Cam clutch

Abstract

To provide a cam clutch which can perform a smooth operation including a switching operation of an operation mode by preventing the occurrence of biting of a cam with a simple structure, and is achieved in a high function and size reduction.SOLUTION: A cam clutch 100 of the present invention comprises: an outer ring side cage ring 160 employed with a first cam 130a and a second cam 130b which are different in engagement directions as engagement pieces for transmitting and blocking the transmission of torque between an inner ring 110 and an outer ring 120, movably arranged in an axial direction as an operation mode switching mechanism 150 for switching an operation mode of the cam clutch 100, and constituted so as to be changeable in a posture of the first cam 130a; an inner ring side cage ring 170 movably arranged in the axial direction, and constituted so as to be changeable in a posture of the second cam 130b; and a position regulation cage ring 180 for regulating a degree of freedom of the movement of the outer ring side cage ring 160 and the inner ring side cage ring 170 in a peripheral direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cam clutch configured to be able to switch its operating mode. [Background technology]

[0002] As a clutch that controls the transmission and interruption of rotational force, a two-way clutch that can switch between driving and idling in both the forward and reverse directions is known. For example, Patent Document 1 describes a clutch that is configured to be able to switch between three operating modes by controlling a retainer that holds both first and second sprags, which are biased by a biasing means so that the rotation lock direction is reversed: a bidirectional free mode that allows rotation in both the forward and reverse directions; a one-way lock mode that allows rotation only in the forward direction and prohibits rotation in the reverse direction; and a one-way lock mode that allows rotation only in the reverse direction and prohibits rotation in the forward direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-231828 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, in the above-mentioned two-way clutch, since all of the first sprags and second sprags are forcibly tilted by controlling the cage when changing the operating mode, it is not possible to realize a bidirectional lock mode that prohibits relative rotation of the outer and inner rings in both the forward and reverse directions.

[0005] In the two-way clutch described above, the first and second sprags are biased so as to come into contact with the outer and inner rings, and when torque is applied to the outer or inner ring, one of the sprags tilts so as to immediately begin meshing with the outer and inner rings, while the other sprag continues to slide against the outer and inner rings while remaining in contact with them, maintaining a state of waiting to mesh. When the torque is released, one of the sprags tilts in the disengagement direction and transitions to a free-spinning state. However, before one sprag is disengaged, the other sprag may tilt in the engagement direction and begin to engage with the outer and inner rings, which could result in a "meshing" in which all cams engage simultaneously. In this state, all of the sprags are engaged with high contact pressure, so when switching the clutch operating mode from a locked mode, which prohibits relative rotation of the outer and inner rings in either or both directions, to a free mode, which allows relative rotation of the outer and inner rings in both directions, a large force is required to change the orientation of the sprags, which could damage the engagement surfaces of the sprags with the outer and inner rings and the raceways of the outer and inner rings, and shorten the life of the clutch. Another problem is that the orientation-changing members used to change the orientation of the sprags require high rigidity.

[0006] Furthermore, the shape of the cam serving as the engaging element in a cam clutch generally has an arc-shaped side surface, and with this type of outer peripheral contour shape, there is the problem that it is difficult to increase the rolling distance of the cam due to the relationship between the contact position of the cam and the retainer which functions as a means for changing the position of the cam.

[0007] The present invention has been made based on the above circumstances, and aims to provide a cam clutch with a simple structure that prevents cam jamming, enables smooth operation including switching between operating modes, and allows for high functionality and miniaturization. [Means for solving the problem]

[0008] The present invention solves the above-mentioned problems by providing a cam clutch including an outer ring and an inner ring rotatably mounted on the same rotation axis, a plurality of cams arranged circumferentially between the outer ring and the inner ring, and a biasing means for biasing each of the plurality of cams so as to contact the outer ring and the inner ring, wherein the plurality of cams include a first cam and a second cam which mesh with the outer ring and the inner ring in mutually different directions, and an operation mode switching mechanism for switching the operation mode of the cam clutch, the operation mode switching mechanism including an outer ring-side cage ring which is provided axially movable independently of the rotational movement of the outer ring and the inner ring and configured to change the attitude of the first cam, an inner ring-side cage ring which is provided axially movable independently of the rotational movement of the outer ring and the inner ring and configured to change the attitude of the second cam, and a position restricting cage ring which is provided between the outer ring-side cage ring and the inner ring-side cage ring and restricts the degree of freedom of circumferential movement of the outer ring-side cage ring and the inner ring-side cage ring. [Effects of the Invention]

[0009] According to the invention of claim 1, the outer cage ring is given the function of controlling the attitude of the first cam, and the inner cage ring is given the function of controlling the attitude of the second cam. Furthermore, the position-regulating cage ring restricts the freedom of movement of the outer cage ring and the inner cage ring in the circumferential direction. This means that simply by moving one or both of the outer cage ring and the inner cage ring in the axial direction, the cam can be tilted and the changed cam attitude can be maintained. Therefore, it is possible to configure a cam clutch that has high functionality and can accommodate four operating modes with a simple configuration. Furthermore, by restricting the degree of freedom of circumferential movement of the outer ring side cage ring and the inner ring side cage ring, it is possible to avoid the first cam and the second cam both meshing with the outer ring and the inner ring when the cam position is changed, thereby achieving smooth operation and high responsiveness.

