Clutch device

Abstract

To provide a clutch device which can enhance a degree of freedom of design while suppressing an increase of a drag loss.SOLUTION: A clutch device 1A comprises an inner ring 2, an outer ring 3, a ratchet engagement mechanism 20 and a switching mechanism 30. The ratchet engagement mechanism 20 has a notch which is provided at an external peripheral part of the inner ring 2, and a claw member 22 provided at an internal peripheral part of the outer ring 3, and regulating rotation between the inner ring 2 and the outer ring 3 to one direction by being engaged with the notch. The switching mechanism 30 has a cam member 31. The cam member 31 has: a cam inner ring part 32 provided so as to rotate together with the inner ring 2; a cam outer ring part 33 arranged outside the cam inner ring part 32 in a radial direction; and a plurality of rolling bodies 34 arranged between the cam inner ring part 32 and the cam outer ring part 33. By the contact of the cam outer ring part 33 with the claw member 22 by the movement of the cam member 31 in an axial direction, the cam member switches a first state that the claw member 22 is engaged with the notch, and a second state that the claw member 22 is not engaged with the notch.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a clutch device.

Background Art

[0002] For example, in the clutch device described in Patent Document 1, an inner ring and an outer ring can be engaged by a ratchet mechanism, and the engagement state of the ratchet mechanism can be switched by a switching mechanism having a cam member. The ratchet mechanism has a notch provided on the inner peripheral portion of the outer ring and a claw member provided on the outer peripheral portion of the inner ring. The cam member is provided so as to rotate together with the inner ring, and when the cam member moves in the axial direction and contacts the claw member, the engagement state of the claw member with respect to the notch is switched.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the switching type ratchet type clutch device as described above, it is necessary to provide both the cam member and the claw member on the inner ring side as in Patent Document 1, or to provide both of them on the outer ring side. This is because if one of the cam member and the claw member is provided on the inner ring side and the other is provided on the outer ring side, wear may occur between the cam member and the claw member due to the difference in the rotational speed between the inner ring and the outer ring, and there is a concern that the sliding loss will increase. On the other hand, for the switching type ratchet type clutch device, it is required to relax such design restrictions and increase the degree of freedom in design.

[0005] An object of the present invention is to provide a clutch device that can increase the degree of freedom in design while suppressing an increase in sliding loss.

Means for Solving the Problems

[0006] The clutch device of the present invention comprises: [1] a ratchet engagement mechanism having an inner ring and an outer ring; a notch provided on one of the outer circumference of the inner ring and the inner circumference of the outer ring; and an engaging member provided on the other of the outer circumference of the inner ring and the inner circumference of the outer ring, which restricts rotation between the inner ring and the outer ring in one direction by engaging with the notch; and a switching mechanism having a cam member that is axially movable relative to the inner ring and the outer ring, wherein the cam member moves axially and contacts the engaging member, thereby switching the engagement state of the ratchet engagement mechanism between a first state in which the engaging member is engaged with the notch and a second state in which the engaging member is not engaged with the notch, wherein the cam member rotates together with the inner ring when the engaging member is provided on the inner circumference of the outer ring. A clutch device comprising: a cam inner ring portion provided to rotate together with the outer ring; a cam outer ring portion located on the outside of the cam inner ring portion in the radial direction; and a plurality of rolling elements located between the cam inner ring portion and the cam outer ring portion, wherein the cam member moves axially and the cam outer ring portion contacts the engaging member, thereby switching between the first state and the second state; and, if the engaging member is provided on the outer circumference of the inner ring, a cam outer ring portion provided to rotate together with the outer ring; a cam inner ring portion located on the inside of the cam outer ring portion in the radial direction; and a plurality of rolling elements located between the cam inner ring portion and the cam outer ring portion, wherein the cam member moves axially and the cam inner ring portion contacts the engaging member, thereby switching between the first state and the second state.

