Ratchet Type Clutch

Abstract

To provide a ratchet type clutch of a torque transmission direction switching type, which can suppress an increase in weight of an entire device in which the clutch is incorporated as a component, and an increase in arrangement space of the device.SOLUTION: In a ratchet type clutch 1, a ratchet mechanism includes: tooth parts 13 provided on an inner ring 5; a plurality of first pawl members 15 that are provided on an outer ring 3 and mesh with the tooth parts 13 to lock relative rotation of the inner ring 5 with respect to the outer ring 3 in a first rotation direction while allowing the relative rotation in a second rotation direction; and second pawl members 17 which are provided on the outer ring 3 and each of which is paired with the first pawl member 15 and meshes with the tooth part 13 to lock the relative rotation of the inner ring 5 with respect to the outer ring 3 in the second direction while allowing the relative rotation in the first direction. Each of the first pawl members 15 is rotationally moved by centrifugal force applied thereto by rotation of the outer ring 3 and, when the centrifugal force exceeds a predetermined magnitude, becomes a state of non-meshing with the tooth part 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a torque transmission direction switching ratchet clutch used as a torque transmission device in vehicles, industrial machines, etc. [Background technology]

[0002] Conventionally, there has been a clutch that uses a ratchet mechanism and can switch the torque transmission direction by switching between a state in which rotation is locked only in one or the opposite rotational direction, a state in which rotation is locked in both one and the opposite rotational directions simultaneously, and a state in which rotation in neither one or the opposite rotational direction is locked, with respect to the rotational direction of the inner ring member relative to the outer ring member or the outer ring member relative to the inner ring member (see, for example, Patent Documents 1 and 2).

[0003] The clutches described in Patent Documents 1 and 2 switch the direction of rotational transmission, i.e., torque transmission, between the inner and outer rings by displacing an annular member, the engagement state of which can be changed by displacement, using an external device such as an actuator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2016-508582 [Patent Document 2] Patent Publication No. 2021-038755 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the development of electric control in vehicles has been remarkable, and the components of various devices mounted on vehicles have become more complex, and the weight and mounting space of these various devices have increased proportionally. When the clutch is used as a component of a transmission device, switching the torque transmission direction using an external device such as an actuator, as in the clutch of Patent Document 1 or 2, there is a risk that the weight of the entire transmission device and the mounting space on the vehicle will increase. This may make it difficult to achieve the recent strict requirements for weight reduction and space saving.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a torque transmission direction switching ratchet clutch that can suppress an increase in the weight of the entire device in which it is incorporated as a component and an increase in the space required to install the device. [Means for solving the problem]

[0007] In order to solve the above problems, the ratchet clutch of the present invention comprises: A first annular member; a second annular member arranged coaxially with and rotatable relative to the first annular member; a ratchet mechanism capable of engaging the first annular member with the second annular member so as to transmit torque; The ratchet mechanism includes a tooth portion provided on the first annular member; a plurality of first claw members provided on the second annular member and meshing with the teeth to lock the relative rotation of the first annular member with respect to the second annular member in a first rotation direction and allow the relative rotation in a second rotation direction; a plurality of second claw members provided on the second annular member, each paired with the first claw member, and meshing with the tooth portion to lock the relative rotation of the first annular member with respect to the second annular member in the second rotation direction and allow the relative rotation in the first rotation direction; Each of the first claw members rotates due to centrifugal force acting due to rotation of the second annular member, and when the centrifugal force exceeds a predetermined magnitude, the first claw members are disengaged from the tooth portion. the law of nature, Each of the second claw members is capable of engaging with the tooth portion even when a centrifugal force exceeding the predetermined magnitude acts on the second claw members. It is characterized by: In addition, the ratchet clutch of the present invention has A first annular member; a second annular member arranged coaxially with and rotatable relative to the first annular member; a ratchet mechanism capable of engaging the first annular member with the second annular member so as to transmit torque; The ratchet mechanism includes a tooth portion provided on the first annular member; a plurality of first claw members provided on the second annular member and meshing with the teeth to lock the relative rotation of the first annular member with respect to the second annular member in a first rotation direction and allow the relative rotation in a second rotation direction; a plurality of second claw members provided on the second annular member, each paired with the first claw member, and meshing with the tooth portion to lock the relative rotation of the first annular member with respect to the second annular member in the second rotation direction and allow the relative rotation in the first rotation direction; Each of the first claw members rotates due to a centrifugal force acting due to the rotation of the second annular member, and when the centrifugal force exceeds a predetermined magnitude, the first claw members are disengaged from the tooth portion, Each of the first claw members is rotatably held by the second annular member, and has a first rotation center portion that is a rotation center of the first claw member, and a first claw portion that is formed integrally with the first rotation center portion and meshes with the tooth portion, The first claw member is characterized in that the center of gravity is on the first claw portion side. Effect of the Invention