[0010] According to the invention of claim 2, by changing the opening shape of the first cam holder and the second cam holder of each of the outer and inner cage rings serving as the operating mode switching mechanism, it is possible to tilt only one of the first and second cams. In other words, by integrating the cam position-changing mechanism into each of the outer and inner cage rings, it is possible to simplify the structure, reduce the size, reduce the number of parts, and increase the holding torque. Furthermore, by using an irregular shape, not a simple rectangular shape, for the opening shape of the first cam holder of the outer cage ring and the second cam holder of the inner cage ring, with an opening width variable portion whose opening width continuously changes, it is possible to release slight engagement caused by manufacturing errors with a small thrust. Furthermore, by appropriately changing the opening shape of the first and second cam holder of the outer and inner cage rings, it is possible to realize a wider range of operating modes and their switching.

[0011] According to the invention as defined in claim 3, it is possible to restrict the degree of freedom of movement of the outer cage ring and the inner cage ring in the circumferential direction with a simple structure. According to the invention of claim 4, when the outer cage ring is in a position that causes the first cam to mesh with the outer and inner rings, the outer protrusions on the position-regulating cage ring are movable in the circumferential direction, thereby providing the outer cage ring with an appropriate degree of freedom relative to the position-regulating cage ring; and when the inner cage ring is in a position that causes the second cam to mesh with the outer and inner rings, the inner protrusions on the position-regulating cage ring are movable in the circumferential direction, thereby providing the inner cage ring with an appropriate degree of freedom relative to the position-regulating cage ring, making it possible to achieve an appropriate meshing state of the first and second cams with the outer and inner rings.

[0012] According to the invention of claim 5, by adding the axial holding function of the cam to the outer ring, the desired function of the cam clutch can be reliably obtained without increasing the number of parts.

[0013] According to the invention of claim 6, it is possible to provide a large rotation angle for a small cam while maintaining high interlocking with the outer cage ring and the inner cage ring, which makes it possible to reduce the size of the cam and the size of the cam clutch, and it also makes it possible to tilt the cam with a small torque, making it possible to keep the meshing torque low. According to the invention of claim 7, the contact position between the cam and the outer cage ring and the inner cage ring can be easily adjusted, making it possible to increase the range of movement of the cam while improving the interlocking with the cage rings. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing one example of a configuration of a cam clutch of the present invention, as viewed from the rear side in the axial direction. FIG. [Figure 2] 2 is a cross-sectional perspective view of the cam clutch shown in FIG. 1, taken along a plane including the rotation axis. [Figure 3] 2 is an axial cross-sectional view showing a part of a cross section cut along a plane including a rotation axis of the cam clutch shown in FIG. 1. FIG. [Figure 4] 2 is a radial cross-sectional view of the cam clutch shown in FIG. 1 taken along a plane perpendicular to the rotation axis, as viewed from the axial rear side. [Figure 5] FIG. 2 is a plan view showing the configuration of a cam. [Figure 6] 2 is a perspective view showing the configuration of a biasing means in the cam clutch shown in FIG. 1, as viewed from the axial rear side. FIG. [Figure 7A] FIG. 4 is a perspective view showing the configuration of the outer ring side cage ring, as viewed from the rear side in the axial direction. [Figure 7B] FIG. 7B is a partial development view of the outer ring side cage ring shown in FIG. 7A. [Figure 8A] FIG. 4 is a perspective view showing the configuration of the inner cage ring, as viewed from the rear side in the axial direction. [Figure 8B] FIG. 8B is a partial development view of the inner cage ring shown in FIG. 8A. [Figure 9A] FIG. 10 is a perspective view showing the configuration of a position-regulating cage ring, as viewed from the rear side in the axial direction. [Figure 9B] 9B is a partial development view of the position regulating cage ring shown in FIG. 9A. FIG. [Figure 10] 1. FIG. 4 is a side view showing the operation of switching the operation mode of the cam clutch shown in FIG. 1 from a forward rotation direction locked mode to a bidirectional free mode. [Figure 11] 1. FIG. 4 is a schematic diagram showing the operation of switching the operation mode of the cam clutch shown in FIG. 1 from a forward rotation direction locked mode to a bidirectional free mode. [Figure 12] 1. FIG. 4 is a side view showing the operation of switching the operation mode of the cam clutch shown in FIG. 1 from a forward direction lock mode to a bidirectional lock mode. [Figure 13] 1. FIG. 4 is a schematic diagram showing the operation of switching the operation mode of the cam clutch shown in FIG. 1 from a forward rotation direction lock mode to a bidirectional lock mode. [Figure 14] 1. FIG. 4 is a side view showing the operation of switching the operation mode of the cam clutch shown in FIG. 1 from a forward direction lock mode to a reverse direction lock mode. [Figure 15] 1. FIG. 4 is a schematic diagram showing the operation of switching the operation mode of the cam clutch shown in FIG. 1 from a forward direction lock mode to a reverse direction lock mode. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the present invention will be described with reference to FIGS.

