Ratchet clutch device

Abstract

A ratchet clutch device capable of reliably moving a torque transmission section to the outside in the radial direction when a claw section and a tooth section mesh, the ratchet clutch device comprising: an outer ring and an inner ring disposed coaxially and capable of rotating relative to each other. A plurality of teeth are formed on the outer peripheral surface of the inner ring. The outer ring is provided with a plurality of claw members that mesh with the teeth. The claw member includes: a shaft portion rotatably supported by the outer ring; a claw portion protruding from the shaft portion and meshing with the tooth portion; and a torque transmission part protruding from the shaft part in a direction opposite to the claw part. The outer peripheral surface of the shaft portion has a first outer peripheral surface facing radially outward. The outer ring has: an outer peripheral holding surface facing the first outer peripheral surface; and an opposing surface that opposes the tip surface of the torque transmission part and is separated from the tip surface. The first outer peripheral surface is provided with a top portion located at a position closest to the radial outer side from the rotation center of the shaft portion. When the claw portion is engaged with the tooth portion, the claw portion is inclined with the top portion abutting against the outer peripheral holding surface as the fulcrum, and the top end surface of the torque transmission portion is in contact with the facing surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a ratchet clutch device. BACKGROUND

[0002] The ratchet clutch device has an outer ring and an inner ring arranged coaxially. In the ratchet clutch device of Patent Document 1 described below, a plurality of tooth portions are formed on an outer peripheral surface of the inner ring. Further, a plurality of pawl members are provided to the outer ring. The general pawl member has a shaft portion rotatably supported between an outer ring main body and a retainer, and a pawl portion protruding from the shaft portion and engaged with the tooth portion.

[0003] Further, when the pawl portion is engaged with the tooth portion, if the contact area of the pawl portion and the tooth portion is small, the surface pressure applied to the tooth portion becomes large. If such an action continues, the durability of the pawl portion and the tooth portion is impaired. In order to eliminate this problem, the pawl member of Patent Document 1 described below has, in addition to the shaft portion and the pawl portion, a torque transmission portion protruding from the shaft portion in a direction opposite to the pawl portion. Further, an opposing surface opposing the tip end surface of the torque transmission portion and abutting against the tip end surface of the torque transmission portion is formed on the outer ring. Also, when the pawl portion is engaged with the tooth portion, the tip end surface of the torque transmission portion presses the opposing surface, thereby transmitting torque to the outer ring. Further, a protrusion protruding toward the tip end surface of the torque transmission portion is formed on the opposing surface of Patent Document 1 described below. The protrusion guides the pressed torque transmission portion to the radial outer side. That is, when the pawl portion is engaged with the tooth portion, the torque transmission portion is moved to the radial outer side (the pawl member is rotated) by the protrusion. On the other hand, the pawl portion on the opposite side of the torque transmission portion is moved to the radial inner side, and the contact area of the pawl portion and the tooth portion becomes large.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-197253

[0007] However, according to the technology of Patent Document 1 described above, when the pawl portion is engaged with the tooth portion, there is a case where the pawl member is sandwiched between the protrusion and the tooth portion, and the torque transmission portion does not move to the radial outer side (a case where the pawl member does not rotate). SUMMARY

[0008] The present disclosure was achieved in view of the above-described problems, and aims to provide a ratchet clutch device in which the contact area of the pawl portion and the tooth portion reliably becomes large when the pawl portion is engaged with the tooth portion.

[0009] To achieve the above object, a ratchet type clutch device according to one aspect of the present disclosure includes an outer ring and an inner ring that are arranged coaxially and are rotatable relative to each other. A plurality of tooth portions are formed on an outer circumferential surface of the inner ring. A plurality of pawl members that engage with the tooth portions are provided on the outer ring. The pawl members each include a shaft portion rotatably supported on the outer ring, a pawl portion protruding from the shaft portion and engaging with the tooth portions, and a torque transmission portion protruding from the shaft portion in a direction opposite to the pawl portion. An outer circumferential surface of the shaft portion has a first outer circumferential surface arranged at a position radially outward of a rotational center of the shaft portion. The outer ring has an outer circumferential holding surface that faces the first outer circumferential surface, and an opposing surface that faces a top end surface of the torque transmission portion and is separated from the top end surface. A top portion located radially outward of the rotational center of the shaft portion is formed on the first outer circumferential surface. When the pawl portion engages with the tooth portion, the pawl portion tilts with the top portion of the outer circumferential holding surface as a fulcrum, and the top end surface of the torque transmission portion comes into contact with the opposing surface.

