Cam clutch

Abstract

To provide a cam clutch having simple construction for transmitting stable torque with good meshing performance while having a high degree of design freedom and reducing manufacturing costs.SOLUTION: A cam clutch comprising a plurality of cams (130) disposed between an inner ring and an outer ring which are coaxially provided so as to be relatively rotatable, at least one auxiliary member (160) disposed between the plurality of cams (130), and an urging means (160) for urging the plurality of cams (130) and the auxiliary member (150) in a radial direction, wherein the auxiliary member (150) has an engaging portion engageable with the urging means (150), and a radial dimension of the auxiliary member (150) is equal to or less than a dimension between the inner ring and the outer ring.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cam clutch comprising a plurality of cams arranged between an inner ring and an outer ring that are coaxially rotatable relative to each other, at least one auxiliary member arranged between the plurality of cams, and a biasing means that radially biases the plurality of cams. [Background technology]

[0002] Conventionally, a cam clutch has been known that includes multiple cams arranged between an inner ring and an outer ring that are coaxially rotatable relative to each other, and a biasing means that biases the multiple cams in the radial direction (see, for example, Patent Document 1). A cam clutch 100 known from Patent Document 1 and the like (the names and symbols of the components in this paragraph follow the notation in Patent Document 1) has an inner ring 110 arranged radially inside an outer ring 120, and multiple cams 131 arranged between the outer ring 120 and the inner ring 110, and the multiple cams 131 are forced radially inward by a force-applying means 139, and is configured to be able to transmit torque between the outer ring 120 and the inner ring 110 by changing the radial height of the multiple cams 131 when the outer ring 120 and the inner ring 110 rotate relative to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-190255 Summary of the Invention [Problem to be solved by the invention]

[0004] A cam clutch 100 known from Patent Document 1 and the like (the names and symbols of the components in this paragraph follow the notation in Patent Document 1) has cams 131 arranged with no gaps in the circumferential direction to ensure a high transmission torque capacity. Since the cams 131 are arranged without gaps, the number of cams 131 is determined by the diameter of the outer surface of the inner ring 110 and the size of the cams 131, which reduces design freedom and may result in excessive performance if the required transmission torque capacity is low. Furthermore, when the cams 131 operate, adjacent cams 131 rotate and slide in opposite directions, which may impede the operation of the cams 131, reducing the meshing with the outer ring 120 and the inner ring 110 and causing the transmitted torque to become unstable, or may cause the cams 131 to wear out. Furthermore, if a cam cage ring 648 made of metal wire bent to form a storage section 649 for the cam 131 is provided to maintain the position of the cam 131, it would be necessary to manufacture cam cage rings 648 to match the number of cams 131, which would complicate the structure and could increase manufacturing costs.

[0005] The present invention is intended to solve these problems, and aims to provide a cam clutch that has a simple configuration, good meshing properties, can transmit stable torque, has a high degree of design freedom, and is inexpensive to manufacture. [Means for solving the problem]

[0006] The cam clutch of the present invention is a cam clutch comprising a plurality of cams arranged between an inner ring and an outer ring which are arranged coaxially and rotatable relative to each other, at least one auxiliary member arranged between the plurality of cams, and a biasing means for biasing the plurality of cams radially, wherein the auxiliary member has an engaging portion which can engage with the biasing means, and the radial dimension of the auxiliary member is equal to or less than the dimension between the inner ring and the outer ring, thereby solving the above-mentioned problem. [Effects of the Invention]

[0007] According to the invention of claim 1, there is provided a cam clutch comprising a plurality of cams arranged between an inner ring and an outer ring which are coaxially rotatable relative to each other, at least one auxiliary member arranged between the plurality of cams, and a biasing means for biasing the plurality of cams in the radial direction, wherein the auxiliary member has an engaging portion which can engage with the biasing means, and the radial dimension of the auxiliary member is equal to or less than the dimension between the inner ring and the outer ring, thereby reducing the sliding resistance of the cams without impeding the free rotation of the inner ring and the outer ring, improving meshing performance and stabilizing the transmitted torque. Furthermore, by reducing the number of cams and rollers to be arranged, it is possible to keep the number to the minimum necessary to satisfy the required performance.