[0008] According to the present invention, it is possible to provide a torque transmission direction switching ratchet clutch that can suppress an increase in the weight of the entire device in which it is incorporated as a component and an increase in the space required for arranging the device. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of a torque transmission direction switching ratchet clutch according to an embodiment, as viewed from the axial direction. [Diagram 2] FIG. 2 is a partially enlarged view of a torque transmission direction switching ratchet clutch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A torque transmission direction switching ratchet clutch according to an embodiment of the present invention will be described below with reference to the drawings. The torque transmission direction switching ratchet clutch according to this embodiment will be described as an example used as a component part of a vehicle transmission. In the following description, the torque transmission direction switching ratchet clutch may be abbreviated to "ratchet clutch".

[0011] First, the directions related to the torque transmission direction switching ratchet clutch of this embodiment are defined. In this embodiment, the "center axis C" refers to the center axis of the ratchet clutch, i.e., the center axis of the outer ring and the inner ring, and the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction with respect to the center axis C. In addition, with respect to the axial direction, in Figs. 1 and 2, the direction toward the front of the paper is defined as one axial direction, and the direction toward the back of the paper is defined as the other axial direction. With respect to the circumferential direction, in Figs. 1 and 2, the direction rotating clockwise toward the paper is defined as one circumferential direction, and the direction rotating counterclockwise toward the paper is defined as the other circumferential direction.

[0012] In addition, the rotation direction of the outer ring and the rotation of the inner ring in a ratchet clutch are relative. For example, if the inner ring can rotate clockwise, the outer ring can also rotate counterclockwise. Even if the inner ring and the outer ring rotate in the same direction, if the rotation speeds of the outer ring and the inner ring are different, it can be said that the outer ring and the inner ring rotate in one direction relative to each other.

[0013] FIG. 1 is a front view of a torque transmission direction switching ratchet clutch according to an embodiment of the present invention, as viewed from one axial direction. FIG. 2 is a partially enlarged view of a torque transmission direction switching ratchet clutch.

[0014] The torque transmission direction switching ratchet clutch 1 according to this embodiment has an annular outer ring 3, an annular inner ring 5 spaced radially inward from the outer ring 3, arranged coaxially with the central axis C of the outer ring 3 and rotatable relative to the outer ring 3, and a torque transmission mechanism that enables torque transmission between the outer ring 3 and the inner ring 5. The torque transmission mechanism in this embodiment is a ratchet mechanism.

[0015] The outer ring 3 has a cylindrical shape having a predetermined length in the axial direction, and holds a plurality of claw mechanisms described below. The outer ring 3 is connected to either an input shaft member (not shown) connected to a driving device (not shown) such as an electric motor, or an output shaft member (not shown) connected to a driven device to which the driving force of the electric motor, etc. is transmitted.

