Reverse input cutoff clutch

Abstract

To realize a structure capable of suppressing rattling of an input member. [Solution] The leaf spring 6 is arranged on either side of the input side engaging portion 14 in a first direction which is the direction of movement of the pressing surface 33 toward and away from the pressed surface 7, and in a second direction which is perpendicular to the central axis of the input member 3, and has two clamped portions 43 which are elastically clamped between the input side engaging portion 14 and the input side engaged portion 34, and a base 44 which connects the two clamped portions 43 together.

Description

[Technical field]

[0001] The present disclosure relates to a reverse input cut-off clutch which transmits rotational torque input to an input member to an output member, while completely cutting off rotational torque input inversely to the output member and not transmitting it to the input member, or which transmits only a portion of the torque to the input member and cuts off the remainder. [Background technology]

[0002] A reverse input cut-off clutch has an input member connected to an input side mechanism such as a drive source, and an output member connected to an output side mechanism such as a reduction mechanism, and has the function of transmitting the rotational torque input to the input member to the output member, while completely cutting off the rotational torque reversely input to the output member and not transmitting it to the input member, or of transmitting only a portion of it to the input member and cutting off the remainder.

[0003] Reverse input cutoff clutches are broadly classified into locking type and free type, depending on the difference in the mechanism for cutting off the rotational torque reversely input to the output member. A locking type reverse input cutoff clutch is equipped with a mechanism for preventing the output member from rotating when a rotational torque is reversely input to the output member. On the other hand, a free type reverse input cutoff clutch is equipped with a mechanism for causing the output member to rotate freely when a rotational torque is input to the output member. The choice of whether to use a locking type reverse input cutoff clutch or a free type reverse input cutoff clutch is appropriately determined depending on the application of the device into which the reverse input cutoff clutch is incorporated, etc.

[0004] WO 2019 / 026794 describes a locking type reverse input cutoff clutch. The reverse input cutoff clutch described in WO 2019 / 026794 includes a pressed member, an input member, an output member, and an engagement element.

[0005] The pressed member has a pressed surface on its inner circumferential surface.

[0006] The input member has an input side engaging portion arranged radially inside the pressed surface, and is arranged coaxially with the pressed surface.

[0007] The output member has an output side engaging portion arranged radially inward of the input side engaging portion on the radially inner side of the pressed surface, and is arranged coaxially with the pressed surface.

[0008] The engaging element has a pressing surface facing the pressed surface, an input side engaged portion engageable with the input side engaging portion, and an output side engaged portion engageable with the output side engaging portion, and is arranged so as to be able to move in a first direction, which is the direction towards or away from the pressed surface.

[0009] In the reverse input cutoff clutch described in WO 2019 / 026794, when a rotational torque is input to the input member, the input side engaging portion engages with the input side engaged portion, so that the engager moves in a direction away from the pressed surface 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 a rotational torque is reversely input to the output member, the engager moves in a direction approaching the pressed surface based on the engagement of the output side engaging portion with the output side engaged portion, so that the pressing surface is pressed against the pressed surface and the pressing surface is frictionally engaged with the pressed surface. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. 2019 / 026794 Brochure Summary of the Invention [Problem to be solved by the invention]

[0011] In the reverse input cut-off clutch described in WO 2019 / 026794, the dimensional relationships of the various parts are not particularly restricted beyond being configured so that, at the position where the engaging element contacts the pressed surface due to the reverse input of rotational torque to the output member, there is a gap between the engaging element and the input member that allows the engaging element to be pressed toward the pressed surface based on engagement with the output member (a gap in the first direction, which is the direction in which the engaging element moves toward or away from the pressed surface).

[0012] However, in the reverse input cutoff clutch described in WO 2019 / 026794, in order to prevent the shape precision of the input member and the engaging element from being excessively high and to ensure the ease of assembly, it is necessary to regulate the dimensions of each part so that the input member and the engaging element can be assembled loosely to some extent. In this case, a gap in the first direction is formed at the engaging portion between the input member and the engaging element.

[0013] In the reverse input cutoff clutch described in WO 2019 / 026794, the gap between the input member and the engaging element in the first direction is not restricted in any way, so a gap in the circumferential direction is formed between the input side engaging portion and the input side engaged portion. As a result, the gap in the circumferential direction causes the input member to rattle more against the engaging element, and when the lock is released or partially released, a harsh noise may be generated due to a collision between the input member and the engaging element. In particular, when the direction of the rotational torque input to the input member is reversed, the rattle of the input member becomes more noticeable, making it more likely to generate abnormal noise.

[0014] An object of the present disclosure is to realize a reverse input cutoff clutch structure that can minimize rattling of the input member. [Means for solving the problem]

[0015] A reverse input disconnect clutch according to one aspect of the present disclosure includes a pressed member, an input member, an output member, an engagement element, and a leaf spring.

[0016] The pressed member has a pressed surface on its inner circumferential surface.