[0008] According to the configuration described in claim 2, the auxiliary member includes a cylindrical portion that can come into contact with an adjacent cam, so that when the cam operates, the auxiliary member itself rolls in accordance with the oscillation of the cam, thereby further improving the meshing performance.

[0009] According to the configuration of claim 3, the circumferential dimension of the auxiliary member may be equal to or greater than the circumferential dimension of the cam, thereby making it possible to optimize the number of cams to be arranged without depending on the diameter of the outer peripheral surface of the inner ring or the size of the cam, thereby reducing the number of parts and improving design freedom.

[0010] According to the configuration recited in claim 4, the auxiliary member includes one having a hanging portion at both circumferential ends, the hanging portion being formed to extend toward the inner ring, and when viewed in the axial direction, the lower end of the hanging portion comes into contact with the outer peripheral surface of the inner ring, thereby reducing the contact area between the auxiliary member and the outer peripheral surface of the inner ring and enabling reduced sliding resistance with the outer peripheral surface of the inner ring even when the auxiliary member is large.

[0011] According to the configuration of claim 5, the auxiliary member includes a retaining recess formed at its circumferential end for rotatably holding the cam, thereby preventing the auxiliary member from moving in the radial direction and reducing sliding resistance between the auxiliary member and the outer ring or the inner ring.

[0012] According to the configuration of claim 6, the outer ring and the inner ring have flange portions that restrict the axial movement of the cam and the auxiliary member, and the engagement portion is formed at one end in the axial direction, so that the auxiliary member can be arranged even when the biasing means is arranged at one end in the axial direction. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a front view of a cam clutch according to a first embodiment of the present invention, viewed from an axial direction. [Figure 2] FIG. 2 is a perspective view of the cam clutch of FIG. 1 from above. [Figure 3] An enlarged top view of the cam clutch in Figure 1. [Figure 4] 2A and 2B are a front view and a side view of a cam related to the cam clutch of FIG. 1; [Figure 5] 2A and 2B are a front view and a side view of a roller of the cam clutch of FIG. 1; [Figure 6] 2A and 2B are a front view and a side view of an auxiliary member for the cam clutch of FIG. 1; [Figure 7] 4 is a cross-sectional view taken along line AA in FIG. 3, illustrating the operation of the cam and the auxiliary member. [Figure 8] FIG. 6 is a front view of a cam clutch according to a second embodiment of the present invention, viewed from the axial direction. [Figure 9] FIG. 9 is a perspective view of the cam clutch of FIG. 8 from above. [Figure 10] FIG. 9 is an enlarged top view of the cam clutch of FIG. [Figure 11] 9A and 9B are a front view and a side view of an auxiliary member for the cam clutch of FIG. 8; [Figure 12] FIG. 10 is a front view of a cam clutch according to a third embodiment of the present invention, viewed from the axial direction. [Figure 13] FIG. 13 is a perspective view from above of the cam clutch of FIG. 12. [Figure 14] 13 is an enlarged top view of the cam clutch of FIG. 12. [Figure 15] 13A and 13B are a front view and a side view of an auxiliary member for the cam clutch of FIG. 12; [Figure 16] 15 is a cross-sectional view taken along the line BB in FIG. 14, illustrating the operation of the cam and the auxiliary member. [Figure 17] FIG. 10 is a front view of a cam clutch according to a fourth embodiment of the present invention, viewed from the axial direction. [Figure 18] FIG. 18 is a perspective view from above of the cam clutch of FIG. 17; [Figure 19] 18 is an enlarged top view of the cam clutch of FIG. 17. [Figure 20] 18 is a cross-sectional view of cross section CC in FIG. 17. [Figure 21] 18A and 18B are a front view and a side view of a cam associated with the cam clutch of FIG. 17; [Figure 22] 18A and 18B are a front view and a side view of a roller associated with the cam clutch of FIG. 17; [Figure 23] 18A and 18B are a front view and a side view of an auxiliary member for the cam clutch of FIG. 17;

[0014] A cam clutch 100 according to a first embodiment of the present invention will be described below with reference to the drawings. 1 to 3 and 7, the inner and outer rings are omitted from the illustration. Also, in FIG. 7, only the auxiliary member 150 and the cam 130 adjacent thereto are shown.