[0007] In this clutch device, when the engaging member is located on the inner circumference of the outer ring, the cam member (inner cam portion) is configured to rotate together with the inner ring, and when the engaging member is located on the outer circumference of the inner ring, the cam member (outer cam portion) is configured to rotate together with the outer ring. That is, one of the engaging member and the cam member is located on the inner ring side, and the other is located on the outer ring side. This increases the degree of design freedom. On the other hand, if such a configuration is adopted, as described above, wear may occur between the cam member and the engaging member due to the difference in rotational speed between the inner and outer rings, potentially increasing drag losses. In this clutch device, the cam member has an inner cam portion, an outer cam portion, and multiple rolling elements, and functions as a bearing. This suppresses the occurrence of wear between the cam member and the engaging member, thereby suppressing the increase in drag losses. Therefore, this clutch device allows for increased design freedom while suppressing the increase in drag losses.

[0008] The clutch device of the present invention may also be [2] "the clutch device according to [1], wherein the notch is provided on the outer circumference of the inner ring and the engaging member is provided on the inner circumference of the outer ring." In this case, since the cam member (cam inner ring portion) is provided on the inner ring side, space can be saved in the radial direction.

[0009] The clutch device of the present invention may also be [3] "the clutch device according to [1], wherein the notch is provided on the inner circumference of the outer ring and the engaging member is provided on the outer circumference of the inner ring." In this case, since the cam member (cam outer ring portion) is provided on the outer ring side, space can be secured inside the cam member in the radial direction for arranging other parts, etc.

[0010] The clutch device of the present invention may also be [4] "the clutch device according to any one of [1] to [3], wherein the engaging member is provided on the inner circumference of the outer ring, the cam outer ring portion is composed of one member, and the engaging member is provided on the outer circumference of the inner ring, the cam inner ring portion is composed of one member." In this case, the number of parts can be reduced, and costs can be lowered. Furthermore, space can be saved in the axial direction. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a clutch device that can increase the degree of design freedom while suppressing the increase in drag loss. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view of the clutch device according to the first embodiment. [Figure 2] This is a front view of the clutch device of the first embodiment in the free state. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4] This is a front view of the clutch device of the first embodiment in a one-way state. [Figure 5] This is a cross-sectional view along the VV line in Figure 4. [Figure 6] This is a perspective view of the clutch device of the second embodiment. [Figure 7] This is a front view of the clutch device of the second embodiment in the free state. [Figure 8] This is a cross-sectional view along line VIII-VIII in Figure 7. [Figure 9] This is a front view of the clutch device of the second embodiment in a one-way state. [Figure 10] This is a cross-sectional view along line XX in Figure 9. [Figure 11] This is a cross-sectional view of the cam member of the first modified example. [Figure 12]It is a cross-sectional view of the cam member of the second modification.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and overlapping descriptions are omitted. [First Embodiment]

[0014] As shown in FIGS. 1 to 5, the clutch device 1A of the first embodiment includes an inner ring 2 and an outer ring 3. The outer ring 3 is disposed outside the inner ring 2 in the radial direction. Each of the inner ring 2 and the outer ring 3 is formed in an annular shape. The inner ring 2 and the outer ring 3 are coaxially arranged with each other and have a common rotation axis AX, and are relatively rotatable. Hereinafter, there may be cases where it is described that the outer ring 3 rotates with respect to the inner ring 2, but the rotation between the inner ring 2 and the outer ring 3 is relative. Further, the direction parallel to the rotation axis AX is defined as the axial direction, the direction perpendicular to the rotation axis AX is defined as the radial direction, and the direction along the circumference centered on the rotation axis AX when viewed from the axial direction is defined as the circumferential direction for the description.

[0015] The inner ring 2 is fitted to the shaft 11 at its inner peripheral portion and rotates together with the shaft 11. In this example, a spline portion 2a is formed at the inner peripheral portion of the inner ring 2 and a spline portion 11a is formed at the outer peripheral portion of the shaft 11, and the inner ring 2 and the shaft 11 are coupled by fitting the spline portions 2a, 11a. The spline portions 2a, 11a are constituted by a combination of groove portions and convex portions extending in the axial direction.

