Reverse input blocking clutch

Abstract

This design realizes a reverse input blocking clutch structure that reduces the number of parts and improves ease of assembly. [Solution] The input member 3 has an input-side engaging portion 14 on a part of its axial direction and an input arm portion 17 through which an input-side engaged portion 46 is inserted in the axial direction. The input arm portion 17 has at least one of the following: a one-side restricting portion 20 located on one axial side of the input-side engaging portion 14 and restricting the movement of the engaging element 5 to the input member 3 in one axial direction; and a other-side restricting portion 21 located on the other axial side of the input-side engaging portion 14 and restricting the movement of the engaging element 5 to the input member 3 in the other axial direction.

Description

[Technical Field]

[0001] This disclosure relates to a reverse input blocking clutch that transmits rotational torque input to an input member to an output member, while completely blocking rotational torque input in reverse to the output member and not transmitting it to the input member, or transmitting only a portion of it to the input member and blocking the remainder. [Background technology]

[0002] A reverse input blocking clutch transmits rotational torque input to an input member connected to an input-side mechanism such as a drive source to an output member connected to an output-side mechanism such as a reduction mechanism. In contrast, it has the function of completely blocking the rotational torque that is reverse-input to the output member and not transmitting it to the input member, or transmitting only a portion of it to the input member and blocking the rest.

[0003] Reverse input blocking clutches differ in the mechanism for blocking the rotational torque applied in reverse to the output member. They include a lock-type reverse input blocking clutch, which has a mechanism to prevent the output member from rotating when rotational torque is applied in reverse, and a free-type reverse input blocking clutch, which has a mechanism to allow the output member to spin freely when rotational torque is applied. The choice between a lock-type and a free-type reverse input blocking clutch is determined appropriately based on the application of the device in which the reverse input blocking clutch is incorporated.

[0004] In the lock-type reverse input blocking clutch described in International Publication No. 2023 / 136149, when rotational torque is input to an input member, the input-side engaging portion of the input member engages with the input-side engaged portion of the engaging element, causing the engaging element to move away from the pressed surface provided on the pressed member, and the output-side engaged portion of the engaging element engages with the output-side engaging portion of the output member, thereby transmitting the rotational torque input to the input member to the output member. On the other hand, when rotational torque is input in reverse to the output member, the output-side engaging portion of the output member engages with the output-side engaged portion of the engaging element, causing the engaging element to move towards the pressed surface, pressing the pressing surface against the pressed surface and frictionally engaging the pressing surface with the pressed surface. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2023 / 136149 brochure [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In a reverse input blocking clutch, if the axial movement of the engaging element relative to the output member is not restricted, the engaging element may tilt axially. If the engaging element remains tilted axially and moves radially outward, the pressing surface and the pressed surface may come into local contact, causing jamming. This can unnecessarily increase the force required to switch from a locked or semi-locked state to an unlocked or semi-unlocked state, or cause plastic deformation or wear on the pressing surface and / or the pressed surface.

[0007] In the reverse input blocking clutch described in International Publication No. 2023 / 136149, the axial movement of the engaging element is restricted by using two spacers and a retaining ring, which acts as a stopper member.

[0008] The reverse input blocking clutch described in International Publication No. 2023 / 136149 requires two spacers and a stopper member to restrict the axial movement of the engaging element. This results in an increased number of parts in the reverse input blocking clutch, leading to higher parts management costs and increased assembly man-hours.

[0009] This disclosure aims to realize a reverse input blocking clutch structure that can reduce the number of parts and improve assembly. [Means for solving the problem]

[0010] A reverse input blocking clutch according to one aspect of the present disclosure comprises a pressed member, an input member, an output member, and an engaging element.

[0011] The member to be pressed has a surface to be pressed on its inner circumferential surface.

[0012] The input member has an input-side engaging portion located radially inward of the pressed surface, is connected to an input-side mechanism on one axial side, and is arranged coaxially with the pressed surface.

[0013] The output member has an output-side engaging portion that is positioned radially inward from the input-side engaging portion, is connected to the output-side mechanism on the other axial side, and is positioned coaxially with the pressed surface.

[0014] The engaging element has a pressing surface facing the pressed surface, an input-side engaged portion that can engage with the input-side engaging portion, and an output-side engaged portion that can engage with the output-side engaging portion, and is arranged to be movable in the radial direction.

[0015] When rotational torque is input to the input member, the engaging element moves in a direction away from the pressed surface in the radial direction based on the engagement of the input-side engaging portion with the input-side engaged portion, and engages the output-side engaged portion with the output-side engaging portion, thereby transmitting the rotational torque input to the input member to the output member. On the other hand, when rotational torque is reversely input to the output member, the output-side engaging portion engages with the output-side engaged portion, and the pressing surface is pressed against the pressed surface, and the pressing surface is frictionally engaged with the pressed surface.

[0016] The input member has the input-side engaging portion in a part of its axial direction, and has an input arm portion through which the input-side engaged portion is axially inserted.

[0017] The input arm portion is disposed in a part on one axial side of the input-side engaging portion, and has at least one of a one-side restricting portion that restricts the movement of the engaging element in the axial direction on one side with respect to the input member, and the input arm portion is disposed in a part on the other axial side of the input-side engaging portion, and has an other-side restricting portion that restricts the movement of the engaging element in the axial direction on the other side with respect to the input member.

[0018] In the reverse-input blocking clutch according to one aspect of the present disclosure, the input arm portion can have the other-side restricting portion, and the other-side restricting portion can project radially inward of the input-side engaging portion.

[0019] In the reverse-input blocking clutch according to one aspect of the present disclosure, the input arm portion can have the one-side restricting portion, and the one-side restricting portion can project in the diametrical direction of the input arm portion from the input-side engaging portion.

[0020] The one-side restricting portion can project radially inward of the input-side engaging portion.

[0021] In the reverse-input blocking clutch according to one aspect of the present disclosure, the input arm portion can have both the one-side restricting portion and the other-side restricting portion.

[0022] If the input arm has both the one-sided restricting portion and the other-sided restricting portion, both the one-sided restricting portion and the other-sided restricting portion can protrude radially inward from the input-side engaging portion. Furthermore, the distance from the central axis of the input member to the one-sided restricting portion can be made smaller than the distance from the central axis of the input member to the other-sided restricting portion.

[0023] In a reverse input shutoff clutch according to one aspect of the present disclosure, the input arm is composed of two input arms, and the two input arms can be arranged on opposite sides of the central axis of the input member. The engaging element can be composed of two engaging elements. [Effects of the Invention]

[0024] According to one embodiment of the reverse input blocking clutch of this disclosure, the number of parts can be reduced and assembly can be improved. [Brief explanation of the drawing]

[0025] [Figure 1] Figure 1 is a cross-sectional view of a reverse input interruption clutch, a first example of an embodiment of the present disclosure. [Figure 2] Figure 2 is a magnified view of a portion of Figure 1. [Figure 3] Figure 3 is a side view showing the input member, engaging element, and biasing member removed from the first example of the reverse input blocking clutch. [Figure 4] Figure 4 is a perspective view showing the input member, engaging element, and biasing member removed from the first example of a reverse input blocking clutch. [Figure 5] Figure 5 is an exploded perspective view showing the input member, engaging element, and biasing member removed from the first example of the reverse input blocking clutch. [Figure 6] Figure 6 is a side view showing the input members removed from the reverse input blocking clutch of the first example. [Figure 7]Figures 7(A) and 7(B) are end views of the input member, engaging member, and biasing member removed from the first example of the reverse input shutoff clutch and viewed from the other axial side. Figure 7(A) shows the reverse input shutoff clutch in use, with the two engaging members closest to each other, and Figure 7(B) shows the biasing member elastically deformed until the protrusions of the two engaging members come into contact with each other. [Figure 8] Figure 8 is a cross-sectional view of section II in Figure 1. [Figure 9] Figure 9 is a cross-sectional view II of Figure 1, showing the state in which rotational torque is applied to the input member, with the biasing member omitted. [Figure 10] Figure 10 is a cross-sectional view II of Figure 1, showing the state in which rotational torque is input to the output member, with the biasing member omitted. [Figure 11] Figure 11 is a diagram corresponding to Figure 1, showing a reverse input interruption clutch of a second example of an embodiment of the present disclosure. [Figure 12] Figure 12 is a diagram corresponding to Figure 1, showing a reverse input interruption clutch of a third embodiment of the present disclosure. [Modes for carrying out the invention]

[0026] [Example 1] A first example of a reverse input interruption clutch according to the embodiments of this disclosure will be described with reference to Figures 1 to 10.

