Cam clutch

Abstract

To provide a cam clutch capable of smoothly switching an operation mode and realizing low noise and a long life, while preventing bite-in of a cam with a simple structure without increasing a size of the clutch or the number of components.SOLUTION: Plural cams including a first cam 131a and a second cam 131b with meshing directions different from each other are arranged, so that the first cam 131a is paired with the second cam 131b. The clutch comprises a transmission member 161 in contact with each of the pair of cams and provided rotatably while a rotation center is fixed by a cage 140 and movably in an axial direction. The transmission member 161 is constituted inclinably between a meshing standby state of the first cam 131a and a non-contact state to an outer ring 110 and an inner ring 120 by rotation, and is constituted inclinably between a meshing standby state of the second cam 131b and a non-contact state to the outer ring 110 and the inner ring 120 by movement in an axial direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a cam clutch configured to be able to switch an operation mode among a two-way engagement mode in which torque can be transmitted in both forward and reverse directions between an outer ring and an inner ring, a one-way engagement mode in which torque can be transmitted in either one of the forward and reverse directions between the outer ring and the inner ring, and a two-way freewheel mode in which the rotating wheel on the input side of the outer ring and the inner ring freewheels in both forward and reverse directions to cut off torque transmission between the outer ring and the inner ring.

Background Art

[0002] As a clutch for controlling torque transmission and interruption, a two-way clutch capable of switching between driving and freewheeling in both forward and reverse directions is known. For example, in Patent Document 1, a holder that holds both a first sprag and a second sprag biased by biasing means so that their rotation locking directions are opposite to each other is controlled, and torque can be transmitted only in the forward direction between the outer ring and the inner ring. A clutch configured to be able to switch an operation mode between a one-way engagement mode and a one-way engagement mode in which torque can be transmitted only in the reverse direction between the outer ring and the inner ring is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a clutch where sprags that engage in only one direction of rotation are arranged symmetrically, and the operating mode can be switched by tilting one sprag and the other, there is a risk of "meshing" occurring, where all cams engage simultaneously. That is, in such a clutch, when torque is applied to the outer or inner ring, one sprag tilts so as to immediately begin engaging with the outer and inner rings. 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, requiring a large force to change the sprag's position when switching the clutch's operating mode. This can damage the engagement surfaces of the sprags with the outer and inner rings, as well as the raceways of the outer and inner rings, potentially shortening the clutch's lifespan.

[0005] To address these problems, the aforementioned two-way clutch prevents jamming by arranging the first and second sprags side-by-side in a common retainer so that their rotational locking directions are opposite, and by holding the first sprag in a state where it is biased in the anti-locking direction and the second sprag in the locking direction. However, in the aforementioned two-way clutch, the cage is controlled during the switching of the operating mode, causing all of the first and second sprags to be forcibly tilted simultaneously. For this reason, the aforementioned two-way clutch cannot realize a bidirectional meshing mode that allows torque transmission in both forward and reverse directions between the outer and inner rings, nor a bidirectional free-spinning mode that interrupts torque transmission between the outer and inner rings by allowing the input-side rotating ring of the outer and inner rings to spin freely in both forward and reverse directions. Furthermore, during free-spinning, slip torque is generated when either the first or second sprag contacts the inner or outer ring, resulting in increased torque during free-spinning. Moreover, due to the configuration in which a load is applied to the cage via a gear mechanism from a load application device to control the cage, the gears connected to the cage act as rotational resistance, further increasing the torque during free-spinning.

[0006] The present invention was made based on the above circumstances, and aims to provide a cam clutch that has a simple structure without increasing size or the number of parts, prevents cam jamming, allows for smooth switching of operating modes, and also achieves low noise and long lifespan. [Means for solving the problem]

