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] 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 the 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 lighter weight devices or equipment installed in vehicles, etc. Therefore, as one method of reducing the weight of 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. In the one-way clutch of Patent Document 1, the cam member accommodating portion of the cage is shaped to fit 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 jammed into the cam member accommodating portion, making it impossible to release the locked state and causing the one-way clutch to malfunction. Therefore, to prevent such jamming of the cam member, it is necessary to ensure 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 inner circle, an outer ring arranged concentrically on the central axis of the inner ring; a plurality of cam members interposed between the inner ring and the outer ring and used to transmit torque between the inner ring and the outer ring; a holding member for holding the plurality of 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 that support an inner peripheral surface of the outer ring, and a number of retaining portions that are equal to the number of the bearing portions and that retain a predetermined number of two or more of the cam members at predetermined intervals in the circumferential direction, 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, The plurality of bearing portions and the plurality of holding portions are arranged alternately in the circumferential direction. 、 the retaining member includes an annular plate disposed on the central axis; the plurality of bearing portions and the plurality of holding portions are formed on a surface of the annular plate on one axial side thereof, The outer diameter side edge of the annular plate engages with the inner peripheral surface of the outer ring.It is characterized by the fact that [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a one-way clutch that can be made lighter while achieving stable operation. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a front view showing a one-way clutch according to an embodiment of the present invention as viewed from one axial side. [Figure 2] 1 is a side view showing a state in which the one-way clutch according to the embodiment is viewed from a radial direction. FIG. [Figure 3] 1 is a perspective view showing the appearance of a one-way clutch according to an embodiment; [Figure 4] 4A and 4B are enlarged cross-sectional views of a main part showing the state of a cam member of a one-way clutch according to an embodiment, with FIG. 4A showing an unloaded state and FIG. 4B showing a torque loaded state. [Figure 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 INVENTION

[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 the outer ring will be described as an example.

[0010] First, the directions related to the one-way clutch in this embodiment will be defined. In this embodiment, the "center axis C" refers to the center axis of the one-way clutch, i.e., the center axes of the outer ring and the inner ring, and the axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions relative to the center axis C. Regarding the axial direction, in each of FIGS. 1 and 4, the direction toward the front of the page is referred to as one axial direction, and the direction toward the back of the page is referred to as the other axial direction. In each of FIGS. 2 and 5(b), the left side of the page is referred to as one axial direction, and the right side of the page is referred to as the other axial direction. Regarding the circumferential direction, in each of FIGS. 1 and 4, the clockwise rotation direction as viewed from the front of the page is referred to as one circumferential direction, and the counterclockwise rotation direction as viewed from the front of the page is referred to as the other circumferential direction.

[0011] For convenience of explanation, the rotation direction of the one-way clutch will be described in terms of the rotation direction 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. Furthermore, 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 are rotating 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. The inner ring 3 and the outer ring 5 are shown by imaginary 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. 4A showing the no-load state and FIG. 4B showing the torque-load 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 members 15 for biasing the plurality of cam members 7 in a direction that brings them 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 members 15 are garter springs.

[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 Figures 4(a) and 4(b), the cross-sectional shape of the cam members 7 is a combination of a semicircular portion 17 and a bulge portion 19 that bulges outward from a line connecting both ends of the arc of the semicircular portion 17. The bulge portion 19 has a gentle mountain shape with a rounded top, and one end of the outline of the bulge portion 19 smoothly connects to one end of the arc of the semicircular portion 17, and the other end of the outline of the bulge portion 19 smoothly connects to the other end of the arc of the semicircular portion 17. The cam members 7 are formed so that the length of the line connecting the top of the bulge portion 19 to the bottom of the arc of the semicircular portion 17 is shorter than the length of the 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 entire cage 9 is 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 the 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 axially from one axial side surface 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. As shown in each drawing in FIG. 4 , the cross-sectional shape of the pillar portions 25 is a rectangle with sides extending radially and sides extending circumferentially. In this embodiment, the cross-sectional shape is a rectangle with long sides extending radially and short sides extending circumferentially. 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 a single imaginary cylindrical surface centered on the central axis C.

[0017] Three radially penetrating window portions 29 are formed at equal intervals in the circumferential direction in the cam member holding portion 23 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 will be described later, each window portion 29 holds one cam member 7 in a swingable manner.

[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 a single 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 a single imaginary cylindrical surface centered on the central axis C.

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

[0020] The inner peripheral surface of bearing portion 31 is disposed on an imaginary cylindrical surface that is different from the inner peripheral surface of cam member holding portion 23, i.e., the inner peripheral surfaces of each pillar portion 25 and flange portion 27. These multiple cam member holding portions 23 and multiple bearing portions 31 are disposed between inner ring outer peripheral surface 11 and outer ring inner peripheral surface 13. As shown in FIG. 2, inner ring 3 is disposed on the inner diameter side of bearing portion 31 and cam member holding portion 23.

[0021] The bearing portion 31 supports the outer ring 5 on its outer peripheral surface 33. The outer peripheral surface 33 of the bearing portion 31 may be curved with 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. Furthermore, a portion of the annular plate 21 extending radially outward from the 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 is fitted 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 one axial end of the outer ring 5 in the axial direction. This fixes the cage 9 to the inner peripheral side of the outer ring 5 so as to be immovable axially relative to the outer ring 5 and imrotatable circumferentially relative to the outer ring 5.

[0022] The multiple cam members 7 are fitted from the outer diameter side into the window portions 29 of the cage 9 in a one-to-one correspondence, 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. One cam member holding portion 23 holds the multiple cam members 7 at equal intervals in the circumferential direction. In this embodiment, one cam member holding portion 23 holds three cam members 7 at equal intervals in the circumferential direction. Both axial end faces of the cam members 7 are located inside the portions of the flange portions 27 and 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 the unloaded state, the cam member 7 has the semicircular portion 17 facing the inner ring 3, the bottom of the semicircular portion 17 in contact with the inner ring outer surface 11, the bulge portion 19 facing the outer ring 5, and the top of the bulge portion 19 in contact with the outer ring inner surface 13.