[0016] As shown in Figures 1 to 4, a cam clutch 100 according to the present invention comprises an outer ring 110 and an inner ring 120 which are coaxially rotatable relative to each other, a plurality of cams which are arranged at intervals in the circumferential direction in the annular space between a raceway surface 111 of the outer ring 110 and a raceway surface 121 of the inner ring 120 and serve as engagers for transmitting and blocking torque between the outer ring 110 and the inner ring 120, a biasing means 140 which biases each of the plurality of cams in the meshing direction so as to contact the outer ring 110 and the inner ring 120, an outer ring side cage ring 160 and an inner ring side cage ring 170 which are coaxially rotatable together with the outer ring 110 or the inner ring 120 between the outer ring 110 and the inner ring 120 and which hold each of the plurality of cams, and a position restricting cage ring 180 which is arranged between the outer ring side cage ring 160 and the inner ring side cage ring 170 and which restricts the degree of freedom of circumferential movement of the outer ring side cage ring 160 and the inner ring side cage ring 170. In FIG. 4, C is the axis of rotation.

[0017] The outer ring 110 is provided with position restriction portions 115 that restrict axial movement of each of the multiple cams. In this embodiment, the position restriction portions 115 are configured by inner rib portions 116 that are provided on each of both axial end portions of the inner peripheral surface of the outer ring 110 so as to protrude radially inward over the entire circumferential direction, and the axial movement of each of the multiple cams is restricted by positioning each of the multiple cams between the inner rib portions 116.

[0018] Each of the plurality of cams includes a first cam 130a and a second cam 130b that mesh with the outer ring 110 and the inner ring 120 in mutually different directions. In this embodiment, the first cam 130a and the second cam 130b have, for example, the same outer shape, and the first cam 130a is turned upside down and used as the second cam 130b.

[0019] The first cams 130a and the second cams 130b are arranged, for example, alternately at equal intervals in the circumferential direction. The arrangement of the first cams 130a and the second cams 130b is not particularly limited, and the first cams 130a and the second cams 130b do not have to be arranged alternately in the circumferential direction, and the number of first cams 130a and the number of second cams 130b may be different.

[0020] The meshing direction of the first cam 130a is clockwise in Figure 4 (hereinafter referred to as the "forward direction"), and the first cam 130a is configured to mesh with the outer ring 110 and the inner ring 120 when the outer ring 110 is rotated in the forward direction or when the inner ring 120 is rotated counterclockwise in Figure 4 (hereinafter referred to as the "reverse direction"). The meshing direction of the second cam 130b is the reverse direction, and the second cam 130b is configured to mesh with the outer ring 110 and the inner ring 120 when the outer ring 110 is rotated in the reverse direction or when the inner ring 110 is rotated in the forward direction.

[0021] The first cam 130a and the second cam 130b have outer peripheral contour shapes that include curved portions that follow involute curves when viewed in an axial plan view. An example of the configuration of the first cam 130a is shown in FIG. 5. In FIG. 5, the solid arrow indicates the engagement direction of the first cam 130a, and the hollow arrow indicates the disengagement direction of the first cam 130a. As mentioned above, the second cam 130b is the inverted version of the first cam 130a and has the same shape as the first cam 130a, so a description of it will be omitted.

[0022] The first cam 130a has a constricted portion 131 in the radial center, and is configured to have a generally gourd-like shape. A head portion 132 on the radially outer side of the constricted portion 131 of this first cam 130a has an outer ring side engagement surface 133, and both side surfaces 134a, 134b that smoothly continue to the outer ring side engagement surface 133 and contact the outer ring side cage ring 160 are configured by curved surfaces configured so that the width dimension of the head portion 132 is constant regardless of the posture of the first cam 130a. Specifically, both side surfaces 134a, 134b of the head portion 132 are configured by curves that follow involute curves that have a common base circle when viewed in an axial plan view. Furthermore, leg portion 135 on the radially inward side of constricted portion 131 of first cam 130a has an inner ring side engagement surface 136, and both side surfaces 137a, 137b that smoothly continue to inner ring side engagement surface 136 and contact inner ring side cage ring 170 are configured by curved surfaces configured so that the width dimension of leg portion 135 is constant regardless of the posture of first cam 130a. Specifically, both side surfaces 137a, 137b of leg portion 135 are configured by curves that follow involute curves that have a common base circle when viewed in an axial plan view. By having such an outer peripheral contour shape for the first cam 130a and the second cam 130b, it is possible to provide a large rotation angle for a small cam while maintaining high interlocking with the outer cage ring 160 and the inner cage ring 170, which makes it possible to reduce the size of the cam and thereby the size of the cam clutch 100. Moreover, because it is possible to tilt the cam with a small torque, it is possible to keep the meshing torque small.