[0010] Effects of Invention

[0011] According to the present disclosure, when the pawl portion engages with the tooth portion, the pawl member tilts with the top portion as a fulcrum. That is, the torque transmission portion moves radially outward, and the pawl portion moves radially inward. Therefore, the contact area of the pawl portion with the tooth portion becomes large. In addition, the top end surface of the torque transmission portion is separated from the opposing surface. Therefore, when the pawl portion engages with the tooth portion, the pawl member is not sandwiched between the convex portion and the tooth portion, and thus the pawl member does not tilt. Therefore, the contact area of the pawl portion with the tooth portion reliably becomes large. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a schematic view of a cross section of the ratchet type clutch device according to the embodiment, which is obtained by cutting the ratchet type clutch device in a direction orthogonal to the axial direction.

[0013] Figure 2 is a schematic view showing a state in which the inner ring is relatively rotated in a first rotational direction with respect to the outer ring in the ratchet type clutch device according to the embodiment.

[0014] Figure 3 is a schematic view showing a state in which the inner ring is relatively rotated in a second rotational direction with respect to the outer ring in the ratchet type clutch device according to the embodiment.

[0015] Figure 4 is an enlarged view of the pawl member according to the embodiment and its vicinity.

[0016] Figure 5 is a schematic view of a time point at which the pawl portion contacts with the tooth portion in the embodiment.

[0017] Figure 6is a schematic view of a point in time when the torque transmission portion comes into contact with the opposing surface in the embodiment.

[0018] Figure 7 is a sectional view of the ratchet-type clutch device of other embodiments taken along a direction orthogonal to the axial direction.

[0019] Explanation of Reference Numerals

[0020] 1: outer ring; 2: inner ring; 3: tooth portion; 5: opening portion; 10: outer ring main body; 13: outer peripheral holding surface; 20: holder; 25: inner peripheral holding surface; 30: shaft housing portion; 31: expansion housing portion; 40: claw member; 41: shaft portion; 42: claw portion; 43: torque transmission portion; 44: outer peripheral surface; 45: first outer peripheral surface; 46: second outer peripheral surface; 47: protrusion; 48: top portion; 100: ratchet-type clutch device. DETAILED DESCRIPTION

[0021] Embodiments for carrying out the present disclosure are explained in detail with reference to the drawings. The present disclosure is not limited by what is described in the following explanation. Furthermore, among the constituent elements described below, there are included constituent elements that can be easily conceived by those skilled in the art, substantially identical constituent elements. Also, the constituent elements described below can be appropriately combined.

[0022] Figure 1 is a sectional view of the ratchet-type clutch device of other embodiments taken along a direction orthogonal to the axial direction.

[0023] A tooth portion 3 that protrudes to the radially outer side is formed on the outer peripheral surface of the inner ring 2 in the circumferential direction. The tooth portion 3 has a one side surface 6 that faces one direction in the circumferential direction and another side surface 7 that faces another direction in the circumferential direction. Hereinafter, with respect to the direction of rotation (circumferential direction) centered on the center axis X, the direction in which the one side surface 6 faces is referred to as a first rotation direction LI, and the direction in which the other side surface 7 faces is referred to as a second rotation direction L2.

[0024] The outer ring 1 has: an annular outer ring main body 10; an annular retainer 20 disposed on the inner peripheral side of the outer ring main body 10; and a plurality of claw members 40. The inner peripheral surface 11 of the outer ring main body 10 is circular with the center axis X as the center. The fitting-into portion 12 recessed toward the radial direction outside is formed in the inner peripheral surface 11 of the outer ring main body 10. The retainer 20 has: a retainer main body 21 extending along the inner peripheral surface 11 of the outer ring main body 10; and a fitting-into portion 22 fitting into the fitting-into portion 12 of the outer ring main body 10.