[0016] As shown in Figs. 1 and 2, a first claw member 15 and a second claw member 17 that is adjacent to one circumferential side of the first claw member 15 and pairs with the first claw member 15 are provided on the inner peripheral portion of the outer ring 3. The first claw member 15 and the second claw member 17 form one claw mechanism. That is, the outer ring 3 is provided with a claw mechanism including the first claw member 15 and the second claw member 17 that are aligned in sequence from the other circumferential side to the one circumferential side as viewed from one axial side. The outer ring 3 is provided with a plurality of such claw mechanisms at predetermined intervals in the circumferential direction.

[0017] The inner ring 5 is disposed radially inward of the outer ring 3. A large number of teeth 13 are formed on the outer periphery of the inner ring 5 at a predetermined interval over the entire circumference. Each tooth 13 protrudes radially outward and extends in the direction of the central axis C. The inner peripheral surface of the outer ring 3 and the outer peripheral portion of the inner ring 5, i.e., the teeth 13, face each other in the radial direction with a predetermined space therebetween. The teeth 13 form ratchet teeth with which the first pawl member 15 and the second pawl member 17 mesh. Specifically, as shown in FIG. 2, a side surface on one circumferential side of each tooth 13 forms a first meshing portion 13a that meshes with the first pawl member 15, and a side surface on the other circumferential side of each tooth 13 forms a second meshing portion 13b that meshes with the second pawl member 17. The other of the shaft members (not shown) for output or input described above is fitted to the inner peripheral surface of the inner ring 5.

[0018] The first claw member 15 is held by a first holding portion 19, which is a recessed portion that opens inward and is provided on the inner peripheral surface of the outer ring 3. The first claw member 15 has a cylindrical portion 21 extending in the direction of the central axis C, and a claw portion 23 extending from the cylindrical portion 21 toward the other circumferential direction. The cylindrical portion 21 of the first claw member 15 is held by the first holding portion 19 so as to be rotatable. That is, the first claw member 15 is held by the first holding portion 19 so that the claw portion 23 can swing radially around the cylindrical portion 21. The first claw member 15 has a rotation center at the cylindrical portion 21, but a center of gravity at the claw portion 23. That is, the claw portion 23 of the first claw member 15 has a mass such that the center of gravity is at the claw portion 23. The claw portion 23 of the first claw member 15 is constantly biased radially inward, that is, in the direction of meshing with the teeth portion 13, by a spring 25 which may be a coil type or of any other type.

[0019] When the claw portions 23 of the first claw members 15 swing radially inward, the claw portions 23 mesh with the first meshing portions 13a of the teeth portion 13 of the inner ring 5, thereby bringing the first claw members 15 into mesh with the teeth portion 13. By meshing with the teeth portion 13, the first claw members 15 lock the clockwise rotation of the inner ring 5 relative to the outer ring 3, i.e., in one circumferential direction. On the other hand, when the inner ring 5 rotates counterclockwise relative to the outer ring 3, i.e., in the other circumferential direction, the claw portions 23 of the first claw members 15 are pushed radially outward by the teeth portion 13 of the inner ring 5 against the biasing force of the spring 25, thereby allowing the rotation of the inner ring 5.

[0020] The second claw member 17 is held by the second holding portion 27, which is a recessed portion that opens inward and is provided on the inner peripheral surface of the outer ring 3. The second claw member 17 has a predetermined circumferential length and is composed of a central portion 29 having a partially cylindrical outer peripheral surface, a claw portion 31 that protrudes from the central portion 29 to one circumferential side, and a protruding portion 33 that protrudes from the central portion 29 to the other circumferential side. The second claw member 17 has the central portion 29 rotatably held by the second holding portion 27. That is, the second claw member 17 is held by the second holding portion 27 so that the claw portion 31 can swing radially around the central portion 29. The second claw member 17 is configured so that the center of rotation is the central portion 29 and the center of gravity is also located at the central portion 29. The second holding portion 27 is provided with a clearance portion 35 through which the protruding portion 33 of the second claw member 17 can swing radially. The claw portion 31 of the second claw member 17 is constantly biased radially inward, that is, in the direction of meshing with the teeth portion 13 of the inner ring 5, by a spring 37 which may be a coil type or of any other type.