[0023] The biasing means 140 is configured by, for example, a ribbon spring. The biasing means 140 may be any elastic body that can bias each of the first cams 130a and each of the second cams 130b in the meshing direction, and may be, for example, a plurality of leaf springs or torsion springs.

[0024] 6, the ribbon spring serving as the biasing means 140 is made up of a pair of annular portions 141 extending parallel to each other in the circumferential direction and a plurality of connecting portions 142 connecting the annular portions 141 in the axial direction at predetermined intervals, and the spaces between adjacent connecting portions 142 form pocket portions 145 each capable of accommodating one first cam 130a and one second cam 130b. The pocket portions 145 are provided at equal intervals along the circumferential direction. The connecting portion 142 has an arc-shaped curved portion 143 formed to be convex radially inward, and pressing arm portions 144 formed to be convex radially outward and continuous with each end of the arc-shaped curved portion 143, and is configured so that these pressing arm portions 144 urge the first cam 130a and the second cam 130b in the direction of engagement with the outer ring 110 and the inner ring 120.

[0025] The cam clutch 100 in this embodiment can be switched between four operating modes by the operating mode switching mechanism 150: a forward direction lock mode that prohibits relative rotation between the outer ring 110 and the inner ring 120 in the forward direction; a reverse direction lock mode that prohibits relative rotation between the outer ring 110 and the inner ring 120 in the reverse direction; a bidirectional lock mode that prohibits relative rotation between the outer ring 110 and the inner ring 120 in both the forward direction and the reverse direction; and a bidirectional free mode that allows relative rotation between the outer ring 110 and the inner ring 120 in both the forward direction and the reverse direction.

[0026] In this embodiment, the outer cage ring 160 , the inner cage ring 170 , and the position restricting cage ring 180 constitute an operation mode switching mechanism 150 .

[0027] 7A and 7B, the outer cage ring 160 has a cylindrical main body 161 extending in the axial direction. The main body 161 is provided with first cam holders 162 that receive the head portions 132 of the first cams 130a and hold the first cams 130a, and second cam holders 165 that receive the head portions of the second cams 130b and hold the second cams 130b, which are arranged alternately in the circumferential direction.

[0028] The first cam holding portion 162 of the outer cage ring 160 is configured to have an opening width varying portion whose opening width changes continuously in the axial direction. Specifically, the first cam holding portion 162 has a guide space 163a configured to have a constant opening width in the axial direction, a first attitude fixing space 163b configured to have a smaller opening width than the guide space 163a and continuing to the axial front side (upper side in FIG. 7B) of the guide space 163a, and a second attitude fixing space 163c configured to have a smaller opening width than the guide space 163a and continuing to the axial rear side (lower side in FIG. 7B) of the guide space 163a. ​​The first attitude fixing space 163b continues to the guide space 163a via a first opening width varying portion 164a formed so that the opening width continuously decreases toward the front in the axial direction, and the second attitude fixing space 163c continues to the guide space 163a via a second opening width varying portion 164b formed so that the opening width continuously decreases toward the rear in the axial direction. The first opening width fluctuation portion 164a is configured such that the opening edge on the side of the first cam 130a in the disengagement direction (left direction in Figure 7B) protrudes inward, and the second opening width fluctuation portion 164b is configured such that the opening edge on the side of the first cam 130a in the engagement direction (right direction in Figure 7B) protrudes inward. The second cam holding portion 165 of the outer cage ring 160 is rectangular and is configured so that the opening width is constant in the axial direction.

[0029] The outer ring side cage ring 160 is arranged to be movable in the axial direction independently of the rotational movement of the outer ring 110 and the inner ring 120, which makes it possible to change the position of the first cam 130a by tilting the first cam 130a while maintaining the position of the second cam 130b. In this way, the first cam holding portion 162 of the outer ring side cage ring 160 is not a simple rectangular opening, but is configured as an irregularly shaped opening window whose opening width narrows at both axial ends. This makes it possible to release slight jamming that occurs due to manufacturing errors, etc., with a small thrust, and by appropriately changing the opening shape of the first cam holding portion 162, it is possible to realize a greater number of operating modes and switch between them.