[0025] The retainer main body 21 and the fitting-into portion 22 are separate from each other. Also, the space between the retainer main body 21 and the fitting-into portion 22 becomes an opening portion 5 for disposing a part (claw portion 42) of the claw member 40 on the radial direction inside of the retainer 20. Further, the shaft portion accommodating portion 30 is formed at the portion between the outer ring main body 10 and the retainer 20 and adjacent to the opening portion 5. Further, the expansion accommodating portion 31 is formed at the portion between the outer ring main body 10 and the retainer 20 and in the direction opposite to the opening portion 5 when viewed from the shaft portion accommodating portion 30. Note that, in the present embodiment, the opening portion 5, the shaft portion accommodating portion 30, and the expansion accommodating portion 31 are disposed in this order from the first rotation direction L1 toward the second rotation direction L2.

[0026] The claw member 40 has: a shaft portion 41 accommodated in the shaft portion accommodating portion 30; a claw portion 42 protruding from the shaft portion 41; and a torque transmission portion 43 disposed in the expansion accommodating portion 31. The shaft portion 41 is rotatably supported by the shaft portion accommodating portion 30. The claw portion 42 is disposed on the inner peripheral side of the retainer 20 by passing through the opening portion 5. The claw portion 42 is always urged toward the radial direction inside by the spring 23 provided to the fitting-into portion 22. The torque transmission portion 43 opposes the opposing surface 32 in the inner surface of the expansion accommodating portion 31. Note that the opposing surface 32 faces the first rotation direction L1.

[0027] Figure 2 is a schematic view showing a state in which the inner ring relatively rotates with respect to the outer ring in the first rotation direction L1 in the ratchet type clutch device of the embodiment. As shown in Figure 2 , in the ratchet type clutch device 100, when the inner ring 2 relatively rotates with respect to the outer ring 1 in the first rotation direction L1, the claw portion 42 climbs over the tooth portion 3 and enters between the tooth portions 3 alternately, and the claw member 40 swings (refer to arrow A1 in Figure 2 . Therefore, the torque is not transmitted from the inner ring 2 to the outer ring 1.

[0028] Figure 3 is a schematic view showing a state in which the inner ring relatively rotates with respect to the outer ring in the second rotation direction L2 in the ratchet type clutch device of the embodiment. As shown in Figure 3As shown, when the inner ring 2 is relatively rotated in the second rotational direction L2 with respect to the outer ring 1, the claw portions 42, which are pressed by the spring 23, enter between the teeth 3 of the inner ring 2. Also, the claw portions 42 come into contact with the other side surfaces 7 of the teeth 3, and the claw member 40 is pressed (refer to arrow A2). Thus, the torque transmission portion 43 presses the opposing surface 32, and transmits torque to the outer ring main body 10. As a result, the outer ring 1 rotates in the second rotational direction L2 at the same speed as the inner ring 2. Figure 3

[0029] The above is the basic configuration of the ratchet type clutch device 100. Next, details of the claw member 40, the shaft portion accommodating portion 30, and the expansion accommodating portion 31 will be described.

[0030] Figure 4 is an enlarged view of the claw member of the embodiment and its vicinity. As shown, the shaft portion 41 of the claw member 40 is formed in a cylindrical shape when viewed in the axial direction so as to easily rotate. That is, the outer peripheral surface 44 of the shaft portion 41 is formed in a circular shape with the center of rotation O41 of the shaft portion 41 as the center. Figure 4

[0031] The claw portion 42 and the torque transmission portion 43 are provided on the outer peripheral surface 44 of the shaft portion 41. Thus, the outer peripheral surface 44 is divided into a first outer peripheral surface 45 and a second outer peripheral surface 46, the first outer peripheral surface 45 is disposed at a position farther radially outward than the center of rotation O41, and the second outer peripheral surface 46 is disposed at a position closer radially inward than the center of rotation O41. Further, the outer diameter of the shaft portion 41 is larger than the width of the opening portion 5. Thus, it is possible to avoid a situation in which the shaft portion 41 (the claw member 40) falls off from the opening portion 5 to the inner peripheral side of the retainer 20.