[0021] In this manner, in this embodiment, the pair of first claw member 15 and second claw member 17 have different shapes. Also, the center of gravity and center of rotation of first claw member 15 are in different positions, whereas the center of gravity and center of rotation of second claw member 17 are in the same position.

[0022] When the claw portion 31 of the second claw member 17 swings radially inward, the claw portion 31 meshes with the second meshing portion 13b of the toothed portion 13 of the inner ring 5, thereby bringing the second claw member 17 into mesh with the toothed portion 13. By meshing with the toothed portion 13, the second claw member 17 locks the counterclockwise rotation of the inner ring 5 relative to the outer ring 3, i.e., in the other circumferential direction. On the other hand, when the inner ring 5 rotates clockwise relative to the outer ring 3, i.e., in one circumferential direction, the second claw member 17 is pushed radially outward by the toothed portion 13 of the inner ring 5 against the biasing force of the spring 37, allowing the rotation of the inner ring 5.

[0023] In this manner, the first and second pawl members 15 and 17 held by the outer ring 3, the springs 25, 37, and the plurality of teeth 13 formed on the inner ring 5 form a ratchet mechanism.

[0024] The ratchet clutch 1 of this embodiment is configured so that when the rotational speed of the outer ring 3 exceeds a predetermined speed, the first pawl member 15 is released from mesh with the teeth 13 of the inner ring 5. That is, when the rotational speed of the outer ring 3 exceeds a predetermined speed, the first pawl member 15 rotates against the spring 25 by centrifugal force as described below, and the pawl portion 23 is positioned radially outward from the teeth 13. The configuration of the ratchet mechanism will be described in more detail below, along with the operation of the first pawl member 15 and the second pawl member 17.

[0025] In the ratchet clutch 1 of this embodiment, the first pawl member 15 and the second pawl member 17 operate as follows. When a driving force is transmitted to the outer ring 3 and the outer ring 3 starts to rotate in one circumferential direction or the other, the centrifugal force caused by the rotation of the outer ring 3 acts on the first claw member 15 and the second claw member 17. When the centrifugal force acts, the first claw member 15, whose center of gravity is in the claw portion 23, tends to rotate or swing in a direction in which the claw portion 23 faces radially outward around the cylindrical portion 21. Then, the spring 25 biasing the first claw member 15 is pressed radially outward by the claw portion 23, i.e., in a direction to compress it. When the rotation of the outer ring 3 becomes faster and the centrifugal force acting thereon becomes larger, the spring 25 is compressed by the claw portion 23 of the rotating first claw member 15. When the rotational speed of the outer ring 3 becomes faster than a predetermined rotational speed and the centrifugal force acting on the first claw member 15 becomes greater than a predetermined magnitude F1, the spring 25 is significantly compressed by the claw portion 23, and the claw portion 23 is positioned entirely radially outward from the tooth portion 13. That is, in this state, the first claw member 15 and the tooth portion 13 are in a non-meshing state. The predetermined rotational speed of the outer ring 3 at which a centrifugal force of the predetermined magnitude F1 is generated is defined as R1.

[0026] On the other hand, even if a centrifugal force due to the rotation of the outer ring 3 acts on the second claw member 17, the center of gravity is at the central portion 29, and the mass of the claw portion 31 is smaller than that of the claw portion 23 of the first claw member 15, so that the force with which the claw portion 31 swings radially outward is smaller than that of the claw portion 23 of the first claw member 15. The spring 37 biasing the second claw member 17 does not compress significantly even if a centrifugal force larger than a predetermined magnitude F1 acts on the second claw member 17, and the second claw member 17 and the tooth portion 13 maintain their meshed state.