[0015] As shown in Figures 1 to 3, the cam clutch 100 according to the first embodiment of the present invention has a plurality of cams 130 as engaging elements that transmit and block torque between the inner and outer rings in the annular space between the raceway surfaces of the inner and outer rings that are rotatable relative to one another on the same central axis, a plurality of rollers 140 that are arranged between the cams 130 and allow the inner and outer rings to rotate freely, a plurality of auxiliary members 150 that are arranged between the cams 130, and an annular spring 160 that serves as a biasing means. An annular spring 160 biases the plurality of cams 130 in the radial direction, causing them to oscillate in the direction of engagement with the inner and outer rings.

[0016] As shown in FIG. 4, the cam 130 has an engaging step 131 that can be engaged with an annular spring 160 at the center in the axial direction. The engagement step 131 has an inclined shape with a convex portion at an eccentric position, and when the spring 160 presses the convex portion at the bottom of the engagement step 131, the cam 130 is forced radially toward the inner ring, causing the cam 130 to swing in a direction that contacts the inner ring and outer ring.

[0017] As shown in FIG. 5, roller 140 is configured to have a dumbbell shape and has a shaft portion 141 extending in the axial direction, a pair of cylindrical portions 142 connected to each end of shaft portion 141, and an engagement portion 143 in the axial center that can engage with an annular spring 160. The engaging portion 143 is formed by a space between the pair of cylindrical portions 142, and the spring 160 is disposed between the pair of cylindrical portions 142.

[0018] As shown in FIG. 6, the auxiliary member 150 is configured to have a dumbbell shape and has an axial portion 151 extending in the axial direction, a pair of cylindrical portions 152 connected to each end of the axial portion 151, and an engaging portion 153 in the axial center that can engage with an annular spring 160. The pair of cylindrical portions 152 are capable of contacting the cam 130 adjacent to the auxiliary member 150, and are configured so that the axial dimension 1sw is equal to or less than the axial dimension 1rw of the cylindrical portion 142 of the roller 140, the diameter 1sd of the cylindrical portion 152 is equal to or less than the radial dimension between the inner and outer rings, and further equal to or less than the diameter 1rd of the cylindrical portion 142 of the roller 140. This allows the auxiliary member 150 to rotate in accordance with the oscillation of the cam 130 adjacent to the auxiliary member 150 without interfering with the free rotation of the inner and outer rings. The engaging portion 153 is formed by a space between the pair of cylindrical portions 152, and is configured so that the spring 160 is disposed between the pair of cylindrical portions 152.

[0019] The spring 160 is, for example, a garter spring, and is looped around the engagement step 131 of the cam 130, the engagement portion 143 of the roller 140, and the engagement portion 153 of the auxiliary member 150 so as to urge the cam 130 radially and cause it to oscillate in the direction of engagement with the inner and outer rings. Depending on the overall diameter of the cam clutch 100, the diameters of the roller 140 and the auxiliary member 150, and the depth of the engagement step 131 of the cam 130, the engagement portion 143 of the roller 140, and the engagement portion 153 of the auxiliary member 150, the spring 160 may also radially bias the roller 140 and the auxiliary member 150.

[0020] In this embodiment, as shown in Figures 1 and 2, the rollers 140 and auxiliary members 150 are arranged between two cams 130, and are arranged alternately as follows: roller 140 - cam 130 - auxiliary member 150 - cam 130 - auxiliary member 150 - cam 130 - roller 140... By providing the auxiliary member 150, the number of cams 130 and rollers 140 to be provided can be reduced to the minimum number necessary to satisfy the required performance. Here, the number and arrangement of the cams 130, rollers 140, and auxiliary members 150 are not particularly limited, as long as a plurality of cams 130 and at least one auxiliary member 150 are included.

