Cam clutch

Abstract

To provide a cam clutch capable of increasing a life by preventing the occurrence of biting of a cam, switching an operation mode by minute force, and achieving downsizing.SOLUTION: A cam clutch is equipped with an inner ring, an outer ring, a plurality of cams, and energizing means for energizing the plurality of cams so as to contact with the inner ring and the outer ring. The plurality of cams includes a first cam and a second cam having different engaging directions from each other. Sliding resistance generating means is provided, which, when switching an operation by an operation mode switching mechanism, if the first cam and the second cam are brought into a both floating state in which they are simultaneously separated from a raceway surface of the inner ring and / or a raceway surface of the outer ring, generates sliding resistance between a member capable of tilting the first cam or the second cam in an engaging direction and the inner ring and / or the outer ring.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to a cam clutch configured to be able to switch an operation mode.

Background Art

[0002] As a clutch for controlling transmission and interruption of rotational force, a two-way clutch capable of switching drive and idling in both forward and reverse directions is known. For example, in Patent Document 1, a retainer that holds both a first sprag and a second sprag biased so that the rotation lock direction becomes the reverse direction by biasing means is controlled, and rotation in both forward and reverse directions is allowed. A clutch is configured to be able to switch between three operation modes: a two-way free mode, 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

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described two-way clutch, when changing the operation mode, by controlling the retainer, all of the first sprag and the second sprag are forcibly tilted. Therefore, it is not possible to realize a two-way lock mode that prohibits relative rotation in both forward and reverse directions between the outer ring and the inner ring.

[0005] Furthermore, in the two-way clutch described above, the first and second sprags are biased to contact the outer and inner rings. When torque is applied to the outer or inner ring, one sprag tilts to immediately engage with the outer and inner rings, while the other sprag continues to slide and make contact with the outer and inner rings, maintaining a state of readiness for engagement. When the torque is released, one sprag tilts in the disengagement direction and enters a free-spinning state. However, before the engagement of one sprag is released, the other sprag may tilt in the engagement direction and begin to engage with the outer and inner rings, potentially causing all cams to engage simultaneously in a state of "meshing." In this condition, all sprags engage with high surface pressure, so when switching the clutch's operating mode from a locked mode, which prohibits relative rotational movement of the outer and inner rings in either forward or reverse direction, to a free mode, which allows relative rotational movement of the outer and inner rings in both directions, a large force is required to change the position of the sprags. This can damage the engagement surfaces of the sprags with the outer and inner rings, as well as the raceway surfaces of the outer and inner rings, potentially shortening the clutch's lifespan. Furthermore, there is the problem that the position-changing member used to change the position of the sprags requires high rigidity.

[0006] On the other hand, as a type of selectable clutch, there is a cam clutch in which one cam and the other cam are positioned in opposite directions so that their meshing directions are opposite, in order to realize a bidirectional lock mode that prohibits relative rotation of the outer ring and inner ring in both the forward and reverse directions. In such a cam clutch, when the torque is released, a slight meshing state is intentionally created in both cams, making it possible to change direction between forward and reverse rotation. This is because if one cam and the other cam are simultaneously disengaged when the torque is released, and both cams remain floating above the raceway surface of the inner ring or outer ring, the next torque cannot be transmitted, causing the inner or outer ring to slip and preventing the normal reversal of the cam meshing direction. Therefore, by creating a slight meshing state in one cam and the other cam when changing direction, the occurrence of unintended slippage is avoided. However, even with a slight engagement state intentionally left, the engagement torque remains as a resistive force, requiring a certain amount of force when switching operating modes. Furthermore, the magnitude of this engagement torque is greatly affected by the tolerance of the cam's orientation-changing member, and depending on the tolerance, the force required when switching operating modes may become problematicly large. Consequently, even with a cam clutch configured in this way, a large force is still required to change the orientation of the cam from its engaged state when switching operating modes. This still leads to problems such as a shortened clutch life due to damage to the outer surface of the cam, the raceway surfaces of the inner and outer rings, and the need for high rigidity in the orientation-changing member to change the cam's orientation.

[0007] The present invention was made based on the above circumstances, and aims to provide a cam clutch that has a simple structure, can prevent cam jamming and thus extend its lifespan, and can be miniaturized by switching the operating mode with a small force. [Means for solving the problem]

[0008] The present invention relates to a cam clutch comprising an inner ring and an outer ring rotatably mounted on the same axis of rotation, a plurality of cams arranged circumferentially between the inner ring and the outer ring, and a biasing means for biasing each of the plurality of cams to contact the inner ring and the outer ring, The plurality of cams include a first cam and a second cam whose meshing directions with respect to the inner ring and the outer ring are different from each other. The cam clutch is equipped with an operating mode switching mechanism that switches the operating mode of the cam clutch, The operating modes that can be switched by the operating mode switching mechanism include a bidirectional lock mode that prohibits relative rotation of the inner ring and the outer ring in both the forward and reverse directions. The problem is solved by providing a member that can tilt the first cam or the second cam in the meshing direction when the first cam and the second cam are simultaneously separated from the raceway surface of the inner ring and / or the raceway surface of the outer ring with a small gap between them, in the bidirectional locking mode, and a means for generating sliding resistance that generates sliding resistance between the first cam and the second cam and the separated inner ring and / or outer ring. [Effects of the Invention]

[0009] According to the cam clutch of the present invention, when the meshing direction is reversed in the bidirectional lock mode, the first cam and the second cam are simultaneously separated from the raceway surface of the inner ring and / or the raceway surface of the outer ring with a small gap between them, resulting in a double-levitation state with the torque released. This prevents the first cam and the second cam from simultaneously meshing with the inner ring and the outer ring. Furthermore, by providing a member that can tilt the first cam and the second cam and a sliding resistance generating means that generates sliding resistance between the separated inner ring and / or outer ring, even when the double-levitation state is achieved, the torque acting on the inner ring or the outer ring is transmitted by the sliding resistance generating means to the first cam or the second cam that is to mesh next. This causes the cam to tilt in the meshing direction and come into contact with the raceway surface of the inner ring and / or the raceway surface of the outer ring. This avoids the occurrence of an unintended free-spinning state in which the torque acting on the inner ring or the outer ring is not transmitted to either the first cam or the second cam, thereby realizing the bidirectional lock mode. Therefore, since there is no remaining engagement when the meshing direction of the first and second cams is reversed, the thrust required to switch to other operating modes can be significantly reduced, allowing for miniaturization of the switching device. Furthermore, even with frequent switching of operating modes, damage to the raceway surfaces of the inner and outer rings can be extremely suppressed, extending the lifespan of the cam clutch.