[0030] An inner surface groove 166 extending in the axial direction is formed on the inner surface of the main body 161 of the outer ring side cage ring 160 between a first cam holding portion 162 and a second cam holding portion 165 adjacent to the first cam holding portion 162 in the meshing direction of the first cam 130a. The inner surface groove 166 has a guide groove 167 that extends linearly from the axial rear edge to the axial front edge of the main body 161, and a slide groove 168 that continues to the axial front end of the guide groove 167. The slide groove 168 is formed to extend circumferentially in the meshing direction of the first cam 130a, and is configured to allow circumferential movement of an outer protrusion 185 of a position-regulating cage ring 180, which will be described later, when the outer ring-side cage ring 160 is in a position where it meshes with the first cam 130a.

[0031] 8A and 8B, the inner cage ring 170 has a cylindrical main body 171 extending in the axial direction. The main body 171 is provided with first cam holders 172 that receive the leg portions 135 of the first cam 130a to hold the first cam 130a and second cam holders 173 that receive the leg portions of the second cam 130b to hold the second cam 130b, which are arranged alternately in the circumferential direction.

[0032] The first cam holding portion 172 of the inner cage ring 170 is rectangular and is configured so that the opening width is constant in the axial direction. The second cam holding portion 173 of the inner cage ring 170 is configured to have an opening width varying portion whose opening width changes continuously in the axial direction. Specifically, the second cam holding portion 173 has a guide space portion 174a configured to have a constant opening width in the axial direction, a first attitude fixing space portion 174b configured to have a smaller opening width than the guide space portion 174a and continuing to the axial front side (upper side in FIG. 8B) of the guide space portion 174a, and a second attitude fixing space portion 174c configured to have a smaller opening width than the guide space portion 174a and continuing to the axial rear side (lower side in FIG. 8B) of the guide space portion 174a. The first attitude fixing space portion 174b continues to the guide space portion 174a via a first opening width varying portion 175a formed so that the opening width continuously decreases toward the front in the axial direction, and the second attitude fixing space portion 174c continues to the guide space portion 174a via a second opening width varying portion 175b formed so that the opening width continuously decreases toward the rear in the axial direction. The first opening width fluctuation portion 175a is configured such that the opening edge on the side of the second cam 130b in the disengagement direction (rightward in Figure 8B) protrudes inward, and the second opening width fluctuation portion 175b is configured such that the opening edge on the side of the second cam 130b in the engagement direction (leftward in Figure 8B) protrudes inward.

[0033] The inner ring side cage ring 170 is arranged to be movable in the axial direction independently of the rotational movement of the outer ring 110 and the inner ring 120, which makes it possible to change the position of the second cam 130b by tilting the second cam 130b while maintaining the position of the first cam 130a. In this way, the second cam holder portion 173 of the inner cage ring 170 is not a simple rectangular opening, but is configured as an irregularly shaped opening window whose opening width narrows at both axial ends. This makes it possible to release slight jamming that occurs due to manufacturing errors, etc., with a small thrust, and by appropriately changing the opening shape of the second cam holder portion 173, it is possible to achieve a greater number of operating modes and switch between them.

[0034] An outer surface groove 176 extending in the axial direction is formed on the outer surface of the main body 171 of the inner ring side cage ring 170 between the second cam holding portion 173 and the first cam holding portion 172 adjacent to the second cam holding portion 173 in the disengagement direction of the second cam 130b. The outer surface groove 176 has a guide groove 177 that extends linearly from the axial front end edge to the axial rear end edge of the main body 171, and a slide groove 178 that continues to the axial rear end of the guide groove 177. The slide groove 178 is formed to extend circumferentially in the meshing direction of the second cam 130b, and is configured to allow circumferential movement of an inward protrusion 186 of a position-regulating cage ring 180, which will be described later, when the inner cage ring 170 is in a position that meshes with the second cam 130b.

[0035] As described above, the operation mode switching mechanism 150 of the cam clutch 100 in this embodiment is configured to include the position restricting cage ring 180 that restricts the degree of freedom of circumferential movement of the outer race side cage ring 160 and the inner race side cage ring 170. This makes it possible to adjust the degree of freedom of circumferential movement of the outer race side cage ring 160 and the inner race side cage ring 170 relative to the position restricting cage ring 180 to an appropriate degree of freedom according to each operation mode, and makes it possible to maintain the first cam 130a and the second cam 130b in an appropriate position.

[0036] 9A and 9B, the position regulating cage ring 180 is made up of a pair of annular portions 181 extending parallel to each other in the circumferential direction, and a plurality of connecting portions 182 that connect the annular portions 181 in the axial direction at predetermined intervals, and the spaces between adjacent connecting portions 182 form pocket portions 183 that can accommodate one each of the first cam 130a and the second cam 130b. The pocket portions 183 are provided at equal intervals along the circumferential direction.

[0037] The position-regulating cage ring 180 has an outer protrusion 185 that protrudes radially outward from its axial front end and is slidably engaged with the inner surface groove 166 of the outer ring-side cage ring 160, and an inner protrusion 186 that protrudes radially inward from its axial rear end and is slidably engaged with the outer surface groove 176 of the inner ring-side cage ring 170.