[0027] In this way, the position of the center of gravity of the first claw member 15 and the elastic force of the spring 25 are configured so that when the rotational speed of the outer ring 3 exceeds the predetermined speed R1 and a centrifugal force greater than F1 acts on the first claw member 15, the spring 25 is compressed by the claw portion 23 and the claw portion 23 is displaced radially outward beyond the tooth portion 13. On the other hand, the position of the center of gravity of the second claw member 17 and the elastic force of the spring 37 are configured so that the meshing state between the second claw member 17 and the tooth portion 13 is maintained even if the rotational speed of the outer ring 3 exceeds the predetermined speed R1 and a centrifugal force greater than F1 acts on the second claw member 17.

[0028] The position of the center of gravity of the first claw member 15, the position of the center of gravity of the second claw member 17, the elastic force of the spring 25, the elastic force of the spring 37, the centrifugal force of the predetermined magnitude F1, and the predetermined rotational speed R1 of the outer ring 3 when the centrifugal force of the predetermined magnitude F1 is generated are appropriately designed taking into consideration the magnitude of the torque to be transmitted, the vehicle speed, etc.

[0029] Next, the operation of the ratchet clutch 1 according to this embodiment will be described. First, a case will be described in which the inner ring 5 is the input side and rotates clockwise, that is, in one circumferential direction.

[0030] When the ratchet clutch 1 is stopped, as shown in FIG. 1, the first claw member 15 and the second claw member 17 are engaged with the tooth portion 13 by the biasing force of the spring 23 and the spring 37, respectively. When the driving force is transmitted to the inner ring 5 from this state and the inner ring 5 starts to rotate in one circumferential direction, the outer ring 3 rotates together with the inner ring 5 in one circumferential direction. Until the rotation speed of the outer ring 3 reaches R1, the outer ring 3 rotates together with the inner ring 5, and torque is transmitted from the inner ring 5 to the outer ring 3. When the rotation speed of the outer ring 3 exceeds R1, the centrifugal force acting on the first claw member 15 exceeds a predetermined magnitude F1, and the engagement between the first claw member 15 and the tooth portion 13 is released. On the other hand, the second claw member 17 maintains engagement with the tooth portion 13. In this state, even if the rotation speed of the inner ring 5 on the driving side further increases, the inner ring 5 will be in an idling state with respect to the outer ring 3 on the driven side. In other words, no torque is transmitted from the inner ring 5 to the outer ring 3 .

[0031] From this state, when the rotation speed of the outer ring 3 drops to a predetermined rotation speed R1, the centrifugal force acting on the first pawl member 15 decreases to a predetermined magnitude F1, and the first pawl member 15 again meshes with the teeth portion 13 due to the biasing force of the spring 25. In other words, torque is transmitted from the inner ring 5 to the outer ring 3.

[0032] Next, a case will be described where the inner ring 5 is the input side and rotates counterclockwise, that is, in the other circumferential direction. In this case, the outer ring 3 rotates together with the inner ring 5 in the other circumferential direction until the rotation speed of the outer ring 3 reaches R1, and torque is transmitted from the inner ring 5 to the outer ring 3. When the rotation speed of the outer ring 3 exceeds R1, the centrifugal force acting on the first claw member 15 exceeds a predetermined magnitude F1, and the meshing between the first claw member 15 and the toothed portion 13 is released. Meanwhile, the second claw member 17 maintains meshing with the toothed portion 13. In this state, when the rotation speed of the inner ring 5 on the driving side further increases, torque is continuously transmitted from the inner ring 5 to the outer ring 3. On the other hand, when the rotation speed of the outer ring 3 is faster than the rotation speed of the inner ring 5, the outer ring 3 rotates idly relative to the inner ring 5, and torque is not transmitted from the inner ring 5 to the outer ring 3.