[0010] Furthermore, with a configuration comprising an outer ring cage ring, an inner ring cage ring, and a position-restricting cage ring that restricts the degree of freedom of their circumferential movement, the outer ring cage ring is given a first cam attitude control function and the inner ring cage ring is given a second cam attitude control function. In addition, the position-restricting cage ring restricts the degree of freedom of movement of the outer ring cage ring and the inner ring cage ring. As a result, the cam can be tilted and the changed cam attitude can be maintained simply by moving one or both of the outer ring cage ring and the inner ring cage ring in the axial direction. Therefore, it is possible to configure the cam clutch with a simple configuration that has high functionality and can handle four operating modes. Furthermore, by restricting the degree of freedom of movement of the outer ring cage ring and the inner ring cage ring in the circumferential direction, jamming of the first cam and the second cam together with the outer ring and inner ring when the cam's orientation changes is avoided, enabling smooth operation and high responsiveness. Furthermore, since the outer ring cage ring and / or inner ring cage ring are members that can tilt the first cam or the second cam in the meshing direction, sliding resistance can be generated between the outer ring cage ring and / or inner ring cage ring and the outer ring and / or inner ring where the first and second cams are separated. As a result, the outer ring cage ring and / or inner ring cage ring can be rotated along with the outer ring and / or inner ring and moved relative to each other in the circumferential direction, thereby tilting the first or second cam in the meshing direction and bringing it into contact with the raceway surface of the inner ring and / or outer ring. Therefore, when the first and second cams are both in a floating state, the torque acting on the inner or outer ring can be reliably transmitted to the first or second cam that is to mesh next.

[0011] Furthermore, if the outer ring cage ring and the inner ring cage ring each have a first cam holding portion and a second cam holding portion with different opening shapes, the phase of the circumferential positions of the corresponding cam holding portions of the inner ring cage ring and the outer ring cage ring can be easily designed so that the first cam and the second cam are both floating. This reliably prevents the first cam and the second cam from unintentionally engaging with the inner and outer rings at the same time. In addition, by changing the opening shapes of the first cam holding portion and the second cam holding portion of the outer ring cage ring and the inner ring cage ring, which serve as an operating mode switching mechanism, only one of the first cam or the second cam can be tilted. In other words, by integrating a mechanism for changing the cam's orientation into each of the outer ring cage ring and the inner ring cage ring, the structure can be simplified, miniaturized, the number of parts reduced, and the holding torque increased. Furthermore, by making the opening shapes of the first cam retaining portion in the outer ring cage ring and the second cam retaining portion in the inner ring cage ring different from simple rectangles, and by having a variable opening width section where the opening width changes continuously, slight jamming caused by manufacturing errors can be released with a small thrust. In addition, by appropriately changing the opening shapes of the first and second cam retaining portions in the outer ring cage ring and inner ring cage ring, it is possible to realize a greater number of operating modes and their switching.

[0012] Furthermore, according to a configuration in which the sliding resistance generating means has a plate spring member fixedly provided on the inner circumferential surface of the inner ring side cage ring and / or on the outer circumferential surface of the outer ring side cage ring, even when both the first cam and the second cam are in a floating state, the force with which the plate spring member rotates together with the outer ring or inner ring due to the sliding resistance causes both the outer ring side cage ring and the inner ring side cage ring to move in the circumferential direction, thereby tilting the cam that is to mesh next in the meshing direction. Thus, the meshing direction of the cams can be reversed with a simple structure that only requires the fixed provision of a plate spring member. Furthermore, in a configuration where a U-shaped plate spring member is positioned on a specific end of the inner circumferential surface of the inner ring cage ring and / or the outer circumferential surface of the outer ring cage ring with its top facing the other end, in the bidirectional lock mode, the plate spring member rotates together with the outer or inner ring due to sliding resistance. However, in the bidirectional free mode, which allows rotation in both forward and reverse directions, the plate spring member does not contact the inner or outer ring, thus eliminating sliding resistance, suppressing wear, and preventing the generation of drag torque. Additionally, the plate spring member begins to contact the inner or outer ring as the inner or outer ring cage ring moves axially during switching of operating modes. However, because its top faces the other end, the plate spring member moves with its top leading, preventing the plate spring member from being forced into an unnatural position. This allows the plate spring member to be inserted between the inner or outer ring without damage, thus ensuring that the above-mentioned effects are reliably achieved.

[0013] Furthermore, in a configuration where the sliding resistance generating means has an O-ring fixedly provided on the raceway surface of the inner ring and / or the raceway surface of the outer ring, similar to the case with a plate spring member, even when the first cam and the second cam are both floating, the outer ring side cage ring or the inner ring side cage ring is moved together in the circumferential direction by sliding resistance via the O-ring and the rotating outer ring or inner ring, thereby tilting the cam that is to mesh next in the meshing direction. Thus, the meshing direction of the cams can be reversed with a simple structure that only requires the fixed provision of an O-ring. In addition, according to the configuration in which the O-ring is disposed at a specific one end on the raceway surface of the inner ring and / or on the raceway surface of the outer ring, during the two-way lock mode, the outer ring or the inner ring that rotates causes the outer ring side cage ring or the inner ring side cage ring to rotate by sliding resistance via the O-ring. While obtaining this effect, during the two-way free mode that allows rotation in both the forward and reverse directions, the O-ring is non-contact with the outer ring side cage ring or the inner ring side cage ring, so that sliding resistance is not generated, wear can be suppressed, and the generation of drag torque can be suppressed.

Brief Description of the Drawings

[0014] [Figure 1] It is a perspective view seen from the front side in the axial direction of the cam clutch according to the first embodiment of the present invention. [Figure 2] It is a cross-sectional perspective view cut along a plane including the rotation axis of the cam clutch shown in FIG. 1. [Figure 3] It is an axial cross-sectional view showing a part of the cross-section cut along a plane including the rotation axis of the cam clutch shown in FIG. 1. [Figure 4] It is a radial cross-sectional view seen from the front side in the axial direction, cut along a plane orthogonal to the rotation axis of the cam clutch shown in FIG. 1. [Figure 5] It is a plan view showing the configuration of the cam. [Figure 6] It is a perspective view seen from the rear side in the axial direction, showing the configuration of the biasing means in the cam clutch shown in FIG. 1. [Figure 7A] It is a perspective view seen from the rear side in the axial direction, showing the configuration of the outer ring side cage ring. [Figure 7B] It is a partially developed view of the outer ring side cage ring shown in FIG. 7A. [Figure 8A] It is a perspective view seen from the rear side in the axial direction, showing the configuration of the inner ring side cage ring. [Figure 8B] It is a partially developed view of the inner ring side cage ring shown in FIG. 8A. [Figure 9] It is a partially developed view in a state where the outer ring side cage ring shown in FIG. 7A and the inner ring side cage ring shown in FIG. 8A are overlapped. [Figure 10] It is a perspective view seen from the front side in the axial direction, showing the configuration of the sliding resistance generating means. [Figure 11] It is an axial cross-sectional view showing the arrangement relationship of the leaf spring members. [Figure 12A] It is a perspective view seen from the rear side in the axial direction, showing the configuration of the position regulating cage ring. [Figure 12B] It is a partial developed view of the position regulating cage ring shown in Fig. 12A. [Figure 13] It is a side view showing the switching operation of the operation mode of the cam clutch shown in Fig. 1 from the forward rotation lock mode to the both-direction lock mode. [Figure 14] It is a schematic diagram for explaining both floating states, forward rotation prohibition state, and reverse rotation prohibition state in the both-direction lock mode. [Figure 15] It is a side view showing the switching operation of the operation mode of the cam clutch shown in Fig. 1 from the forward rotation lock mode to the both-direction free mode. [Figure 16] It is a side view showing the switching operation of the operation mode of the cam clutch shown in Fig. 1 from the forward rotation lock mode to the reverse rotation lock mode. [Figure 17] It is an axial cross-sectional view showing a part of the cross-section cut in a plane including the rotation axis of the cam clutch according to the second embodiment of the present invention.