[0027] In the following description, unless otherwise specified, axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions of the pressed surface 7. The axial, radial, and circumferential directions of the pressed surface 7 coincide with the axial, radial, and circumferential directions of the input member 3, and also coincide with the axial, radial, and circumferential directions of the output member 4. Furthermore, one axial side refers to the input side of the reverse input blocking clutch 1 (the right side in Figures 1-3, 5, and 6), and the other axial side refers to the output side of the reverse input blocking clutch 1 (the left side in Figures 1-3, 5, and 6).

[0028] <Explanation of the structure of the reverse input blocking clutch> The reverse input blocking clutch 1 of this disclosure comprises a pressed member 2, an input member 3, an output member 4, and an engaging element 5.

[0029] Of the elements constituting the reverse input blocking clutch 1, the pressed member 2, the output member 4, and the engaging element 5 have the same configuration and function as a conventional reverse input blocking clutch.

[0030] The pressed member 2 has a pressed surface 7 on its inner circumferential surface. The input member 3 has an input-side engaging portion 14 located radially inward of the pressed surface 7 and is arranged coaxially with the pressed surface 7. The output member 4 has an output-side engaging portion 31 located radially inward of the input-side engaging portion 14 and is arranged coaxially with the pressed surface 7. The engaging element 5 has a pressing surface 45 facing the pressed surface 7, an input-side engaged portion 46 that can engage with the input-side engaging portion 14, and an output-side engaged portion 47 that can engage with the output-side engaging portion 31, and is arranged to allow radial movement.

[0031] When rotational torque is input to the input member 3, the engaging element 5 moves radially away from the pressed surface 7 based on the input-side engaging portion 14 engaging with the input-side engaged portion 46, and transmits the rotational torque input to the input member 3 to the output member 4 by engaging the output-side engaged portion 47 with the output-side engaging portion 31.

[0032] In response to this, when rotational torque is input in reverse to the output member 4, the engaging element 5, based on the fact that the output-side engaging part 31 engages with the output-side engaged part 47, presses its pressing surface 45 against the pressed surface 7, causing the pressing surface 45 to frictionally engage with the pressed surface 7. In other words, the reverse input blocking clutch 1 either completely blocks the rotational torque that is input in reverse to the output member 4 and does not transmit it to the input member 3, or transmits only a portion of it to the input member 3 and blocks the rest.

[0033] In this specification, the direction of the pressing surface 45 of the engaging element 5 relative to the pressed surface 7 is defined as the first direction (up and down direction in Figures 7 to 10), and the direction perpendicular to both the axial direction of the pressed surface 7 and the first direction is defined as the second direction (left and right direction in Figures 7 to 10). With respect to the engaging element 5, the direction coinciding with the first direction is defined as the radial direction of the engaging element 5 (direction indicated by arrow α in Figure 8), and the direction coinciding with the second direction is defined as the width direction of the engaging element 5 (direction indicated by arrow β in Figure 8).

[0034] The input-side engaging portion 14 of the input member 3 and the output-side engaging portion 31 of the output member 4 are positioned radially inward of the pressed surface 7. With respect to the first direction, the input-side engaging portion 14, the portion of the input-side engaged portion 46 that engages with the input-side engaging portion 14, the output-side engaged portion 47, and the output-side engaging portion 31 are positioned radially inward of the pressed surface 7 in that order. Furthermore, the input-side engaging portion 14, the output-side engaging portion 31, and the engaging element 5 are rotatable radially inward of the pressed surface 7.

[0035] In particular, the reverse input blocking clutch 1 of this disclosure is characterized by an improved input member 3, which allows the axial movement of the engaging element 5 to be directly restricted by the input member 3. The components of the reverse input blocking clutch 1 will be described below, focusing on the configuration of the input member 3.

[0036] [Subjected component] The pressed member 2 has a pressed surface 7 on its inner circumferential surface. The pressed surface 7 constitutes a surface that contacts the pressing surface 45 of the engaging element 5 when the engaging element 5 moves radially outward in a direction approaching the pressed surface 7 with respect to the first direction. In other words, the pressed surface 7 has the function of frictionally engaging with the pressing surface 45 of the engaging element 5 when rotational torque is input in reverse to the output member 4.

[0037] The pressed member 2 is supported by a fixed part that does not rotate even when the reverse input blocking clutch 1 is in use, or is integrally provided with the fixed part so that its rotation is restrained.

[0038] The shape of the pressed member 2 is not limited, as long as it is configured to have a pressed surface 7 on its inner circumferential surface. The pressed surface 7 is circular when viewed from the axial direction, but is not limited to this; however, in this example, it is cylindrical in shape with no change in inner diameter with respect to the axial direction.

[0039] In this example, the pressed member 2 includes a housing element 8. The housing element 8 is an element for incorporating the pressed member 2 into a mechanical element to which the reverse input blocking clutch 1 is applied.

[0040] The housing element 8 has a stepped cylindrical inner surface. Specifically, the inner surface of the housing element 8 is formed by connecting a large-diameter cylindrical surface portion 9 on one axial side and a small-diameter cylindrical surface portion 10 on the other axial side with a connecting surface portion 11 facing one axial side. In this example, the large-diameter cylindrical surface portion 9 constitutes the pressed surface 7.

[0041] The housing element 8 has an inwardly projecting flange portion 12 at one axial end of the small-diameter cylindrical surface portion 10, and has screw holes 13 opening at multiple locations in the circumferential direction on the other axial side surface.

[0042] The pressed member 2 may also include another housing element that closes the opening on one axial side of the housing element 8. In this case, the pressed member 2 is constructed by fitting the other housing element to the axial end of the housing element 8 without any play (spigot fitting), thereby positioning the housing element 8 and the other housing element radially, and then connecting the housing element 8 and the other housing element with a connecting member such as a bolt.

[0043] [Input components] The input member 3 has an input-side engaging portion 14 located radially inward of the pressed surface 7 and is arranged coaxially with the pressed surface 7.

[0044] The input member 3 is connected to an input-side mechanism such as an electric motor on one axial side, and rotational torque is input to it. Specifically, the input member 3 is composed of the output shaft of the input-side mechanism, or it is composed as a separate member from the output shaft and can be fixed coaxially to the output shaft.

[0045] The input-side engaging portion 14 is an element that, when rotational torque is applied to the input member 3, engages with the input-side engaged portion 46 of the engaging element 5, thereby rotating the engaging element 5.

[0046] The input-side engaging portion 14 is provided on a part of the input member 3 that is radially outward from the rotational axis O, and has a portion that engages, specifically contacts, with the input-side engaged portion 46 of the engaging element 5. The input-side engaging portion 14 is configured to engage (contact) its radially inner surface 16 with the radially inner surface 48 of the input-side engaged portion 46 as the input member 3 or engaging element 5 rotates.

[0047] The input member 3 has an input-side engaging portion 14 in a part of its axial direction, and an input arm portion 17 through which the input-side engaged portion 46 of the engaging element 5 is inserted in the axial direction.

[0048] The input arm 17 is inserted through the input-side engaged portion 46 of the engaging element 5 and is an element for positioning the input-side engaging portion 14 inside the input-side engaged portion 46 of the engaging element 5.