[0033] When the rotation speed of the outer ring 3 drops to a predetermined rotation speed R1, the centrifugal force acting on the first claw member 15 decreases to a predetermined magnitude F1, and the first claw member 15 again meshes with the teeth portion 13 due to the biasing force of the spring 25. That is, torque is transmitted from the inner ring 5 to the outer ring 3.

[0034] Next, a case will be described where the outer ring 3 is the input side and rotates counterclockwise, i.e., in the other circumferential direction. In this case, the inner ring 5 rotates together with the outer ring 3 in the other circumferential direction until the rotational speed of the outer ring 3 reaches R1, and torque is transmitted from the outer ring 3 to the inner ring 5. When the rotational speed of the outer ring 3 exceeds R1, the centrifugal force acting on the first claw member 15 exceeds a predetermined magnitude F1, and the meshing between the first claw member 15 and the toothed portion 13 is released. Meanwhile, the second claw member 17 maintains its meshing with the toothed portion 13. In this state, even if the rotational speed of the driving side outer ring 3 further increases, the outer ring 3 will be in a free-spinning state relative to the driven side inner ring 5. In other words, torque is not transmitted from the outer ring 3 to the inner ring 5.

[0035] When the rotation speed of the outer ring 3 drops to a predetermined rotation speed R1, the centrifugal force acting on the first claw member 15 decreases to a predetermined magnitude F1, and the first claw member 15 is again brought into mesh with the teeth portion 13 by the biasing force of the spring 25. In other words, torque is transmitted from the outer ring 3 to the inner ring 5.

[0036] Next, a case will be described where the outer ring 3 is the input side and rotates clockwise, i.e., in one circumferential direction. In this case, the inner ring 5 rotates together with the outer ring 3 in one circumferential direction until the rotation speed of the outer ring 3 reaches R1, and torque is transmitted from the outer ring 3 to the inner ring 5. When the rotation speed of the outer ring 3 exceeds R1, the centrifugal force acting on the first claw member 15 exceeds a predetermined magnitude F1, and the meshing between the first claw member 15 and the toothed portion 13 is released. Meanwhile, the second claw member 17 maintains meshing with the toothed portion 13. In this state, when the rotation speed of the outer ring 3 on the driving side further increases, torque continues to be transmitted from the outer ring 3 to the inner ring 5. On the other hand, when the rotation speed of the inner ring 5 is faster than the rotation speed of the outer ring 3, the inner ring 5 rotates idly relative to the outer ring 3, and torque is not transmitted from the outer ring 3 to the inner ring 5.

[0037] When the rotation speed of the outer ring 3 drops to a predetermined rotation speed R1, the centrifugal force acting on the first claw member 15 decreases to a predetermined magnitude F1, and the first claw member 15 is again brought into mesh with the teeth portion 13 by the biasing force of the spring 25. In other words, torque is transmitted from the outer ring 3 to the inner ring 5.

[0038] Thus, according to this embodiment, the engagement and disengagement between the first claw member 15 and the toothed portion 13 can be controlled by the centrifugal force acting on the first claw member 15, in other words, by the rotational speed of the outer ring 3 on which the first claw member 15 is provided. Therefore, it is not necessary to provide a separate device for switching between engagement and disengagement between the first claw member 15 and the toothed portion 13. Therefore, according to this embodiment, it is possible to suppress an increase in the weight of the entire device in which the ratchet clutch 1 is incorporated as a component and an increase in the installation space of the device. If the device in which the ratchet clutch 1 is incorporated as a component is a transmission for a vehicle as in this embodiment, it is possible to suppress an increase in the weight of the entire transmission and an increase in the installation space in the vehicle. Furthermore, by controlling the rotational direction of the inner ring 5 or the outer ring 3, which is the input side, the torque transmission direction can be switched as described above.