[0016] The outer ring 3 is fitted to the housing member 4 at its outer peripheral portion and rotates together with the housing member 4. In this example, a spline portion 3a is formed at the outer peripheral portion of the outer ring 3 and a spline portion 4a is formed at the inner peripheral portion of the housing member 4, and the outer ring 3 and the housing member 4 are coupled by fitting the spline portions 3a, 4a. The spline portions 3a, 4a are constituted by a combination of groove portions and convex portions extending in the axial direction.

[0017] The inner ring 2 and the outer ring 3 can be engaged by a ratchet engagement mechanism 20. The ratchet engagement mechanism 20 has a plurality of notches 21 provided on the outer peripheral portion of the inner ring 2 and a plurality of claw members 22 (engagement members) provided on the inner peripheral portion of the outer ring 3.

[0018] On the outer peripheral portion (outer peripheral surface) of the inner ring 2, a plurality of tooth portions 23 that protrude outward in the radial direction and extend in the axial direction are formed. The plurality of tooth portions 23 are provided over the entire circumference so as to be arranged at equal intervals along the circumferential direction. One notch 21 (groove portion) is formed by the space between adjacent tooth portions 23 in the circumferential direction. Therefore, a plurality of notches 21 arranged at equal intervals over the entire circumference in the circumferential direction are formed on the outer peripheral portion of the inner ring 2.

[0019] The claw member 22 has a cylindrical portion 22b and is supported by the outer ring 3 so as to be swingable in the radial direction (along a plane perpendicular to the axial direction) with the cylindrical portion 22b as an axis. Specifically, the claw member 22 is arranged in each of a plurality of recesses 24 formed on the inner peripheral portion (inner peripheral surface) of the outer ring 3, so that it can swing in the radial direction with the cylindrical portion 22b as an axis. Each recess 24 opens to the inner peripheral surface of the outer ring 3. The plurality of recesses 24 are provided over the entire circumference so as to be arranged at equal intervals along the circumferential direction.

[0020] An urging member 25 is further arranged in each recess 24. That is, the recess 24 has a first portion 24a in which the claw member 22 is arranged and a second portion 24b in which the urging member 25 is arranged. The second portion 24b is connected to the first portion 24a. The urging member 25 is, for example, a coil spring, and urges the end portion 22a of the claw member 22 toward the inside in the radial direction (the inner ring 2 side). The end portion 22a is one end of the claw member 22 in the circumferential direction and functions as a claw that engages with the notch 21 as described later. The claw member 22 is arranged obliquely so that the end portion 22a can protrude from the recess 24. In each recess 24, the urging member 25 is arranged in a compressed state between the bottom surface of the second portion 24b and the end portion 22a of the claw member 22.

[0021] In the clutch device 1A, the engagement state between the inner ring 2 and the outer ring 3 by the ratchet engagement mechanism 20 can be switched by the switching mechanism 30. In other words, the clutch device 1 is a selectable ratchet-type clutch device. The switching mechanism 30 switches the engagement state of the ratchet engagement mechanism 20 between a one-way state (first state) (Figures 4 and 5) and a free state (second state) (Figures 1, 2, and 3). Note that in Figures 3 and 5, the hatching indicating the cross-section is omitted. This is also the case for Figures 8 and 10-12, which will be described later.

[0022] In the one-way state, when the outer ring 3 rotates relative to the inner ring 2 in one direction (clockwise in Figure 4), the end 22a of the claw member 22 engages with the notch 21, locking (restricting) the rotation of the outer ring 3 relative to the inner ring 2 in that direction. On the other hand, when the outer ring 3 rotates relative to the inner ring 2 in the other direction (opposite direction to the one direction) (counterclockwise in Figure 4) in the one-way state, the claw member 22 does not engage with the notch 21, and the rotation of the outer ring 3 relative to the inner ring 2 in the other direction is permitted (the outer ring 3 spins freely). In other words, in the one-way state, torque is transmitted between the inner ring 2 and the outer ring 3 only when the outer ring 3 rotates relative to the inner ring 2 in one direction. In this example, torque is transmitted from the housing member 4 to the inner ring 2 (shaft 11) via the outer ring 3 and the claw member 22.