[0017] The input member has an input side engaging portion arranged radially inside the pressed surface, and is arranged coaxially with the pressed surface.

[0018] The output member has an output side engaging portion arranged radially inward of the input side engaging portion on the radially inner side of the pressed surface, and is arranged coaxially with the pressed surface.

[0019] The engaging element has a pressing surface facing the pressed surface, an input-side engaged portion engageable with the input-side engaging portion, and an output-side engaged portion engageable with the output-side engaging portion, and is arranged to be movable in a first direction that is a direction in which the pressing surface moves away from the pressed surface with respect to the pressed surface. Furthermore, when a rotational torque is input to the input member, the engaging element moves in a direction away from the pressed surface in the first direction based on the engagement of the input-side engaging portion 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, whereas when a rotational torque is input inversely to the output member, the engaging element presses the pressing surface against the pressed surface based on the engagement of the output-side engaged portion with the output-side engaged portion, thereby frictionally engaging the pressing surface with the pressed surface.

[0020] The leaf spring has two clamped portions arranged on either side of the input side engaging portion in a second direction perpendicular to the central axis of the input member and the first direction, and is elastically clamped between the input side engaging portion and the input side engaged portion, and a base connecting the two clamped portions to each other.

[0021] In a reverse input cut-off clutch according to one embodiment of the present disclosure, the two clamped portions can impart an elastic force to the input side engagement portion having a component facing each other in the second direction and a component oriented in a direction that brings the pressing surface closer to the pressed surface in the first direction.

[0022] A reverse input cut-off clutch according to one embodiment of the present disclosure may further include a biasing member that elastically biases the engaging element in a direction that brings the pressing surface closer to the pressed surface in the first direction, and the component of the direction that is imparted to the engaging element by the biasing member, that brings the pressing surface closer to the pressed surface in the first direction, may be greater than the component of the direction that is imparted to the engaging element by the two clamped portions, that moves the pressing surface away from the pressed surface in the first direction.

[0023] In the reverse input cutoff clutch according to one aspect of the present disclosure, the two clamped portions can apply to the input side engagement portion an elastic force having only a component in a direction facing each other with respect to the second direction.

[0024] In a reverse input cut-off clutch according to one embodiment of the present disclosure, the two clamped portions can impart to the input side engaging portion an elastic force having a component facing each other in the second direction and a component facing a direction moving the pressing surface away from the pressed surface in the first direction.

[0025] In the reverse input cutoff clutch according to one aspect of the present disclosure, the leaf spring may have a restricting portion that restricts relative displacement in the axial direction with respect to the engagement element.

[0026] In a reverse input cut-off clutch according to one embodiment of the present disclosure, the regulating portion can have two bent pieces that are bent from both axial ends of the two clamped portions or the base portion, and that are arranged on both axial sides of the peripheral portion of the input side engaged portion of the engaging element.

[0027] In the reverse input cutoff clutch according to one aspect of the present disclosure, at least one position of the base portion can be brought into contact with a portion of the inner surface of the input side engaged portion that faces radially inward.

[0028] In the reverse input cutoff clutch according to one aspect of the present disclosure, the engagement element may be configured by two engagement elements, in which case the input side engagement portion is configured by two input side engagement portions. Effect of the Invention

[0029] In the reverse input cutoff clutch according to one aspect of the present disclosure, when the input member rotates, the clamped portion disposed in front of the input side engaging portion in the rotation direction of the input member out of the two clamped portions constituting the leaf spring needs to be elastically deformed, thereby suppressing rattling of the input member. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a perspective view of a reverse input cutoff clutch according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is an end view of the reverse input cutoff clutch of the first example, as viewed from the input member side in the axial direction. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB of FIG. [Diagram 5] FIG. 5 is a cross-sectional view taken along line CC in FIG. 3, in which the leaf spring and the biasing member are omitted. [Figure 6] FIG. 6 is a view similar to FIG. 5, showing a state in which a rotational torque is input to the input member. [Figure 7] FIG. 7 is a view similar to FIG. 5, showing a state in which a rotational torque is reversely input to the output member. [Figure 8] FIG. 8 is an exploded perspective view of the reverse input cutoff clutch of the first example. [Figure 9] FIG. 9 is an end view of an engagement element, a leaf spring, and a biasing member that configure the reverse input cutoff clutch of the first example, as viewed from the axial direction. [Figure 10] FIG. 10 is an end view of an engagement element that constitutes the reverse input cutoff clutch of the first example, as viewed from the axial direction. [Figure 11]Figure 11(A) is an oblique view of a leaf spring that constitutes a first example reverse input cut-off clutch, Figure 11(B) is an end view of the leaf spring as viewed from the axial direction, Figure 11(C) is a plan view as viewed from above Figure 11(B), and Figure 11(C) is a side view as viewed from the side of Figure 11(B). [Figure 12] FIG. 12 is a front view showing another example of the engaging element. [Figure 13] FIG. 13 is a view similar to FIG. 4, showing a reverse input cutoff clutch according to a second embodiment of the present disclosure. [Figure 14] FIG. 14 is a perspective view of a leaf spring that constitutes the reverse input cutoff clutch of the second example. [Figure 15] FIG. 15 is a diagram illustrating a main portion of a reverse input cutoff clutch according to a third example of an embodiment of the present disclosure. [Figure 16] FIG. 16 is a view similar to FIG. 15, showing a reverse input cutoff clutch according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] [Example 1] A first example of an embodiment of the present disclosure will be described with reference to Figs. 1 to 11(D). The axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions of the reverse input cutoff clutch 1 unless otherwise specified. In this example, the axial, radial, and circumferential directions of the reverse input cutoff clutch 1 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. Moreover, one axial side refers to the input member 3 side (the right side in Fig. 3), and the other axial side refers to the output member 4 side (the left side in Fig. 3).