[0039] The ratchet clutch 1 of the present invention is not limited to the above embodiment and can be modified. For example, the pawl mechanism may be provided on the inner ring side, and teeth that mesh with the pawl mechanism may be provided on the inner peripheral surface of the outer ring. The number of pawl mechanisms can be changed as appropriate depending on the torque capacity to be transmitted. [Explanation of symbols]

[0040] 1 Ratchet type clutch 3 Outer ring 5. Inner Circle 13 Teeth 15 First claw member 17 Second claw member 19 1st holding part 23 Claw 25 Spring 27 Second holding part 31 Claw part 37 Spring

Claims

1. A first annular member; a second annular member arranged coaxially with and rotatable relative to the first annular member; a ratchet mechanism capable of engaging the first annular member with the second annular member so as to transmit torque; The ratchet mechanism includes a tooth portion provided on the first annular member; a plurality of first claw members provided on the second annular member and meshing with the teeth to lock the relative rotation of the first annular member with respect to the second annular member in a first rotation direction and allow the relative rotation in a second rotation direction; a plurality of second claw members provided on the second annular member, each paired with a first claw member, and meshing with the tooth portion to lock the relative rotation of the first annular member with respect to the second annular member in the second rotation direction and allow the relative rotation in the first rotation direction, Each of the first claw members rotates due to a centrifugal force acting due to the rotation of the second annular member, and when the centrifugal force exceeds a predetermined magnitude, the first claw members are disengaged from the tooth portion, A ratchet clutch, characterized in that each of the second pawl members is capable of meshing with the tooth portion even when a centrifugal force exceeding the predetermined magnitude acts on the second pawl members.

2. A first annular member; a second annular member arranged coaxially with and rotatable relative to the first annular member; a ratchet mechanism capable of engaging the first annular member with the second annular member so as to transmit torque; The ratchet mechanism includes a tooth portion provided on the first annular member; a plurality of first claw members provided on the second annular member and meshing with the teeth to lock the relative rotation of the first annular member with respect to the second annular member in a first rotation direction and allow the relative rotation in a second rotation direction; a plurality of second claw members provided on the second annular member, each paired with a first claw member, and meshing with the tooth portion to lock the relative rotation of the first annular member with respect to the second annular member in the second rotation direction and allow the relative rotation in the first rotation direction, Each of the first claw members rotates due to a centrifugal force acting due to the rotation of the second annular member, and when the centrifugal force exceeds a predetermined magnitude, the first claw members are disengaged from the tooth portion, Each of the first claw members is rotatably held by the second annular member, and has a first rotation center portion that is a rotation center of the first claw member, and a first claw portion that is formed integrally with the first rotation center portion and meshes with the tooth portion, A ratchet clutch, wherein the first pawl member has a center of gravity on the side of the first pawl portion.

3. Each of the first claw members is rotatably held by the second annular member, and has a first rotation center portion that is a rotation center of the first claw member, and a first claw portion that is formed integrally with the first rotation center portion and meshes with the tooth portion, 2. The ratchet clutch according to claim 1, wherein the first pawl member has a center of gravity on a side of the first pawl portion.

4. Each of the second claw members is rotatably held by the second annular member, and has a second rotation center portion that is a rotation center of the second claw member, and a second claw portion that is integrally formed with the second rotation center portion and meshes with the tooth portion, 4. The ratchet clutch according to claim 2, wherein the center of gravity of the second pawl member is located at the second rotation center portion.

5. the first claw member is biased in a direction of meshing with the tooth portion by a first elastic member held by the second annular member, 5. The ratchet clutch according to claim 2, wherein the elastic force of the first elastic member is such that engagement with the teeth portion is released when a centrifugal force exceeding the predetermined magnitude acts on the first elastic member.

6. the second claw member is biased in a direction of meshing with the tooth portion by a second elastic member held by the second annular member, 6. The ratchet clutch according to claim 4, wherein the elastic force of the second elastic member is large enough to maintain engagement with the teeth even when a centrifugal force exceeding the predetermined magnitude acts on the second elastic member.

Images