[0023] In the free state, regardless of whether the outer ring 3 rotates relative to the inner ring 2 in one direction (clockwise in Figure 2) or the other direction (counterclockwise in Figure 2), the claw member 22 does not engage with the notch 21, and rotation of the outer ring 3 relative to the inner ring 2 in both directions is permitted. In other words, in the free state, regardless of whether the outer ring 3 rotates relative to the inner ring 2 in one direction or the other, no torque is transmitted between the inner ring 2 and the outer ring 3.

[0024] As shown in Figures 3 and 5, the switching mechanism 30 has a cam member 31 (switching cam) that is movable in the axial direction relative to the inner ring 2 and the outer ring 3. The cam member 31 moves in the axial direction and contacts the pawl member 22, thereby switching the engagement state of the ratchet engagement mechanism 20 between a one-way state and a free state. The cam member 31 is configured as a cam bearing with bearing function and has a cam inner ring portion 32, a cam outer ring portion 33, and a plurality of rolling elements 34. In this example, the rolling elements 34 are balls. Each of the cam inner ring portion 32 and the cam outer ring portion 33 is formed in an annular shape. The cam inner ring portion 32 and the cam outer ring portion 33 are arranged coaxially with the inner ring 2 and the outer ring 3 and have a common rotation axis AX with the inner ring 2 and the outer ring 3. Each of the cam inner ring portion 32 and the cam outer ring portion 33 is composed of a single member.

[0025] The cam inner ring portion 32 has a raceway surface 32a facing radially outward. The raceway surface 32a is formed in a shape corresponding to the rolling element 34. The cam inner ring portion 32 is attached to the shaft 11 via a support member 35 and rotates together with (synchronously with) the inner ring 2. The support member 35 is an annular member attached to the shaft 11 so as to be movable in the axial direction, and moves in the axial direction by the driving force of the actuator 36. The cam inner ring portion 32 is fitted with the end 35a of the support member 35 at its inner circumference. The end 35a is the end of the support member 35 in the axial direction (the end on the inner ring 2 side). In this example, a retaining ring 37 is provided on the inner ring 2 side of the cam inner ring portion 32, and the axial movement of the cam inner ring portion 32 is restricted by positioning the cam inner ring portion 32 between the support member 35 and the retaining ring 37.

[0026] The cam outer ring portion 33 is positioned outside the cam inner ring portion 32 in the radial direction. The cam outer ring portion 33 has a raceway surface 33a facing inward in the radial direction. The raceway surface 33a is formed in a shape corresponding to the rolling element 34. The cam outer ring portion 33 has a projection portion 33b that protrudes from the cam inner ring portion 32 in the axial direction (located on the inner ring 2 side). An inclined surface 33c, which is inclined with respect to the axial direction, is formed on the outer circumference of the projection portion 33b over its entire circumference. The inclined surface 33c is formed over the entire projection portion 33b in the axial direction. The inclined surface 33c contacts the claw member 22, as will be described later. Thus, the length of the cam outer ring portion 33 in the axial direction is longer than the length of the cam inner ring portion 32 in the axial direction. Also, the thickness of the cam outer ring portion 33 in the radial direction is thicker than the thickness of the cam inner ring portion 32 in the radial direction. Furthermore, the length of the outer cam ring portion 33 in the axial direction may be less than or equal to the length of the inner cam ring portion 32 in the axial direction, and the thickness of the outer cam ring portion 33 in the radial direction may also be less than or equal to the thickness of the inner cam ring portion 32 in the radial direction.