[0032] The convex portion 47 is formed on the first outer peripheral surface 45 so as to protrude radially outward. A portion of the convex portion 47 disposed farthest radially outward is referred to as a top portion 48. The outer shape of the convex portion 47 is in a circular arc shape when viewed in the axial direction.

[0033] The inner surface of the shaft portion accommodating portion 30 is constituted by the outer peripheral surface of the retainer main body 21 (hereinafter referred to as an inner peripheral retaining surface 25), the corner portion 22a of the fitting portion 22, and the inner peripheral surface of the outer ring main body 10 (hereinafter referred to as an outer peripheral retaining surface 13).

[0034] The inner peripheral retaining surface 25 is a portion of the outer peripheral surface of the retainer main body 21, and is formed at a position close to the opening portion 5. The inner peripheral retaining surface 25 opposes the second outer peripheral surface 46 of the shaft portion 41. The inner peripheral retaining surface 25 is formed in a circular arc shape with the center of rotation O41 of the shaft portion 41 as the center. The corner portion 22a of the fitting portion 22 opposes the first outer peripheral surface 45 of the shaft portion 41. Further, the corner portion 22a of the fitting portion 22 is in a circular arc shape.

[0035] ​​The outer peripheral holding surface 13 is a portion of the inner peripheral surface of the outer ring main body 10, and extends from the side surface 12a of the fitting portion 12 toward the second rotation direction L2. The outer peripheral holding surface 13 is formed in a circular arc shape with the center O13 of the outer peripheral holding surface 13 as the center when viewed in the axial direction.

[0036] As shown in Figure 4 , the first imaginary line K1 is an imaginary line (straight line) drawn from the center axis X (refer to Figure 1 ) of the outer ring 1 toward one end 13a of the outer peripheral holding surface 13. The second imaginary line K2 is an imaginary line (straight line) drawn from the center axis X (refer to Figure 1 ) of the outer ring 1 toward the other end 13b of the outer peripheral holding surface 13. The convex portion 47 (the top portion 48) is disposed between the first imaginary line K1 and the second imaginary line K2. Therefore, the convex portion 47 (the top portion 48) is opposed to the outer peripheral holding surface 13.

[0037] Further, as shown in Figure 4 , the imaginary circle K3 is an imaginary circle with the center axis X (refer to Figure 1 ) of the outer ring 1 as the center and passing through the rotation center O41 of the shaft portion 41. The center O13 of the outer peripheral holding surface 13 is disposed on the imaginary circle K3. That is, the distance from the center O13 of the outer peripheral holding surface 13 and the rotation center O41 of the shaft portion 41 to the center axis X (refer to Figure 1 ) of the outer ring 1 is equal. Further, the center O13 of the outer peripheral holding surface 13 is offset from the rotation center O41 of the shaft portion 41 toward the first rotation direction L1. In other words, the angle formed by the center O13 of the outer peripheral holding surface 13 and the rotation center O41 of the shaft portion 41 becomes θ°.

[0038] The top end surface 43a of the torque transmission portion 43 is opposed to the opposed surface 32 of the expansion accommodation portion 31. The top end surface 43a of the torque transmission portion 43 and the opposed surface 32 are separated from each other. Therefore, a gap is formed between the top end surface 43a and the opposed surface 32. Further, the limiting surface 33 of the expansion accommodation portion 31 is formed on the radially outer side of the torque transmission portion 43. When the torque transmission portion 43 moves toward the radially outer side, the torque transmission portion 43 comes into contact with the limiting surface 33, and thus the rotation of the claw member 40 is restricted.

[0039] Further, in order to enable the contact (torque transmission) of the torque transmission portion 43 and the opposed surface 32, a gap is formed between the inner surface (the inner peripheral holding surface 25, the corner portion 22a of the fitting portion 22, and the outer peripheral holding surface 13) of the shaft portion accommodation portion 30 and the shaft portion 41.

[0040] Next, the operation when the claw portion 42 engages with the tooth portion 3 will be described. Figure 5 is a schematic view of the timing at which the claw portion and the tooth portion come into contact in the embodiment. Figure 6 is a schematic view of the timing at which the torque transmission portion and the opposed surface come into contact in the embodiment.

