Cam clutch

Abstract

To provide a cam clutch capable of improving productivity and assemblability and having a high degree of freedom in design while reducing manufacturing cost.SOLUTION: A cam clutch 100 includes an inner ring 110 and an outer ring 120 coaxially provided so as to be relatively rotatable, and a plurality of cams 130 arranged in a row in a circumferential direction between the inner ring 110 and the outer ring 120. The cam clutch 100 further includes a position fixing member 140 for fixing a relative position of the adjacent two cams 130. The position fixing member 140 connects the adjacent two cams to be independently swingable.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cam clutch that transmits and interrupts torque between an input shaft and an output shaft.

Background Art

[0002] A cam clutch mainly includes a plurality of cams disposed between an inner ring and an outer ring, a retainer that holds the plurality of cams, and biasing means that biases each cam in the meshing direction with respect to the inner ring and the outer ring. For example, Patent Document 1 discloses a one-way clutch that uses a wire cage formed by bending a wire rod into a U-shaped zigzag endless shape of an axial direction portion and a circumferential direction portion as a retainer. Such a retainer is configured to hold the cams at equal intervals in the circumferential direction by arranging the cams at portions formed by the circumferential direction portion and the axial direction portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a cam clutch including a retainer, even if they are of the same size, there are many cases where the required characteristics are different. For example, depending on the required transmission torque capacity, cams with an optimal shape may be incorporated, or the number and arrangement of the cams may be changed. Along with this, it becomes necessary to change the configuration of the retainer. As described above, a dedicated retainer has to be manufactured according to the characteristics, size, etc. required for the cam clutch. There is a problem that the versatility of the parts is lacking, it is difficult to manufacture the retainer, the productivity is lowered, and the manufacturing cost is increased. In addition, when the cage is constituted by a wire cage, due to its structure, the number of cams needs to be an even number, which has the disadvantage that the number of cams is restricted.

[0005] The present invention has been made based on the above circumstances, and an object thereof is to provide a cam clutch that realizes reduction of manufacturing cost, improves productivity and assemblability, and has a high degree of design freedom.

Means for Solving the Problems

[0006] The present invention is a cam clutch including an inner ring and an outer ring that are rotatable relative to each other coaxially, and a plurality of cams arranged side by side in the circumferential direction between the inner ring and the outer ring, and includes a position fixing member that fixes the relative positions of two adjacent cams, and the position fixing member is is configured to connect two adjacent cams so that they can swing independently of each other formed, and the cam includes a plurality of cam plates having the same outer peripheral contour shape and arranged in parallel in the rocking axis direction, and a connecting pin provided to extend in the rocking axis direction and connecting each of the plurality of cam plates to each other, and the position fixing member is loosely fitted to each of the connecting pins of two adjacent cams Thereby, the above problems are solved.

Effects of the Invention

[0007] According to the cam of claim 1, since it does not include a cage and two adjacent cams are connected by a position fixing member to fix the relative positional relationship between the two cams, the structure is simple, easy to manufacture, and it is possible to improve productivity and reduce manufacturing cost. Moreover, since there is no need to manufacture a dedicated cage, high versatility can be obtained. Moreover, unlike a cam clutch including a cage constituted by a wire cage, there is no limitation on the number of cams, so a high degree of design freedom can be obtained.

[0008] Also Each cam plate and the position fixing member can be manufactured simultaneously with the pin holes by punching a plate material, and only simple hole processing needs to be performed on the cam plate and the position fixing member, so the processing burden can be reduced, productivity can be improved, and manufacturing cost can be reduced. Also, Claim 2According to the configuration described in , a plurality of cam plates are fixed by two connecting pins, facilitating phase alignment during cam assembly, improving assemblability, and enabling weight reduction since the cam has no waste (unnecessary parts).