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

[0024] As shown in Fig. 3 , each cam member 7 has a groove 39 formed in its radially outer portion in an assembled state, the groove 39 extending in the circumferential direction of the inner ring 3 or the outer ring 5. Groove 39 is formed in the axial center of the radially outer portion of cam member 7, penetrates circumferentially through the radially outer portion, and has a depth that reaches near the center of cam member 7. In addition, a groove 41 extending in the circumferential direction is also formed in the radially outer portion of bearing portion 31. Groove 41 is formed in the axial center of the radially outer portion of bearing portion 31, penetrates circumferentially through the radially outer portion, and has a depth that reaches near the center of bearing portion 31.

[0025] A single annular spring member 15 is installed 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, when the biasing force toward the inner diameter side is applied by the spring member 15, the cam member 7 swings toward the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13. Therefore, each cam member 7 is biased toward the inner diameter side by the elastic force of the spring member 15, and is constantly in contact with the inner ring outer peripheral surface 11 and the outer ring inner peripheral surface 13. The state of contact 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 toward a torque non-transmitting position.

[0026] The annular plate 21 and flange portion 22 of the cage 9 are provided with radially extending cutouts 43 on one circumferential side and the other circumferential side of each bearing portion 31. The cutouts 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 also has four cutouts 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 with these cutouts 43, 45 to have rigidity suitable for the one-way clutch 1 to be assembled thereto.

[0027] Next, the operating state of the one-way clutch 1 according to this embodiment having the above-described configuration will be described. In the no-load state shown in Figure 4(a), the elastic force of spring member 15 causes cam member 7 to contact inner ring outer peripheral surface 11 and outer ring inner peripheral surface 13, but they are not engaged in a way that allows torque to be transmitted. When torque is applied to inner ring 3 from this state, cam member 7 swings in a direction that allows the inner ring 3 and outer ring 5 to engage in a way that allows torque to be transmitted. That is, as shown in Figure 4(b), when inner ring 3 rotates clockwise in Figure 4(b), cam member 7, which is in contact with inner ring outer peripheral surface 11, rotates, i.e., swings, counterclockwise. As cam member 7 swings in this way, it engages with inner ring outer peripheral surface 11 and outer ring inner peripheral surface 13, and torque is transmitted from inner ring 3 to outer ring 5 through this engagement.

[0028] At this time, the outer ring 5 is mounted on the cage 9, and its inner peripheral surface 13 is supported by four bearing portions 31, each disposed at an angular position of 90° around the central axis C in the circumferential direction. This allows the cage 9 and the outer ring 5 to rotate stably together with the inner ring 3. Furthermore, the multiple cam members 7 are held by four cam member holders 23, each disposed at an angular position of 90° around the central axis C in the circumferential direction. Each cam member holder 23 holds three cam members, so the inner ring 3 and the outer ring 5 are stably engaged with each other in the circumferential direction. As a result, the inner ring 3 and the outer ring 5 rotate stably, and the cam members 7 do not become caught in the pair of pillar portions 25 of the window portion 29. This prevents the one-way clutch 1 from malfunctioning due to the cam members 7 becoming 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, torque is not transmitted from the inner ring 3 to the outer ring 5.

[0030] As described above, in the one-way clutch 1 of this embodiment, the cage 9 is made of resin, which enables weight reduction of the one-way clutch 1 and an automatic transmission (not shown) into which the one-way clutch 1 is incorporated. Furthermore, because the bearing portion 31 that supports the inner peripheral surface 13 of the outer ring 5 is formed in the cage 9, there is no need to provide a bearing for supporting the outer ring 5 as a separate part from the cage 9. This prevents an increase in the axial dimension of the one-way clutch 1, reduces the installation space for the one-way clutch 1, and contributes to weight reduction by reducing the number of parts. Furthermore, as described above, the inner ring 3 and the outer ring 5 rotate stably, which prevents malfunction of the one-way clutch 1 due to the cam member 7 getting caught in the cage 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 a one-way clutch 1 that transmits torque from the inner ring 3 to the outer ring 5 is shown. However, the present invention may also be applied to a one-way clutch that transmits torque from the outer ring 5 to the inner ring 3. The number of bearing portions 31 and cam member holders 23 can also be set as appropriate depending on the size and torque capacity of the one-way clutch 1. The number of cam members 7 held by one cam member holder 23 can also be set as appropriate. In the above embodiment, a predetermined number of notches 43 and 45 are provided in the annular plate 21 of the cage 9. However, the number of notches 43 and 45 can also be changed as appropriate depending on the rigidity required of the cage 9. Alternatively, the 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 inner circle, an outer ring arranged concentrically on the central axis of the inner ring; a plurality of cam members interposed between the inner ring and the outer ring and used to transmit torque between the inner ring and the outer ring; a holding member for holding the plurality of 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 that support an inner peripheral surface of the outer ring, and a number of retaining portions that are equal to the number of the bearing portions and that retain a predetermined number of two or more of the cam members at predetermined intervals in the circumferential direction, 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, The plurality of bearing portions and the plurality of holding portions are arranged alternately in the circumferential direction, the retaining member includes an annular plate disposed on the central axis; the plurality of bearing portions and the plurality of holding portions are formed on a surface of the annular plate on one axial side thereof, A one-way clutch characterized in that the outer diameter side edge of the annular plate is engaged with the inner circumferential surface of the outer ring.

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

3. 3. The one-way clutch according to claim 1, 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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