the outer peripheral surface of the cam member 7, so that the cam member 7 is held by the window portion 29 of the cage 9 and comes into stable contact with the inner ring outer peripheral surface 11. With this configuration, the cam member 7 is in sliding contact with the pair of pillar portions 25 of the cage 9 and can swing, and its axial movement is restricted by the flange portion 27 and the annular plate 21.

[0024] As shown in Fig. 3, each cam member 7 has a groove 39 formed in the radial outer portion in an assembled state, the groove 39 extending in the circumferential direction of the inner ring 3 or the outer ring 5. The groove 39 is formed in the axial center of the radial outer portion of the cam member 7, penetrates the radial outer portion in the circumferential direction, and has a depth reaching the vicinity of the center of the cam member 7. In addition, a groove 41 extending in the circumferential direction is also formed in the radial outer portion of the bearing portion 31. The groove 41 is formed in the axial center of the radial outer portion of the bearing portion 31, penetrates the radial outer portion in the circumferential direction, and has a depth reaching the vicinity of the center of the bearing portion 31.

[0025] One annular spring member 15 is attached through the grooves 39 of each cam member 7 and the grooves 41 of each bearing portion 31. The spring member 15 biases each cam member 7 toward the inner diameter side. The bottom surface of the groove 39 of the cam member 7 is formed in a mountain shape with an angle such that the cam member 7 swings in a direction in which it contacts the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13 when the biasing force toward the inner diameter side is applied by the spring member 15. Therefore, each cam member 7 is biased toward the inner diameter side by the elastic force of the spring member 15, and is always in contact with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13. The contact state of each cam member 7 with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13 by the spring member 15 is a torque non-transmitting state. In this way, the spring member 15 biases each cam member 7 to a torque non-transmitting position.

[0026] The annular plate 21 and the flange portion 22 of the cage 9 are provided with radially extending cutout portions 43 on one circumferential side and the other circumferential side of each bearing portion 31. The cutout portions 43 open to the outer diameter side of the flange portion 22 of the annular plate 21 and extend to a radial position on the inner diameter side of the cam member holding portion 23. The annular plate 21 further has four cutout portions 45 formed at equal intervals in the circumferential direction, which open to the inner diameter side of the annular plate 21 and extend radially to a radial position near the cam member holding portion 23. The cage 9 is designed to have rigidity suitable for the one-way clutch 1 to be assembled thereto by the cutout portions 43, 45.

[0027] Next, the operating state of the one-way clutch 1 according to this embodiment having the above-mentioned configuration will be described. In the unloaded state shown in Fig. 4(a), the cam member 7 is in contact with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13 due to the elastic force of the spring member 15, but is not engaged so as to transmit torque. When torque is applied to the inner ring 3 from this state, the cam member 7 swings in a direction in which the inner ring 3 and the outer ring 5 engage so as to transmit torque. That is, as shown in Fig. 4(b), when the inner ring 3 rotates clockwise in Fig. 4(b), the cam member 7, which is in contact with the inner ring outer peripheral surface 11, rotates, i.e. swings, counterclockwise. By swinging in this way, the cam member 7 engages with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13, and this engagement transmits torque from the inner ring 3 to the outer ring 5.

[0028] At this time, the outer ring 5 is provided in the cage 9, and the inner peripheral surface 13 is supported by four bearing portions 31 arranged at 90° angular positions in the circumferential direction with respect to the central axis C. Therefore, the cage 9 and the outer ring 5 rotate stably together with the inner ring 3. In addition, the multiple cam members 7 are held by four cam member holding portions 23 arranged at 90° angular positions in the circumferential direction with respect to the central axis C, and each cam member holding portion 23 holds three cam members, so that the inner ring 3 and the outer ring 5 are engaged stably in the circumferential direction. As a result, the inner ring 3 and the outer ring 5 rotate stably, and the cam member 7 does not get caught in the pair of pillar portions 25 of the window portion 29. Therefore, the one-way clutch 1 can be prevented from malfunctioning due to the cam member 7 getting caught in the cage 9.

[0029] 4(a) , when the inner ring 3 rotates counterclockwise, the cam member 7 does not engage with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13, and the inner ring 3 rotates freely relative to the outer ring 5. Therefore, in this state, no torque is transmitted from the inner ring 3 to the outer ring 5.

[0030] As described above, in the one-way clutch 1 of this embodiment, since the retainer 9 is made of resin, it is possible to realize a reduction in weight of the one-way clutch 1 and an automatic transmission (not shown) in which the one-way clutch 1 is incorporated. Furthermore, since the bearing portion 31 that supports the inner peripheral surface 13 of the outer ring 5 is formed in the retainer 9, it is not necessary to provide a bearing for supporting the outer ring 5 as a separate part from the retainer 9. This prevents an increase in the axial dimension of the one-way clutch 1, reduces the installation space of the one-way clutch 1, and contributes to a reduction in the weight of the one-way clutch 1 because the number of parts is reduced. Furthermore, as described above, since the inner ring 3 and the outer ring 5 rotate stably, it is possible to prevent the one-way clutch 1 from malfunctioning due to the cam member 7 getting caught in the retainer 9.

[0031] The one-way clutch 1 of the present invention is not limited to the above embodiment, and can be modified as appropriate. In the above embodiment, an example of the one-way clutch 1 that transmits torque from the inner ring 3 to the outer ring 5 is shown, but the present invention may be applied to a one-way clutch that transmits torque from the outer ring 5 to the inner ring 3. The number of bearings 31 and cam member holding parts 23 can also be set appropriately depending on the size and torque capacity of the one-way clutch 1. The number of cam members 7 held by one cam member holding part 23 can also be set appropriately. In the above embodiment, the annular plate 21 of the cage 9 is provided with a predetermined number of notches 43 and 45, but the number of these notches 43 and 45 can also be changed as appropriate depending on the rigidity required for the cage 9. Alternatively, these notches 43 and 45 may not be provided. [Explanation of symbols]

[0032] 1 One-way clutch 3. Inner Circle 5 Outer ring 7 Cam section 9 Cage 11 Inner ring outer surface 13 Inner surface of outer ring 15 Spring member 21 Annular plate 23 Cam member holding portion 29 Window 31 Bearing section

Claims

1. With the inner circle, an outer ring arranged concentrically on a central axis of the inner ring; a plurality of cam members interposed between the inner ring and the outer ring and used for transmitting torque between the inner ring and the outer ring; a holding member for holding a plurality of the cam members; a spring member that biases the plurality of cam members to a torque non-transmitting position, the retaining member includes a plurality of bearing portions for supporting an inner peripheral surface of the outer ring, and a number of retaining portions for retaining a predetermined number of the cam members (two or more) at predetermined intervals in a circumferential direction, the number of the retaining portions being equal to the number of the bearing portions; The plurality of bearing portions are respectively disposed at diagonal positions of equal angles in a circumferential direction with respect to the central axis, and the plurality of holding portions are respectively disposed at angular positions of equal angles in a circumferential direction with respect to the central axis, A one-way clutch, characterized in that the plurality of bearing portions and the plurality of holding portions are arranged alternately in a circumferential direction.

2. 2. The one-way clutch according to claim 1, wherein the retaining member is made of resin.

3. The retaining member includes an annular plate disposed on the central axis, the bearing portions and the holding portions are formed on one axially-direction side surface of the annular plate, 3. A one-way clutch according to claim 1, wherein an outer peripheral edge of said annular plate is engaged with an inner peripheral surface of said outer ring.

4. 4. The one-way clutch according to claim 3, wherein the bearing portion includes a flange portion that faces in the axial direction a surface on one axial side of the outer ring.

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