Reverse input blocking clutch

Abstract

This reverse input blocking clutch (1) comprises: an input member (2) having an input shaft (21); an output member (3) having an output shaft (31); a pressed surface (62); a pair of engaging elements (5); a first bearing mechanism (7) that rotatably supports the input member (2); and a second bearing mechanism (8) that rotatably supports the output member (3). The outer ring of the first bearing mechanism (7) and the second bearing mechanism (8) is an integrated outer ring (61) in which a first outer ring raceway groove (73) in which a first rolling element (70) of the first bearing mechanism (7) rolls, a second outer ring raceway groove (83) in which a second rolling element (80) of the second bearing mechanism (8) rolls, and the pressed surface (62) are integrally provided.

Description

Reverse input cutoff clutch

[0001] This application claims priority from Japanese Patent Application No. 2024-098128, filed June 18, 2024, the contents of which are incorporated herein by reference.

[0002] Conventionally, there has been known a reverse input cutoff clutch configuration that includes an input member connected to an input mechanism such as a drive source and an output member connected to an output mechanism such as a reducer, and that allows transmission of rotational force from the input member to the output member while cutting off reverse input of rotational force from the output member to the input member. Various techniques have been proposed for improving the performance of these reverse input cutoff clutches.

[0003] For example, Patent Document 1 discloses the configuration of a locking reverse input cutoff clutch that cuts off reverse input from the output member by preventing rotation of the output member. The reverse input cutoff clutch has an input shaft and an output shaft that are coaxially arranged with each other, a pressed member having a pressed surface, and a pair of engaging elements that are movable in the radial direction. According to the technology described in Patent Document 1, when a rotational force is reversely input to the output member, the engaging elements move in a direction approaching the pressed surface based on engagement between the engaging elements and the output member, and frictionally engage with the pressed surface, thereby cutting off the rotational force reversely input to the output shaft.

[0004] In such a reverse input cutoff clutch, the hardness of the pressed member needs to be high to suppress wear when the engaging element slides on the pressed surface. Also, for example, if the input member, output member, and pressed surface are not coaxial with each other, there is a risk of performance degradation due to the occurrence of backlash in the rotational direction and increased loss caused by sliding between the pressed surface and the engaging element.

[0005] Therefore, various technologies have been proposed for suppressing wear when the engaging element slides on the pressed surface and deformation of the pressed member due to stress when blocking the reverse input. For example, Patent Document 2 discloses a configuration using a bearing outer ring made of a heat-treated high-hardness steel material (bearing steel, etc.), in which the outer ring raceway surface and the pressed surface are integrally formed. According to the technology described in Patent Document 2, since the pressed member (i.e., the bearing outer ring) has high hardness, it is possible to suppress wear when the engaging element slides on the pressed surface.

[0006] Patent No. 6658965 International Publication No. 2023 / 195203

[0007] However, in the technology described in Patent Document 2, the housing is formed by joining an input member housing and an output member housing together. From the perspective of assembly, this joint is likely to be a clearance fit. Therefore, the clearance fit can cause radial misalignment between the housings, making it difficult to ensure coaxiality between the input member, the output member, and the housing.

[0008] Here, for example, if the coaxiality between the input member and the pressed member (pressed surface) is poor, the size of the gap between each engaging element and the input member will differ. Therefore, when a rotational force is input to the input member, only one engaging element will contact the input member first, and torque will be concentrated on that engaging element until the other engaging element contacts the input member. This may result in a decrease in performance due to wear, vibration, or the inclusion of foreign matter. Furthermore, for example, if the coaxiality between the output member and the pressed member (pressed surface) is poor, the size of the gap between each engaging element and the pressed member will differ. Therefore, when a rotational force is input in reverse to the output member, only one engaging element will contact the pressed member first, and the pressing force will be weak until the other engaging element contacts the output member, preventing the locking function from functioning properly. This may result in a time loss until the locking mechanism is locked. Furthermore, since only one engaging element contacts the output member, bending of the output member may occur, resulting in a decrease in performance.

[0009] Therefore, in the conventional technologies described in Patent Documents 1 and 2, etc., there was room for improvement in terms of suppressing wear on the pressed surface when the engaging element slides over the pressed surface, while improving the coaxiality between each part, such as the input member, output member, and pressed surface.

[0010] Therefore, an object of the present invention is to provide a reverse input cutoff clutch that can suppress wear on the pressed surface and improve the coaxiality of each component compared to conventional techniques.

[0011] In order to solve the above problems, the present invention proposes the following means: A reverse input cutoff clutch according to a first aspect of the present invention comprises an input member having an input shaft, an output member having an output shaft arranged coaxially with the input shaft and arranged axially alongside the input member, a pair of engagers provided radially outward of the input member and the output member, each having a pressed surface facing inward in the radial direction, a pressing surface opposing the pressed surface, an input-side engaged portion engageable with the input member, and an output-side engaged portion engageable with the output member, the engagers being movable relative to each other along a first radial direction, a first bearing mechanism rotatably supporting the input member, and a second bearing mechanism rotatably supporting the output member, wherein when a rotational torque is input to the input shaft, the pair of engagers move relative to the input member and the input-side Based on engagement with the engaged portion, the engaging elements move toward each other radially inward in the first radial direction, and based on engagement between the output member and the output side engaged portion, the rotational torque is transmitted to the output shaft. When rotational torque is input in reverse to the output shaft, the pair of engaging elements move away from each other radially outward in the first radial direction based on engagement between the output member and the output side engaged portion, causing frictional engagement between the pressed surface and the pressing surface. The outer rings of the first bearing mechanism and the second bearing mechanism are one-piece outer rings in which a first outer ring raceway surface on which the rolling elements of the first bearing mechanism roll, a second outer ring raceway surface on which the rolling elements of the second bearing mechanism roll, and the pressed surface are integrally formed.

[0012] According to the reverse input cutoff clutch of the present invention, it is possible to provide a reverse input cutoff clutch that can suppress wear on the pressed surface and improve the coaxiality between the respective parts, compared to the prior art.

[0013] A cross-sectional view of the reverse input cutoff clutch according to the first embodiment. A cross-sectional view taken along line II-II in FIG. 1. A schematic configuration diagram of the reverse input cutoff clutch according to the first embodiment. A schematic configuration diagram of the reverse input cutoff clutch according to a modified example of the first embodiment. A schematic configuration diagram of the reverse input cutoff clutch according to the second embodiment. A schematic configuration diagram of the reverse input cutoff clutch according to the third embodiment. A schematic configuration diagram of the reverse input cutoff clutch according to the fourth embodiment.