[0049] The input arm portion 17 has at least one of the following: a one-side restricting portion 20 positioned on one axial side of the input-side engaging portion 14 and restricting the movement of the engaging element 5 to the input member 3 in one axial direction; and a other-side restricting portion 21 positioned on the other axial side of the input-side engaging portion 14 and restricting the movement of the engaging element 5 to the input member 3 in the other axial direction.

[0050] The one-sided restricting portion 20 is an element for restricting the axial movement of the engaging element 5 with respect to the input member 3 to one side.

[0051] The other-side restricting portion 21 is an element for restricting the axial movement of the engaging element 5 to the other side relative to the input member 3.

[0052] In this example, the input member 3 has an input shaft portion 18 and an input flange portion 19 in addition to the input arm portion 17.

[0053] The input shaft portion 18 is an element for connecting the input member 3 to the input-side mechanism in a way that enables the transmission of rotational torque. In this example, the input shaft portion 18 has a cylindrical shape. The input member 3 is connected to the output shaft of the input-side mechanism in a way that enables torque transmission, for example, by non-circular engagement such as spline engagement between the inner circumferential surface of the input shaft portion 18 and the outer circumferential surface of the output shaft of the input-side mechanism, such as an electric motor, or by press-fitting or the like.

[0054] The input flange portion 19 is an element for positioning the input arm portion 17 at a location radially outward from the rotational axis O of the input member 3. In this example, the input flange portion 19 protrudes radially outward from the outer circumferential surface of the other axial end of the input shaft portion 18 over its entire circumference.

[0055] The input arm 17 has an input-side engaging portion 14 and at least one of one of a one-side restricting portion 20 and a other-side restricting portion 21, and its shape is not limited as long as the input-side engaging portion 14 is configured to be positioned inside the input-side engaged portion 46 of the engaging element 5.

[0056] In this example, the input arm 17 has a partially annular shape, a substantially trapezoidal shape, or a similar cross-sectional shape, where the length in the second direction increases as it extends outward in the first direction. The radially outer surface 22 of the input arm 17 has a radius of curvature r centered on the central axis O of the input member 3 over its entire axial length. 17 It is composed of a partially cylindrical convex surface. The side surfaces 23 on both sides of the input arm 17 in the second direction are composed of inclined surfaces that are inclined in a direction that is inclined outward in the first direction as they extend along the entire axial length toward both sides in the second direction. The inner surface 24 of the input arm 17 in the first direction is composed of a stepped surface.

[0057] Radius of curvature r of the radial outer surface 22 of the input arm 17 17 The input arm portion 17 is set to a size that allows it to be inserted into the input-side engaged portion 46 of the engaging element 5. Specifically, in this example, as shown in Figure 7(B), the radius of curvature r 17 This involves elastically deforming two biasing members 55 positioned between the two engaging elements 5, bringing the two engaging elements 5 closer together until the protrusions 52 of each engaging element 5 come into contact, and then determining the radius R of the inscribed circle passing through the radial outer surface 49 of the two input-side engaged parts 46. 46 Smaller than (r 17 <R 46 Therefore, even when the input-side engaged portion 46 of the engaging element 5 is configured as a through hole during the assembly of the reverse input blocking clutch 1, the two input arms 17 can be inserted simultaneously into the input-side engaged portions 46 of the two engaging elements 5.

[0058] The number of input arms 17 is determined according to the number of engaging elements 5. If the engaging elements 5 are composed of multiple engaging elements 5, the input arms 17 are also composed of multiple input arms 17.

[0059] In this example, the engaging element 5 is composed of two engaging elements 5. Therefore, the input arm 17 is composed of two input arms 17, corresponding to the number of engaging elements 5. The two input arms 17 are positioned on opposite sides of the central axis O of the input member 3. The two input arms 17 are equally spaced 180 degrees apart in the circumferential direction.

[0060] In this example, the input arm portion 17 has one axial end connected to the radially outer end of the input flange portion 19. Therefore, the input arm portion 17 is inserted through the input-side engaged portion 46 of the engaging element 5 from its other axial end.

[0061] The shape of the input-side engaging portion 14 is not limited, as long as it is positioned inside the input-side engaged portion 46 of the engaging element 5 and configured to engage with the input-side engaged portion 46.

[0062] For example, the input-side engaging portion 14 may have a cross-sectional shape that is symmetrical with respect to the circumferential direction, or it may have a cross-sectional shape that is asymmetrical with respect to the circumferential direction. In this example, the input-side engaging portion 14 has a cross-sectional shape that is symmetrical with respect to the circumferential direction.

[0063] For example, the input-side engaging portion 14 can have a partially annular shape, a trapezoidal shape, or a similar cross-sectional shape, where the length in the second direction increases as it extends outward in the first direction. In this example, the input-side engaging portion 14 has a cross-sectional shape similar to a trapezoid. Of the radially inner surface 16 of the input-side engaging portion 14, the intermediate portion in the second direction is composed of a flat surface perpendicular to the line connecting the central axis O of the input member 3 and the center of the input-side engaging portion 14 when viewed from the axial direction, and the portions on both sides in the second direction are composed of partially cylindrical convex surfaces that are inclined in the direction outward in the first direction as they extend to both sides in the second direction. The radially outer surface of the input-side engaging portion 14 is composed of the axial intermediate portion of the radially outer surface 22 of the input arm portion 17. In addition, the sides of the input-side engaging portion 14 on both sides in the second direction are composed of the axial intermediate portion of the sides 23 of the input arm portion 17 on both sides in the second direction.

[0064] The axial position of the input-side engaging portion 14 in the input arm 17 is not particularly limited, as long as the input-side engaging portion 14 can be positioned inside the input-side engaged portion 46, and the one-side restricting portion 20 can be positioned on one axial side of the input-side engaging portion 14, and / or the other-side restricting portion 21 can be positioned on the other axial side of the input-side engaging portion 14. In this example, the input-side engaging portion 14 is positioned in the axial middle portion of the input arm 17.

[0065] The restricting portion 20 on one side and / or the restricting portion 21 on the other side face the engaging element 5 in the axial direction, regardless of whether the engaging element 5 is stationary or moving (including rotating) relative to the pressed member 2, and restrict the axial movement of the engaging element 5 relative to the input member 3.

[0066] The input arm 17 may be comprised of only the one-side restricting section 20, only the other-side restricting section 21, or both the one-side restricting section 20 and the other-side restricting section 21.

[0067] If the input arm 17 is equipped with only the one-sided restricting portion 20 of the one-sided restricting portion 20 and the other-sided restricting portion 21, the input member 3 can directly restrict the axial movement of the engaging element 5 to one side by the one-sided restricting portion 20. Therefore, dedicated parts for restricting the axial movement of the engaging element 5, namely spacers and stopper members, become unnecessary. The axial movement of the engaging element 5 to the other side can be restricted, for example, by using a spacer placed between the engaging element and the axial end face of the output shaft portion, or by using the axial end face of the output shaft portion.

[0068] If the input arm 17 is equipped with only the other-side restricting portion 21 of the one-side restricting portion 20 and the other-side restricting portion 21, the input member 3 can directly restrict the axial movement of the engaging element 5 to the other side by the other-side restricting portion 21. Therefore, a dedicated part for restricting the axial movement of the engaging element 5 to the other side, i.e., a spacer, becomes unnecessary. The axial movement of the engaging element 5 to one side is restricted, for example, by using a stopper member attached to the output member and, if necessary, a spacer.

[0069] If the input arm 17 includes both a one-sided restricting portion 20 and a other-sided restricting portion 21, the input member 3 can directly restrict the movement of the engaging element 5 in one axial direction by the one-sided restricting portion 20, and can also directly restrict the movement of the engaging element 5 in the other axial direction by the other-sided restricting portion 21. Therefore, dedicated parts for restricting the movement of the engaging element 5 in one axial direction and the other axial direction, namely two spacers and a stopper member, are not required.

[0070] In this example, the input arm 17 includes both a one-sided restricting portion 20 and a other-sided restricting portion 21. Therefore, the input member 3 can directly restrict the axial movement of the engaging element 5 in one direction by the one-sided restricting portion 20, and can also directly restrict the axial movement of the engaging element 5 in the other direction by the other-sided restricting portion 21.