[0038] The operation of the cam clutch 100 of this embodiment will now be described. First, as shown in Figure 10(a), when the outer ring side cage ring 160 and the inner ring side cage ring 170 are both positioned axially rearward, as shown in Figure 11(a), the first cam 130a maintains a meshing standby state so that meshing with the outer ring 110 and the inner ring 120 will immediately begin when torque is applied to the outer ring 110 or the inner ring 120. On the other hand, the second cam 130b maintains a state in which the inner ring side engagement surface 136 is spaced from the raceway surface 121 of the inner ring 120, and therefore the cam clutch 100 is in a forward rotation lock mode in which relative rotation in the forward rotation direction of the outer ring 110 and the inner ring 120 is prohibited.

[0039] For example, as shown in Fig. 10(b), when the outer ring side cage ring 160 is moved axially forward, as shown in Fig. 11(b), the head portion 132 of the first cam 130a is pressed by the action of the second opening width fluctuating portion 164b of the first cam holding portion 162 of the outer ring side cage ring 160. As a result, the first cam 130a is tilted in the meshing release direction, and the posture of the first cam 130a is maintained in a state where the inner ring side engaging surface 136 of the first cam 130a is separated from the raceway surface 121 of the inner ring 120. On the other hand, the second cam holding portion 165 of the outer ring side cage ring 160 is formed in a rectangular shape with a constant opening width in the axial direction, and the circumferential freedom of the outer ring side cage ring 160 and the inner ring side cage ring 170 is restricted by the position restricting cage ring 180, so the posture of the second cam 130b is maintained in a state where the inner ring side engagement surface 136 is separated from the raceway surface 121 of the inner ring 120. As a result, the operation mode of the cam clutch 100 is switched from the forward rotation direction locked mode to a bidirectional free mode that allows relative rotation of the outer ring 110 and the inner ring 120 in both the forward and reverse directions. 11(a) and 11(b), for convenience, the raceway surface 111 of the outer ring 110 and the raceway surface 121 of the inner ring 120 are shown as parallel planes.

[0040] Conversely, when the operating mode of the cam clutch 100 is switched from the bidirectional free mode to the forward rotation locked mode, the outer race-side cage ring 160 is moved axially rearward. As a result, the head portion 132 of the first cam 130a is pressed by the action of the first opening width varying portion 164a of the first cam holding portion 162 of the outer race-side cage ring 160, tilting the first cam 130a in the meshing direction and applying torque to the outer race 110 or the inner race 120, so that the first cam 130a is held in a meshing standby state so that meshing with the outer race 110 or the inner race 120 can immediately begin. At this time, the inner surface groove 166 of the outer race-side cage ring 160 has the slide groove 168, allowing the outer protrusion 185 of the position limiting cage ring 180 to move circumferentially. Therefore, the degree of freedom of movement of the outer cage ring 160 in the circumferential direction relative to the position restricting cage ring 180 is adjusted appropriately, and the first cam 130a is held in an appropriate position. On the other hand, the attitude of the second cam 130b is maintained in a state in which the inner ring side engagement surface 136 is separated from the raceway surface 121 of the inner ring 120, as described above. As a result, the operation mode of the cam clutch 100 is switched from the bidirectional free mode to the forward rotation direction locked mode.

[0041] 12(a) and 13(a), when the operating mode of the cam clutch 100 is the forward rotation direction lock mode shown in FIG. 12(b), when the inner cage ring 170 is moved axially forward as shown in FIG. 12(b), the leg portion 135 of the second cam 130b is pressed by the action of the second opening width fluctuating portion 175b of the second cam holding portion 173 of the inner cage ring 170 as shown in FIG. 13(b). This tilts the second cam 130b in the meshing direction, and torque acts on the outer ring 110 or the inner ring 120, so that the second cam 130b is held in a meshing standby state so that meshing with the outer ring 110 or the inner ring 120 can immediately begin. At this time, the outer surface groove 176 of the inner cage ring 170 has the slide groove 178, allowing the inward protrusion 186 of the position limiting cage ring 180 to move circumferentially. Therefore, the degree of freedom of movement of the inner cage ring 170 in the circumferential direction relative to the position restricting cage ring 180 is adjusted appropriately, and the second cam 130b is held in an appropriate position. On the other hand, since the first cam holding portion 172 on the inner ring side cage ring 170 is formed in a rectangular shape with a constant opening width in the axial direction, the posture of the first cam 130a is maintained in a meshing standby state so that when torque is applied to the outer ring 110 or the inner ring 120, the first cam 130a immediately begins meshing with the outer ring 110 and the inner ring 120. As a result, the operation mode of the cam clutch 100 is switched from the forward direction lock mode to a bidirectional lock mode in which relative rotation between the outer ring 110 and the inner ring 120 is prohibited in both the forward direction and the reverse direction.