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the center axis C of the reverse input cutoff clutch 1, unless otherwise specified.

[0015] (First embodiment) Fig. 1 is a cross-sectional view of a reverse input cutoff clutch 1 according to a first embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a schematic diagram of the reverse input cutoff clutch 1 according to the first embodiment. Note that Fig. 3 is a schematic diagram for easily explaining the characteristic configuration of the reverse input cutoff clutch 1 according to this embodiment, and is a simplified version of Fig. 1. Also, some components (e.g., the housing 4) are not shown in Fig. 3.

[0016] As shown in Figure 1, the reverse input cutoff clutch 1 of this embodiment is used in, for example, an electric caliper brake or a rear wheel steering device of an automobile or the like. The reverse input cutoff clutch 1 has a locking function (reverse input cutoff function) that cuts off rotational force that is reversely input to the output shaft 31. This realizes a parking brake function in an electric caliper brake, and a function to maintain the steering angle of the wheels when power is cut off in a rear wheel steering device.

[0017] 1 to 3, the reverse input cutoff clutch 1 includes an input member 2, an output member 3, a housing 4, a pair of engagers 5, and a plurality of bearing mechanisms 7 and 8. The reverse input cutoff clutch 1 transmits the rotational force input to the input member 2 to the output member 3. On the other hand, the reverse input cutoff clutch 1 has a reverse input cutoff function that cuts off the rotational force reversely input to the output member 3 and does not transmit it to the input member 2, or that transmits only a portion of the rotational force to the input member 2 and cuts off the remainder.

[0018] The input member 2 is connected to an input mechanism such as an electric motor (not shown). A rotational force from the input mechanism is input to the input member 2. The input member 2 has an input shaft 21 and a pair of arms 23. The input shaft 21 is provided on the input mechanism side in the axial direction. The input shaft 21 is formed in a columnar (or cylindrical) shape centered on a central axis C. In the following description, the side of the input shaft 21 connected to the input mechanism may be referred to as a first axial side, and the opposite side may be referred to as a second axial side.

[0019] The pair of arms 23 extend from the input shaft 21 toward the second side in the axial direction. The arms 23 are integrally formed with the input shaft 21. A pair of the arms 23 is provided at both ends of the input shaft 21 in the first radial direction D1. As shown in FIG. 2 , the arms 23 are trapezoidal in shape with one curved side when viewed in the axial direction. Specifically, the arms 23 have a planar input-side engagement portion 25 facing radially inward, a curved portion 26 facing radially outward, and two side portions 27 connecting the ends of the input-side engagement portion 25 and the curved portion 26. The curved portion 26 is formed in an arc shape centered on the central axis C. Note that the shape of the arms 23 is not limited to the above-described shape. The shape of the arms 23 may be, for example, a semicircular shape, a polygonal shape, an elliptical shape, or the like having an arc-shaped curved portion and a flat portion.

[0020] A plurality of arm portions 23 are provided in accordance with the number of engaging elements 5 described below. In this embodiment, a pair of arm portions 23 is provided in accordance with the number of engaging elements 5. The number of arm portions 23 is not limited to two, and may be one, or three or more, in accordance with the number of engaging elements 5.

[0021] 1 to 3 , the output member 3 is connected to an output mechanism such as a reducer (not shown) and outputs a rotational force (rotational torque). The output member 3 has an output shaft 31 and an insertion portion 32. The output shaft 31 is arranged coaxially with the input shaft 21. The output shaft 31 is provided on the output mechanism side in the axial direction (second axial side). The output shaft 31 is formed in a columnar (or cylindrical) shape centered on a central axis C.

[0022] The insertion portion 32 extends from a first axial end of the output shaft 31 toward the first axial side. The insertion portion 32 is integrally formed with the output shaft 31. The insertion portion 32 is inserted between a pair of engaging elements 5 (described later) and is disposed radially inward of a pair of arm portions 23 of the input member 2. A base end of the insertion portion 32 inserted between the pair of engaging elements 5 (e.g., a portion located on the second axial side relative to the retaining ring 39 in FIG. 1 ) is formed in a plate shape (see also FIG. 2 ). A tip end of the insertion portion 32 (e.g., a portion located on the first axial side relative to the retaining ring 39) is formed in a cylindrical shape. Note that the shape of the base end of the insertion portion 32 is not limited to a plate shape. The tip end of the insertion portion 32 may be rotatably supported on the input shaft 21 via a bearing (not shown).

[0023] As shown in FIG. 2 , the outer peripheral surface of the base end of the insertion portion 32 has a pair of output-side engaging portions 35 facing both sides in the thickness direction (first radial direction D1) of the insertion portion 32, and a pair of side surfaces 36 connecting the ends of the pair of output-side engaging portions 35. Each output-side engaging portion 35 is configured with a flat surface along the second radial direction D2. Each output-side engaging portion 35 faces a pair of engaging elements 5. The output-side engaging portion 35 is provided more inward in the first radial direction D1 than the input-side engaging portion 25 of the input member 2. The pair of side surfaces 36 connect both ends of the output-side engaging portion 35.

[0024] The insertion portion 32 is provided with a plurality of output side engaging portions 35 and side surface portions 36 in accordance with the number of engaging elements 5 described below. In this embodiment, a pair of output side engaging portions 35 and side surface portions 36 is provided in accordance with the provision of a pair of engaging elements 5. The number of output side engaging portions 35 is not limited to two, and the number of output side engaging portions 35 may be one, or three or more, in accordance with the number of engaging elements 5.

[0025] As shown in FIG. 1 , the housing 4 is disposed radially outward of the input member 2 and output member 3 described above. The housing 4 is a housing component having a cylindrical inner periphery. The housing 4 is fixed to another member (not shown) and its rotation is restricted. The input member 2, output member 3, and a pair of engaging elements 5 are housed inside the inner periphery of the housing 4. The housing 4 houses the input member 2 and output member 3 in a rotatable state via a plurality of bearing mechanisms 7 and 8, which will be described in detail later.

[0026] 1 to 3 , the pair of engaging elements 5 are semicircular and disposed radially inward of the housing 4. The pair of engaging elements 5 face each other in the first radial direction D1 and are configured to be movable toward and away from each other in the first radial direction D1. Each of the pair of engaging elements 5 has a pressing surface 51, a bottom surface 52, an input-side engaged portion 55, and an output-side engaged portion 56.