[0007] The present invention provides a cam clutch comprising an outer ring and an inner ring rotatably mounted coaxially, a plurality of cams positioned between the outer ring and the inner ring, and a cage that holds the plurality of cams in the circumferential direction, wherein the plurality of cams include a first cam and a second cam, which have different meshing directions with respect to the outer ring and the inner ring, and the first cam and the second cam are paired together, and the transmission member is provided to contact each of the paired first cam and second cam, to be rotatable with its rotation center fixed by the cage, and to be movable in the axial direction, thereby solving the above problem. The transmission member is configured to tilt the first cam between a meshing standby state and a state of non-contact with the outer ring or the inner ring when rotated, and to tilt the second cam between a meshing standby state and a state of non-contact with the outer ring or the inner ring when moved in the axial direction. [Effects of the Invention]

[0008] According to the invention of claim 1, since the tilting of the first cam and the tilting of the second cam are performed independently by different movements of the transmission member, the cam clutch can be configured to switch between three operating modes: bidirectional meshing mode, unidirectional meshing mode, and bidirectional free-spinning mode, with a simple configuration. Moreover, since the switching of the operating mode between the bidirectional meshing mode and the bidirectional free-spinning mode is performed in stages by the tilting of the first cam and the second cam, the number of cams that rotate at the same time is reduced. As a result, the release torque required to release the cam meshing under torque load can be reduced, enabling smooth operation and preventing damage to the cam engagement surface, the outer ring raceway surface, and the inner ring raceway surface, thus extending the lifespan. Furthermore, since the tilting of the first cam is performed by rotating the transmission member, and only the tilting of the second cam is performed by the axial movement of the transmission member, the axial range of motion of the transmission member can be reduced compared to a configuration in which the tilting of the cam is performed only by the axial movement of the operating mode switching means, thus avoiding an increase in axial dimensions. Furthermore, when the operating mode is set to bidirectional free-spinning mode, all cams are in a state where they do not contact the outer or inner ring, so no slip torque is generated during free-spinning. In this respect as well, there is no risk of damaging the engagement surface of the cam, the raceway surface of the outer ring, and the raceway surface of the inner ring, which makes it possible to extend the lifespan and reduce noise.

[0009] According to the invention of claim 2, when torque is applied to the outer ring or inner ring, the first cam tilts to engage with the outer ring and inner ring, and in conjunction with this, the second cam, which normally maintains a waiting state for engagement, is tilted in the disengagement direction, thereby separating the engagement surface of the second cam from the raceway surface of the outer ring and / or the raceway surface of the inner ring. As a result, even if the second cam tilts in the engagement direction when the torque is removed, the second cam can avoid engaging with the outer ring and inner ring before the engagement of the first cam is disengaged. Therefore, smooth operation can be achieved and high responsiveness can be obtained. Furthermore, by suppressing the occurrence of engagement, it becomes unnecessary to use a large drive source for moving the transmission member in the axial direction, making it possible to save energy and miniaturize the device.

[0010] According to the invention of claim 3, there is no need to provide a separate drive source for rotating the transmission member, and rotation and axial movement of the transmission member can be achieved simply by moving the selector in the axial direction, thereby avoiding the complexity and size increase of the cam clutch structure.

[0011] According to the invention of claim 4, by providing the transmission member with the function of tilting the first cam and the function of tilting the second cam, other components that contribute to switching the operating mode can have a simple structure, thus simplifying the structure and making it easier to manufacture.

[0012] According to the invention of claim 5, the mechanism for rotating and axially moving the transmission member does not become a rotational resistance, and it is possible to reduce torque during free rotation.

[0013] According to the invention according to claim 6, the axial size of the cam clutch can be reduced, and since it is possible to use a common component as the biasing means for all cams, the number of parts can be reduced and the structure can be easily simplified.