Mode for Carrying Out the Invention

[0017] The outer ring 110 is provided with a position restricting portion 115 that restricts the axial movement of each of the multiple cams. In this embodiment, the position restricting portion 115 is composed of an inner rib portion 116 provided at each of the axial ends on the inner circumferential surface of the outer ring 110 so as to protrude radially inward along the entire circumference, and each of the multiple cams is positioned between the inner rib portions 116 so as to restrict the axial movement of each of the multiple cams.

[0018] Each of the multiple cams includes a first cam 130a and a second cam 130b, which have different meshing directions with respect to the outer ring 110 and the inner ring 120. In this embodiment, the first cam 130a and the second cam 130b have, for example, the same external shape, and the second cam 130b is used by flipping the first cam 130a inside out.

[0019] The first cam 130a and the second cam 130b are arranged, for example, alternately at equal intervals in the circumferential direction. The arrangement of the first cam 130a and the second cam 130b is not particularly limited. The first cam 130a and the second cam 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 rotation 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 rotation direction, or when the inner ring 120 is rotated counterclockwise in Figure 4 (hereinafter referred to as the "reverse rotation 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 an outer contour shape that includes a curved portion along an involute curve in an axial plan view. An example configuration of the first cam 130a is shown in Figure 5. In Figure 5, the filled arrows indicate the engagement direction of the first cam 130a, and the open arrows indicate 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 its explanation is omitted.

[0022] This first cam 130a has a constricted portion 131 in the radial center and is configured to have a roughly gourd-like shape. The head portion 132 of the first cam 130a, which is radially outward from the constricted portion 131, has an outer ring engagement surface 133. Both sides 134a and 134b, which are smoothly continuous with the outer ring engagement surface 133 and in contact with the outer ring cage ring 160, are composed of curved surfaces configured such that the width dimension of the head portion 132 remains constant regardless of the orientation of the first cam 130a. Specifically, both sides 134a and 134b of the head portion 132 are composed of curves that follow an involute curve having a common base circle in an axial plan view. Furthermore, the leg portion 135 on the radially inward side of the constricted portion 131 of the first cam 130a has an inner ring side engagement surface 136, and both sides 137a and 137b that smoothly continue from the inner ring side engagement surface 136 and contact the inner ring side cage ring 170 are composed of curved surfaces configured such that the width dimension of the leg portion 135 remains constant regardless of the orientation of the first cam 130a. Specifically, both sides 137a and 137b of the leg portion 135 are composed of curves that follow an involute curve having a common base circle in an axial plan view. Because the first cam 130a and the second cam 130b have such an outer circumferential contour shape, it is possible to give a large rotation angle to a small cam while maintaining high interlocking with the outer ring cage ring 160 and the inner ring cage ring 170. This makes it possible to reduce the size of the cam and thus the size of the cam clutch 100. Moreover, because it is possible to tilt the cam with a small torque, the engagement torque can be suppressed to a small level.

[0023] The biasing means 140 is composed of, for example, a ribbon spring. The biasing means 140 can be any elastic body capable of biasing 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] The ribbon spring, which serves as the biasing means 140, consists of, for example, a pair of annular portions 141 extending parallel to each other in the circumferential direction, and a plurality of connecting portions 142 that connect the annular portions 141 axially at predetermined intervals. The space between adjacent connecting portions 142 forms pocket portions 145 capable of accommodating one first cam 130a and one second cam 130b, respectively. 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 these pressing arm portions 144 are configured to bias the first cam 130a and the second cam 130b in the direction of meshing with the outer ring 110 and the inner ring 120.

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

[0026] In this embodiment, the operating mode switching mechanism 150 is composed of an outer ring cage ring 160, an inner ring cage ring 170, and a position-regulating cage ring 180.

[0027] The first cam holding portion 162 of the outer ring side cage ring 160 is configured to have an opening width variable portion in which the opening width changes continuously in the axial direction. Specifically, the first cam holding portion 162 includes a guide space portion 163a configured such that the opening width is constant in the axial direction, a first posture fixing space portion 163b configured such that the opening width is smaller than that of the guide space portion 163a and is continuous with the axial forward side (upward side in Figure 7B) of the guide space portion 163a, and a second posture fixing space portion 163c configured such that the opening width is smaller than that of the guide space portion 163a and is continuous with the axial rear side (downward side in Figure 7B) of the guide space portion 163a. ​​The first posture fixing space portion 163b is continuous with the guide space portion 163a via a first opening width variation portion 164a formed such that the opening width continuously decreases as the opening width moves axially forward, and the second posture fixing space portion 163c is continuous with the guide space portion 163a via a second opening width variation portion 164b formed such that the opening width continuously decreases as the opening width moves axially rearward. The first opening width variation 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 variation 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 ring cage ring 160 is rectangular in shape and is configured to have a constant opening width in the axial direction.

[0028] The outer ring cage ring 160 is provided to be movable in the axial direction independently of the rotational movement of the outer ring 110 and the inner ring 120. This makes it possible to tilt the first cam 130a and change its position while maintaining the position of the second cam 130b. Thus, the first cam holding portion 162 of the outer ring cage ring 160 is not a simple rectangular opening, but rather an irregularly shaped opening window whose opening width narrows at both axial ends. This makes it possible to release slight jamming caused by manufacturing errors with a small thrust, and by appropriately changing the opening shape of the first cam holding portion 162, it is possible to realize a wider range of operating modes and their switching.