[0027] As shown in FIG. 2 , the pressing surface 51 is a radially outer surface that presses a pressed surface 62 provided on an outer ring 61 (an integrated outer ring 61 in the claims) of the first bearing mechanism 7 and the second bearing mechanism 8 described below, and is an arc-shaped convex surface. Note that a portion of the outer circumferential surface of the engaging element 5 that faces the pressed surface 62 may be used as the pressing surface 51. The pressing surface 51 presses the pressed surface 62 when the reverse input disconnection clutch 1 is in a locked state (a state in which the reverse input from the output member 3 is disconnected). The radius of curvature of the pressing surface 51 is equal to or smaller than the radius of curvature of the pressed surface 62. Two pressing surfaces 51 are provided for each engaging element 5, and are formed so as to increase the frictional engagement force between the engaging element 5 and the pressed surface 62 due to a wedge effect. The two pressing surfaces 51 are provided at positions spaced apart from each other in the circumferential direction of the engaging element 5. The pressing surface 51 may be directly formed by the entire or part of the outer circumferential surface of the engaging element 5, or may be formed to have a surface property with a higher friction coefficient than other parts of the engaging element 5. For example, the pressing surface 51 may be formed by a friction material fixed to the engaging element 5 by sticking or bonding.

[0028] The bottom surface 52 of the engaging element 5 is located inward in the first radial direction D1 from the pressing surface 51. The bottom surface 52, together with an output-side engaged portion 56 of the engaging element 5, which will be described in detail later, forms a linear portion of the semicircular engaging element 5. In the present embodiment, the bottom surface 52 is formed as a substantially flat surface except for a pair of protrusions 53, which will be described later. The bottom surfaces 52 of the pair of engaging elements 5 face each other in the first radial direction D1. The inner diameter dimension of the pressed surface 62 and the outer dimensions of the engaging element 5 are set so that, when the pair of engaging elements 5 are arranged inside the pressed surface 62, a gap exists between at least one of the pressed surface 62 and the pressing surface 51 and between the pair of bottom surfaces 52 and the output member 3.

[0029] The input side engaged portion 55 is a hole that penetrates the axial direction through the center of the engaging element 5 when viewed from the axial direction. The input side engaged portion 55 is formed in the shape of an elongated hole extending in the second radial direction D2. The arm portions 23 of the input member 2 are inserted into the input side engaged portions 55, respectively. The input side engaged portions 55 engage with the arm portions 23. The input side engaged portions 55 have a size that allows the arm portions 23 of the input member 2 to be loosely inserted therein. Specifically, the input side engaged portions 55 are formed so that when the arm portions 23 of the input member 2 are inserted inside the input side engaged portions 55, a gap exists between the arm portions 23 and the inner peripheral surface of the input side engaged portions 55.

[0030] The output-side engaged portion 56 is provided near the center in the second radial direction D2 of the straight portion (bottom surface 52) of the semicircular engaging element 5. The output-side engaged portion 56 is provided more inward in the first radial direction D1 than the input-side engaged portion 55. The output-side engaged portion 56 is engaged with the insertion portion 32 of the output member 3. The output-side engaged portion 56 is formed as a flat surface continuous with the bottom surface 52.

[0031] 1 and 2, when the reverse input cutoff clutch 1 is assembled, the arm portion 23 of the input member 2 is axially inserted into the input-side engaged portions 55 of the pair of engagers 5, and the insertion portion 32 of the output member 3 is axially inserted between the output-side engaged portions 56 of the pair of engagers 5. In other words, the pair of engagers 5 are arranged so that the output-side engaged portions 56 sandwich the insertion portion 32 of the output member 3 from the radially outer side.

[0032] As shown in FIG. 1 , a leaf spring 38 is provided between the pair of engaging elements 5. The leaf spring 38 is elastically sandwiched and disposed between the engaging elements 5 and the output member 3. The leaf spring 38 biases the engaging elements 5 radially outward, i.e., toward the pressed surface 62. A retaining ring 39 for positioning each component is provided on a first axial side of the engaging elements 5. Furthermore, end plates (not shown) or the like for positioning each component may be provided on both axial sides of the engaging elements 5. In addition to the positioning function, components such as end plates may be provided to prevent contact between the engaging elements 5 and the output member 3 and input member 2, thereby suppressing wear, for example. The leaf spring 38 may be omitted.

[0033] 1 and 3, the reverse input disconnecting clutch 1 has a plurality of bearing mechanisms, namely, a first bearing mechanism 7 and a second bearing mechanism 8. In this embodiment, the first bearing mechanism 7 and the second bearing mechanism 8 are both deep groove ball bearings.

[0034] The first bearing mechanism 7 rotatably supports the input member 2 relative to the housing 4. The first bearing mechanism 7 includes a first rolling element 70 (the rolling element of the first bearing mechanism in the claims) that rolls around the input shaft 21, an integral outer ring 61 (common to a second bearing mechanism 8 described later in detail), a first outer ring raceway groove 73 (an outer ring raceway surface in the claims) and a pressed surface 62 formed in the integral outer ring 61, and a first inner ring raceway groove 75 (an inner ring raceway surface in the claims) formed in the input shaft 21. The integral outer ring 61 is formed in a cylindrical shape centered on the central axis C. The outer peripheral surface of the integral outer ring 61 is attached to the inner peripheral portion of the housing 4 (see FIG. 1 ). The integral outer ring 61 is provided axially from the portion where the input shaft 21 is located to the portion where the output shaft 31 is located. On the inner peripheral surface of the one-piece outer ring 61, a first outer ring raceway groove 73 in which the first rolling element 70 rolls, a pressed surface 62 that comes into contact with the engaging element 5, and a second outer ring raceway groove 83 in which the second rolling element 80 of the second bearing mechanism 8 rolls are formed, lined up in this order from the first side in the axial direction. That is, the pressed surface 62 is disposed axially between the first outer ring raceway groove 73 and the second outer ring raceway groove 83. The outer ring of the first bearing mechanism 7 is the one-piece outer ring 61 in which the first outer ring raceway groove 73 in which the first rolling element 70 of the first bearing mechanism 7 rolls, the second outer ring raceway groove 83 in which the second rolling element 80 of the second bearing mechanism 8 rolls, and the pressed surface 62 are integrally formed in a single component.