[0027] Multiple rolling elements 34 are arranged between the raceway surface 32a of the inner ring portion 32 of the cam and the raceway surface 33a of the outer ring portion 33 of the cam. The multiple rolling elements 34 are held in place by a retainer (not shown) so as to be able to roll, and are arranged in a line along the circumferential direction at predetermined intervals.

[0028] In the free state shown in Figures 1, 2, and 3, the outer ring portion 33 of the cam contacts the end portion 22a of the claw member 22 at its outer circumference. As a result, the end portion 22a is lifted (moved radially outward), compressing the biasing member 25 and positioning the end portion 22a in a position where it does not engage with the notch 21. Consequently, as described above, regardless of whether the outer ring 3 rotates relative to the inner ring 2 in one rotational direction or the other, the claw member 22 does not engage with the notch 21, and rotation of the outer ring 3 relative to the inner ring 2 in both rotational directions is permitted. In the free state, if there is a difference in rotational speed between the inner ring 2 and the outer ring 3, a difference in rotational speed also occurs between the inner ring portion 32 of the cam, which rotates synchronously with the inner ring 2, and the claw member 22, which rotates synchronously with the outer ring 3. However, this difference in rotational speed is absorbed by the rotation of the outer ring portion 33, which is in contact with the claw member 22, relative to the inner ring portion 32 of the cam.

[0029] When the cam member 31 (cam inner ring portion 32) moves axially away from the inner ring 2 and outer ring 3 from the free state, the cam outer ring portion 33 separates from the end portion 22a of the claw member 22, resulting in the one-way state shown in Figures 4 and 5. In the one-way state, the biasing force of the biasing member 25 positions the end portion 22a to engage with the notch 21. As a result, as described above, when the outer ring 3 rotates relative to the inner ring 2 in one rotational direction, the end portion 22a engages with the notch 21, locking the rotation of the outer ring 3 relative to the inner ring 2 in that rotational direction. When the cam member 31 (cam inner ring portion 32) moves axially away from the one-way state, resulting in the cam outer ring portion 33 contacting the end portion 22a on its outer circumference, it returns to the free state. At this time, the cam outer ring portion 33 first contacts the end portion 22a on its inclined surface 33c, and then contacts the end portion 22a on its outer circumference. This allows the cam outer ring portion 33 to suitably move the end portion 22a of the claw member 22 radially outward. [Second Embodiment]

[0030] In the clutch device 1B of the second embodiment shown in Figures 6 to 10, the notch 21 is provided on the inner circumference of the outer ring 3, and the claw member 22 is provided on the outer circumference of the inner ring 2. Therefore, the teeth 23 constituting the notch 21 are also provided on the inner circumference of the outer ring 3, and the recess 24 where the claw member 22 is located is also provided on the outer circumference of the inner ring 2. The biasing member 25 biases the end 22a of the claw member 22 radially outward (towards the outer ring 3).

[0031] The clutch device 1B has a cam member 41 in place of the cam member 31. The cam member 41 is configured as a cam bearing with bearing function and has a cam outer ring portion 42, a cam inner ring portion 43, and a plurality of rolling elements 34. Each of the cam outer ring portion 42 and the cam inner ring portion 43 is formed in an annular shape. The cam outer ring portion 42 and the cam inner ring portion 43 are arranged coaxially with the inner ring 2 and the outer ring 3, and have a common rotation axis AX with the inner ring 2 and the outer ring 3. Each of the cam outer ring portion 42 and the cam inner ring portion 43 is made of a single member.