[0009] According to the configuration described in claim 3, since the position fixing member is arranged and the space where the cam plate does not exist can be used as the mounting portion of the annular spring, machining of the annular spring mounting groove is not required in the manufacturing process of the cam. Also in this regard, the processing burden can be reduced, productivity can be improved, and manufacturing costs can be reduced. Further, since the position fixing member also serves as a spring receiving portion, the biasing force from the annular spring can be properly applied in the meshing direction of the cam, so that a difference in the degree of meshing of each cam can be avoided.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Modes for Carrying Out the Invention

[0011] As shown in FIGS. 1 to 3, the cam clutch 100 according to the present embodiment includes an inner ring 110 and an outer ring 120 that are relatively rotatable on the same axis, and a plurality of cams 130 as engaging elements that are provided in the circumferential direction in the annular space between the raceway surface 111 of the inner ring 110 and the raceway surface 121 of the outer ring 120 and transmit and cut off torque between the inner ring 110 and the outer ring 120, and an annular spring 160 that biases each of the plurality of cams 130 in the meshing direction with respect to the inner ring 110 and the outer ring 120.

[0012] As shown in FIG. 4, each of the plurality of cams 130 is composed of two cam plates 131 arranged in parallel in the rocking axis direction and two connecting pins 135 provided so as to extend in the rocking axis direction at two circumferentially spaced positions and connecting the two cam plates 131 to each other. By fixing the pair of cam plates 131 with the two connecting pins 135, the phase alignment at the time of cam assembly becomes easy, the assemblability can be improved, and since the cam has no waste (unnecessary part), weight reduction can be achieved. In the present embodiment, in the state where the cam 130 is assembled, as shown in FIG. 5, the positions of the two connecting pins 135 are set so that the center of gravity position G of the cam 130 is formed at a position shifted in the meshing direction with respect to the normal line H at the contact point C between the outer ring side engaging surface 133 of the cam 130 and the raceway surface 121 of the outer ring 120.

[0013] In the cam 130 according to the present embodiment, the number of cam plates 131 is two, but the number of cam plates is not limited to two and may be three or more. For example, in a cam having three cam plates, the space between two adjacent cam plates can be used as a mounting portion for the annular spring, and thus two annular springs can be mounted. Therefore, it is possible to surely apply a biasing force suitable for the required function to the cam. In addition, the cam 130 according to the present embodiment is configured such that two cam plates 131 are connected by two connecting pins 135, but it may be configured to be connected by one connecting pin or may be configured to be connected by three or more connecting pins.

[0014] Each cam plate 131 has the same outer peripheral contour shape as each other. As a result, there is no difference in the degree of meshing between the cam plates 131, and it is possible to reduce friction loss. In addition, it is possible to improve productivity and reduce manufacturing costs. As shown in FIG. 5, the cam plate 131 has an inner ring side engaging surface 132 that contacts the raceway surface 111 of the inner ring 110 and an outer ring side engaging surface 133 that contacts the raceway surface 121 of the outer ring 120. The cross-sectional shape of the inner ring side engaging surface 132 is, for example, an arc shape, and the cross-sectional shape of the outer ring side engaging surface 133 is a curved shape including an arc-shaped portion having a smaller radius of curvature than the inner ring side engaging surface 132. In FIG. 5, for the sake of convenience, the raceway surface 111 of the inner ring 110 and the raceway surface 121 of the outer ring 120 are shown as parallel planes.

[0015] Two pin holes 134 penetrating in the thickness direction are formed in the cam plate 131, and the two cam plates 131 are integrally fixed by press-fitting the connecting pins 135 into the pin holes 134. With such a configuration, it is possible to avoid a deviation in the relative positional relationship (the posture of the cam plate 131) between the two cam plates 131, so it is possible to avoid a difference in the degree of meshing of each cam plate 131. In addition, since each cam plate 131 can be manufactured simultaneously with the pin hole 134 by punching a plate material, also in this respect, it is possible to reduce the processing burden, improve productivity, and reduce the manufacturing cost.

[0016] In this embodiment, for example, a columnar connecting pin 135 is used, and the pin hole 134 is configured such that the opening shape is circular and has a hole diameter of uniform size in the thickness direction. However, the cross-sectional shape of the connecting pin and the opening shape of the pin hole are not limited to circular shapes, and may be, for example, polygonal shapes, elliptical shapes, oblong shapes, etc., as long as they are shapes that are mainly easy to manufacture. When the cross-sectional shape of the connecting pin and the opening shape of the pin hole are polygonal shapes, it is possible to more reliably obtain a function of preventing relative rotation of the two cam plates. Also, the connecting pin does not necessarily have a columnar shape with a uniform outer diameter in the axial direction, and may have portions with different outer diameters. The connecting pin is configured as a separate member from the cam plate, but may be configured integrally with one of the cam plates.