[0029] On the inner surface of the main body portion 161 of the outer ring cage ring 160, an inner groove portion 166 extending in the axial direction is formed between the first cam holding portion 162 and the second cam holding portion 165 which is adjacent to the first cam holding portion 162 in the meshing direction of the first cam 130a. The inner groove portion 166 has a guide groove portion 167 that extends linearly from the axial rear end edge to the axial front end edge of the main body portion 161, and a slide groove portion 168 that is continuous with the axial front end of the guide groove portion 167. The slide groove portion 168 is formed to extend in the circumferential direction in the direction of engagement with the first cam 130a, and is configured to allow circumferential movement of the outer projection portion 185 of the position-regulating cage ring 180, which will be described later, when the outer ring side cage ring 160 is in a position where it is engaged with the first cam 130a.

[0030] As shown in Figures 8A and 8B, the inner ring cage ring 170 includes a cylindrical main body 171 extending in the axial direction. The main body 171 is provided with a first cam holding portion 172 that receives the leg portion 135 of the first cam 130a and holds the first cam 130a, and a second cam holding portion 173 that receives the leg portion of the second cam 130b and holds the second cam 130b, arranged alternately in the circumferential direction.

[0031] The first cam holding portion 172 of the inner ring cage ring 170 is rectangular in shape and is configured such that the opening width is constant in the axial direction. The second cam holding portion 173 of the inner ring cage ring 170 is configured to have an opening width variation portion in which the opening width changes continuously in the axial direction. Specifically, the second cam holding portion 173 includes a guide space portion 174a configured such that the opening width is constant in the axial direction, a first posture fixing space portion 174b configured such that the opening width is smaller than that of the guide space portion 174a and is continuous with the axial forward side (upward side in Figure 8B) of the guide space portion 174a, and a second posture fixing space portion 174c configured such that the opening width is smaller than that of the guide space portion 174a and is continuous with the axial rear side (downward side in Figure 8B) of the guide space portion 174a. The first posture fixing space portion 174b is continuous with the guide space portion 174a via a first opening width variation portion 175a formed such that the opening width continuously decreases as the opening width moves axially forward, and the second posture fixing space portion 174c is continuous with the guide space portion 174a via a second opening width variation portion 175b formed such that the opening width continuously decreases as the opening width moves axially rearward. The first opening width variation portion 175a is configured such that the opening edge on the side of the second cam 130b that is disengaged (to the right in Figure 8B) protrudes inward, and the second opening width variation portion 175b is configured such that the opening edge on the side of the second cam 130b that is engaged (to the left in Figure 8B) protrudes inward.

[0032] The inner ring cage ring 170 is provided to be movable in the axial direction independently of the rotational movement of the outer ring 110 and the inner ring 120. This makes it possible to tilt the second cam 130b and change its position while maintaining the position of the first cam 130a. Thus, the second cam holding portion 173 of the inner ring cage ring 170 is not a simple rectangular opening, but rather an irregularly shaped opening window with a narrower opening width at both axial ends. This makes it possible to release slight jamming caused by manufacturing errors with a small thrust, and by appropriately changing the opening shape of the second cam holding portion 173, it is possible to realize a wider range of operating modes and their switching.

[0033] On the outer surface of the main body portion 171 of the inner ring cage ring 170, an outer groove portion 176 extending in the axial direction is formed between the second cam holding portion 173 and the first cam holding portion 172 adjacent to the second cam holding portion 173 in the direction of disengaging the second cam 130b. The outer groove portion 176 has a guide groove portion 177 that extends linearly from the axial front end edge to the axial rear end edge of the main body portion 171, and a slide groove portion 178 that is continuous with the axial rear end of the guide groove portion 177. The slide groove portion 178 is formed to extend in the circumferential direction in the direction of engagement with the second cam 130b, and is configured to allow circumferential movement of the inner projection portion 186 of the position-regulating cage ring 180, which will be described later, when the inner ring side cage ring 170 is in a position where it is engaged with the second cam 130b.

[0034] Furthermore, in the cam clutch 100 of the present invention, in the bidirectional lock mode, which prohibits relative rotation of the outer ring 110 and inner ring 120 in both the forward and reverse directions as detailed later, the phases of the cam holding portions of the outer ring side cage ring 160 and the inner ring side cage ring 170 align in the unloaded state when the torque is removed, as shown in Figure 9. Specifically, the guide space portion 163a of the first cam holding portion 162 of the outer ring side cage ring 160 and the first cam holding portion 172 of the inner ring side cage ring 170 overlap radially, and the guide space portion 174a of the second cam holding portion 173 of the second cam holding portion 173 of the inner ring side cage ring 170 also overlap radially. At this time, the dimensions of the guide space 163a of the first cam holding portion 162 of the outer ring cage ring 160, the second cam holding portion 165 of the outer ring cage ring 160, the first cam holding portion 172 of the inner ring cage ring 170, and the guide space 174a of the second cam holding portion 173 of the inner ring cage ring 170 should be designed to be such that both the first cam 130a and the second cam 130b are simultaneously separated from the raceway surface 121 of the inner ring 120 by a small gap, that is, to be such that no jamming occurs.

[0035] In the cam clutch 100 of this embodiment, when the meshing direction is reversed in the bidirectional lock mode and the first cam 130a and the second cam 130b are in a floating state when the torque is released and the load is removed, a sliding resistance generating means 190 is provided that generates sliding resistance between the inner ring side cage ring 170, which is a member that can tilt the first cam 130a or the second cam 130b in the meshing direction, and the raceway surface 121 of the inner ring 120 where the first cam 130a and the second cam 130b are separated. The sliding resistance generating means 190 generates sliding resistance between the inner ring cage ring 170 and the raceway surface 121 of the inner ring 120, starting from a state where the phases of the cam holding portions of the outer ring cage ring 160 and the inner ring cage ring 170 are aligned. By intentionally shifting the phase of the inner ring cage ring 170 relative to the outer ring cage ring 160 in the circumferential direction, either the first cam 130a or the second cam 130b is brought into contact with the raceway surface 121 of the inner ring 120, and from a state where both are floating, the one of the first cam 130a and the second cam 130b that is in contact with the raceway surface 121 of the inner ring 120 is tilted in the meshing direction, thereby enabling the meshing direction to be reversed. The sliding resistance generating means 190 consists of a support ring portion 191 fitted and fixed to the inner circumference of the inner ring side cage ring 170, as shown in Figure 10, for example, and a plate spring member 192 fixedly provided on the support ring portion 191. Furthermore, as shown in Figures 14(a) to 14(c), the plate spring member 192 is provided at equal intervals along the circumferential direction on the support ring portion 191 so as to be located between the first cam 130a and the second cam 130b, which are adjacent to each other in the direction of disengaging. As shown in Figure 11, the plate spring member 192 has a U-shaped cross-section, with two parallel flat plate portions 192a connected by a semi-cylindrical top portion 192b. On the inner circumferential surface of the inner ring cage ring 170, at the rear circumferential end in the cage ring movement direction (right end in Figure 11), which is one axial end facing the raceway surface 121 of the inner ring 120 in the floating state, the top portion 192b is positioned so that it faces the other end of the inner ring cage ring 170, i.e., the front side in the cage ring movement direction (right side in Figure 11), and the flat plate portion 192a faces the rear side in the cage ring movement direction. The cage ring movement direction refers to the direction of movement when transitioning from a certain operating mode in which the other axial end of the inner ring cage ring 170 faces the raceway surface 121 of the inner ring 120 to the next operating mode in which one axial end of the inner ring cage ring 170 faces the raceway surface 121 of the inner ring 120.