[0071] In this example, the one-sided restricting portion 20 is provided at one axial end of the input arm portion 17, and the other-sided restricting portion 21 is provided at the other axial end of the input arm portion 17.

[0072] The one-sided restricting portion 20 can protrude diametrically from the input-side engaging portion 14. Since the one-sided restricting portion 20 is positioned on one axial side of the input arm portion 17, relative to the input-side engaging portion 14 which is located inside the input-side engaged portion 46 of the engaging element 5, it does not pass through to the inside of the input-side engaged portion 46. Therefore, the portion of the input arm portion 17 having the one-sided restricting portion 20 does not need to be configured to pass through the input-side engaged portion 46, and the one-sided restricting portion 20 only needs to be configured to restrict the movement of the engaging element 5 to one axial side. Thus, the direction of protrusion of the one-sided restricting portion 20 is not limited, and it can protrude radially inward and / or radially outward from the input-side engaging portion 14. Furthermore, the one-sided restricting portion 20 can also protrude circumferentially to one side and / or the other side from the input-side engaging portion 14.

[0073] The one-sided restricting portion 20 has an end face 25 on the other axial side that faces the end face 53 on the one axial side of the engaging element 5. In this example, the end face 25 on the other axial side of the one-sided restricting portion 20 is formed by a flat surface that is substantially perpendicular to the central axis O of the input member 3.

[0074] In this example, the one-sided restricting portion 20 protrudes radially inward from the input-side engaging portion 14. Specifically, the one-sided restricting portion 20 is provided at one axial end of the first-direction inward surface 24 of the input arm portion 17, and protrudes radially inward from the radially inward inner surface 16 of the input-side engaging portion 14.

[0075] The sides of the one-side restricting portion 20 in the second direction are formed by the axial end of the side surfaces 23 of the input arm portion 17 in the second direction. Of the radially inner surface 27 of the one-side restricting portion 20, the intermediate portion in the second direction is formed by a flat surface arranged substantially parallel to the radially inner surface 16 of the input-side engaging portion 14, and the portions on both sides in the second direction are formed by partially cylindrical convex surfaces that are inclined outward in the first direction as they extend toward both sides in the second direction.

[0076] The input arm portion 17 preferably has a relief groove 28 between the axial end face 25 of the one-side restricting portion 20 and the radially inner surface 16 of the input-side engaging portion 14. By providing the relief groove 28, it is possible to prevent interference between the connecting portion that connects the axially opposite end face 25 of the one-side restricting portion 20 and the radially inner surface 16 of the input-side engaging portion 14 and the engaging element 5, which would prevent the axial movement of the engaging element 5 from being restricted by the axially opposite end face 25 of the one-side restricting portion 20.

[0077] The other-side restricting portion 21 is positioned on the axial side of the input arm portion 17 that is on the other side of the input-side engaging portion 14, so that it can be inserted inside the input-side engaged portion 46 when assembling the reverse input blocking clutch 1. For this reason, the other-side restricting portion 21 must be configured to restrict the movement of the engaging element 5 to the other axial side, and the portion of the input arm portion 17 having the other-side restricting portion 21 must be configured so that the input-side engaged portion 46 can be inserted during assembly.

[0078] The input-side engaging portion 14 engages its radially inner surface 16 with the radially inner surface 48 of the input-side engaged portion 46 when rotational torque is applied to the input member 3. Therefore, in the assembled state of the reverse input blocking clutch 1, the gap between the radially inner surface 16 of the input-side engaging portion 14 and the radially inner surface 48 of the input-side engaged portion 46 is set to a sufficiently small value. For this reason, in this example, in order to ensure a large engagement clearance with the engaging element 5, the other-side restricting portion 21 has a configuration that protrudes radially inward from the input-side engaging portion 14. Specifically, the other-side restricting portion 21 is provided at the axially opposite end of the first-direction inner surface 24 of the input arm portion 17, and protrudes radially inward from the radially inner surface 16 of the input-side engaging portion 14. In this example, the other-side restricting portion 21 is configured in a flange shape.

[0079] The other-side restricting portion 21 has an axial end face 26 that faces the axial end face 54 of the engaging element 5 on the other side. In this example, the axial end face 26 of the other-side restricting portion 21 is formed by a flat surface that is substantially perpendicular to the central axis O of the input member 3.

[0080] The axial dimension D between the end face 25 on the other axial side of the one-sided restricting portion 20 and the end face 26 on the one axial side of the other-sided restricting portion 21 is slightly larger than the axial dimension d of the engaging element 5 (D > d). Therefore, the end face 25 on the other axial side of the one-sided restricting portion 20 and the end face 26 on the one axial side of the other-sided restricting portion 21 are prevented from becoming a resistance when the engaging element 5 moves radially.

[0081] In this example, the sides of the other-side restricting portion 21 in the second direction are formed by the ends of the sides 23 of the input arm portion 17 in the second direction that are on the other axial side. Of the radially inner surface 29 of the other-side restricting portion 21, the intermediate portion in the second direction is formed by a flat surface arranged substantially parallel to the radially inner surface 16 of the input-side engaging portion 14, and the portions on both sides in the second direction are formed by partially cylindrical convex surfaces that are inclined outward in the first direction as they extend toward both sides in the second direction.

[0082] The input wrist portion 17 preferably has a relief groove 30 between the end face 26 on one axial side of the other-side regulating portion 21 and the radially inner surface 16 of the input-side engaging portion 14. By providing the relief groove 30, it is possible to prevent the connecting portion connecting the end face 26 on one axial side of the other-side regulating portion 21 and the radially inner surface 16 of the input-side engaging portion 14 from interfering with the engaging element 5, so that the axial movement of the engaging element 5 cannot be restricted by the end face 26 on one axial side of the other-side regulating portion 21.

[0083] The overhang amount L of the one-side regulating portion 20 corresponding to the radial dimension from the radially inner surface 16 of the input-side engaging portion 14 to the radially inner surface 27 of the one-side regulating portion 20 20 and the overhang amount L of the other-side regulating portion 21 corresponding to the radial dimension from the radially inner surface 16 of the input-side engaging portion 14 to the radially inner surface 29 of the other-side regulating portion 21 21 The size relationship therebetween is not particularly limited. The overhang amount L 20 can be larger than the overhang amount L 21 or can be smaller than the overhang amount L 21 or can be the same as the overhang amount L 21 .

[0084] In this example, as shown in FIG. 6, the overhang amount L 20 is larger than the overhang amount L 21 . Specifically, the overhang amount L 20 is approximately twice as large as the overhang amount L 21 . Thereby, during the assembly operation of the reverse input blocking clutch 1, the end face 25 on the other axial side of the one-side regulating portion 20 can be used as a stopper surface for restricting the insertion amount of the input wrist portion 17, or in other words, for positioning the engaging element 5 with respect to the input wrist portion 17.

[0085] In this example, when the two biasing members 55 positioned between the two engaging elements 5 are elastically deformed to bring the two engaging elements 5 closer together until the protrusions 52 of each engaging element 5 come into contact, and the two input arms 17 are simultaneously inserted into the input-side engaged portions 46 of the two engaging elements 5, the axial end faces 25 of the one-side restricting portions 20 provided on each of the two input arms 17 abut against the axial end faces 53 of each of the two engaging elements 5. Therefore, the insertion amount of the input arms 17 can be limited by the axial end faces 25 of the one-side restricting portions 20. This allows the input-side engaging portion 14 to be reliably and easily positioned inside the input-side engaged portion 46.

[0086] The relative size of the axial dimension of the one-sided restricting portion 20 and the axial dimension of the other-sided restricting portion 21 is not particularly limited. The axial dimension of the one-sided restricting portion 20 can be larger than the axial dimension of the other-sided restricting portion 21, smaller than the axial dimension of the other-sided restricting portion 21, or the same as the axial dimension of the other-sided restricting portion 21.