[0035] The one-piece outer ring 61 is formed of a high-hardness steel material such as bearing steel. An example of a high-hardness steel material is a heat-treated high-carbon steel such as SUJ3 or SUJ2. Note that the steel material is not limited to the above-mentioned materials as long as it has high hardness.

[0036] A first inner ring raceway groove 75 that contacts the first rolling element 70 and allows the first rolling element 70 to roll is formed on the outer peripheral surface of the input shaft 21. In other words, the first bearing mechanism 7 of this embodiment is formed without having a separate component that constitutes an inner ring. Therefore, the first rolling element 70 rolls in a rolling element raceway that is formed between the first inner ring raceway groove 75 formed on the input shaft 21 and the first outer ring raceway groove 73 formed on the one-piece outer ring 61.

[0037] The second bearing mechanism 8 is provided on a second axial side of the first bearing mechanism 7. The second bearing mechanism 8 rotatably supports the output member 3 with respect to the housing 4. The second bearing mechanism 8 has a second rolling element 80 (the rolling element of the second bearing mechanism in the claims) that rolls around the output shaft 31, an integrated outer ring 61 shared with the above-mentioned first bearing mechanism 7, a second outer ring raceway groove 83 (the outer ring raceway surface in the claims) formed in the integrated outer ring 61, and a second inner ring raceway groove 85 (the inner ring raceway surface in the claims) formed in the output shaft 31.

[0038] In this embodiment, the first bearing mechanism 7 and the second bearing mechanism 8 are of the same type of bearing (deep groove ball bearing), but have different parameters such as bearing size. In this embodiment, the bearing of the first bearing mechanism 7 has a larger PCD (Pitch Circle Diameter) value and bearing diameter than the bearing of the second bearing mechanism 8. Note that, in addition to PCD, other bearing parameters may also be different, such as the diameter of the rolling elements, the diameters of the inner and outer rings, and the load rating.

[0039] Furthermore, in this embodiment, since the bearing sizes of the first bearing mechanism 7 and the second bearing mechanism 8 are different, the inner diameter dimension of the integrated outer ring 61 is formed to be different on the input member 2 side and the output member 3 side. Specifically, the inner diameter dimension R1 of the integrated outer ring 61 on the first axial side where the first outer ring raceway groove 73 and the pressed surface 62 are formed is larger than the inner diameter dimension R2 of the integrated outer ring 61 on the second axial side where the second outer ring raceway groove 83 is formed (R1 > R2). A step 63 is provided on the inner peripheral portion of the integrated outer ring 61 between the pressed surface 62 and the second outer ring raceway groove 83 in the axial direction.

[0040] A second inner ring raceway groove 85 that comes into contact with the second rolling element 80 and allows the second rolling element 80 to roll is formed on the outer peripheral surface of the output shaft 31. In other words, the second bearing mechanism 8 of this embodiment is formed without having a separate component that constitutes an inner ring, similar to the first bearing mechanism 7. Therefore, the second rolling element 80 rolls in a rolling element raceway that is formed between the second inner ring raceway groove 85 formed on the output shaft 31 and the second outer ring raceway groove 83 formed on the one-piece outer ring 61.

[0041] In this embodiment, the first bearing mechanism 7 and the second bearing mechanism 8 are of the same type of bearing, but this is not limited to this. The first bearing mechanism 7 and the second bearing mechanism 8 may be of different types of bearing. Furthermore, the type of bearing is not limited to deep groove ball bearings. As an example, the type of bearing may be any of angular contact ball bearings, deep groove ball bearings, four-point contact ball bearings, tapered roller bearings, and cylindrical roller bearings. These may also be used in combination.

[0042] (Operation of the Reverse Input Disconnect Clutch) Next, the operation of the reverse input disconnect clutch 1 of this embodiment will be described. First, a case where a rotational force is input to the input shaft 21 from the input mechanism will be described. When a rotational force is input to the input shaft 21, as shown in FIG. 2 , the arm portion 23 of the input member 2 rotates around the central axis C inside the input-side engaging portion 25 in the rotational direction of the input shaft 21 (counterclockwise CCW in the example shown in FIG. 2 ). Then, a corner portion (point P1 in FIG. 2 ) between the input-side engaging portion 25 and the side surface portion 27 on the counterclockwise CCW side of the arm portion 23 presses the inner surface of the input-side engaged portion 55 radially inward, causing the pair of engaging elements 5 to move in a direction away from the pressed surface 62 (inward in the first radial direction D1). In other words, the pair of engaging elements 5 move radially inward and closer to each other due to the rotational force from the input shaft 21 acting on them via the input-side engaged portion 55. As a result, the bottom surfaces 52 of the pair of engaging elements 5 move in a direction approaching each other, and the pair of output-side engaged portions 56 clamp the insertion portion 32 of the output shaft 31 from both radial sides.

[0043] As a result, the output member 3 is rotated so that the longitudinal axis direction of the insertion portion 32 is parallel to the bottom surface 52 of the engagement element 5, and the insertion portion 32 and the pair of output-side engaged portions 56 are engaged without rattle. Therefore, the rotational force input to the input shaft 21 is transmitted to the output member 3 via the pair of engagement elements 5 and output from the output shaft 31. When a rotational force is input to the input shaft 21, the reverse input cutoff clutch 1 of this embodiment moves the pair of engagement elements 5 in directions away from the pressed surface 62, regardless of the rotational direction of the input shaft 21. Then, regardless of the rotational direction of the input shaft 21, the rotational force input to the input shaft 21 is transmitted to the output shaft 31 via the pair of engagement elements 5.

[0044] Next, a case where a rotational force is input from the output mechanism to the output shaft 31 will be described. When a rotational force is input to the output shaft 31 in a reverse direction, as shown in FIG. 2 , the insertion portion 32 of the output member 3 rotates in the rotational direction of the output shaft 31 (clockwise CW in the example shown in FIG. 2 ) inside the pair of output-side engaged portions 56. Then, the corner portion (point P2 in FIG. 2 ) between the side surface portion 36 of the insertion portion 32 and the output-side engaging portion 35 presses the output-side engaged portion 56 radially outward, moving each of the pair of engaging elements 5 in a direction approaching the pressed surface 62. In other words, based on the engagement between the output member 3 and the output-side engaged portion 56, the pair of engaging elements 5 move away from each other radially outward in the first radial direction D1. As a result, the pressing surface 51 of each of the pair of engaging elements 5 is pressed against the pressed surface 62. At this time, the pressing surface 51 and the pressed surface 62 are frictionally engaged over the entire circumferential range of the pressing surface 51 or at least a portion thereof.