[0036] Furthermore, the operating mode switching mechanism 150 of the cam clutch 100 in this embodiment is configured to include a position-restricting cage ring 180 that restricts the degree of freedom of circumferential movement of the outer ring cage ring 160 and the inner ring cage ring 170, as described above. This allows the degree of freedom of circumferential movement of the outer ring cage ring 160 and the inner ring cage ring 170 relative to the position-restricting cage ring 180 to be adjusted to an appropriate degree of freedom according to each operating mode, making it possible to maintain the first cam 130a and the second cam 130b in the correct position.

[0037] As shown in Figures 12A and 12B, the position-regulating cage ring 180 consists 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 axially at predetermined intervals. The space between adjacent connecting portions 182 forms pocket portions 183 capable of accommodating one first cam 130a and one second cam 130b, respectively. The pocket portions 183 are provided at equal intervals along the circumferential direction.

[0038] The position-regulating cage ring 180 has an outward projection 185 that protrudes radially outward from its axial front end and is slidably engaged with the inner groove 166 of the outer ring cage ring 160, and an inward projection 186 that protrudes radially inward from its axial rear end and is slidably engaged with the outer groove 176 of the inner ring cage ring 170.

[0039] The operation of the cam clutch 100 in this embodiment will be described below. First, as shown in Figure 13(a), when both the outer ring cage ring 160 and the inner ring cage ring 170 are positioned axially rearward, torque is applied to either the outer ring 110 or the inner ring 120, causing the first cam 130a to maintain a meshing standby state so that meshing with the outer ring 110 and the inner ring 120 begins immediately. On the other hand, the second cam 130b maintains a state in which the inner ring engagement surface 136 is separated from the raceway surface 121 of the inner ring 120. Therefore, the cam clutch 100 is in a forward rotation lock mode, which prohibits relative rotation of the outer ring 110 and the inner ring 120 in the forward rotation direction.

[0040] When the operating mode of the cam clutch 100 is set to the forward rotation lock mode shown in Figure 13(a), moving the inner ring cage ring 170 axially forward (forward in the direction of cage ring movement) as shown in Figure 13(b) switches the operating mode of the cam clutch 100 from the forward rotation lock mode to a bidirectional lock mode that prohibits relative rotation of the outer ring 110 and inner ring 120 in both the forward and reverse directions. When switching from forward-rotation lock mode to bidirectional lock mode, moving the inner ring cage ring 170 axially forward causes the plate spring member 192, provided at one end of the inner ring cage ring 170 on the axial rear side, to move ahead of its top 192b to a position radially opposite the raceway surface 121 of the inner ring 120 and begin to contact the raceway surface 121. In bidirectional lock mode, the inner ring cage ring 170 is positioned axially forward, so the plate spring member 192 provided at one end of the inner ring cage ring 170 on the axial rear side and one end of the raceway surface 121 of the inner ring 120 face each other radially (vertical direction in Figure 14(b)), and sliding resistance is generated between the plate spring member 192 and the raceway surface 121 of the inner ring 120.

[0041] In the bidirectional lock mode, the first cam 130a and the second cam 130b are essentially in a floating state, simultaneously separated from the raceway surface 121 of the inner ring 120 by a small gap when the torque is removed and the load is unloaded. When torque is applied to the outer ring 110 or the inner ring 120, either the first cam 130a or the second cam 130b comes into contact with the raceway surface 121 of the inner ring 120, causing the cam that comes into contact with the raceway surface 121 of the inner ring 120 to tilt in the meshing direction, thereby transitioning to a forward rotation prohibited state or a reverse rotation prohibited state. Specifically, as shown in Figure 14(a), the system is capable of transitioning between two states: a double-levitation state in which the first cam 130a and the second cam 130b simultaneously maintain a state where they are separated from the raceway surface 121 of the inner ring 120 by a small gap, and a forward rotation prohibited state in which, as shown in Figure 14(b), the first cam 130a maintains a meshing state with the outer ring 110 and the inner ring 120, while the second cam 130b maintains a state where it is separated from the raceway surface 121 of the inner ring 120 by a small gap, thus prohibiting relative rotation in the forward direction. Furthermore, the system is capable of transitioning between two states and a reverse rotation prohibited state in which, as shown in Figure 14(c), the first cam 130a maintains a state where it is separated from the raceway surface 121 of the inner ring 120 by a small gap, while the second cam 130b maintains a meshing state with the outer ring 110 and the inner ring 120, thus prohibiting relative rotation in the reverse direction. In other words, in the bidirectional lock mode, it is possible to transition between a forward rotation prohibited state and a reverse rotation prohibited state via both floating states, thereby enabling the reversal of the meshing direction via both floating states. In both levitation states, the head portion 132 of the first cam 130a is held in the first attitude fixing space 163b of the first cam holding portion 162 of the outer ring cage ring 160, and the leg portion 135 of the first cam 130a is held in the first cam holding portion 172 of the inner ring cage ring 170, causing the first cam 130a to tilt in the disengagement direction and be held in a state separated from the raceway surface 121 of the inner ring 120 with a small gap between them. In addition, the head portion of the second cam 130b is held in the second cam holding portion 163 of the outer ring cage ring 160, and the leg portion of the second cam 130b is held in the second attitude fixing space 174c of the second cam holding portion 173 of the inner ring cage ring 170, causing the second cam 130b to tilt in the disengagement direction and be held in a state separated from the raceway surface 121 of the inner ring 120 with a small gap between them. In the transition from the floating state to the forward rotation prohibited state, the head portion 132 of the first cam 130a is pressed by the action of the first opening width variation portion 164a in the first cam holding portion 162 of the outer ring side cage ring 160, causing the first cam 130a to tilt in the meshing direction. In the transition from the fully levitated state to the reverse direction prohibited state, the leg portion 135 of the second cam 130b is pressed by the action of the second opening width variation portion 175b in the second cam holding portion 173 of the inner ring cage ring 170, causing the second cam 130b to tilt in the meshing direction. Note that in Figures 14(a) to 14(c), 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. Also, Figures 14(a) to 14(c) are schematic diagrams to explain each state and do not accurately reflect the actual dimensions of each component. For example, the inclination of the first cam 130a and the second cam 130b and the distance of the inner ring 120 from the raceway surface 121 are exaggerated. In reality, the distance from the inner ring 120 to the raceway surface 121 is very small (for example, several tens to several hundred μm), and is closer than the distance of the first cam 130a and the second cam 130b from the raceway surface 121 of the inner ring 120 in the bidirectional free mode described later.