Brief Description of the Drawings

[0014] [Figure 1] It is an exploded perspective view showing the configuration in an example of the cam clutch of the present invention. [Figure 2] It is a cross-sectional view taken along a plane along the rotation axis, showing a part of the cam clutch shown in FIG. 1. [Figure 3] It is a cross-sectional view taken along a plane perpendicular to the rotation axis of the cam clutch shown in FIG. 1. [Figure 4] It is a (a) perspective view and (b) one-end side end face view showing the configuration of the first cam. [Figure 5] It is a (a) one-end side end face view and (b) perspective view showing the configuration of the second cam. [Figure 6] It is a cross-sectional perspective view showing a part of the cage. [Figure 7] It is a side view showing the configuration of the transmission member. [Figure 8] It is a (a) one-end side end face view and (b) the other-end side end face view showing the configuration of the transmission member shown in FIG. 7. [Figure 9] It is a plan view seen from one axial end side with a part of the cam clutch shown in FIG. 1 omitted. [Figure 10] It is a side view schematically showing the state of the cam clutch when the operation mode of the cam clutch shown in FIG. 1 is the bidirectional engagement mode. [Figure 11A] It is a view showing the contact state between the cam contact portion of the transmission member and the stepped portion of the cam when the first cam and the second cam are in the meshing standby state in the bidirectional engagement mode. [Figure 11B] It is a view seen from one axial end side schematically showing the positional relationship between the cam and the transmission member when the first cam and the second cam are in the meshing standby state in the bidirectional engagement mode. [Figure 12] It is a side view schematically showing the state of the cam clutch when the operation mode of the cam clutch shown in FIG. 1 is a one-way engagement mode. [Figure 13A] It is a view seen from one end side in the axial direction schematically showing the positional relationship between the cam and the transmission member when the second cam is in the engagement standby state in the one-way engagement mode. [Figure 13B] It is a view showing the contact state between the cam contact portion of the transmission member and the stepped portion of the cam when the second cam is in the engagement standby state in the one-way engagement mode. [Figure 14] It is a side view schematically showing the state of the cam clutch when the operation mode of the cam clutch shown in FIG. 1 is a two-way freewheeling mode. [Figure 15] It is a view showing the contact state between the cam contact portion of the transmission member and the stepped portion of the cam when the operation mode of the cam clutch shown in FIG. 1 is a two-way freewheeling mode.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] As shown in FIG. 1, the cam clutch 100 of the present invention has an outer ring 110, an inner ring 120, a cam mechanism 130, and an operation mode switching mechanism 160. As shown in FIGS. 2 and 3, in the assembled state of the cam clutch 100, the outer ring 110 and the inner ring 120 are provided so as to be relatively rotatable on the same rotation axis X, and the raceway surface 111 of the outer ring 110 and the raceway surface 121 of the inner ring 120 are configured to face each other.

[0016] As shown in FIG. 1, the cam mechanism 130 includes a plurality of cams 131, a cage 140 that holds the plurality of cams 131 at intervals in the circumferential direction, and biasing means 150 that biases each of the plurality of cams 131 in the meshing direction so as to contact the outer ring 110 and the inner ring 120.

[0017] Each of the multiple cams 131 includes a first cam 131a and a second cam 131b, which have different meshing directions with respect to the outer ring 110 and the inner ring 120, as shown in Figure 3. The first cam 131a and the second cam 131b form a pair, and the multiple cam pairs 132 are arranged at predetermined intervals in the circumferential direction on the same circumference. Hereafter, unless the first cam 131a and the second cam 131b are specifically distinguished, they will simply be referred to as cam 131. By arranging multiple cams 131 on the same circumference, the axial size of the cam clutch 100 can be reduced, and a common biasing means 150 can be used for all cams 131, thus reducing the number of parts and simplifying the structure. In this embodiment, 10 pairs of cams 132 are arranged at equal intervals in the circumferential direction. However, the number of cam pairs 132 is not particularly limited and can be changed as appropriate depending on the desired torque capacity. Furthermore, the spacing between the cam pairs 132 does not have to be equal.