[0032] The cam outer ring portion 42 has a raceway surface 42a facing radially inward. The raceway surface 42a is formed in a shape corresponding to the rolling element 34. The cam outer ring portion 42 is attached to the housing member 4 via a support member 45 and rotates together with the outer ring 3 (synchronously with the outer ring 3). The support member 45 is an annular member attached to the housing member 4 so as to be movable in the axial direction, and moves in the axial direction by the driving force of the actuator 46. The cam outer ring portion 42 is fitted with the end 45a of the support member 45 at its outer circumference. The end 45a is the end of the support member 45 in the axial direction (the end on the outer ring 3 side). In this example, a retaining ring 47 is provided on the outer ring 3 side of the cam outer ring portion 42, and the axial movement of the cam outer ring portion 42 is restricted by positioning the cam outer ring portion 42 between the support member 45 and the retaining ring 47.

[0033] The inner cam ring portion 43 is positioned inside the outer cam ring portion 42 in the radial direction. The inner cam ring portion 43 has a raceway surface 43a facing radially outward. The raceway surface 43a is formed in a shape corresponding to the rolling element 34. The inner cam ring portion 43 has a projection portion 43b that protrudes from the outer cam ring portion 42 in the axial direction (located on the outer ring 3 side). An inclined surface 43c, which is inclined with respect to the axial direction, is formed on the inner circumference of the projection portion 43b over its entire circumference. The inclined surface 43c is formed over the entire projection portion 43b in the axial direction. The inclined surface 43c contacts the claw member 22, as will be described later. Thus, the length of the inner cam ring portion 43 in the axial direction is longer than the length of the outer cam ring portion 42 in the axial direction. Also, the thickness of the inner cam ring portion 43 in the radial direction is thicker than the thickness of the outer cam ring portion 42 in the radial direction. Furthermore, the length of the inner cam ring portion 43 in the axial direction may be less than or equal to the length of the outer cam ring portion 42 in the axial direction, and the thickness of the inner cam ring portion 43 in the radial direction may also be less than or equal to the thickness of the outer cam ring portion 42 in the radial direction.

[0034] In the free state shown in Figures 7 and 8, the inner ring portion 43 of the cam contacts the end portion 22a of the claw member 22 at its inner circumference. As a result, the end portion 22a is pushed down (moved radially inward), compressing the biasing member 25 and positioning the end portion 22a in a position where it does not engage with the notch 21. Consequently, regardless of whether the outer ring 3 rotates relative to the inner ring 2 in one rotational direction or the other, the claw member 22 does not engage with the notch 21, and rotation of the outer ring 3 relative to the inner ring 2 in both rotational directions is permitted. In the free state, if there is a difference in rotational speed between the inner ring 2 and the outer ring 3, a difference in rotational speed also occurs between the outer ring portion 42 of the cam, which rotates synchronously with the outer ring 3, and the claw member 22, which rotates synchronously with the inner ring 2. However, this difference in rotational speed is absorbed by the rotation of the inner ring portion 43, which is in contact with the claw member 22, relative to the outer ring portion 42 of the cam.

[0035] When the cam member 41 (cam outer ring portion 42) moves axially away from the inner ring 2 and outer ring 3 from the free state, the cam inner ring portion 43 separates from the end portion 22a of the claw member 22, resulting in the one-way state shown in Figures 9 and 10. In the one-way state, the biasing force of the biasing member 25 positions the end portion 22a to engage with the notch 21. As a result, when the outer ring 3 rotates relative to the inner ring 2 in one rotational direction, the end portion 22a engages with the notch 21, locking the rotation of the outer ring 3 relative to the inner ring 2 in that rotational direction. When the cam member 41 (cam outer ring portion 42) moves axially away from the one-way state, resulting in the cam inner ring portion 43 contacting the end portion 22a at its inner circumference, it returns to the free state. At this time, the cam inner ring portion 43 first contacts the end portion 22a at its inclined surface 43c, and then contacts the end portion 22a at its inner circumference. This allows the inner ring portion 43 of the cam to suitably move the end portion 22a of the claw member 22 radially inward. [Mechanism of Action and Effects]