[0087] In this example, the axial dimension of the one-sided restricting portion 20 is larger than the axial dimension of the other-sided restricting portion 21. Therefore, the amount of protrusion of the input arm portion 17 from the other axial end face 54 of the engaging element 5 can be suppressed, thereby reducing the axial dimension of the reverse input blocking clutch 1. In addition, the rigidity of the input arm portion 17 can be ensured.

[0088] In this example, when the input arm 17 has both a one-sided restricting portion 20 and a other-sided restricting portion 21, and both the one-sided restricting portion 20 and the other-sided restricting portion 21 are configured to protrude radially inward from the input-side engaging portion 14, it is preferable to make the distance from the central axis O of the input member 3 to the one-sided restricting portion 20 smaller than the distance from the central axis O of the input member 3 to the other-sided restricting portion 21.

[0089] In this example, the input arm portion 17 is composed of two input arm portions 17 arranged on opposite sides across the central axis O of the input member 3, and both the one-side regulating portion 20 and the other-side regulating portion 21 are configured to project radially inwardly more than the input-side engaging portion 14. For this reason, as shown in FIG. 6, the distance X between the radially inner surfaces 27 of the two one-side regulating portions 20 is smaller than the distance Y between the radially inner surfaces 29 of the two other-side regulating portions 21 (X < Y). That is, the distance (X / 2) from the central axis O of the input member 3 to the one-side regulating portion 20 is smaller than the distance (Y / 2) from the central axis O of the input member 3 to the other-side regulating portion 21 ((X / 2) < (Y / 2)).

[0090] The distance Y is set to a size such that the end portions on the other axial side of each of the two input arm portions 17 can be simultaneously inserted into the input-side engaged portions 46 of the two engaging members 5. Specifically, in this example, as shown in FIG. 7(B), the distance Y is such that the two biasing members 55 arranged between the two engaging members 5 are elastically deformed, and the two engaging members 5 are brought closer to each other until the convex portions 52 of the respective engaging members 5 abut against each other, and Y is larger than the distance Z1 between the radially inner surfaces 48 of the two input-side engaged portions 46 (Y > Z1). For this reason, during the assembly operation of the reverse input blocking clutch 1, the end portions on the other axial side of each of the two input arm portions 17 can be simultaneously inserted into the input-side engaged portions 46 of the two engaging members 5.

[0091] Further, the distance Y is set to a size that can prevent the two input arms 17 from coming out of the input-side engaged portions 46 of the two engaging elements 5 in the usage state of the reverse input blocking clutch 1. Specifically, as shown in FIG. 7(A), the distance Y is smaller than the distance Z2 between the radially inner surfaces 48 of the two input-side engaged portions 46 in the state where the two engaging elements 5 are closest to each other in the usage state of the reverse input blocking clutch 1 (Y < Z2). Specifically, the distance Y is such that when the two engaging elements 5 move radially inward, which is the direction in which they approach each other based on the engagement with the input member 3, and the output-side engaged portions 47 of the two engaging elements 5 sandwich the output-side engaging portion 31 of the output member 4 (not shown) from both sides in the radial direction, the distance Y is smaller than the distance Z2 between the radially inner surfaces 48 of the two input-side engaged portions 46 (Y < Z2). Therefore, in the usage state of the reverse input blocking clutch 1, it is possible to prevent the two input arms 17 from coming out of the input-side engaged portions 46 of the two engaging elements 5.

[0092] Since the one-side regulating portion 20 does not need to be configured to be able to insert through the input-side engaged portion 46, within the range where the weight of the input member 3 does not become too heavy and within the range where it does not interfere with any component of the output member 4, the amount of overhang in the radial direction can be arbitrarily set. That is, it is possible to make the amount of overhang in the radial direction of the one-side regulating portion 20 sufficiently large. In this example, the amount of overhang L of the one-side regulating portion 20 20 is larger than the amount of overhang L of the other-side regulating portion 21 21 (that is, X < Y). Therefore, the rigidity of the input arm 17 can be ensured.

[0093] The input member 3 can be rotatably supported by the pressed member 2 or the other housing element or the like.

[0094] 〔Output Member〕 The output member 4 has an output-side engaging portion 31 disposed radially inward of the input-side engaging portion 14 and is disposed coaxially with the pressed surface 7. That is, the output member 4 is also disposed coaxially with the input member 3.

[0095] The output member 4 is connected to an output mechanism, such as a reduction gear, on the other axial side, and is configured to output rotational torque to the output mechanism as it rotates. Specifically, the output member 4 can be formed from the input shaft of the output mechanism, or it can be formed as a separate member from the input shaft and fixed coaxially to the input shaft. In this example, the output member 4 is fixed coaxially to the drive pulley 41, which is the input shaft of the reduction gear 40. A toothed belt 42 is stretched between the drive pulley 41 and a driven pulley (not shown).

[0096] The output member 4 has an output shaft portion 32 in addition to the output-side engaging portion 31.

[0097] The output-side engaging portion 31 and the output shaft portion 32 are directly connected in the axial direction. Specifically, the output-side engaging portion 31 protrudes in one axial direction from the end face 33 on one axial side of the output shaft portion 32.

[0098] The output-side engaging portion 31 has a portion that engages with the output-side engaged portion 47 of the engaging element 5, and is an element that receives rotational torque from the engaging element 5 when rotational torque is input to the input member 3 and the engaging element 5 rotates. Also, when rotational torque is input in reverse to the output member 4, it engages with the output-side engaged portion 47 of the engaging element 5 and moves the engaging element 5 in a direction toward the pressed surface 7.

[0099] The portion of the output-side engaging portion 31 that engages with the output-side engaged portion 47 of the engaging element 5 is located radially inward from the input-side engaging portion 14 and radially outward from the rotational axis O of the output member 4, and is positioned to engage with the output-side engaged portion 47 of the engaging element 5. The output-side engaging portion 31 is configured to engage (contact) its outer circumferential surface with the output-side engaged portion 47 as the output member 4 or engaging element 5 rotates.

[0100] The output-side engaging portion 31 has a cam function. The distance from the rotational axis of the output member 4 to the outer circumferential surface of the output-side engaging portion 31, which engages with the output-side engaged portion 47, is not constant in the circumferential direction.

[0101] The number of parts of the output-side engaging portion 31 that engage with the output-side engaged portion 47 is determined according to the number of engaging elements 5. If the engaging element 5 is composed of multiple engaging elements 5, the output-side engaging portion 31 is also configured to have multiple engaging parts. In this example, the output-side engaging portion 31 is configured to have two parts that engage with the output-side engaged portion 47, in accordance with the number of engaging elements 5.

[0102] When the output-side engaging portion 31 is cut by a virtual plane perpendicular to the rotational axis O of the output member 4, the cross-sectional shape of the output-side engaging portion 31 is arbitrary as long as the output-side engaging portion 31 has a cam function, and can be, for example, a quadrilateral such as a square, rectangle, parallelogram, or trapezoid, an oval, or a shape similar to these quadrilaterals or ovals.

[0103] In this example, the output-side engaging portion 31 has a substantially rectangular cross-sectional shape, as shown in Figure 8, when cut by a virtual plane perpendicular to the rotational axis O of the output member 4. More specifically, the outer circumferential surface of the output-side engaging portion 31 is composed of two parallel flat surfaces 34 and two convex curved surfaces 35, each partially cylindrical in shape.

[0104] In this example, the output-side engaging portion 31 is symmetric with respect to a virtual plane that passes through the rotational axis O of the output member 4 and is perpendicular to the two flat surfaces 34. Furthermore, the output-side engaging portion 31 is symmetric with respect to a virtual plane that passes through the rotational axis O of the output member 4 and is parallel to the two flat surfaces 34. That is, the output-side engaging portion 31 has a shape that is twice symmetric with respect to the central axis of the output member 4. The output-side engaging portion 31 is located radially inside the two input-side engaging portions 14 and is positioned between the output-side engaged portions 47 of the two engaging elements 5.