[0018] As shown in Figures 4(a) and (b), the first cam 131a has an outer ring side engagement surface 133 formed in a curved shape including an arc-shaped portion, and an inner ring side engagement surface 134 formed in an arc shape with a larger radius of curvature than the outer ring side engagement surface 133, and is configured to engage with the outer ring 110 and inner ring 120 when the outer ring 110 rotates in the forward direction (counterclockwise in Figure 3) or when the inner ring 120 rotates in the reverse direction (clockwise in Figure 3). In this embodiment, for example, an annular garter spring is used as the biasing means 150, and a circumferentially extending garter spring mounting groove 135 is formed on the outer ring side engagement surface 133 of the first cam 131a. The garter spring mounting groove 135 is configured such that when a garter spring is mounted, a counterclockwise rotational moment is applied to the first cam 131a in Figure 3. Furthermore, the first cam 131a has a stepped portion 136 that extends axially outward on one end face of the axial side. In this embodiment, the stepped portion 136 is configured to have a planar shape formed by cutting out the outer ring side portion of one end of the first cam 131a with two planes that intersect with an obtuse apex angle and are perpendicular to the cam end face. The apex of the stepped portion 136 is located on the outer ring side engagement surface 133 side with respect to the curvature center C1 of the inner ring side engagement surface 134, and is formed at a position displaced on the side where the paired second cam 131b is located (right side in Figure 4(b)) with respect to the normal H at the contact point P between the first cam 131a and the raceway surface 121 of the inner ring 120.

[0019] The second cam 131b 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 120 is rotated in the forward direction. As shown in Figures 5(a) and (b), the second cam 131b according to this embodiment has the same configuration as the first cam 131a and is configured opposite to the first cam 131a. That is, the second cam 131b has an outer peripheral contour shape that is the inverted version of the first cam 131a, and the top of the stepped portion 136 is on the outer ring engagement surface 133 side with respect to the curvature center C2 of the inner ring engagement surface 134, and is formed at a position displaced to the side where the paired first cam 131a is located (left side in Figure 5(a)) with respect to the normal H at the contact point P between the second cam 131b and the raceway surface 121 of the inner ring 120. The garter spring mounting groove 135 is configured such that, when the garter spring is mounted, a clockwise rotational moment is applied to the second cam 131b in Figure 3.

[0020] As shown in Figure 6, the cage 140 has a small-diameter cylindrical portion 141, a flange portion 145 formed at one axial end of the small-diameter cylindrical portion 141 so as to protrude radially outward over the entire circumference in the circumferential direction, and a large-diameter cylindrical portion 147 formed on one axial end face of the flange portion 145 such that its inner circumferential surface is continuous with the inner circumferential surface of the small-diameter cylindrical portion 141. The small-diameter cylindrical portion 141 is provided with openings 142 arranged at equal intervals in the circumferential direction. Each opening 142 is partitioned in the circumferential direction by a column portion 143 extending in the axial direction, with the space on the forward rotation side configured as the first cam holding portion 144a and the space on the reverse rotation side configured as the second cam holding portion 144b. The circumferential dimensions of the first cam holding portion 144a and the second cam holding portion 144b are configured to be smaller than the maximum outer diameter of the cam 131. The outer circumferential surface of the large-diameter cylindrical portion 147 is configured with a transmission member housing portion 148, which is a cylindrical space with an open radially outward orientation. The transmission member housing portion 148 is formed by creating through holes 146 that extend axially at circumferential positions in the flange portion 145 corresponding to the columnar portions 143 of each opening 142.

[0021] The first cam 131a and the second cam 131b are inserted from the radially outward side into the corresponding first cam retaining portion 144a and second cam retaining portion 144b, and are positioned such that the inner ring side engagement surface 134 protrudes radially inward from the inner circumferential surface of the cage 140, and are held in place by the cage 140 when a garter spring is attached.

[0022] The cam mechanism 130 is arranged such that the small-diameter cylindrical portion 141 of the cage 140 is inserted into the annular space between the raceway surface 111 of the outer ring 110 and the raceway surface 121 of the inner ring 120. As a result, multiple cams 131 are arranged in this annular space, and the cage 140 is provided to rotate independently of the outer ring 110 and the inner ring 120. By providing the cage 140 to rotate independently of the outer ring 110 and the inner ring 120, it is possible to reduce the torque during free rotation.

[0023] The cam clutch 100 according to this embodiment is equipped with an operating mode switching mechanism 160 that switches between three operating modes: a bidirectional meshing mode in which torque can be transmitted in both forward and reverse directions between the outer ring 110 and the inner ring 120; a unidirectional meshing mode in which torque can be transmitted in either forward or reverse direction between the outer ring 110 and the inner ring 120; and a bidirectional free-spinning mode in which the input-side rotating ring of the outer ring 110 and the inner ring 120 rotates freely in both forward and reverse directions, interrupting torque transmission between the outer ring 110 and the inner ring 120.