[0045] As a result, the rotational force reversely input to the output shaft 31 is blocked and not transmitted to the input member 2, or only a portion of the rotational force reversely input to the output shaft 31 is transmitted to the input member 2 and the remainder is blocked. To completely block the rotational force reversely input to the output shaft 31 and prevent it from being transmitted to the input member 2, the pair of engaging elements 5 are tensioned between the insertion portion 32 and the pressed surface 62 so that the pressing surface 51 does not slide (rotate relative to) the pressed surface 62, thereby locking the output member 3. On the other hand, to transmit only a portion of the rotational force reversely input to the output shaft 31 to the input member 2 and block the remainder, the pair of engaging elements 5 are tensioned between the insertion portion 32 and the pressed surface 62 so that the pressing surface 51 slides against the pressed surface 62, thereby semi-locking the output member 3. When a rotational force is further input in reverse to the output shaft 31 while the output member 3 is half-locked, the pair of engaging elements 5 rotate about the central axis C while sliding the pressing surface 51 against the pressed surface 62 based on the engagement between the insertion portion 32 of the output member 3 and the output-side engaged portion 56. When the pair of engaging elements 5 rotate, the inner surface of the input-side engaged portion 55 presses the radially inner surface of the arm portion 23 of the input member 2 in the circumferential direction (rotational direction), and part of the rotational force is transmitted to the input member 2.

[0046] (Operations and Effects) According to the reverse input cutoff clutch 1 of this embodiment, the outer rings of the first bearing mechanism 7 and the second bearing mechanism 8 are configured as an integral outer ring 61 in which the first outer ring raceway groove 73 (first outer ring raceway surface in the claims) in which the first rolling element 70 of the first bearing mechanism 7 rolls, the second outer ring raceway groove 83 (second outer ring raceway surface in the claims) in which the second rolling element 80 of the second bearing mechanism 8 rolls, and the pressed surface 62 are integrally provided as a single component. Since the pressed surface 62 is integrally formed with the outer ring of the bearing (the integral outer ring 61 in this embodiment) which is generally made of a hard material, the hardness of the pressed surface 62 can be increased. This makes it possible to suppress wear caused by the pressing surface 51 of the engaging element 5 sliding on the pressed surface 62. Furthermore, the one-piece outer ring 61 is integrally provided with the first outer ring raceway groove 73 in which the first rolling element 70 on the input member 2 side rolls, the second outer ring raceway groove 83 in which the second rolling element 80 on the output member 3 side rolls, and the pressed surface 62, making it easier to ensure coaxiality between the input member 2, the output member 3, and the pressed surface 62. Therefore, a reverse input cutoff clutch 1 can be provided that can reduce wear on the pressed surface 62 while improving the coaxiality between each component compared to the prior art. By improving the coaxiality between the input member 2 and the pressed surface 62, the pair of arms 23 can press against the engaging element 5 at the same time, thereby reducing the occurrence of component wear, vibration, and foreign matter contamination due to one arm 23 pressing against the engaging element 5 first. Similarly, improving the coaxiality between the output member 3 and the pressed surface 62 makes it easier to equalize the gap between the pair of engaging elements 5 and the pressed surface 62. Therefore, deterioration of the locking function and occurrence of bending in the output member 3 can be suppressed, and the performance of the reverse input cutoff clutch 1 can be improved.

[0047] The first bearing mechanism 7 and the second bearing mechanism 8 have bearings of different sizes, which allows the bearing mechanisms to be configured in a variety of combinations, thereby increasing the versatility of the reverse input disconnecting clutch 1.

[0048] The first bearing mechanism 7 and the second bearing mechanism 8 may have different bearing types. In this case, the bearing mechanisms can be configured in various combinations. This further increases the versatility of the reverse input disconnecting clutch 1.

[0049] The input member 2 is integrally formed with a first inner ring raceway groove 75 (inner ring raceway surface in the claims) of the first bearing mechanism 7. This eliminates the need to provide a separate component as an inner ring, thereby reducing the number of components. Furthermore, since the first inner ring raceway groove 75 and the arm portion 23 of the input member 2 can be machined in the same process using a single chuck, for example, the coaxiality between the input member 2 and other components can be improved. Furthermore, since the mating surfaces in the first bearing mechanism 7 are smaller than when a separate inner ring is provided, the coaxiality between the components connected via the first bearing mechanism 7 can be improved.

[0050] The output member 3 is integrally formed with a second inner ring raceway groove 85 (inner ring raceway surface in the claims) of the second bearing mechanism 8. This eliminates the need to provide a separate component as an inner ring, thereby reducing the number of components. Furthermore, since the second inner ring raceway groove 85 and the insertion portion 32 of the output member 3 can be machined in the same process using a single chuck, for example, the coaxiality between the output member 3 and other components can be improved. Furthermore, since the mating surfaces in the second bearing mechanism 8 are smaller than when a separate inner ring is provided, the coaxiality between the components connected via the second bearing mechanism 8 can be improved.

[0051] The first bearing mechanism 7 and the second bearing mechanism 8 may be any of a deep groove ball bearing, an angular contact ball bearing, a four-point contact ball bearing, a tapered roller bearing, and a cylindrical roller bearing. This allows various types of bearings to be applied to the present invention, thereby increasing the versatility of the reverse input disconnecting clutch 1.

[0052] (Modification of First Embodiment) Next, a modification of the first embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment described above will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Note that the specific configuration is not limited to these embodiments, and can be modified as appropriate without departing from the gist of the present invention. FIG. 4 is a schematic diagram of a reverse input cutoff clutch 1A according to a modification of the first embodiment. The modification of the first embodiment differs from the first embodiment described above in that the bearing load rating of the second bearing mechanism 8 is configured to be greater than the bearing load rating of the first bearing mechanism 7.

[0053] In this modification of the first embodiment, the bearing of the second bearing mechanism 8 has a larger PCD value, bearing diameter, and ball diameter than the bearing of the first bearing mechanism 7. As a result, the load rating of the bearing of the second bearing mechanism 8 is configured to be larger than the load rating of the bearing of the first bearing mechanism 7. More specifically, the load rating of the bearing of the second bearing mechanism 8 is configured to be larger than at least one of the dynamic load rating and static load rating of the bearing of the first bearing mechanism 7. Furthermore, since the bearing sizes of the first bearing mechanism 7 and the second bearing mechanism 8 are different, the inner diameter dimensions of the one-piece outer ring 61 on the input member 2 side and the output member 3 side are different. Specifically, the inner diameter dimension R4 of the one-piece outer ring 61 on the second axial side where the second outer ring raceway groove 83 and the pressed surface 62 are formed is larger than the inner diameter dimension R3 of the one-piece outer ring 61 on the first axial side where the first outer ring raceway groove 73 is formed (R4>R3). A step 63 is provided on the inner peripheral portion of the one-piece outer ring 61 between the pressed surface 62 and the first outer ring raceway groove 73 in the axial direction.