[0105] The output shaft portion 32 is an element for connecting the output member 4 and the input portion of the output mechanism so as to be able to transmit rotational torque.

[0106] In this example, the output shaft portion 32 has a stepped cylindrical shape. Specifically, the output shaft portion 32 has a large diameter portion 36, a medium diameter portion 37, and a small diameter portion 38, in that order from one side in the axial direction. The large diameter portion 36 has an outward-facing flange portion 39 that protrudes radially outward along its entire circumference in the axial middle portion of its outer circumferential surface. In this example, the drive pulley 41 of the reduction gear 40 is externally fitted and fixed to the medium diameter portion 37.

[0107] In this example, the large-diameter portion 36 of the output shaft 32 is rotatably supported relative to the pressed member 2. Specifically, the large-diameter portion 36 of the output shaft 32 is rotatably supported relative to the pressed member 2 by a radial rolling bearing 43a. The radial rolling bearing 43a is axially sandwiched between an outward-facing flange portion 39 provided on the outer circumferential surface of the large-diameter portion 36 and an inward-facing flange portion 12 provided on the inner circumferential surface of the pressed member 2.

[0108] In this example, the output member 4 is provided with a corner radius 44 having a concave arc cross-sectional shape at the connection point between the axial end face 33 of the output shaft portion 32 and the outer circumferential surface of the output side engaging portion 31.

[0109] In this example, the output-side engaging portion 31 is provided at one end of the output member 4 on the axial side. However, the output member 4 may also be provided with a shaft portion, for example, inserted inside the input shaft portion 18 on one axial side of the output-side engaging portion 31, to increase the coaxiality between the output member 4 and the input member 3.

[0110] [Engagement element] The engaging element 5 has a pressing surface 45 facing the pressed surface 7, an input-side engaged portion 46 that can engage with the input-side engaging portion 14, and an output-side engaged portion 47 that can engage with the output-side engaging portion 31, and is arranged to allow movement in a first direction, which is the near-far direction relative to the pressed surface 7.

[0111] When rotational torque is input to the input member 3, the engaging element 5 moves away from the pressed surface 7 in the first direction, based on the input-side engaging portion 14 engaging with the input-side engaged portion 46, and transmits the rotational torque input to the input member 3 to the output member 4 by engaging the output-side engaged portion 47 with the output-side engaging portion 31. Conversely, when rotational torque is input in reverse to the output member 4, the engaging element 5 presses the pressing surface 45 against the pressed surface 7, based on the output-side engaging portion 31 engaging with the output-side engaged portion 47, thereby frictionally engaging the pressing surface 45 with the pressed surface 7.

[0112] The input-side engaged portion 46 is an element through which the input arm portion 17 of the input member 3 is inserted, and which engages with the input-side engaged portion 14 as the input member 3 rotates, thereby receiving the rotational torque input from the input member 3.

[0113] The shape of the input-side engaged portion 46 is not limited, as long as the input-side engaged portion 14 is positioned inside it and is configured to engage with the input-side engaged portion 14. The input-side engaged portion 46 opens into the axial end face 53 and the other axial end face 54 of the engaging element 5. The input-side engaged portion 46 can be composed of a through hole opening only into the axial end face 53 and the other axial end face 54 of the engaging element 5, or notches opening into the axial end face 53 and the other axial end face 54 of the engaging element 5 and the radial outer surface of the engaging element 5, respectively.

[0114] In this example, the input-side engaged portion 46 is formed by a through-hole that penetrates the engaging element 5 in the axial direction. The input arm portion 17 is inserted through the input-side engaged portion 46. An input-side engaged portion 14, provided on a part of the input arm portion 17 in the axial direction, is positioned inside the input-side engaged portion 46. The input-side engaged portion 46 opens only on one end face 53 and the other end face 54 on the axial side of the engaging element 5. The input-side engaged portion 46 is provided in the radial intermediate portion of the center in the width direction of the engaging element 5.

[0115] The input-side engaged portion 46 is sized to allow the input-side engaged portion 14 to be loosely inserted. Therefore, when the input-side engaged portion 14 is inserted inside the input-side engaged portion 46, there are gaps between the input-side engaged portion 14 and the inner surface of the input-side engaged portion 46 in the width direction and the radial direction of the engaging element 5. As a result, the input-side engaged portion 14 can be displaced relative to the input-side engaged portion 46 in the rotational direction of the input member 3, and the input-side engaged portion 46 can be displaced relative to the input-side engaged portion 14 in the radial direction of the engaging element 5.

[0116] In this example, the radially inner surface 48 of the inner surface of the input-side engaged portion 46, which faces radially outward, is composed of a flat surface perpendicular to the first direction, and the radially outer surface 49 of the inner surface of the input-side engaged portion 46, which faces radially inward, is composed of a curved surface having a substantially arc-shaped contour or a composite surface having a substantially V-shaped contour when viewed from the axial direction. The circumferential surface 50 connecting the ends on both sides of the radially inner surface 48 in the second direction and the ends on both sides of the radially outer surface 49 in the second direction is composed of a partially cylindrical concave curved surface.

[0117] The output-side engaged portion 47 engages with the output-side engaged portion 31 as the engaging element 5 rotates, and is an element for outputting the rotational torque input from the input member 3 to the engaging element 5 to the output member 4. The shape of the output-side engaged portion 47 is not limited as long as it is configured to engage with the output-side engaged portion 31. In this example, the output-side engaged portion 47 is provided at the center in the width direction of the radially inner surface of the engaging element 5.

[0118] The pressing surface 45 is provided on the radially outer surface of the engaging element 5 facing the pressed surface 7. The shape and size of the pressing surface 45 are arbitrary as long as they can frictionally engage with the pressed surface 7. The pressing surface 45 can be composed of the entire radially outer surface of the engaging element 5, or of a part thereof. One pressing surface 45 can be provided for one engaging element 5, or multiple pressing surfaces 45 can be provided. The radius of curvature of the pressing surface 45 can be the same as the radius of curvature of the pressed surface 7, or it can be smaller than the radius of curvature of the pressed surface 7.

[0119] In this example, the pressing surface 45 is composed of two pressing surfaces 45 located at two positions on the radially outer surface of the engaging element 5 that are spaced apart from each other in the circumferential direction. Each pressing surface 45 is composed of a partially cylindrical convex curved surface having a radius of curvature smaller than the radius of curvature of the surface to be pressed 7.

[0120] The portion of the radially outer surface of the engaging element 5 that is circumferentially separated from the two pressing surfaces 45 is located radially inward from the circumscribed circle that is centered on the rotation center O of the input member 3 and tangent to the two pressing surfaces 45, when viewed from the axial direction. In other words, when the two pressing surfaces 45 are in contact with the surface to be pressed 7, the portion that is circumferentially separated from the two pressing surfaces 45 does not come into contact with the surface to be pressed 7.

[0121] The pressing surface 45 preferably has a surface property that results in a higher coefficient of friction with respect to the pressed surface 7 than the other parts of the engaging element 5. Furthermore, the pressing surface 45 can be integrally formed with the other parts of the engaging element 5, or it can be formed from the surface of a friction material fixed to the other parts of the engaging element 5 by adhesive or other means.

[0122] The engaging element 5 can be composed of two engaging elements 5, or it can be composed of three or more engaging elements 5.

[0123] The engaging element 5 can be manufactured by any method. For example, the engaging element 5 can be manufactured by pressing, sintering, forging, casting, and / or machining. In this example, the engaging element 5 is a press-formed metal sheet manufactured by pressing.

[0124] The shape of the engaging element 5 is arbitrary as long as it comprises a pressing surface 45, an input-side engaged portion 46, and an output-side engaged portion 47, and can achieve the above-mentioned functions; therefore, a wide range of conventional engaging element shapes can be adopted.

[0125] In this example, the engaging element 5 is composed of two engaging elements 5. Each engaging element 5 has the function of an engaging element 5. Each engaging element 5 has a substantially semicircular end face shape when viewed from the axial direction and has a shape that is symmetrical with respect to the width direction.