[0024] The operating mode switching mechanism 160 includes a plurality of transmission members 161, each of which is provided in accordance with a plurality of cam pairs 132 and configured to allow the paired first cam 131a and second cam 131b to be tilted separately, and a selector 170 that moves each of the plurality of transmission members 161 simultaneously.

[0025] The transmission member 161 is configured to rotate around an axis extending along the rotation axis X of the cam clutch 100, thereby allowing the first cam 131a to tilt between a meshing standby state and a state in which it is not in contact with the outer ring 110 or inner ring 120, and is also configured to move in the axial direction, thereby allowing the second cam 131b to tilt between a meshing standby state and a state in which it is not in contact with the outer ring 110 or inner ring 120. As shown in Figure 7, the transmission member 161 according to this embodiment has a cylindrical base portion 162, a load-applying portion 163 formed to extend axially outward at one axial end of the base portion 162, and a cam contact portion 166 formed to extend axially outward at the other axial end of the base portion 162.

[0026] As shown in Figure 8(a), the load-applying section 163 is formed to have a columnar shape with a substantially semicircular cross-section, and includes, for example, a flat rotational force acting surface 164 positioned on a plane perpendicular to one end face of the base section 162 including the central axis O, and a guide surface 165 that is continuous with the rotational force acting surface 164 and extends inclined toward the outer circumferential surface as it moves toward one end in the axial direction. As shown in Figure 8(b), the cam contact portion 166 is formed in a columnar shape with a substantially semicircular cross-section at a position opposite the load-applying portion 163 across the central axis in a plan view. For example, it has a flat cam pressing surface 167 located on a plane perpendicular to the other end face of the base portion 162 including the central axis O, and inclined in the rotational direction with respect to the rotational force acting surface 164, and a cam acting surface 168 formed continuously on one axial end side of the cam pressing surface 167 to tilt the cam 131. The cam acting surface 168 is inclined in a direction away from the cam pressing surface 167 as it approaches one axial end, and one end edge 168a is formed to extend along the inclination direction of the rotational force acting surface 164 with respect to the cam pressing surface 167.

[0027] With a transmission member 161 having the function of tilting the first cam 131a and the function of tilting the second cam 131b, other components that contribute to switching the operating mode of the cam clutch 100 can have a simple structure, thus simplifying the structure and making it easier to manufacture.

[0028] The transmission member 161 is housed in the transmission member housing 148 with its base portion 162 inserted into the through hole 146 in the cage 140, and is rotatable and axially movable with its rotation center fixed by the cage 140.

[0029] When the operating mode of the cam clutch 100 is set to the bidirectional meshing mode, in other words, when the first cam 131a and the second cam 131b are each in a meshing standby state, the transmission member 161 has a cam pressing surface 167 of the cam contact portion 166 that contacts the stepped portion 136 of the paired first cam 131a and the stepped portion 136 of the second cam 131b. The transmission member 161 is configured to rotate in conjunction with the tilting of the first cam 131a in the meshing direction, causing the second cam 131b to tilt in the disengagement direction. Therefore, when torque is applied to the outer ring 110 or inner ring 120, the first cam 131a tilts to mesh with the outer ring 110 and the inner ring 120, and in conjunction with this, the second cam 131b, which normally maintains a meshing standby state, is tilted in the disengagement direction. This allows the outer ring-side engagement surface 133 of the second cam 131b to be separated from the raceway surface 111 of the outer ring 110. As a result, even if the second cam 131b tilts in the meshing direction when the torque is released, it is possible to avoid the second cam 131b meshing with the outer ring 110 and inner ring 120 before the meshing of the first cam 131a is released. Therefore, smooth operation can be achieved and high responsiveness can be obtained. Furthermore, by suppressing the occurrence of jamming, it becomes unnecessary to use a large drive source for moving the transmission member 161 in the axial direction, making it possible to save energy and reduce size.