[0054] According to the reverse input cutoff clutch 1A of the modified example of the first embodiment, the second bearing mechanism 8 located on the output mechanism side of the reverse input cutoff clutch 1A is configured so that the rated load of the second bearing mechanism 8 is greater than the rated load of the first bearing mechanism 7 located on the input mechanism side. Here, a motor shaft or the like is connected to the input shaft 21 of the reverse input cutoff clutch 1A, and a gear or the like is connected to the output shaft 31. Therefore, the load received by the output member 3 tends to be greater than that received by the input member 2. According to this modified example, the rated load of the second bearing mechanism 8 located on the output member 3 side is greater than the rated load of the first bearing mechanism 7, so that a relatively large load such as a gear load can be supported by the second bearing mechanism 8. Therefore, the reverse input cutoff clutch 1A can be made particularly suitable for cases where the load of the output mechanism is greater than that of the input mechanism.

[0055] In the modified example of the first embodiment, the parameters such as PCD of the first bearing mechanism 7 and the second bearing mechanism 8 are not limited to those of the above-described embodiment. For example, the second bearing mechanism 8 may be formed so that the PCD value is smaller and the ball diameter is larger than that of the first bearing mechanism 7. In other words, it is only necessary that the second bearing mechanism 8 is formed so that the rated load of the bearing is larger than the rated load of the bearing of the first bearing mechanism 7, and the magnitude of each parameter is not limited to that of the above-described embodiment.

[0056] Second Embodiment Next, a second embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment described above will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Note that the specific configuration is not limited to these embodiments, and can be modified as appropriate without departing from the gist of the present invention. FIG. 5 is a schematic diagram of a reverse input cutoff clutch 201 according to the second embodiment. The second embodiment differs from the first embodiment described above in that the inner rings of the first bearing mechanism 7 and the second bearing mechanism 8 are formed separately from the input member 2 and the output member 3.

[0057] In the second embodiment, a first inner ring 245 is attached to the outer periphery of the input shaft 21 of the input member 2. A first inner ring raceway groove 275 for rolling of the first rolling element 70 is formed on the outer periphery of the first inner ring 245. In other words, in this embodiment, the first bearing mechanism 207 has the first rolling element 70, the one-piece outer ring 61, the first outer ring raceway groove 73 and the pressed surface 62 formed on the one-piece outer ring 61, the first inner ring 245 attached to the input member 2, and the first inner ring raceway groove 275 formed on the first inner ring 245.

[0058] A second inner ring 246 is attached to the outer periphery of the output shaft 31 of the output member 3. A second inner ring raceway groove 285 in which the second rolling element 80 rolls is formed on the outer periphery of the second inner ring 246. In other words, in this embodiment, the second bearing mechanism 208 has the second rolling element 80, the one-piece outer ring 61, the second outer ring raceway groove 83 and the pressed surface 62 formed on the one-piece outer ring 61, the second inner ring 246 attached to the output member 3, and the second inner ring raceway groove 285 formed on the second inner ring 246.

[0059] The reverse input cutoff clutch 201 of the second embodiment can achieve the same effects as those of the first embodiment. That is, the pressed surface 62 is integrally formed with the outer ring (integral outer ring 61) of the bearing, which is generally made of a hard material, so the hardness of the pressed surface 62 can be increased. This can suppress wear, etc., caused by the pressing surface 51 of the engagement element 5 sliding on the pressed surface 62. Furthermore, the integrated outer ring 61 is integrally provided with the first outer ring raceway groove 73, the second outer ring raceway groove 83, and the pressed surface 62, so the coaxiality of the input member 2, the output member 3, and the pressed surface 62 can be improved. Therefore, it is possible to provide a reverse input cutoff clutch 201 that can suppress wear of the pressed surface 62 and improve the coaxiality of each component, compared to the prior art.

[0060] Third Embodiment Next, a third embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment described above will be denoted by the same reference numerals, and description thereof will be omitted where appropriate. Figure 6 is a schematic diagram of a reverse input cutoff clutch 301 according to the third embodiment. The third embodiment differs from the first embodiment described above in that the first bearing mechanism 7 and the second bearing mechanism 8 have the same bearing type and size.

[0061] In the third embodiment, the bearings of the first bearing mechanism 307 and the second bearing mechanism 308 are the same type and size (diameter of the rolling elements, PCD, etc.). Therefore, the inner peripheral portion of the one-piece outer ring 361 is formed without the step 63 (see FIG. 3) of the first embodiment, and is formed to have a substantially uniform inner diameter dimension R3 in the axial direction. In other words, the first outer ring raceway groove 373, the pressed surface 62, and the second outer ring raceway groove 383 formed on the inner peripheral portion of the one-piece outer ring 361 are located at substantially the same radial position.

[0062] As in the first embodiment, a first inner ring raceway groove 375 is formed on the outer peripheral surface of the input shaft 21, which comes into contact with the first rolling element 370 and allows the first rolling element 370 to roll thereon. As in the first embodiment, a second inner ring raceway groove 385 is formed on the outer peripheral surface of the output shaft 31, which comes into contact with the second rolling element 380 and allows the second rolling element 380 to roll thereon.

[0063] The reverse input cutoff clutch 301 of the third embodiment is particularly suitable when the same bearing is used for the first bearing mechanism 307 and the second bearing mechanism 308. This increases the versatility of the reverse input cutoff clutch 301. Furthermore, since the integral outer ring 361 is formed without the step portion 63, the integral outer ring 361 can be formed more easily than when the step portion 63 is included. Furthermore, the radial thickness of the integral outer ring 361 can be kept small. Note that in the third embodiment, the inner rings (first inner ring 245 and second inner ring 246) may be provided as separate members, as in the second embodiment described above.

[0064] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment described above will be denoted by the same reference numerals, and description thereof will be omitted as appropriate. Figure 7 is a schematic diagram of a reverse input cutoff clutch 401 according to the fourth embodiment. The fourth embodiment differs from the first embodiment described above in that tapered roller bearings are used as the bearings for the first bearing mechanism 7 and the second bearing mechanism 8.