[0126] In this example, the engaging element 5 has a flat surface portion 51 on its radially inner surface that is perpendicular to the radial direction of the engaging element 5, and has two protrusions 52 projecting radially inward at two positions on the flat surface portion 51 in the width direction of the engaging element 5. The output-side engaged portion 47 is composed of the portion of the flat surface portion 51 that is located between the two protrusions 52 in the width direction. In this example, the width dimension of the output-side engaged portion 47, i.e., the distance between the two protrusions 52, is larger than the width dimension of the flat surface 34 of the output-side engaging portion 31.

[0127] In the reverse input blocking clutch 1 of this example, the pressing surfaces 45 of the two engaging elements 5 are oriented radially toward opposite sides of each other, and their flat surfaces 51 are facing each other, with each engaging element 5 positioned radially inward of the housing element 8, allowing movement in the first direction. Furthermore, the two input arms 17 of the input member 3, positioned on one axial side, are inserted axially through the respective input-side engaged portions 46 of the two engaging elements 5, and the output-side engaging portion 31 of the output member 4, positioned on the other axial side, is inserted axially between the output-side engaged portions 47 of the two engaging elements 5. In other words, the two engaging elements 5 are positioned so that their respective output-side engaged portions 47 sandwich the output-side engaging portion 31 from the radial outside.

[0128] With the two engaging elements 5 positioned radially inward of the pressed member 2, the inner diameter of the pressed surface 7 and the radial dimensions of the engaging elements 5 are regulated such that there are gaps between the pressed surface 7 and the two pressing surfaces 45, and between the tip surfaces of the two combinations of protrusions 52 formed by the two protrusions 52 of the two engaging elements facing each other.

[0129] In this example, the engaging element 5 has a constant axial dimension d in the radial direction. The end face 53 on one axial side and the end face 54 on the other axial side of the engaging element 5 are arranged parallel to each other and are each configured as flat surfaces. Furthermore, the radial inner surface 48 of the input-side engaged portion 46 of the engaging element 5 is connected at a right angle to the end face 53 on one axial side and the end face 54 on the other axial side.

[0130] [Biasing member] The reverse input blocking clutch 1 in this example further comprises a biasing member 55 as an optional component.

[0131] The biasing member 55 elastically biases the engaging element 5 toward the pressed surface 7. The biasing member 55 can be made of a spring such as a leaf spring, coil spring, or disc spring, or an elastic material such as rubber, elastomer, or synthetic resin. The number of biasing members 55 is not particularly limited and is determined appropriately according to the number of engaging elements 5.

[0132] In this example, the biasing member 55 is composed of two biasing members 55 positioned at two locations in the width direction between the radially inner surfaces of the two engaging elements 5, and each biasing member 55 is composed of a compression coil spring. A protrusion 52 is inserted into the inside of both ends in the extension direction of each biasing member 55. This prevents each biasing member 55 from falling out of the space between the two engaging elements 5.

[0133] The two biasing members 55 elastically bias the two engaging elements 5 toward the pressed surface 7 by the force that attempts to restore their elasticity. As a result, in the neutral state where no torque is applied to either the input member 3 or the output member 4, the pressing surfaces 45 of the two engaging elements 5 come into contact with the pressed surface 7.

[0134] [Support members] The reverse input blocking clutch 1 in this example further comprises a support member 56 as an optional component.

[0135] The support member 56 is an element for rotatably supporting the other axial end (small diameter portion 38) of the output shaft portion 32.

[0136] The support member 56 comprises a cylindrical bearing holder 57, a partial cylindrical portion 58 extending axially from a single circumferential position at one end of the bearing holder 57 on one axial side, and an outward flange portion 59 extending radially outward from one end of the partial cylindrical portion 58 on one axial side.

[0137] The support member 56 is supported and fixed to the housing element 8 by screwing a bolt 61, which is inserted through a through hole 60 provided in the outward flange portion 59, into a threaded hole 13 provided in the housing element 8.

[0138] The other axial end (small diameter portion 38) of the output shaft portion 32 is rotatably supported by the support member 56 via a radial rolling bearing 43b held by the bearing holding portion 57.

[0139] In the illustrated example, the radial rolling bearings 43a and 43b that rotatably support the output shaft 32 are each ball bearings using balls as rolling elements. However, the radial rolling bearings for supporting the output shaft 32 can also be constructed using tapered roller bearings or cylindrical roller bearings using tapered rollers as rolling elements. Furthermore, different types of bearings can be used for the radial rolling bearings 43a and 43b.

[0140] <Explanation of the operation of the reverse input blocking clutch> The operation of the reverse input blocking clutch 1 in this example will be explained using Figures 9 and 10. Note that Figures 9 and 10 omit the biasing member 55 and exaggerate the radial gap between the input member 3 and the output member 4 and the two engaging elements 5.

[0141] When rotational torque is applied to the input member 3, the two engaging elements 5 move away from the pressed surface 7, regardless of the rotation direction of the input member 3. More specifically, as shown in Figure 9, the input-side engaging portion 14 rotates inside the input-side engaged portion 46 in the direction of rotation of the input member 3 (counterclockwise in the example of Figure 9).

[0142] This reduces the gap between the radially inner surface 16 of the input-side engaging portion 14 and the radially inner surface 48 of the input-side engaged portion 46, causing the radially inner surface 16 of the input-side engaging portion 14 to come into contact with the radially inner surface 48 of the input-side engaged portion 46.

[0143] From this state, as the input member 3 rotates further, the radially inner surface 16 of the input-side engaging portion 14 presses the radially inner surface 48 of the input-side engaged portion 46 radially inward, causing the engaging element 5 to move away from the pressed surface 7. That is, the two engaging elements 5 move radially inward, moving closer to each other based on their engagement with the input member 3, so that the radially inner surfaces of the two engaging elements 5 come closer to each other, and the output-side engaged portion 31 of the output member 4 is clamped from both radial sides by the output-side engaged portions 47 of the two engaging elements 5.

[0144] In this way, the output member 4 is rotated so that the flat surface 34 of the output-side engaging portion 31 is parallel to the output-side engaged portion 47, while the output-side engaging portion 31 and the output-side engaged portion 47 of the engaging element 5 are engaged without any rattle. As a result, the rotational torque input to the input member 3 is transmitted to the output member 4 via the two engaging elements 5 and output from the output member 4.

[0145] When rotational torque is applied in reverse to the output member 4, the two engaging elements 5 move toward the pressed surface 7, regardless of the rotation direction of the output member 4. Specifically, as shown in Figure 10, the output-side engaging portion 31 rotates in the direction of rotation of the output member 4 (clockwise in the example of Figure 10) inside the output-side engaged portions 47 of the two engaging elements 5. The flat surface 34 of the outer circumferential surface of the output-side engaging portion 31 presses the output-side engaged portions 47 radially outward, causing the two engaging elements 5 to move toward the pressed surface 7.

[0146] In other words, the two engaging elements 5 move radially outward, away from each other, based on their engagement with the output member 4, so that the pressing surfaces 45 of the two engaging elements 5 come into contact with the pressed surface 7 and frictionally engage with the pressed surface 7.

[0147] As a result, the rotational torque reversed into the output member 4 is either completely blocked and not transmitted to the input member 3, or only a portion of the rotational torque reversed into the output member 4 is transmitted to the input member 3 and the rest is blocked.

[0148] In order to completely block the rotational torque that is reverse-input to the output member 4 and prevent it from being transmitted to the input member 3, the engaging element 5 is braced (clamped) between the output-side engaging part 31 and the pressed member 2 so that the pressing surface 45 of the engaging element 5 does not slide (rotate relative to) the pressed surface 7, thereby locking the output member 4.

[0149] To ensure that only a portion of the rotational torque in reverse input to the output member 4 is transmitted to the input member 3 and the remainder is blocked, the engaging element 5 is braced (clamped) between the output-side engaging portion 31 and the pressed member 2 so that the pressing surface 45 of the engaging element 5 slides against the pressed surface 7, thereby semi-locking the output member 4.