[0030] The selector 170 according to this embodiment is composed of, for example, an annular member and is fitted onto the large-diameter cylindrical portion 147 of the cage 140 so as to be movable in the axial direction. In this cam clutch 100, when the first cam 131a and the second cam 131b are in a meshing standby state, the transmission member 161 is configured such that a portion of the load-applying portion 163 protrudes radially outward from the opening edge of the transmission member housing portion 148, as shown in Figure 9. Therefore, the selector 170 is configured to rotate the transmission member 161 by engaging with it. With this configuration, there is no need to provide a separate drive source for rotating the transmission member 161, and rotation and axial movement of the transmission member 161 can be achieved simply by moving the selector 170 in the axial direction, thus avoiding complexity and size increase in the structure of the cam clutch 100. The selector 170 is moved axially either manually or by an actuator (not shown).

[0031] The operation of the cam clutch 100 described above will be explained below. First, as shown in Figure 10, when the selector 170 is fixed in the first fixed position and the selector 170 is not in contact with the transmission member 161, torque is applied to the outer ring 110 or inner ring 120, maintaining a meshing standby state so that the first cam 131a and the second cam 131b immediately begin meshing with the outer ring 110 and inner ring 120. Therefore, the operating mode of the cam clutch 100 is a bidirectional meshing mode in which torque can be transmitted between the outer ring 110 and the inner ring 120 in both forward and reverse directions.

[0032] When the first cam 131a and the second cam 131b are in a meshing standby state, the cam pressing surface 167 of the cam contact portion 166 of the transmission member 161 is in contact with both the stepped portion 136 of the first cam 131a and the stepped portion 136 of the second cam 131b, as shown in Figure 11A. Therefore, when torque is applied and the first cam 131a rotates to tilt in the meshing direction, the transmission member 161 rotates in conjunction with the tilt of the first cam 131a. As a result, the second cam 131b rotates to tilt in the disengagement direction, and the outer ring side engagement surface 133 of the second cam 131b separates from the raceway surface 111 of the outer ring 110. When the torque is removed, the first cam 131a rotates to tilt in the disengagement direction and transitions to a meshing standby state. At this time, the second cam 131b rotates to tilt in the meshing direction. However, since the outer ring side engagement surface 133 of the second cam 131b is separated from the raceway surface 111 of the outer ring 110 when the first cam 131a is meshed, it is possible to avoid the second cam 131b meshing with the outer ring 110 and the inner ring 120 before the meshing of the first cam 131a is released. Similarly, when the second cam 131b rotates to tilt in the meshing direction, the transmission member 161 rotates in conjunction with the tilting of the second cam 131b, causing the first cam 131a to rotate to tilt in the disengagement direction, thereby separating the outer ring side engagement surface 133 of the first cam 131a from the raceway surface 111 of the outer ring 110. When the torque is released and the second cam 131b rotates to tilt in the disengagement direction and transitions to the meshing standby state, it is possible to avoid the first cam 131a meshing with the outer ring 110 and the inner ring 120 until the meshing of the second cam 131b is disengaged. In this way, by linking the rotational movements of the first cam 131a and the second cam 131b with the transmission member 161, smooth operation can be achieved without causing jamming.

[0033] When the cam clutch 100 is set to the bidirectional meshing mode and the first cam 131a and the second cam 131b are in a meshing standby state, the rotational force acting surface 164 of the load-applying portion 163 of the transmission member 161 is inclined in the rotational direction with respect to the cam pressing surface 167, as shown in Figure 11B, and a portion of it protrudes radially outward from the opening edge of the transmission member housing portion 148 (see Figure 9). As shown in Figure 12, when the selector 170 is moved axially toward the other end and fixed in the second fixed position, the selector 170 engages with the transmission member 161, causing the transmission member 161 to rotate, as shown in Figure 13A. As a result, as shown in Figure 13B, the stepped portion 136 of the first cam 131a is pressed by the cam pressing surface 167 of the cam contact portion 166 on the transmission member 161, causing the first cam 131a to rotate so that it tilts in the disengagement direction. As a result, the outer ring side engagement surface 133 of the first cam 131a is held in a state separated from the raceway surface 111 of the outer ring 110, and the operating mode of the cam clutch 100 is switched to the one-way engagement mode. In the one-way engagement mode according to this embodiment, for example, when the inner ring 120 is rotated in the forward direction, the second cam 131b engages with the outer ring 110 and the inner ring 120, enabling torque transmission.