[0021] Next, the rolling operation of the cam 130 and the auxiliary member 150 in the cam clutch 100 according to the first embodiment of the present invention will be described with reference to FIG. First, in cam clutch 100, when the inner or outer ring rotates and cam 130 oscillates in the direction indicated by the black arrow in FIG. 7, cylindrical portion 152 of auxiliary member 150 and cam 130 can come into contact with each other. Therefore, even if the cams 130 on both sides adjacent to auxiliary member 150 are pressed toward each other, auxiliary member 150 rolls in the opposite direction to the oscillation of cam 130 as indicated by the black arrow in FIG. 7 in accordance with the oscillation of cam 130. Conversely, when the cam 130 swings in the direction indicated by the white arrow in FIG. 7, the auxiliary member 150 rolls in the direction indicated by the white arrow in FIG. As a result, when the cam 130 operates, the auxiliary member 150 itself rolls, thereby reducing the sliding resistance of the cam 130, improving meshing performance and stabilizing the transmitted torque.

[0022] Next, a cam clutch 200 according to a second embodiment of the present invention will be described with reference to the drawings. Here, since this embodiment is similar to the first embodiment described above except for some configurations, the reference numerals in the 100s shown in the specification and drawings relating to the first embodiment will be replaced with reference numerals in the 200s, and explanations of the configurations other than the differences will be omitted. 8 to 10, the inner and outer rings are not shown.

[0023] As shown in Figures 8 to 11, the auxiliary member 250 of the cam clutch 200 is configured to have a bridge shape when viewed from the axial direction, and has an engaging portion 253 in the axial center that can engage with the annular spring 260, and hanging portions 254 at both circumferential ends. Hanging portion 254 is formed to extend radially toward the inner ring, and is configured so that the lower end of hanging portion 254 comes into contact with the outer peripheral surface of the inner ring when viewed from the axial direction, thereby reducing the contact area between auxiliary member 250 and the outer peripheral surface of the inner ring, and making it possible to reduce sliding resistance with the outer peripheral surface of the inner ring even when auxiliary member 250 is large. As shown in FIG. 8, the circumferential dimension 2sc of auxiliary member 250 is configured to be equal to or greater than the circumferential dimension 2cc of cam 230. This makes it possible to optimize the number of cams to be arranged without depending on the diameter of the outer peripheral surface of the inner ring or the size of the cams, thereby reducing the number of parts and improving design freedom. Furthermore, when hanging portions 254 at both circumferential ends come into contact with the outer peripheral surface of the inner ring, the outer peripheral surface of auxiliary member 250 is configured to have a shape that does not come into contact with the inner peripheral surface of the outer ring (in this embodiment, the outer peripheral surface of auxiliary member 250 is formed in an arc shape, and radius 2so is equal to or less than the radius of the inner peripheral surface of the outer ring), and since annular spring 260 always urges auxiliary member 250 toward the inner ring, the opportunity for contact with the inner peripheral surface of the outer ring is reduced, and even when auxiliary member 250 is large, contact resistance with the inner peripheral surface of the outer ring can be reduced.

[0024] In this embodiment, as shown in FIG. 8, the roller 240 and the auxiliary member 250 are arranged between two cams 230, and two cams 230 are arranged consecutively on one side of the circumference of the roller 240, and three cams 230 are arranged consecutively on the other side, with the cams 230 at the end of each consecutive arrangement being arranged adjacent to the auxiliary member 250.

[0025] Next, a cam clutch 300 according to a third embodiment of the present invention will be described with reference to the drawings. Here, since this embodiment is similar to the second embodiment described above except for some configurations, the reference numerals in the 200s shown in the specification and drawings relating to the second embodiment will be replaced with reference numerals in the 300s, and explanations of the configurations other than the differences will be omitted. 12 to 14 and 16, the inner and outer rings are omitted from the illustration. Also, in FIG. 16, only the auxiliary member 350 and the cam 330 adjacent thereto are shown.