[0036] In clutch devices 1A and 1B, when the claw member 22 (engaging member) is provided on the inner circumference of the outer ring 3 (clutch device 1A), the cam member 31 (cam inner ring portion 32) is provided to rotate together with the inner ring 2, and when the claw member 22 is provided on the outer circumference of the inner ring 2 (clutch device 1B), the cam member 41 (cam outer ring portion 42) is provided to rotate together with the outer ring 3. That is, one of the claw member 22 and the cam members 31, 41 is provided on the inner ring 2 side, and the other is provided on the outer ring 3 side. This increases the degree of design freedom. On the other hand, if such a configuration is adopted, wear may occur between the cam members 31, 41 and the claw member 22 due to the difference in rotational speed between the inner ring 2 and the outer ring 3, and drag losses may increase. In this regard, in clutch devices 1A and 1B, the cam member 31 (41) has a cam inner ring portion 32 (43), a cam outer ring portion 33 (42), and a plurality of rolling elements 34, and has the function of a bearing. This suppresses wear between the cam members 31 and 41 and the claw member 22, thereby suppressing the increase in drag loss. Therefore, the clutch devices 1A and 1B allow for increased design flexibility while suppressing the increase in drag loss.

[0037] In the clutch device 1A, the notch 21 is provided on the outer circumference of the inner ring 2, and the claw member 22 is provided on the inner circumference of the outer ring 3. In this case, since the cam member 31 (cam inner ring portion 32) is provided on the inner ring 2 side, space can be saved in the radial direction. For example, in a case where the cam member is made of a single piece of material that does not have bearing function, unlike the clutch device 1A, and the claw member 22 is provided on the inner circumference of the outer ring 3, as described above, in order to avoid wear between the cam member and the claw member 22, both the cam member and the claw member 22 must be provided on the outer ring 3 side. In this case, for example, the cam member would be spline-coupled to the outer circumference of the housing member 4, which could lead to an increase in radial size. In contrast, in the clutch device 1A, since the cam member 31, which has bearing function, is provided on the inner ring 2 side, space can be saved in the radial direction. Furthermore, since there is no need to form splines on the housing member 4 for coupling with the cam member, costs can be reduced.

[0038] In the clutch device 1B, the notch 21 is provided on the inner circumference of the outer ring 3, and the claw member 22 is provided on the outer circumference of the inner ring 2. In this case, since the cam member 41 (cam outer ring portion 42) is provided on the outer ring 3 side, space can be secured inside the cam member 41 in the radial direction for arranging other parts, etc.

[0039] In clutch device 1A, the cam outer ring portion 33 is made of a single component, and in clutch device 1B, the cam inner ring portion 43 is made of a single component. In this case, compared to the case where the cam outer ring portion 33 or the cam inner ring portion 43 is made of multiple components, the number of parts can be reduced, and costs can be lowered. Furthermore, space can be saved in the axial direction. For example, if we compare clutch device 1A with a case where the cam outer ring portion 33 has an inner member having a raceway surface 33a and an outer member that contacts the claw member 22 (for example, the first modified example described later), the number of parts can be reduced compared to the comparison case. Also, in the comparison case, a retaining ring is required to fix the outer member to the inner member, but when the cam outer ring portion 33 is made of a single component, such a retaining ring can be omitted. In addition, in the comparison case, the outer member protrudes axially from the inner member, which may result in increased size in the axial direction, but when the cam outer ring portion 33 is made of a single component, this does not happen, and space can be saved in the axial direction.

[0040] The present invention is not limited to the embodiments described above. For example, the materials and shapes of each component are not limited to those described above, but can be made from a variety of materials and shapes. The rolling elements 34 are not limited to balls, but may be rollers or the like.