[0034] Furthermore, in this cam clutch 100, as shown in Figure 14, when the selector 170 is moved from the second fixed position toward the other axial end and fixed to the third fixed position, as shown in Figure 15, the transmission member 161 is pressed by the selector 170 and moved axially, causing the second cam 131b to rotate so that it tilts in the disengagement direction due to the action of the cam working surface 168 at the cam contact portion 166, and the outer ring side engaging surface 133 of the second cam 131b is held in a state where it is separated from the raceway surface 111 of the outer ring 110. The first cam 131a is maintained in a state where the outer ring side engaging surface 133 is separated from the raceway surface 111 of the outer ring 110. As a result, regardless of whether the input side rotating wheel is rotated in the forward or reverse direction, the input side rotating wheel will spin freely, and the operating mode of the cam clutch 100 is switched to a bidirectional free-spinning mode that cuts off torque transmission between the outer ring 110 and the inner ring 120.

[0035] Thus, with the cam clutch 100 described above, the tilting of the first cam 131a and the tilting of the second cam 131b are performed independently by different operations of the transmission member 161. Therefore, with a simple configuration, the cam clutch 100 can be configured to switch between three operating modes: bidirectional meshing mode, unidirectional meshing mode, and bidirectional free-spinning mode. Furthermore, the switching between the bidirectional meshing mode and the bidirectional free-spinning mode is performed in stages by the tilting of the first cam 131a and the second cam 131b, thus reducing the number of cams 131 that rotate at the same time. This reduces the release torque required to disengage the cams 131 under torque load, enabling smoother operation. It also eliminates the risk of damaging the outer ring engagement surface 133 and inner ring engagement surface 134 of the cam 131, as well as the raceway surface 111 of the outer ring 110 and the raceway surface 121 of the inner ring 120, thus extending the lifespan. Furthermore, since the tilting of the first cam 131a is performed by rotating the transmission member 161, and only the tilting of the second cam 131b is performed by the axial movement of the transmission member 161, the axial range of motion of the transmission member 161 can be reduced compared to a configuration in which the tilting of the cam 131 is performed only by the axial movement of the operating mode switching means, thereby avoiding an increase in axial dimensions. Furthermore, when the operating mode is set to the bidirectional free-spinning mode, all cams 131 are in a state where they do not contact the outer ring 110 or the inner ring 120. As a result, no slip torque is generated during free-spinning, and in this respect as well, there is no risk of damaging the outer ring side engagement surface 133 and the inner ring side engagement surface 134 of the cam 131, as well as the raceway surface 111 of the outer ring 110 and the raceway surface 121 of the inner ring 120. This makes it possible to extend the lifespan and reduce noise.

[0036] 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, in the above embodiment, the transmission member is configured to have a load-applying portion which is formed so that the rotational force-applying surface is inclined in the rotational direction relative to the pressing surface when the cam pressing surface is in contact with the first cam and the second cam, and which protrudes from the opening edge of the transmission member housing, thereby rotating the transmission member by engagement with a selector made of an annular body. However, the selector may also be provided with an inclined surface portion which is configured to rotate the transmission member by moving the selector in the axial direction. Furthermore, in the above embodiment, the rotational force acting surface and the cam pressing surface of the transmission member are configured as flat surfaces, but they do not necessarily have to be flat surfaces. Furthermore, the cam is configured to have a stepped portion on one axial end face that contacts the cam contact portion of the transmission member, but it may also be configured to receive the load from the transmission member by providing, for example, a pin member. Furthermore, in the above embodiment, the cam located on the forward rotation side of the cam pair is designated as the first cam, and the cam pressing surface of the transmission member is inclined with respect to the load-applying surface so that the rotation of the transmission member rotates the cam on the forward rotation side of the cam pair. However, the cam located on the reverse rotation side of the cam pair may be designated as the first cam, and the cam pressing surface may be inclined with respect to the load-applying surface so that the rotation of the transmission member rotates the cam on the reverse rotation side. In such a configuration, when the outer ring is rotated in the forward rotation direction, or when the inner ring is rotated in the reverse rotation direction, the cam located on the forward rotation side of the cam pair engages with the outer ring and the inner ring, making it possible to transmit torque in the opposite direction to that of the above embodiment. Furthermore, although the above embodiment described a configuration in which the cam is tilted so as to move away from the outer ring, the cam clutch of the present invention may also be configured in which the cam is tilted so as to move away from the inner ring. Furthermore, although the above embodiment describes a configuration with a biasing means, a configuration without a biasing means is also possible. Also, the biasing means is not limited to a garter spring, but may be composed of multiple leaf springs or torsion springs or other elastic bodies. [Explanation of Symbols]