[0026] As shown in Figures 12 to 15, the auxiliary member 350 of the cam clutch 300 has an engagement portion 353 in the axial center that can engage with the annular spring 360, and holding recesses 355 at both circumferential ends that rotatably hold the cam 330. The holding recess 355 is a recess formed toward the center of the circumferential direction of the auxiliary member 350, and is configured to hold the cam 330 rotatably.

[0027] Here, in cam clutch 300, as shown in Figure 16, when the inner ring or outer ring rotates and cam 330 swings in the direction indicated by the black arrow in Figure 16, retaining recess 355 of auxiliary member 350 holds cam 330 rotatably without interfering with the operation of cam 330 adjacent to auxiliary member 350. Conversely, even if the cam 330 swings in the direction indicated by the white arrow in Figure 16, the holding recess 355 of the auxiliary member 350 holds the cam 330 rotatably without interfering with the operation of the cam 330 adjacent to the auxiliary member 350. The radial position of cam 330 is restricted by the inner and outer rings, and the circumferential side of cam 330 fits into the retaining recess 355 of auxiliary member 350, preventing auxiliary member 350 from moving radially and reducing the sliding resistance between auxiliary member 350 and the outer or inner ring.

[0028] In this embodiment, as shown in FIG. 12, the roller 340 and the auxiliary member 350 are disposed between two cams 330, with one cam 330 disposed on one side of the circumference of the roller 340 and two cams 330 disposed consecutively on the other side, with each cam 330 disposed adjacent to the auxiliary member 350.

[0029] Next, a cam clutch 400 according to a fourth embodiment of the present invention will be described with reference to the drawings. Here, since this embodiment is similar to the third embodiment described above except for some configurations, the reference numerals in the 300s shown in the specification and drawings relating to the third embodiment will be replaced with reference numerals in the 400s, and explanations of the configurations other than the differences will be omitted. 17 and 18, only the outline of the outer ring 420 is shown. In addition, the outer ring 420 is not shown in FIG.

[0030] As shown in Figures 17 to 20, a cam clutch 400 according to the fourth embodiment of the present invention has, in the annular space between the raceway surface of an inner ring 410 and the raceway surface of an outer ring 420 which are arranged on the same central axis so as to be capable of relative rotation, a plurality of cams 430 as engaging elements which transmit and block torque between the inner ring 410 and the outer ring 420, a plurality of rollers 440 which are arranged between the cams 430 and allow the inner ring 410 and the outer ring 420 to rotate freely, a plurality of auxiliary members 450 which are arranged between the cams 430, and an annular spring 460 which serves as a biasing means. The annular spring 460 biases the plurality of cams 430 in the radial direction, causing them to oscillate in the meshing direction with the inner ring 410 and the outer ring 420 .

[0031] As shown in FIG. 21 and other figures, the cam 430 has an engaging step 431 at one axial end that can be engaged with an annular spring 460. The engagement step 431 has an inclined shape with a convex portion at an eccentric position, and when the spring 460 presses the convex portion at the bottom of the engagement step 431, the cam 430 is forced radially toward the inner ring 410, causing the cam 430 to swing in a direction that brings it into contact with the inner ring and outer ring. As shown in FIG. 22, the roller 440 is configured to have a cylindrical shape, and has a cylindrical portion 442 whose axial dimension is approximately equal to the axial dimension of the cam 430 excluding the engaging step portion 431 .

[0032] As shown in Figure 20, the inner ring 410 has a flange portion 411 on the axially opposite side of the engagement step portion 431 of the cam 430 so as to restrict movement of the cam 430, the roller 440, and the auxiliary member 450 in one axial direction (hereinafter referred to as the "right direction"). As shown in Figure 20, the outer ring 420 has a flange portion 421 on the same side as the engagement step portion 431 of the cam 430 so as to restrict the movement of the cam 430, the auxiliary member 450, and the spring 460 in the other axial direction (hereinafter referred to as the "left direction").

[0033] As shown in FIG. 23, the auxiliary member 450 has an engaging portion 453 at its left end that can engage with an annular spring 460, and holding recesses 455 at both circumferential ends that rotatably hold the cam 430. The holding recess 455 is a recess formed toward the center in the circumferential direction, and is configured to hold the cam 430 rotatably.