[0065] In the fourth embodiment, the first bearing mechanism 407 and the second bearing mechanism 408 are both tapered roller bearings. The first bearing mechanism 407 rotatably supports the input shaft 21 and has a pair of third tapered roller bearings 493 and fourth tapered roller bearings 494. The third tapered roller bearing 493 is provided at a first axial end of the integral outer ring 461. The third tapered roller bearing 493 has tapered rollers as third rolling elements 470, the integral outer ring 461, a third outer ring raceway groove 473 formed in the integral outer ring 461, and a third inner ring raceway groove 475 formed in the input shaft 21. The third tapered roller bearing 493 is provided so that the apex of the conical surface of the third rolling element 470 is located on the second axial side. The third outer ring raceway groove 473 formed on the inner peripheral portion of the integral outer ring 461 is formed so that its inner diameter gradually increases from the second axial side toward the first axial side.

[0066] The fourth tapered roller bearing 494 is disposed at a distance from the third tapered roller bearing 493 to the first axial direction. The fourth tapered roller bearing 494 is configured symmetrically to the third tapered roller bearing 493, and therefore detailed description of portions that overlap with the configuration of the third tapered roller bearing 493 will be omitted. The fourth tapered roller bearing 494 is disposed so that the apex of the conical surface of the conical roller, which is the fourth rolling element 471, is located on the first axial direction. In addition, in this embodiment, the outer ring 463 of the fourth tapered roller bearing 494 is formed as a component separate from the one-piece outer ring 461. An input mechanism 491 is connected to the input shaft 21 between the third tapered roller bearing 493 and the fourth tapered roller bearing 494. As a result, a rotational force from the input mechanism 491 is input to the input member 2.

[0067] The second bearing mechanism 408 rotatably supports the output shaft 31 and has a pair of fifth and sixth tapered roller bearings 495 and 496. The fifth tapered roller bearing 495 is provided at the second axial end of the one-piece outer ring 461. The fifth tapered roller bearing 495 has tapered rollers as fifth rolling elements 480, the one-piece outer ring 461, a fifth outer ring raceway groove 483 formed in the one-piece outer ring 461, and a fifth inner ring raceway groove 485 formed in the output shaft 31. The fifth tapered roller bearing 495 is provided so that the apex of the conical surface of the fifth rolling element 480 is located on the first axial side. The fifth outer ring raceway groove 483 formed on the inner peripheral portion of the one-piece outer ring 461 is formed so that the inner diameter gradually increases from the first axial side toward the second axial side.

[0068] The sixth tapered roller bearing 496 is disposed at a distance from the fifth tapered roller bearing 495 to the second axial direction. The sixth tapered roller bearing 496 is configured symmetrically to the fifth tapered roller bearing 495, and therefore detailed description of portions that overlap with the configuration of the fifth tapered roller bearing 495 will be omitted. The sixth tapered roller bearing 496 is disposed so that the apex of the conical surface of the tapered roller, which is the sixth rolling element 481, is located on the second axial direction. In addition, in this embodiment, the outer ring 464 of the sixth tapered roller bearing 496 is formed as a component separate from the one-piece outer ring 461. An output mechanism 492 is connected to the output shaft 31 between the fifth tapered roller bearing 495 and the sixth tapered roller bearing 496. As a result, the rotational force (rotational torque) transmitted from the input member 2 to the output member 3 is output to the output mechanism 492.

[0069] According to the reverse input disconnection clutch 401 of the fourth embodiment, tapered roller bearings can be used as the bearings of the first bearing mechanism 407 and the second bearing mechanism 408. Furthermore, the configuration using tapered roller bearings can achieve the same effects as those of the first embodiment. Therefore, the versatility of the reverse input disconnection clutch 401 can be improved.

[0070] The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described first embodiment, the pressed surface 62 and the first outer ring raceway groove 73 are formed at equivalent radial positions in the one-piece outer ring 61, but this is not limited to this. The pressed surface 62 and the first outer ring raceway groove 73 may be positioned at different radial positions in the one-piece outer ring 61. In this case, a second step (not shown) or the like may be provided between the pressed surface 62 and the first outer ring raceway groove 73 in the axial direction to make the inner diameter dimension different. The same applies to the third and fourth embodiments.

[0071] In the above-described embodiments, a configuration has been described in which the pressed surface 62 is disposed between the first outer ring raceway groove 73, 373, 473 and the second outer ring raceway groove 83, 383, 483 in the axial direction in the one-piece outer ring 61, 361, 461, but this is not limited to this. For example, the first outer ring raceway groove 73, 373, 473, the second outer ring raceway groove 83, 383, 483, and the pressed surface 62 may be disposed in this order from the first side in the axial direction. The arrangement order is not limited to this.

[0072] In the above-described embodiments, the input shaft 21 and the arm portion 23 of the input member 2 are integrally formed. However, this is not limiting. The input member 2 may be formed by combining multiple parts. Similarly, the output shaft 31 and the insertion portion 32 of the output member 3 may be formed by combining separate parts. In this case, a portion of the output shaft 31 may be inserted between the bottom surfaces 52 of the pair of engaging elements 5, and the insertion portion 32 formed separately from the output shaft 31 may be extrapolated to the outer periphery of the portion inserted between the pair of engaging elements 5. Alternatively, the output shaft 31 and the insertion portion 32 may be connected to each other in the axial direction.

[0073] In the fourth embodiment described above, the first bearing mechanism 407 and the second bearing mechanism 408 have the same type and size of bearings, but this is not limited to this. For example, the third tapered roller bearing 493 and the fourth tapered roller bearing 494 may have different bearing sizes from the fifth tapered roller bearing 495 and the sixth tapered roller bearing 496. In the fourth embodiment, the one-piece outer ring 461 and the outer ring 463 of the fourth tapered roller bearing 494 may be the same part. Similarly, the one-piece outer ring 461 and the outer ring 464 of the sixth tapered roller bearing 496 may be the same part.

[0074] The reverse input cutoff clutches 1, 201, 301, and 401 of the above-described embodiments may be applied to a system in which the direction of the reverse input torque is not constant, for example. Similarly, they may be applied to a system in which the direction of the input torque is not constant.