[0041] like Figure 5 As shown, when the inner ring 2 rotates relative to the outer ring 1 in the second rotational direction L2, the other side surface 7 of the tooth portion 3 contacts the top surface 42a of the claw portion 42. Consequently, the claw member 40 receives a load B1 from the tooth portion 3. It should be noted that the direction of load B1 is perpendicular to the other side surface 7. Furthermore, a gap is formed between the top surface 43a of the torque transmission portion 43 and the opposing surface 32. Consequently, the claw member 40 moves in the direction of load B1.

[0042] Here, a convex portion 47 is formed on the first outer peripheral surface 45 of the shaft portion 41. Therefore, when the claw member 40 moves in the direction of the load B1, the top 48 of the convex portion 47 abuts against the outer peripheral holding surface 13, and the claw member 40 tilts with the top 48 as a fulcrum. That is, the torque transmission portion 43 moves radially outward (refer to Figure 5 Arrow B2), on the other hand, the claw portion 42 moves radially inward (refer to Figure 5 arrow B3).

[0043] And, as Figure 6 As shown, when the top surface 43a of the torque transmission portion 43 contacts the opposing surface 32, torque is transmitted to the outer ring body 10 (see arrow B4), causing the outer ring 1 to rotate in the second rotational direction L2. It should be noted that when the top surface 43a of the torque transmission portion 43 contacts the opposing surface 32, the tilting of the claw member 40 stops.

[0044] In summary, according to this embodiment, the contact area between the claw portion 42 and the tooth portion 3 is greater than the contact area between the torque transmission portion 43 and the facing surface 32 (see Figure 6 ) than when the claw portion 42 contacts the tooth portion 3 (refer to Figure 5 Therefore, the surface pressure when the tooth portion 3 and the claw portion 42 come into contact becomes smaller, and the durability of the claw portion 42 and the tooth portion 3 is improved.

[0045] Furthermore, a gap is formed between the torque transmission portion 43 and the facing surface 32. This ensures a sufficient time from the moment the claw portion 42 contacts the tooth portion 3 to the moment the torque transmission portion 43 contacts the facing surface 32, that is, the time it takes for the claw member 40 to tilt. Consequently, the contact area between the claw portion 42 and the tooth portion 3 is reliably increased.

[0046] It should be noted that, although not specifically shown, when the claw portion 42 contacts the tooth portion 3, the contact area between the claw portion 42 and the tooth portion 3 is already large (when the torque transmission portion 43 contacts the restriction surface 33), the claw member 40 moves linearly in the direction of the load B1, and the top end surface 43a of the torque transmission portion 43 contacts the opposing surface 32. Therefore, the claw member 40 does not fall.

[0047] Figure 5the claw member 40 is not tilted). In the present embodiment, in order to prevent this, the center O13 of the outer peripheral holding surface 13 is arranged so as to be offset from the rotation center O41 of the shaft portion 41 in the first rotation direction LI. Thus, as compared with the case where the center O13 of the outer peripheral holding surface 13 is coaxial with the rotation center O41 of the shaft portion 41 (see the imaginary line K4), one end 13a of the outer peripheral holding surface 13 is arranged on the radially inner side. As a result, the convex portion 47 (the top portion 48) is easily caught by the outer peripheral holding surface 13, so that tilting of the claw member 40 is reliably performed. Note that the angle Θ formed by the center O13 of the outer peripheral holding surface 13 and the rotation center O41 of the shaft portion 41 is not particularly limited, and is preferably in the range of 0.1° or more and 5.0° or less. Figure 5

[0048] The above describes the embodiment, but the present disclosure is not limited to the example shown in the embodiment. For example, the convex portion 47 of the embodiment is in the shape of a circular arc when viewed in the axial direction, but in the present disclosure, the convex portion 47 (the top portion 48) can be in the shape of a triangle, a quadrangle, or the like, as long as it functions as a fulcrum for tilting the claw member 40. That is, the shape of the convex portion 47 (the top portion 48) is not particularly limited. Also, in the first outer peripheral surface 45 of the embodiment, it is also in the shape of a circular arc (a circle) when viewed in the axial direction, but the present disclosure is not limited thereto.