[0042] During the bidirectional lock mode, the outer ring cage ring 160 and the inner ring cage ring 170 do not move axially, and sliding resistance due to the plate spring member 192 is always present. In the bidirectional lock mode with both sides lifted, the torque is released, and the phases of the first cam retaining portion 162 of the outer ring cage ring 160 and the first cam retaining portion 172 of the inner ring cage ring 170, as well as the second cam retaining portion 163 of the outer ring cage ring 160 and the second cam retaining portion 173 of the inner ring cage ring 170, are aligned. For example, when transitioning from a forward rotation prohibited state to a reverse rotation prohibited state via a double-levitation state, the meshing torque on the first cam 130a is gradually released, and when it is completely released, the first cam 130a tilts in the disengagement direction, causing both the first cam 130a and the second cam 130b to be in a double-levitation state. Next, the meshing torque in the reverse direction acts on the inner ring 120, and the sliding resistance generated between the raceway surface 121 of the inner ring 120 and the leaf spring member 192 causes the inner ring side cage ring 170 to rotate together, moving circumferentially relative to the outer ring side cage ring 160 as the inner ring 120 rotates. As a result, the phases of the cam holding portions of the outer ring side cage ring 160 and the inner ring side cage ring 170 are shifted, causing the second cam 130b, which is to mesh next, to tilt in the meshing direction and contact the raceway surface 121 of the inner ring 120, resulting in the reverse rotation prohibited state. On the other hand, when transitioning from a reverse rotation prohibited state to a forward rotation prohibited state via a double-levitation state, the meshing torque on the second cam 130b is gradually released, and when it is completely released, the second cam 130b tilts in the disengagement direction, causing both the first cam 130a and the second cam 130b to be in a double-levitation state. Next, the meshing torque in the opposite direction acts on the inner ring 120, and the sliding resistance generated between the raceway surface 121 of the inner ring 120 and the leaf spring member 192 causes the inner ring side cage ring 170 to rotate together, moving circumferentially relative to the outer ring side cage ring 160 as the inner ring 120 rotates. As a result, the phases of the cam holding portions of the outer ring side cage ring 160 and the inner ring side cage ring 170 are shifted, causing the first cam 130a, which is to mesh next, to tilt in the meshing direction and contact the raceway surface 121 of the inner ring 120, resulting in a forward rotation prohibited state. Thus, in the lifted state with the torque removed, the sliding resistance generating means 190 controls the meshing direction of the first cam 130a and the second cam 130b, and the force of the inner ring cage ring 170 rotating together with the inner ring 120 reverses the meshing direction of the cams, transitioning to a forward rotation prohibited state or a reverse rotation prohibited state. In this way, a bidirectional lock mode can be achieved without any jamming occurring.

[0043] Conversely, when switching the operating mode of the cam clutch 100 from the bidirectional lock mode to the forward rotation lock mode, the inner ring cage ring 170 is moved axially rearward. As a result, the leg portion 135 of the second cam 130b is pressed by the action of the first opening width variation portion 175a in the second cam holding portion 173 of the inner ring cage ring 170, causing the second cam 130b to tilt in the disengagement direction, and the posture of the second cam 130b is maintained such that the inner ring side engagement surface 136 of the second cam 130b is separated from the raceway surface 121 of the inner ring 120. On the other hand, as described above, the position of the first cam 130a is maintained in a meshing-waiting state so that when torque is applied to the outer ring 110 or the inner ring 120, the first cam 130a immediately begins to mesh with the outer ring 110 and the inner ring 120. This switches the operating mode of the cam clutch 100 from bidirectional lock mode to forward rotation lock mode.

[0044] Furthermore, when the operating mode of the cam clutch 100 is set to the forward rotation lock mode shown in Figure 15(a), moving the outer ring cage ring 160 axially forward, as shown in Figure 15(b), switches the operating mode of the cam clutch 100 from the forward rotation lock mode to a bidirectional free mode that allows relative rotation of the outer ring 110 and inner ring 120 in both the forward and reverse directions. Specifically, when the outer ring cage ring 160 is moved axially forward, the head portion 132 of the first cam 130a is pressed by the action of the second opening width variation portion 164b in the first cam holding portion 162 of the outer ring cage ring 160. As a result, the first cam 130a is tilted in the disengagement direction, and the posture of the first cam 130a is maintained such that the inner ring side engagement 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 in the outer ring cage ring 160 is formed in a rectangular shape with a constant opening width in the axial direction, and the circumferential degrees of freedom of the outer ring cage ring 160 and the inner ring cage ring 170 are restricted by the position-restricting cage ring 180. As a result, the position of the second cam 130b is maintained such that the inner ring engagement surface 136 is separated from the raceway surface 121 of the inner ring 120. In both the forward-rotation lock mode and the bidirectional free mode, the inner ring cage ring 170 is positioned on the axial rear side. Therefore, the plate spring member 192 provided at one end of the inner ring cage ring 170 on the axial rear side is not radially opposed to the inner ring 120. Consequently, no sliding resistance is generated between the plate spring member 192 and the raceway surface 121 of the inner ring 120.

[0045] Conversely, when switching the operating mode of the cam clutch 100 from the bidirectional free mode to the forward rotation lock mode, the outer ring 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 variation portion 164a in the first cam holding portion 162 of the outer ring side cage ring 160, causing the first cam 130a to tilt in the meshing direction, and torque is applied to the outer ring 110 or inner ring 120, holding the first cam 130a in a meshing standby state so that meshing with the outer ring 110 and inner ring 120 can be started immediately. At this time, the inner groove portion 166 of the outer ring side cage ring 160 has a sliding groove portion 168, which allows circumferential movement of the outer projection portion 185 of the position regulating cage ring 180. Therefore, the degree of freedom of circumferential movement of the outer ring side cage ring 160 relative to the position-regulating cage ring 180 is properly adjusted, and the first cam 130a is held in the correct position. On the other hand, the position of the second cam 130b is maintained such that the inner ring side engagement surface 136 is separated from the raceway surface 121 of the inner ring 120, as described above.