[0150] In the reverse input blocking clutch 1 of this example, the size of the gaps between each component is adjusted so that the above operation is possible. In particular, when the pressing surfaces 45 of the two engaging elements 5 are in contact with the pressed surface 7, a gap exists between the radially inner surface 16 of the input-side engaging portion 14 and the radially inner surface 48 of the input-side engaged portion 46.

[0151] This prevents the radial outward movement of the engaging element 5 from being blocked by the input-side engaging part 14 when rotational torque is input in reverse to the output member 4, and also ensures that even after the pressing surface 45 contacts the pressed surface 7, the surface pressure acting on the contact area between the pressing surface 45 and the pressed surface 7 changes according to the magnitude of the rotational torque input in reverse to the output member 4, thereby ensuring that the output member 4 is properly locked or partially locked.

[0152] In the reverse input shut-off clutch 1 of this disclosure, the input arm portion 17, which is inserted through the input-side engaged portion 46 of the engaging element 5 among the input members 3, is provided with at least one of a one-side restricting portion 20 that restricts the movement of the engaging element 5 in one axial direction and a other-side restricting portion 21 that restricts the movement of the engaging element 5 in the other axial direction. Therefore, a dedicated part for restricting the movement of the engaging element 5 in one axial direction and / or a dedicated part for restricting the movement of the engaging element 5 in the other axial direction is not required. Accordingly, the reverse input shut-off clutch 1 of this disclosure can reduce the number of parts and improve ease of assembly.

[0153] [Example 2] A second example of the embodiment of this disclosure will be described with reference to Figure 11.

[0154] In this example, the reverse input blocking clutch 1a differs from the structure of the input arm 17a of the input member 3a in the structure of the input arm 17 of the first example.

[0155] The input arm 17a has an input-side engaging portion 14 and a one-side restricting portion 20 for restricting the movement of the engaging element 5 in one axial direction, but does not have a other-side restricting portion for restricting the movement of the engaging element 5 in the other axial direction.

[0156] In this example, the reverse input blocking clutch 1a has a spacer 62 between the axial end face 54 of the engaging element 5 on the other axial side and the axial end face 33 of the output shaft portion 32 of the output member 4 in order to restrict the movement of the engaging element 5 to the other axial side.

[0157] In this example, the one-sided restricting portion 20 provided on the input member 3a directly restricts the axial movement of the engaging element 5 to one side, eliminating the need for a dedicated part to restrict the axial movement of the engaging element 5 to one side. Furthermore, there are no assembly constraints due to the presence of the other-sided restricting portion 21. As a result, the number of parts can be reduced and assembly efficiency can be improved.

[0158] The composition and effects of the other parts of the second example are the same as those of the first example.

[0159] [Example 3] A third example of the embodiments of this disclosure will be described with reference to Figure 12.

[0160] In this example, the reverse input blocking clutch 1b differs in the structure of the input arm portion 17b of the input member 3b from the structure of the input arm portion 17 of the first example and the input arm portion 17a of the second example.

[0161] The input arm 17b has an input-side engaging portion 14 and a other-side restricting portion 21 for restricting the movement of the engaging element 5 in the other axial direction, but does not have a one-side restricting portion for restricting the movement of the engaging element 5 in one axial direction.

[0162] The reverse input blocking clutch 1b in this example has a stopper member 63 attached to one axial end of the output member 4, and a spacer 64 positioned between the stopper member 63 and the other axial end face 53 of the engager 5, in order to restrict the movement of the engager 5 to one axial side.

[0163] In this example, the other-side restricting portion 21 provided on the input member 3b directly restricts the axial movement of the engaging element 5 to the other side, eliminating the need for a dedicated part to restrict the axial movement of the engaging element 5 to the other side. This reduces the number of parts and improves ease of assembly.

[0164] The composition and effects of the other parts of the third example are the same as those of the first example. [Explanation of Symbols]

[0165] 1, 1a, 1b Reverse input cutoff clutch 2 Pressed member 3, 3a, 3b input parts 4 Output component 5 Engagement element 7 Pressed surface 8 Housing elements 9. Large diameter cylindrical surface 10 Small diameter cylindrical surface part 11 Connection surface 12 Inward flange section 13 screw holes 14 Input side engagement part 16 Radial inner surface 17, 17a, 17b Input arm 18 Input shaft section 19 Input flange section 20 One-sided regulatory section 21 Other side regulating section 22 Radial outer surface 23 Side view 24 sides 25 End face 26 End face 27 Radial inner surface 28 Escape ditch 29 Radial inner surface 30 escape grooves 31 Output side engagement part 32 Output shaft section 33 End face 34 Flat surface 35 Convex curved surface 36 Large diameter section 37 Medium diameter part 38 Small diameter section 39 Outward flange section 40 Reducer 41 Drive pulley 42 Toothed belt 43a, 43b Radial rolling bearings 44. Corner radius 45 Pressing surface 46 Input side engaged portion 47 Output side engaged part 48 Radial inner surface 49 Radial outer surface 50 Circumferential side view 51 Flat surface part 52 Convex part 53 End face 54 End face 55 Biasing member 56 Support member 57 Bearing retaining section 58 Partial cylindrical section 59 Outward flange section 60 through hole 61 volts 62 Spacers 63 Stopper component 64 Spacers

Claims

1. A member to be pressed having a surface to be pressed on its inner circumferential surface, An input member having an input-side engaging portion located radially inward of the pressed surface, connected to an input-side mechanism on one axial side, and arranged coaxially with the pressed surface, An output member having an output-side engaging portion located radially inward from the input-side engaging portion, connected to the output-side mechanism on the other axial side, and arranged coaxially with the pressed surface, An engaging element having a pressing surface facing the pressed surface, an input-side engaged portion that can engage with the input-side engaging portion, and an output-side engaged portion that can engage with the output-side engaging portion, and arranged to be movable in the radial direction, Equipped with, When rotational torque is input to the input member, the engaging element moves radially away from the pressed surface based on the input-side engaging portion engaging with the input-side engaged portion, and transmits the rotational torque input to the input member to the output member by engaging the output-side engaged portion with the output-side engaging portion. Conversely, when rotational torque is input in reverse to the output member, the engaging element presses the pressing surface against the pressed surface based on the output-side engaging portion engaging with the output-side engaged portion, thereby frictionally engaging the pressing surface with the pressed surface. The input member has an input-side engaging portion in a part of its axial direction, and an input arm portion through which the input-side engaged portion is inserted in the axial direction. The input arm portion has at least one of the following: a one-side restricting portion located on one axial side of the input-side engaging portion and restricting the movement of the engaging element in one axial direction relative to the input member; and a other-side restricting portion located on the other axial side of the input-side engaging portion and restricting the movement of the engaging element in the other axial direction relative to the input member. Reverse input blocking clutch.

2. The input arm portion has the other side restricting portion, The other side restricting portion protrudes radially inward from the input side engaging portion. The reverse input interruption clutch according to claim 1.

3. The input arm portion has the one-sided restricting portion, The aforementioned one-sided restricting portion protrudes more in the diametrical direction of the input arm than the aforementioned input-side engaging portion. The reverse input interruption clutch according to claim 1.

4. The reverse input shutoff clutch according to claim 3, wherein the one-sided restricting portion protrudes radially inward from the input-side engaging portion.

5. The reverse input shutoff clutch according to claim 1, wherein the input arm portion has both the one-side restricting portion and the other-side restricting portion.

6. The reverse input shutoff clutch according to claim 5, wherein both the one-sided restricting portion and the other-sided restricting portion protrude radially inward from the input-side engaging portion, and the distance from the central axis of the input member to the one-sided restricting portion is smaller than the distance from the central axis of the input member to the other-sided restricting portion.

7. The aforementioned input arm is composed of two input arms, The two input arms are positioned on opposite sides of the central axis of the input member. The aforementioned engaging element is composed of two engaging elements. The reverse input interruption clutch according to claim 1.

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