[0017] Each cam 130 is configured such that an annular spring 160 can be mounted between the two cam plates 131. That is, in the cam 130 of this embodiment, since the space where the cam plate 131 does not exist can be used as the mounting portion of the annular spring 160, machining of an annular spring mounting groove is not required in the manufacturing process of the cam 130, and it is possible to reduce the machining burden, improve productivity, and reduce the manufacturing cost. In this embodiment, the annular spring 160 is configured to be mounted between the two cam plates 131, but at least one connecting pin may be provided such that the end portion protrudes from the outer end surface of the cam plate, and the annular spring 160 may be configured to be mounted on the outer side in the swinging axis direction of the cam plate.

[0018] In the cam clutch 100 of this embodiment, for example, an annular garter spring is used as the annular spring 160. As shown in FIG. 6A, by mounting the garter spring from the outer ring side engaging surface 133 side of the cam 130, each of the plurality of cams 130 is biased radially inward to apply a rotational moment M in the meshing direction. By restraining each of the plurality of cams 130 with the garter spring, all the cams 130 are stably held without variation in posture (tilt). In this embodiment, the annular spring 160 is provided to bias each of the plurality of cams 130 radially inward, but the configuration may be such that the annular spring is provided to bias each of the plurality of cams 130 radially outward. Further, the annular spring may be any spring as long as it biases each of the plurality of cams 130 in the meshing direction with respect to the inner ring 110 and the outer ring 120, and is not limited to a garter spring.

[0019] Moreover, in the above-described cam clutch 100, a position fixing member 140 for fixing the relative positions of two adjacent cams 130 is provided. Therefore, the configuration is such that it does not have a retainer such as a cage ring for holding the cams 130. The position fixing member 140 is configured to connect two adjacent cams 130 so as to be independently swingable. The position fixing member 140 in this embodiment is composed of a plate-shaped member having an oval planar shape, and two pin holes 141 are provided at positions separated in the major axis direction. Then, so that the cam plate 131 can swing with respect to the connecting pin 135, each of the connecting pins 135 of two adjacent cams 130 is inserted into the pin hole 141 in a loosely fitted state, whereby two adjacent cams 130 are connected so as to be independently swingable without inhibiting the behavior of the cams 130, and the relative positional relationship is fixed. With such a configuration, the structure is simple and easy to manufacture, and it is possible to improve productivity and reduce manufacturing costs. Moreover, since there is no need to manufacture a dedicated retainer, high versatility can be obtained. In addition, unlike a cam clutch having a retainer composed of a wire cage, there is no limit on the number of cams, so a high degree of design freedom can be obtained. In this embodiment, the number of cams 130 is an even number, for example, 22, but it may be an odd number, and the number of cams 130 can be appropriately changed according to the purpose.

[0020] The position fixing member 140 is disposed inside the outer peripheral edge of the cam plate 131 so as not to contact the inner ring 110 and the outer ring 120 between the two cam plates 131, and is configured to contact the annular spring 160 and receive the biasing force from the annular spring 160. Since the position fixing member 140 also serves as a spring receiving portion, the biasing force from the annular spring 160 can be properly applied in the meshing direction of the cam 130, so that it is possible to avoid a difference in the degree of meshing of each cam 130.