[0046] Furthermore, when the operating mode of the cam clutch 100 is set to the forward rotation lock mode shown in Figure 16(a), moving both the outer ring cage ring 160 and the inner ring cage ring 170 axially forward, as shown in Figure 16(b), switches the operating mode of the cam clutch 100 from the forward rotation lock mode to the reverse rotation lock mode, which prohibits relative rotation of the outer ring 110 and the inner ring 120 in the reverse direction. Specifically, when both the outer ring cage ring 160 and the inner ring cage ring 170 are moved axially forward, the head portion 132 of the first cam 130a is pressed by the action of the second opening width variation portion 164b in the first cam holding portion 162 of the outer ring cage ring 160. As a result, the first cam 130a is tilted in the disengagement direction, and the posture of the first cam 130a is maintained such that the inner ring 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 variation portion 175b in the second cam holding portion 173 of the inner ring 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 inner ring 120, holding the second cam 130b in a meshing standby state so that meshing with the outer ring 110 and inner ring 120 can begin immediately. At this time, the outer groove portion 176 of the inner ring cage ring 170 has a sliding groove portion 178, which allows circumferential movement of the inner projection portion 186 of the position regulating cage ring 180. Therefore, the degree of freedom of circumferential movement of the inner ring cage ring 170 relative to the position regulating cage ring 180 is appropriately adjusted, and the second cam 130b is held in the correct position.

[0047] Conversely, when switching the operating mode of the cam clutch 100 from the reverse direction lock mode to the forward direction lock mode, both the outer ring cage ring 160 and the inner ring 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 variation portion 164a in the first cam holding portion 162 of the outer ring cage ring 160, causing the first cam 130a to tilt in the meshing direction, and torque is applied to the outer ring 110 or inner ring 120, holding the first cam 130a in a meshing standby state so that meshing with the outer ring 110 and inner ring 120 can be started immediately. At this time, as described above, the degree of freedom of circumferential movement of the outer ring cage ring 160 relative to the position regulating cage ring 180 is appropriately adjusted, and the first cam 130a is held in the correct position. On the other hand, the leg portion 135 of the second cam 130b is pressed by the action of the first opening width variation portion 175a in the second cam holding portion 173 of the inner ring cage ring 170, causing the second cam 130b to tilt in the disengagement direction, and the posture of the second cam 130b is maintained such that the inner ring side engagement surface 136 of the second cam 130b is separated from the raceway surface 121 of the inner ring 120. This switches the operating mode of the cam clutch 100 from reverse-direction lock mode to forward-direction lock mode.

[0048] As described above, in the cam clutch 100 of this embodiment, when the operating mode is switched by the operating mode switching mechanism, the first cam 130a and the second cam 130b pass through a state of simultaneous floating, separated from the raceway surface 121 of the inner ring 120. Therefore, it is possible to avoid the first cam 130a and the second cam 130b simultaneously engaging with the inner ring 120 and the outer ring 110 when the torque is released. Furthermore, by providing a sliding resistance generating means 190 that generates sliding resistance between the inner ring cage ring 170 and the inner ring 120, which is separated from the first cam 130a and the second cam 130b when both rings are in a floating state, the torque acting on the inner ring 120 or the outer ring 110 when both rings are floating is transmitted by the sliding resistance generating means 190 to the first cam 130a or the second cam 130b that is to engage next, causing the cam to tilt in the engagement direction. This avoids an unintended free-spinning state in which the torque acting on the inner ring 120 or the outer ring 110 is not transmitted to either the first cam 130a or the second cam 130b, thereby achieving a bidirectional lock mode. Therefore, since there is no remaining engagement when the meshing direction of the first cam 130a and the second cam 130b is reversed, the thrust required to switch to other operating modes can be significantly reduced, allowing for miniaturization of the switching device. Furthermore, even if the operating mode is switched frequently, damage to the raceway surfaces of the inner and outer rings can be suppressed to an extreme degree, thereby extending the lifespan of the cam clutch. [Examples]

[0049] As shown in Figure 17, the cam clutch 200 according to the second embodiment of the present invention is equipped with a sliding resistance generating means 290 using an O-ring 291 instead of the sliding resistance generating means 190, and further, the inner ring side cage ring 170 is provided with an annular projection 179 that can contact the O-ring 291, and the other configurations are the same as those of the first embodiment described above. In Figure 17 showing the second embodiment, the same reference numerals are used for components that are the same as those of the cam clutch 100 according to the first embodiment. The sliding resistance generating means 290 consists of an O-ring 291 fixedly provided on the raceway surface 121 of the inner ring 120, where the first cam 130a and the second cam 130b are spaced apart, so as to generate sliding resistance by contacting the inner circumferential surface of the inner ring side cage ring 170. The O-ring 291 is positioned to extend around the entire circumference of the raceway surface 121 of the inner ring 120, fitted into an annular groove 122 provided around the entire circumference at one axial end (the lower end in Figure 17) that faces the inner circumferential surface of the inner ring side cage ring 170 in the floating state. On the inner circumferential surface of the inner ring cage ring 170, an annular projection 179 is provided at the circumferential end (lower end in Figure 17) at the rear in the direction of cage ring movement, which is one end in the axial direction that faces the O-ring 291 when both are floating, so as to protrude toward the inner ring 120.

[0050] When the cam clutch 200 is in forward rotation lock mode, if the inner ring cage ring 170 is moved axially forward to switch to bidirectional lock mode, the annular projection 179 provided at one end of the axial rear side of the inner ring cage ring 170 and the O-ring 291 fixed to the raceway surface 121 of the inner ring 120 face each other radially (left-right direction in Figure 17), and sliding resistance is generated between them. When transitioning from a forward rotation prohibited state to a reverse rotation prohibited state via a double-levitation state, the meshing torque on the first cam 130a is gradually released. When the torque is completely released, the first cam 130a tilts in the disengagement direction, causing both the first cam 130a and the second cam 130b to be in a double-levitation state. Next, the meshing torque in the reverse direction acts on the inner ring 120, causing the inner ring cage ring 170 to rotate due to the sliding resistance generated between the o-ring 291 and the inner ring cage ring 170. This causes the inner ring cage ring 170 to move circumferentially relative to the outer ring cage ring 160 as the inner ring 120 rotates. This shifts the phase, causing the second cam 130b, which is to mesh next, to tilt in the meshing direction and contact the raceway surface 121 of the inner ring 120, resulting in a reverse rotation prohibited state. On the other hand, when transitioning from a reverse rotation prohibited state to a forward rotation prohibited state via a double-levitation state, the meshing torque on the second cam 130b is gradually released, and when it is completely released, the second cam 130b tilts in the disengagement direction, causing both the first cam 130a and the second cam 130b to be in a double-levitation state. Next, the meshing torque in the reverse direction acts on the inner ring 120, and the sliding resistance generated between the o-ring 291 and the inner ring side cage ring 170 causes the inner ring side cage ring 170 to rotate together, moving circumferentially relative to the outer ring side cage ring 160 along with the rotation of the inner ring 120. As a result, the phases of the cam holding portions of the outer ring side cage ring 160 and the inner ring side cage ring 170 are shifted, causing the first cam 130a, which is to mesh next, to tilt in the meshing direction and contact the raceway surface 121 of the inner ring 120, resulting in a forward rotation prohibited state.