[0049] Also, the outer peripheral holding surface 13 of the embodiment is also in the shape of a circular arc (a circle) when viewed in the axial direction, but the present disclosure is not limited thereto. For example, in order to make the top portion 48 of the convex portion 47 less likely to slide when the claw portion 42 contacts the tooth portion 3 (in order to reliably tilt the claw member 40), a recess or a convex portion can be formed in the outer peripheral holding surface 13.

[0050] Also, in the embodiment, in order to improve the reliability of tilting of the claw member 40, the center O13 of the outer peripheral holding surface 13 is arranged so as to be offset from the rotation center O41 of the shaft portion 41 in the first rotation direction LI, but the present disclosure is not limited thereto. That is, if the reliability of tilting of the claw member 40 is high, the center O13 of the outer peripheral holding surface 13 and the rotation center O41 of the shaft portion 41 can also be coaxial.

[0051] Also, in the present embodiment, the case where the ratchet type clutch device (ratchet type one-way clutch device) that transmits the torque of the inner ring 2 to the outer ring 1 only when the inner ring 2 relatively rotates with respect to the outer ring 1 in the second rotation direction L2 is applied as an example, but the present disclosure is not limited thereto.​Figure 7 is a sectional view of the ratchet-type clutch device 100A taken along a direction orthogonal to the axial direction. For example, as shown in Figure 7 , the ratchet-type clutch device 100A has a plurality of first pawl members (pawl members 40) and a plurality of second pawl members 50. The first pawl members are the pawl members 40 described in the embodiments, and engage with the tooth portions 3 from the second rotation direction L2. The second pawl members 50 engage with the tooth portions 3 from the first rotation direction LI. Therefore, in the ratchet-type clutch device 100A, torque is transmitted to the outer ring 1 regardless of which of the first rotation direction LI and the second rotation direction L2 the inner ring 2 relatively rotates with respect to the outer ring 1 (the outer ring 1 is locked in both directions). The present disclosure can also be applied to such a ratchet-type clutch device 100A. Furthermore, Figure 7 The second pawl members 50 are composed only of shaft portions and pawl portions in the above embodiment, but in the present disclosure, the kind of the second pawl members 50 is not particularly limited. Therefore, the second pawl members 50 can also be pawl members having protrusions 47 (top portions 48) (pawl members of the same shape as the pawl members 40).

[0052] Note that the present disclosure can also be a combination of the following configurations. (1)

[0054] A ratchet-type clutch device has:

[0055] an outer ring and an inner ring disposed coaxially and relatively rotatable to each other,

[0056] a plurality of tooth portions formed on an outer circumferential surface of the inner ring,

[0057] a plurality of pawl members provided to the outer ring and engaging with the tooth portions,

[0058] the pawl members have:

[0059] a shaft portion rotatably supported to the outer ring;

[0060] a pawl portion protruding from the shaft portion and engaging with the tooth portions; and

[0061] a torque transmission portion protruding from the shaft portion in a direction opposite to the pawl portion,

[0062] an outer circumferential surface of the shaft portion has a first outer circumferential surface disposed at a position radially outward from a rotation center of the shaft portion,

[0063] the outer ring has:

[0064] an outer circumferential retaining surface facing the first outer circumferential surface; and

[0065] an opposing surface facing a top end surface of the torque transmission portion and separated from the top end surface,

[0066] a top portion located most radially outward from a rotation center of the shaft portion is formed on the first outer peripheral surface,

[0067] when the claw portion is engaged with the tooth portion, the claw portion tilts with the top portion of the outer peripheral surface as a fulcrum, and a tip end surface of the torque transmission portion comes into contact with the opposing surface. (2)

[0069] The ratchet type clutch device according to (1), wherein

[0070] a direction parallel to a central axis of the outer ring is set as an axial direction,

[0071] the first outer peripheral surface is formed in a circular arc shape when viewed from the axial direction. (3)