[0037] 100... Cam clutch 110 ··· Outer ring 111 ... Raceway surface 120 ··· Inner circle 121 ... raceway surface 130... Cam mechanism 131 ··· Cam 131a ··· First cam 131b ··· Second Cam 132 ··· Cam vs 133 ··· Outer ring side engagement surface 134 ··· Inner ring engagement surface 135 ··· Garter spring mounting groove 136... Step section 140 ··· Cage 141 ··· Small diameter cylindrical part 142 ··· Opening 143 · · Column part 144a ··· First cam retaining part 144b ··· Second cam retaining part 145 ··· Tsuba (guard) 146 ··· Through hole 147 ··· Large diameter cylindrical section 148 ··· Transmission member housing section 150 ··· biasing means 160 ··· Operating mode switching mechanism 161 ··· Transmission member 162 ··· Base part 163 ··· Load application section 164 ··· Rotational force acting surface 165 ··· Guide surface 166... ​​Cam contact area 167... Cam pressing surface 168... Cam action surface 168a ··· One end edge 170 ··· Selector

Claims

1. A cam clutch comprising an outer ring and an inner ring that are coaxially rotatable relative to each other, a plurality of cams disposed between the outer ring and the inner ring, and a cage that holds the plurality of cams in the circumferential direction, The plurality of cams include a first cam and a second cam whose meshing directions with respect to the outer ring and the inner ring are different from each other, and the first cam and the second cam are arranged to form a pair. The system includes a transmission member that contacts each of the paired first and second cams, is rotatable with its rotation center fixed by the cage, and is movable in the axial direction. The transmission member is configured to be tiltable between a state in which the first cam is engaged and a state in which it is not in contact with the outer ring or the inner ring when rotated, and is configured to be tiltable between a state in which the second cam is engaged and a state in which it is not in contact with the outer ring or the inner ring when moved in the axial direction, characterized in that the transmission member is configured to be tiltable between a state in which the first cam is engaged and a state in which it is not in contact with the outer ring or the inner ring.

2. The cam clutch according to claim 1, characterized in that the transmission member is configured to rotate in conjunction with the tilting of the first cam in the meshing direction when the first cam and the second cam are each in a meshing standby state, thereby tilting the second cam in the disengagement direction.

3. The cage is provided to be axially movable and has a selector for moving the transmission member, The cam clutch according to claim 1, characterized in that the selector is configured to rotate the transmission member by engaging with the transmission member.

4. The transmission member comprises a cylindrical base portion, a load-applying portion provided on one axial end of the base portion, and a cam contact portion provided on the other axial end of the base portion. The load-applying part has a rotational force acting surface, The cam contact portion has a cam pressing surface that is inclined in the rotational direction with respect to the rotational force acting surface and a cam acting surface that tilts the cam, and the cam acting surface is inclined in a direction that moves away from the cam pressing surface as it approaches one end in the axial direction, and the edge of one end is formed to extend along the direction of inclination of the rotational force acting surface with respect to the cam pressing surface, as described in claim 1.

5. The cam clutch according to claim 1, characterized in that the cage is provided to be rotatable independently of the outer ring and the inner ring.

6. The first cam and the second cam are arranged on the same circumference. The cam clutch according to claim 1, further comprising a biasing means for biasing the first cam and the second cam to engage and enter a standby state.

Images