[0034] The spring 460 is configured by, for example, a garter spring, and is wound around the engaging step portion 431 of the cam 430 and the engaging portion 453 of the auxiliary member 450 so as to restrict the movement of the roller 440 in the left direction.

[0035] In this embodiment, as shown in FIG. 17, the roller 440 and the auxiliary member 450 are arranged between two cams 430, and three cams 430 are arranged consecutively on one side of the circumference of the roller 440, and four cams 430 are arranged consecutively on the other side, with the cams 430 at the end of each consecutive arrangement being arranged adjacent to the auxiliary member 450. As shown in Figures 19 and 20, the engagement step 431 of the cam 430 and the engagement portion 453 of the auxiliary member 450 are arranged in the direction of the flange portion 421 of the outer ring 420, and the roller 440 is arranged between the cams 430, the flange portion 411 of the inner ring 410, and the spring 460. This allows the auxiliary member 450 to be arranged even when the spring 460 is arranged at the end.

[0036] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the present invention as set forth in the claims. In the above-described embodiment, the end of the auxiliary member 250 in the circumferential direction has a convex shape, but like the auxiliary member 350, a holding recess that holds the cam 230 rotatably may be formed. Furthermore, like the auxiliary member 250, the auxiliary members 350 and 450 may be formed so that the circumferential dimension thereof is equal to or greater than the circumferential dimension of the cams 230 and 330. Furthermore, like the auxiliary member 250, the auxiliary members 350 and 450 may have hanging portions formed at both ends in the circumferential direction. [Explanation of symbols]

[0037] 100, 200, 300, 400... Cam clutch 410 ··· Inner circle 411 Flange 420 Outer ring 421 Flange 130, 230, 330, 430... Cam 131, 231, 331, 431... Engagement stepped portion 140, 240, 340, 440... Roller 141, 241, 341... Shaft 142, 242, 342, 442... Cylindrical section 143, 243, 343 Engagement part 150, 250, 350, 450... Auxiliary parts 151 Shaft 152 Cylindrical part 153, 253, 353, 453 Engagement part 254 ... Drooping part 355, 455 Retaining recess 160, 260, 360, 460... Spring 2so, 3so, 4so... Radius of the outer surface of the auxiliary part 1sw: Axial dimension of the cylindrical part of the auxiliary member 1rw: Axial dimension of the cylindrical part of the roller 1sd: diameter of the cylindrical part of the auxiliary member 1st: diameter of the cylindrical part of the roller 2sc Circumferential dimension of auxiliary member 2cc Circumferential dimension of the cam

Claims

1. A cam clutch comprising: a plurality of cams arranged between an inner ring and an outer ring that are coaxially and relatively rotatable; at least one auxiliary member arranged between the plurality of cams; and biasing means that biases the plurality of cams in a radial direction, the auxiliary member has an engaging portion that can be engaged with the biasing means, A cam clutch characterized in that the radial dimension of the auxiliary member is equal to or smaller than the dimension between the inner ring and the outer ring.

2. 2. The cam clutch according to claim 1, wherein the auxiliary member includes a cylindrical portion that can come into contact with the adjacent cam.

3. 2. The cam clutch according to claim 1, wherein the circumferential dimension of the auxiliary member is equal to or greater than the circumferential dimension of the cam.

4. The auxiliary member includes a member having a hanging portion at both ends in the circumferential direction, 2. The cam clutch according to claim 1, wherein the hanging portion is formed to extend toward the inner ring, and when viewed from the axial direction, a lower end of the hanging portion contacts the outer peripheral surface of the inner ring.

5. 2. The cam clutch according to claim 1, wherein the auxiliary member includes a retaining recess formed at a circumferential end thereof for rotatably retaining the cam.

6. the outer ring and the inner ring have flange portions that restrict axial movement of the cam and the auxiliary member, 2. The cam clutch according to claim 1, wherein the engaging portion is formed at one end in the axial direction.

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