[0042] Conversely, when the operating mode of the cam clutch 100 is switched from the bidirectional lock mode to the forward lock mode, the inner cage ring 170 is moved axially rearward. As a result, the leg portions 135 of the second cam 130b are pressed by the action of the first opening width varying portions 175a of the second cam holding portions 173 of the inner cage ring 170, tilting the second cam 130b in the disengagement direction and maintaining the posture of the second cam 130b in a state in which the inner engagement surface 136 of the second cam 130b is separated from the raceway surface 121 of the inner ring 120. On the other hand, the posture of the first cam 130a is maintained in a meshing standby state so that when torque is applied to the outer ring 110 or the inner ring 120, the first cam 130a immediately begins meshing with the outer ring 110 and the inner ring 120, as described above. As a result, the operation mode of the cam clutch 100 is switched from the bidirectional lock mode to the forward rotation direction lock mode.

[0043] Furthermore, when the operating mode of the cam clutch 100 is in the forward rotation direction lock mode shown in Figures 14(a) and 15(a), if the outer ring side cage ring 160 and the inner ring side cage ring 170 are both moved axially forward as shown in Figure 14(b), the head portion 132 of the first cam 130a is pressed by the action of the second opening width fluctuating portion 164b of the first cam holding portion 162 of the outer ring side cage ring 160 as shown in Figure 15(b). As a result, the first cam 130a is tilted in the disengagement direction and the attitude of the first cam 130a is maintained in a state in which the inner ring side engagement surface 136 of the first cam 130a is separated from the raceway surface 121 of the inner ring 120. Meanwhile, the leg portion 135 of the second cam 130b is pressed by the action of the second opening width fluctuating portion 175b of the second cam holding portion 173 of the inner cage ring 170. As a result, the second cam 130b is tilted in the meshing direction, and torque is applied to the outer ring 110 or the inner ring 120, so that the second cam 130b is held in a meshing standby state so that meshing with the outer ring 110 or the inner ring 120 can immediately begin. At this time, as described above, the degree of freedom of circumferential movement of the inner cage ring 170 relative to the position-regulating cage ring 180 is appropriately adjusted, and the second cam 130b is held in an appropriate posture. As a result, the operation mode of the cam clutch 100 is switched from the forward direction lock mode to the reverse direction lock mode in which the relative rotation of the outer ring 110 and the inner ring 120 in the reverse direction is prohibited.

[0044] Conversely, when the operating mode of the cam clutch 100 is switched from the reverse direction lock mode to the forward direction lock mode, both the outer ring side cage ring 160 and the inner ring side cage ring 170 are moved axially rearward. As a result, the head portion 132 of the first cam 130a is pressed by the action of the first opening width varying portion 164a of the first cam holding portion 162 of the outer ring side cage ring 160, tilting the first cam 130a in the meshing direction and applying torque to the outer ring 110 or the inner ring 120, so that the first cam 130a is held in a meshing standby state so that meshing with the outer ring 110 or the inner ring 120 can immediately begin. At this time, as described above, the degree of freedom of circumferential movement of the outer ring side cage ring 160 relative to the position-regulating cage ring 180 is appropriately adjusted, and the first cam 130a is held in an appropriate posture. On the other hand, the leg portion 135 of the second cam 130b is pressed by the action of the first opening width fluctuation portion 175a in the second cam holding portion 173 of the inner ring side cage ring 170, causing the second cam 130b to tilt in the direction of disengagement and maintaining the posture of the second cam 130b in a state where the inner ring side engagement surface 136 of the second cam 130b is separated from the track surface 121 of the inner ring 120. As a result, the operation mode of the cam clutch 100 is switched from the reverse direction lock mode to the forward direction lock mode.

[0045] As described above, in the cam clutch 100 of this embodiment, the outer cage ring 160 is provided with the function of controlling the attitude of the first cam 130a, and the inner cage ring 170 is provided with the function of controlling the attitude of the second cam 130b, and further, the position-regulating cage ring 180 restricts the degrees of freedom of the outer cage ring 160 and the inner cage ring 170, so that simply by moving one or both of the outer cage ring 160 and the inner cage ring 170 in the axial direction, it is possible to tilt one or both of the first cam 130a and the second cam 130b and maintain the changed attitude. Therefore, the cam clutch 100 can be configured as a highly functional device that can accommodate four operating modes with a simple configuration. Furthermore, by restricting the degree of freedom of the outer ring side cage ring 160 and the inner ring side cage ring 170, it is possible to prevent the first cam 130a and the second cam 130b from both meshing with the outer ring 110 and the inner ring 120 when the cam position is changed, thereby realizing smooth operation and achieving high responsiveness.