[0021] Thus, in the above-described cam clutch 100, as shown in FIG. 6A, when the rotational moment M is applied by the annular spring 160, the inner ring engaging surface 132 of the cam 130 contacts the raceway surface 111 of the inner ring 110 and the outer ring side engaging surface 133 of the cam 130 contacts the raceway surface 121 of the outer ring 120, and all Cam 130 maintains a meshing standby state so that meshing is immediately started when torque acts on the inner ring 110 or the outer ring 120 with respect to the inner ring 110 and the outer ring 120. For example, when the inner ring 110 is rotated in one direction (clockwise in FIG. 6A), the inner ring side engaging surface 132 of the cam 130 frictionally engages with the raceway surface 111 of the inner ring 110 and the outer ring side engaging surface 133 of the cam 130 frictionally engages with the raceway surface 121 of the outer ring 120, and torque transmission between the inner ring 110 and the outer ring 120 is performed. On the other hand, as shown in FIG. 6B, when the inner ring 110 is rotated in the other direction (counterclockwise in FIG. 6B), by receiving a predetermined centrifugal force, the cam 130 swings against the rotational moment due to the biasing force of the annular spring (omitted in FIG. 6B), and the cam 130 floats upward with respect to the inner ring 110 due to the centrifugal force. When the inner ring side engaging surface 132 of the cam 130 and the raceway surface 111 of the inner ring 110 are in a non-contact state, the inner ring 110 idles, and torque transmission between the inner ring 110 and the outer ring 120 is interrupted. Therefore, it is possible to prevent wear of the inner ring side engaging surface 132 and the outer ring side engaging surface 133 of the cam 130 during high-speed idling. Further, since each of the connecting pins 135 of two adjacent cams 130 is inserted into the pin hole 141 in a loosely fitted state in the position fixing member 140, as the cam 130 swings, the position fixing member 140 rotates, so that the position fixing member 140 does not inhibit the behavior of the cam 130, enabling smooth operation and obtaining high responsiveness.

[0022] As described above, one embodiment of the present invention has been described in detail. However, the present invention is not limited to the above embodiment, and various design changes can be made without departing from the present invention described in the claims. For example, in the above embodiment, two adjacent cams are connected by a plate-shaped position fixing member. However, the means for fixing the relative positional relationship between two adjacent cams is not limited to a plate-shaped position fixing member as long as two adjacent cams can be independently and swingably connected. Also, although the connecting pin for fixing the two cam plates is inserted into the pin hole of the position fixing member, a cylindrical bush may be press-fitted into the pin hole of the position fixing member, and the connecting pin may be inserted into the bush in a loosely fitted state. Furthermore, a configuration in which two position fixing members are attached to one connecting pin may be adopted. Also, in the above embodiment, the position fixing member is configured to be mounted between two cam plates. However, at least one connecting pin may be provided such that the end portion protrudes from the outer end surface of the cam plate, and the position fixing member may be mounted outside the cam plate in the swinging axis direction. In such a configuration, a retaining member for the position fixing member may be provided. Also, in the above embodiment, a configuration having biasing means for biasing the cam in the meshing direction with respect to the inner ring and the outer ring has been described. However, a configuration without biasing means may be adopted. In this case, the center of gravity position of the cam may be appropriately changed so that the cam is frictionally engaged with the inner ring and the outer ring by the action of centrifugal force. In the above description, the case where the present invention is applied to a one-way cam clutch has been explained. However, for example, it is also possible to apply it to a two-way cam clutch provided with two types of cams configured to apply rotational moments in different directions from each other, or a cam clutch provided with an operation mode switching mechanism for forcibly switching the operation mode of the cam clutch.

Explanation of Signs

[0023] 100 ··· Cam clutch 110 ··· Inner ring 111 ··· Raceway surface 120 ··· Outer ring 121 ··· Raceway surface 130 ··· Cam 131 ··· Cam plate 132 ··· Inner ring side engaging surface 133 ··· Outer ring side engaging surface 134 ··· Pin hole 135 ··· Connecting pin 140 ··· Position fixing member 141 ··· Pin hole 160 ··· Annular spring

Claims

1. A cam clutch comprising an inner ring and an outer ring that are rotatable relative to each other on the same axis, and a plurality of cams arranged side by side in the circumferential direction between the inner ring and the outer ring, comprising a position fixing member for fixing the relative positions of two adjacent cams, wherein the position fixing member is configured to connect two adjacent cams so as to be independently swingable, wherein the cams include a plurality of cam plates having the same outer peripheral contour shape and arranged in parallel in the swing axis direction, and connecting pins provided so as to extend in the swing axis direction and connecting each of the plurality of cam plates to each other, wherein the position fixing member is fitted in a loose state to each of the connecting pins of two adjacent cams. The cam clutch is characterized by this.

2. The cam clutch according to claim 1, wherein the plurality of cam plates are connected by the connecting pins at two positions spaced apart in the circumferential direction.

3. Further comprising an annular spring for biasing the plurality of cams in the meshing direction with respect to the inner ring and the outer ring, wherein the position fixing member is configured to contact the annular spring and receive the biasing force from the annular spring. The cam clutch according to claim 1 or claim 2 is characterized by this.

Images