[0041] The first modified example shown in Figure 11 is a modified example of the cam member 31 in the clutch device 1A of the first embodiment. In the first modified example, the cam outer ring portion 33 has an inner member 51 having a raceway surface 33a, and an outer member 52 positioned radially outside the inner member 51 and in contact with the claw member 22. The outer member 52 has a projection 33b with an inclined surface 33c, which contacts the claw member 22. The inner member 51, together with the cam inner ring portion 32, constitutes a bearing, and the outer member 52 is a cam ring that lifts the claw member 22. In this example, a retaining ring 53 is provided on the side of the inner member 51 opposite to the inner ring 2, and the axial movement of the inner member 51 is restricted by positioning the inner member 51 between the outer member 52 and the retaining ring 53. Even when using the cam member 31 of this first modified example, it is possible to increase the degree of design freedom while suppressing the increase in drag loss, similar to the first embodiment.

[0042] The second modified example shown in Figure 12 is a modified example of the cam member 41 in the clutch device 1B of the second embodiment. In the second modified example, the cam inner ring portion 43 has an outer member 61 having a raceway surface 43a, and an inner member 62 positioned inside the outer member 61 in the radial direction and in contact with the claw member 22. The inner member 62 has a projection 43b with an inclined surface 43c, which contacts the claw member 22 at the inclined surface 43c. The outer member 61, together with the cam outer ring portion 42, constitutes a bearing, and the inner member 62 is a cam ring that pushes down the claw member 22. In this example, a retaining ring 63 is provided on the side of the outer member 61 opposite to the outer ring 3, and the axial movement of the outer member 61 is restricted by positioning the outer member 61 between the inner member 62 and the retaining ring 63. Even when using the cam member 41 of this second modified example, it is possible to increase the degree of design freedom while suppressing an increase in drag loss, similar to the second embodiment. [Explanation of Symbols]

[0043] 1A, 1B... Clutch device, 2... Inner ring, 3... Outer ring, 20... Ratchet engagement mechanism, 21... Notch, 22... Pawl member (engaging member), 30... Switching mechanism, 31, 41... Cam member, 32, 43... Cam inner ring section, 33, 42... Cam outer ring section, 34... Rolling element.

Claims

1. Inner ring and outer ring, A ratchet engagement mechanism having a notch provided on one of the outer circumference of the inner ring and the inner circumference of the outer ring, and an engaging member provided on the other of the outer circumference of the inner ring and the inner circumference of the outer ring, which restricts rotation between the inner ring and the outer ring in one direction by engaging with the notch, The ratchet engagement mechanism includes a cam member that is movable in the axial direction relative to the inner ring and the outer ring, and a switching mechanism that switches the engagement state of the ratchet engagement mechanism between a first state in which the engaging member is engaged with the notch and a second state in which the engaging member is not engaged with the notch, by the cam member moving in the axial direction and contacting the engaging member. The cam member is When the engaging member is provided on the inner circumference of the outer ring, the cam comprises a cam inner ring portion provided to rotate together with the inner ring, a cam outer ring portion positioned radially outside the cam inner ring portion, and a plurality of rolling elements positioned between the cam inner ring portion and the cam outer ring portion, wherein the cam member moves axially and the cam outer ring portion comes into contact with the engaging member, thereby switching between the first state and the second state. A clutch device having, when the engaging member is provided on the outer circumference of the inner ring, a cam outer ring portion provided to rotate together with the outer ring, a cam inner ring portion arranged inside the cam outer ring portion in the radial direction, and a plurality of rolling elements arranged between the cam inner ring portion and the cam outer ring portion, wherein the cam member moves in the axial direction and the cam inner ring portion comes into contact with the engaging member, thereby switching between the first state and the second state.

2. The clutch device according to claim 1, wherein the notch is provided on the outer circumference of the inner ring, and the engaging member is provided on the inner circumference of the outer ring.

3. The clutch device according to claim 1, wherein the notch is provided on the inner circumference of the outer ring, and the engaging member is provided on the outer circumference of the inner ring.

4. When the engaging member is provided on the inner circumference of the outer ring, the cam outer ring portion is composed of a single member. The clutch device according to any one of claims 1 to 3, wherein the engaging member is provided on the outer circumference of the inner ring, and the cam inner ring portion is composed of a single member.

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