[0073] The ratchet type clutch device according to (1) or (2), wherein

[0074] a protruding portion protruding radially outward is formed on the first outer peripheral surface,

[0075] a radially outer end of the protruding portion becomes the top portion. (4)

[0077] The ratchet type clutch device according to (3), wherein

[0078] a direction parallel to a central axis of the outer ring is set as an axial direction,

[0079] the protruding portion is in a circular arc shape when viewed from the axial direction. (5)

[0081] The ratchet type clutch device according to any one of (1) to (4), wherein

[0082] an imaginary line drawn from a central axis of the outer ring to one end of the outer peripheral surface is set as a first imaginary line,

[0083] an imaginary line drawn from the central axis of the outer ring to the other end of the outer peripheral surface is set as a second imaginary line,

[0084] the top portion is disposed between the first imaginary line and the second imaginary line. (6)

[0086] The ratchet type clutch device according to any one of (1) to (5), wherein

[0087] a direction parallel to a central axis of the outer ring is set as an axial direction,

[0088] a direction in which the claw portion is arranged when viewed from the shaft portion and which is a rotational direction centered on the central axis is set as a first rotational direction,

[0089] the outer peripheral holding surface is formed in a circular arc shape when viewed in the axial direction,

[0090] a center of the outer peripheral holding surface and a center of the shaft portion are arranged at the same distance from the central axis of the outer ring,

[0091] the center of the outer peripheral holding surface is arranged so as to be offset from the center of the shaft portion in the first rotational direction.

Claims

1. A ratchet clutch device, characterized in that Having: an outer ring and an inner ring arranged coaxially so as to be rotatable relative to each other, a plurality of tooth portions formed on an outer peripheral surface of the inner ring, a plurality of pawl members provided on the outer ring so as to engage with the tooth portions, the pawl members having: a shaft portion rotatably supported on the outer ring; a pawl portion protruding from the shaft portion so as to engage with the tooth portions; and a torque transmission portion protruding from the shaft portion in a direction opposite to the pawl portion, an outer peripheral surface of the shaft portion having a first outer peripheral surface arranged at a position radially outward of a rotational center of the shaft portion, the outer ring having: an outer peripheral retaining surface facing the first outer peripheral surface; and an opposing surface facing a tip end surface of the torque transmission portion and separated from the tip end surface, a tip portion being formed on the first outer peripheral surface at a position radially outward of the rotational center of the shaft portion, when the pawl portion engages with the tooth portion, the pawl portion tilts with the tip portion of the outer peripheral retaining surface as a fulcrum, and the tip end surface of the torque transmission portion comes into contact with the opposing surface.

2. The ratchet-type clutch device according to claim 1, wherein: a direction parallel to a central axis of the outer ring is defined as an axial direction, the first outer peripheral surface is formed in a circular arc shape when viewed from the axial direction.

3. The ratchet-type clutch device according to claim 1, wherein: a protrusion protruding radially outward is formed on the first outer peripheral surface, a radially outer end of the protrusion is the tip portion.

4. The ratchet-type clutch device according to claim 3, wherein: a direction parallel to a central axis of the outer ring is defined as an axial direction, the protrusion is in a circular arc shape when viewed from the axial direction.

5. The ratchet-type clutch device according to any one of claims 1 to 4, wherein: an imaginary line drawn from a central axis of the outer ring to one end of the outer peripheral retaining surface is defined as a first imaginary line, an imaginary line drawn from the central axis of the outer ring to the other end of the outer peripheral retaining surface is defined as a second imaginary line, the tip portion is arranged between the first imaginary line and the second imaginary line.

6. The ratchet-type clutch device according to any one of claims 1 to 4, wherein: a direction parallel to a central axis of the outer ring is defined as an axial direction, a direction in which the pawl portion is arranged when viewed from the shaft portion and which is a rotational direction centered on the central axis is defined as a first rotational direction, the outer peripheral retaining surface is formed in a circular arc shape when viewed from the axial direction, a center of the outer peripheral retaining surface and a center of the shaft portion are equal in distance from the central axis of the outer ring, the center of the outer peripheral retaining surface is arranged so as to be offset from the center of the shaft portion in the first rotational direction.

Images