[0046] 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 scope of the present invention as set forth in the claims. In the above embodiment, the cam clutch is configured to operate in the forward lock mode when the outer cage ring and the inner cage ring are positioned axially rearward, but the relationship between the cam clutch operation mode and the axial positions of the outer cage ring and the inner cage ring is not particularly limited. For example, the cam clutch may be configured to operate in the two-way lock mode, the two-way lock mode, or the reverse lock mode when the outer cage ring and the inner cage ring are positioned axially rearward. Furthermore, in the above embodiment, a configuration has been described in which one or both of the first cam and the second cam are separated from the inner ring in operation modes other than the bidirectional locking mode, but the cam may be configured to be separated from the outer ring. [Explanation of symbols]

[0047] 100 ··· Cam clutch 110 Outer ring 111 ... Raceway surface 115...Position regulation part 116 Inner rib 120 ··· Inner circle 121 ... raceway surface 130a First cam 130b Second cam 131 ··· Waist 132 ... head part 133 Outer ring side engagement surface 134a Side 134b... side 135 ... leg part 136 Inner ring engagement surface 137a... side 137b... side 140..... biasing means 141 Annular part 142... Connecting part 143 Arc-shaped curved section 144 ··· Pressing arm 145 ··· Pocket 150 ··· Operation mode switching mechanism 160 Outer cage ring 161 Main body 162 First cam holder 163a Guide space 163b... First posture fixing space 163c...Second posture fixing space 164a First opening width variation section 164b Second opening width variable section 165 Second cam holder 166 ··· Inner groove 167 Guide groove 168 Slide groove 170 Inner cage ring 171 Main body 172 First cam holder 173 Second cam holder 174a Guide space 174b... Space for fixing the first posture 174c...Second posture fixing space 175a First opening width varying portion 175b Second opening width varying portion 176 ... External groove 177 Guide groove 178 Slide groove 180 ··· Position control cage ring 181 Annular part 182 ··· Connection part 183 ··· Pocket 185 ... outward protrusion 186 ... Inward protrusion C...Rotation axis center

Claims

1. A cam clutch comprising an outer ring and an inner ring that are rotatable relative to each other on the same rotation shaft, a plurality of cams arranged in a circumferential direction between the outer ring and the inner ring, and biasing means that biases each of the plurality of cams so as to contact the outer ring and the inner ring, the plurality of cams include a first cam and a second cam that mesh with the outer ring and the inner ring in mutually different directions, an operation mode switching mechanism for switching the operation mode of the cam clutch; the operation mode switching mechanism comprises: an outer race-side cage ring that is axially movable independently of the rotational movements of the outer race and the inner race and configured to change the attitude of the first cam; an inner race-side cage ring that is axially movable independently of the rotational movements of the outer race and the inner race and configured to change the attitude of the second cam; and a position-regulating cage ring that is disposed between the outer race-side cage ring and the inner race-side cage ring and that regulates the degree of freedom of circumferential movement of the outer race-side cage ring and the inner race-side cage ring.

2. the outer cage ring and the inner cage ring each have a first cam holding portion that holds the first cam and a second cam holding portion that holds the second cam, the second cam holding portion of the outer cage ring and the first cam holding portion of the inner cage ring are configured so that opening widths are constant in the axial direction, 2. The cam clutch according to claim 1, wherein the first cam holding portion of the outer cage ring and the second cam holding portion of the inner cage ring are configured to have an opening width varying portion whose opening width changes continuously in the axial direction.

3. the outer cage ring has an inner surface groove extending in the axial direction on its inner surface, the inner cage ring has an outer surface groove extending in the axial direction on its outer surface, 3. The cam clutch according to claim 1, wherein the position-regulating cage ring has an outer protrusion at one axial end thereof that protrudes radially outward and is slidably engaged with an inner groove on the outer ring-side cage ring, and an inner protrusion at the other axial end thereof that protrudes radially inward and is slidably engaged with an outer groove on the outer ring-side cage ring.

4. the inner surface groove portion has a slide groove portion that is provided to extend in a circumferential direction and that allows the outer protrusion portion to move in the circumferential direction when the outer ring side cage ring is at a position where it meshes with the first cam, 4. The cam clutch according to claim 3, wherein the outer surface groove portion has a slide groove portion that is provided to extend in a circumferential direction and that allows the inner protrusion portion to move in the circumferential direction when the inner cage ring is in a position that meshes with the second cam.

5. 5. A cam clutch according to claim 1, wherein the outer ring is provided with a position restricting portion that restricts axial movement of the plurality of cams.

6. 6. A cam clutch according to claim 1, wherein both side surfaces of the plurality of cams that contact the outer cage ring and both side surfaces that contact the inner cage ring are formed by curved surfaces that are configured so that the widthwise dimension is constant regardless of the posture of the cam.

7. both side surfaces of the plurality of cams that contact the outer ring-side cage ring are configured by curves that follow an involute curve having a common base circle when viewed in an axial plane, 7. The cam clutch according to claim 6, wherein both side surfaces of the plurality of cams that contact the inner cage ring are configured by curves that follow involute curves having a common base circle when viewed in an axial plane.

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