[0075] In the above-described embodiments, the reverse input cutoff clutches 1, 201, 301, and 401 are linkless reverse input cutoff clutches that do not use a link structure as a reverse input cutoff mechanism, but the present invention is not limited to this. A link-type reverse input cutoff clutch that uses a link mechanism, which is a known technology, may also be used as the reverse input cutoff mechanism.

[0076] The present disclosure may also be a combination of the following configurations: (1) An input member having an input shaft, an output member having an output shaft arranged coaxially with the input shaft and arranged side by side with the input member in the axial direction, a pressed surface provided radially outward of the input member and the output member and facing inward in the radial direction, a pair of engagers having a pressing surface opposing the pressed surface, an input-side engaged portion engageable with the input member, and an output-side engaged portion engageable with the output member, and being movable relative to each other along a first radial direction, a first bearing mechanism that rotatably supports the input member, and a second bearing mechanism that rotatably supports the output member, wherein when a rotational torque is input to the input shaft, the pair of engagers move toward each other radially inward in the first radial direction based on the engagement between the input member and the input-side engaged portion, and transmit the rotational torque to the output shaft based on the engagement between the output member and the output-side engaged portion, When a rotational torque is reverse input to the output shaft, the pair of engaging elements move away from each other radially outward in the first radial direction based on engagement between the output member and the output-side engaged portion, frictionally engaging the pressed surface and the pressing surface, and the outer rings of the first bearing mechanism and the second bearing mechanism are integral outer rings in which a first outer ring raceway surface on which the rolling elements of the first bearing mechanism roll, a second outer ring raceway surface on which the rolling elements of the second bearing mechanism roll, and the pressed surface are integrally provided. (2) The reverse input cutoff clutch according to (1), in which the first bearing mechanism and the second bearing mechanism have bearings of different sizes. (3) The reverse input cutoff clutch according to (1) or (2), in which the first bearing mechanism and the second bearing mechanism have bearings of different types. (4) The reverse input cutoff clutch according to any one of (1) to (3), in which an inner ring raceway surface of the first bearing mechanism is integrally formed with the input member. (5) The reverse input cutoff clutch according to any one of (1) to (4), wherein an inner ring raceway surface of the second bearing mechanism is integrally formed with the output member.(6) The reverse input cutoff clutch according to any one of (1) to (5), wherein the load rating of the bearing in the second bearing mechanism is greater than at least one of the dynamic load rating and the static load rating of the bearing in the first bearing mechanism. (7) The reverse input cutoff clutch according to any one of (1) to (6), wherein the first bearing mechanism and the second bearing mechanism are deep groove ball bearings, angular contact ball bearings, four-point contact ball bearings, tapered roller bearings, and cylindrical roller bearings.

[0077] DESCRIPTION OF SYMBOLS 1, 201, 301, 401 Reverse input cutoff clutch 2 Input member 3 Output member 5 Engagement element 7, 207, 307, 407 First bearing mechanism 8, 208, 308, 408 Second bearing mechanism 21 Input shaft 31 Output shaft 51 Pressing surface 55 Input-side engaged portion 56 Output-side engaged portion 61, 361, 461 Integrated outer ring (outer ring of first bearing mechanism and outer ring of second bearing mechanism) 62 Pressing surface 70, 370 First rolling element (rolling element of first bearing mechanism) 73, 373 First outer ring raceway groove (first outer ring raceway surface) 75, 275, 375 First inner ring raceway groove (inner ring raceway surface) 80, 380 Second rolling element (rolling element of second bearing mechanism) 83, 383 Second outer ring raceway groove (second outer ring raceway surface) 85, 285, 385 Second inner ring raceway groove (inner ring raceway surface) 470 Third rolling element (rolling element of first bearing mechanism) 473 Third outer ring raceway groove (first outer ring raceway surface) 475 Third inner ring raceway groove (inner ring raceway surface) 480 Fifth rolling element (rolling element of second bearing mechanism) 483 Fifth outer ring raceway groove (second outer ring raceway surface) 485 Fifth inner ring raceway groove (inner ring raceway surface) D1 First radial direction

Claims

1. An input member having an input shaft, The output shaft is arranged coaxially with the input shaft, and the output member is arranged parallel to the input member in the axial direction, A surface to be pressed is provided radially outward from the input member and the output member, and facing radially inward, A pair of engaging elements having a pressing surface facing the pressed surface, an input-side engaging portion that can engage with the input member, and an output-side engaging portion that can engage with the output member, and which are movable relative to each other along the first radial direction, A first bearing mechanism that rotatably supports the input member, A second bearing mechanism that rotatably supports the output member, Equipped with, When rotational torque is applied to the input shaft, the pair of engaging elements move toward each other radially inward in the first radial direction based on the engagement between the input member and the input-side engaged portion, and transmit the rotational torque to the output shaft based on the engagement between the output member and the output-side engaged portion. When rotational torque is applied in reverse to the output shaft, the pair of engaging elements move apart from each other radially outward in the first radial direction based on the engagement between the output member and the output-side engaged portion, causing frictional engagement between the pressed surface and the pressing surface. The outer rings of the first bearing mechanism and the second bearing mechanism are integrated outer rings in which the first outer ring raceway surface on which the rolling elements of the first bearing mechanism roll, the second outer ring raceway surface on which the rolling elements of the second bearing mechanism roll, and the pressed surface are provided as a single unit. Reverse input blocking clutch.

2. The first bearing mechanism and the second bearing mechanism have bearings of different sizes. The reverse input interruption clutch according to claim 1.

3. The first bearing mechanism and the second bearing mechanism have bearings of different types. The reverse input interruption clutch according to claim 1 or claim 2.

4. The inner ring raceway surface of the first bearing mechanism is integrally formed on the input member. The reverse input interruption clutch according to claim 1 or claim 2.

5. The inner ring raceway surface of the second bearing mechanism is integrally formed on the output member. The reverse input interruption clutch according to claim 1 or claim 2.

6. The rated load of the bearing in the second bearing mechanism is formed to be greater than at least one of the dynamic rated load and static rated load of the bearing in the first bearing mechanism. The reverse input interruption clutch according to claim 1 or claim 2.

7. The first bearing mechanism and the second bearing mechanism are one of the following: deep groove ball bearings, angular contact ball bearings, four-point contact ball bearings, tapered roller bearings, and cylindrical roller bearings. The reverse input interruption clutch according to claim 1 or claim 2.

8. The outer diameter dimension of at least one of the first outer ring raceway surface and the second outer ring raceway surface is larger than the outer diameter dimension of the pressed surface. The reverse input interruption clutch according to claim 1 or claim 2.