[0051] The cam clutch 200 of this embodiment can also obtain the same effects as the cam clutch 100 of Embodiment 1 described above.

[0052] Although 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 described in the claims. For example, the specific configuration of the sliding resistance generating means is not limited to the above-described embodiment, as long as it generates sliding resistance between at least the inner ring or outer ring and a member capable of controlling the tilting state of the first cam or second cam, in both the floating states of the first cam and the second cam, thereby enabling the first cam or second cam to come into contact with the inner ring or outer ring. Furthermore, in the above embodiment, a configuration was described in which the operating mode of the cam clutch is set to the forward rotation lock mode when the outer ring side cage ring and the inner ring side cage ring are positioned on the axial rearward side. However, the relationship between the operating mode of the cam clutch and the axial position of the outer ring side cage ring and the inner ring side cage ring is not particularly limited. For example, the cam clutch may be configured to be set to the bidirectional lock mode, the bidirectional lock mode, or the reverse rotation lock mode when the outer ring side cage ring and the inner ring side cage ring are positioned on the axial rearward side. Furthermore, in the above embodiment, a configuration was described in which one or both of the first cam and the second cam are separated from the inner ring in each operating mode, but the cam may also be configured to be separated from the outer ring. [Explanation of Symbols]

[0053] 100... Cam clutch 110 ··· Outer ring 111 ... Raceway surface 115...Position regulation part 116 ··· Inner rib section 120 ··· Inner circle 121 ... raceway surface 122 ··· Ring groove 130a ··· First cam 130b ··· 2nd cam 131 ··· Waist area 132 ... head part 133 ··· Outer ring side engagement surface 134a ··· Side view 134b... side 135 ... leg part 136 ··· Inner ring engagement surface 137a... side 137b... side 140 ··· biasing means 141 ··· Circular section 142... Connecting part 143 ··· Arc-shaped curved section 144... Pressing arm 145 ··· Pocket section 150 ··· Operating mode switching mechanism 160 ··· Outer ring cage ring 161 ··· Main body 162 ··· First cam retaining part 163a ··· Guide space section 163b... First posture fixing space 163c...Second posture fixing space 164a ··· First opening width variation section 164b... Second opening width variation section 165 ··· Second cam retaining part 166 ··· Inner groove section 167 ··· Guide groove section 168... Slide groove section 170 ··· Inner ring cage ring 171 ··· Main body 172 ··· First cam retaining part 173 ··· Second cam retaining part 174a ··· Guide space section 174b... Space for fixing the first posture 174c...Second posture fixing space 175a ··· First opening width variation section 175b ··· Second opening width variation section 176 ... External groove 177 ··· Guide groove section 178... Slide groove section 179 ··· Annular protrusion 180 ··· Positioning Cage Ring 181 ··· Circular section 182 ··· Connection part 183 ··· Pocket section 185 ... outward protrusion 186 ... Inward protrusion 190 ··· Sliding resistance generating means 191 ··· Support ring section 192 ··· Plate spring component 200... Cam clutch 290 ··· Sliding resistance generating means 291 ··· O-ring C...Rotation axis center

Claims

1. A cam clutch comprising an inner ring and an outer ring rotatably mounted on the same axis of rotation, a plurality of cams arranged circumferentially between the inner ring and the outer ring, and a biasing means for biasing each of the plurality of cams to contact the inner ring and the outer ring, The plurality of cams include a first cam and a second cam whose meshing directions with respect to the inner ring and the outer ring are different from each other. The cam clutch is equipped with an operating mode switching mechanism that switches the operating mode of the cam clutch, The operating modes that can be switched by the operating mode switching mechanism include a bidirectional lock mode that prohibits relative rotation of the inner ring and the outer ring in both the forward and reverse directions. A cam clutch characterized in that, in the bidirectional lock mode, when the first cam and the second cam are simultaneously in a floating state with a minute gap between them and the raceway surface of the inner ring and / or the raceway surface of the outer ring, the clutch comprises a member that can tilt the first cam or the second cam in the meshing direction, and a sliding resistance generating means that generates sliding resistance between the first cam and the second cam and the inner ring and / or outer ring where they are separated.

2. The operation mode switching mechanism comprises an outer ring side cage ring that is axially movable independently of the rotational movement of the outer ring and the inner ring and configured to change the position of the first cam; an inner ring side cage ring that is axially movable independently of the rotational movement of the outer ring and the inner ring and configured to change the position of the second cam; and a position restricting cage ring provided between the outer ring side cage ring and the inner ring side cage ring to restrict the degree of freedom of circumferential movement of the outer ring side cage ring and the inner ring side cage ring. The cam clutch according to claim 1, characterized in that the member that can tilt the first cam or the second cam in the meshing direction is the outer ring side cage ring and / or the inner ring side cage ring.

3. The outer ring side cage ring and the inner ring side cage ring each have a first cam holding portion for holding the first cam and a second cam holding portion for holding the second cam, The second cam retaining portion in the outer ring cage ring and the first cam retaining portion in the inner ring cage ring are configured such that the opening width is constant in the axial direction. The cam clutch according to claim 2, characterized in that the first cam holding portion in the outer ring side cage ring and the second cam holding portion in the inner ring side cage ring are configured to have opening width variable portions in which the opening width changes continuously in the axial direction.

4. The cam clutch according to claim 2, characterized in that the sliding resistance generating means has a plate spring member fixedly provided on the inner circumferential surface of the inner ring side cage ring and / or the outer circumferential surface of the outer ring side cage ring, such that the first cam and the second cam are spaced apart and contact the raceway surface of the inner ring and / or the raceway surface of the outer ring to generate sliding resistance.

5. The aforementioned plate spring member has a U-shaped cross-section, The cam clutch according to claim 4, characterized in that, on the inner circumferential surface of the inner ring cage ring and / or the outer circumferential surface of the outer ring cage ring, the top of the first cam and the second cam are positioned such that they face the opposite end to the other end when both are in a floating state, at one end facing the raceway surface of the inner ring and / or the raceway surface of the outer ring.

6. The cam clutch according to claim 2, characterized in that the sliding resistance generating means has an O-ring fixedly provided on the raceway surface of the inner ring and / or the raceway surface of the outer ring, where the first cam and the second cam are spaced apart, so as to generate sliding resistance by contacting the inner circumferential surface of the inner ring side cage ring and / or the outer circumferential surface of the outer ring side cage ring.

7. The cam clutch according to claim 6, characterized in that the O-ring is provided at one end on the raceway surface of the inner ring and / or the raceway surface of the outer ring, facing the inner circumferential surface of the inner ring side cage ring and / or the outer circumferential surface of the outer ring side cage ring when the first cam and the second cam are both in a floating state.

Images