[0032] <Explanation of the structure of the reverse input cutoff clutch> The reverse input cutoff clutch 1 of this example includes a pressed member 2, an input member 3, an output member 4, an engagement element 5, and a leaf spring 6. The reverse input cutoff clutch 1 transmits the rotational torque input to the input member 3 to the output member 4, while having a reverse input cutoff function that completely blocks the rotational torque reversely input 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 cuts off the remainder.

[0033] The pressed member 2 has a pressed surface 7 on its inner circumferential surface. The input side engaging portion 14 of the input member 3 and the output side engaging portion 21 of the output member 4 are coaxially arranged radially inside the pressed surface 7, and the engaging element 5 is arranged so as to be movable toward and away from the pressed surface 7. The input side engaging portion 14, the output side engaging portion 21, and the engaging element 5 are rotatable radially inside the pressed surface 7. In addition, the pressed surface 7 forms a surface that comes into contact with the pressing surface 33 of the engaging element 5 when the engaging element 5 moves in a direction approaching the pressed surface 7.

[0034] In this example, the pressed surface 7 has a circular ring shape when viewed in the axial direction, and although not limited to this, in this example, it has a cylindrical surface shape whose inside diameter does not change in the axial direction.

[0035] In this example, the pressed member 2 is supported and fixed to a fixed part that does not rotate even when in use, such as a housing, and its rotation is restricted. Alternatively, the pressed member 2 is constituted by the fixed part. The shape of the pressed member 2 is not limited as long as it has a pressed surface 7 on its inner circumferential surface.

[0036] In this example, the pressed member 2 includes an output element 8 and an input element (not shown).

[0037] The output element 8 has an inner peripheral surface in the form of a stepped cylindrical surface. That is, the inner peripheral surface of the output 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 by a connection surface portion 11 facing one axial side. In this example, the large diameter cylindrical surface portion 9 forms the pressed surface 7. The output element 8 also has an inward flange portion 12 that protrudes radially inward at the end portion on the other axial side of the small diameter cylindrical surface portion 10.

[0038] The input element 8 is fitted (spigot-fitted) to the output element 8 without any rattle, and the output element 8 and the input element are positioned in the radial direction, and then the output element 8 and the input element are joined to each other with a joining member such as a bolt to form the pressed member 2. The pressed member 2 is supported and fixed to the fixed portion by threading a bolt inserted into a through hole provided in the fixed portion into a screw hole 13 opening on the side surface of the output element 8 on the other axial side.

[0039] The input member 3 has an input-side engaging portion 14 arranged radially inside the pressed surface 7, and is arranged coaxially with the pressed surface 7. The input member 3 is connected to an input-side mechanism such as an electric motor, and is configured to be rotatable radially inside the pressed surface 7 by the input of rotational torque. The input-side engaging portion 14 is provided in a portion radially outwardly displaced from the rotation center O of the input member 3, and has a portion that engages with the input-side engaged portion 34 of the engager 5. The input-side engaging portion 14 is configured to engage (contact) its radially inner surface 17 with the radially inner surface 36 of the input-side engaged portion 34 as the input member 3 or the engager 5 rotates.

[0040] In this example, the input member 3 has an input shaft portion 15 and an input flange portion 16 in addition to the input side engagement portion 14 .

[0041] The input shaft portion 15 has a cylindrical shape.

[0042] The input flange portion 16 protrudes radially outward from the outer circumferential surface of the other axial end of the input shaft portion 15 over the entire circumference.

[0043] The input side engaging portion 14 protrudes toward the other axial side from a portion of the side surface of the input flange portion 16 that is radially outwardly spaced from the center of rotation O.

[0044] There are no limitations on the shape of the input side engaging portion 14, so long as it is configured to engage with the input side engaged portion 34 of the engaging element 5. Furthermore, the number of input side engaging portions 14 is determined according to the number of engaging elements 5, and when the engaging element 5 is composed of a plurality of engaging elements 5, the input side engaging portion 14 is also composed of a plurality of input side engaging portions 14.

[0045] In the reverse input cutoff clutch 1 of this example, the engaging element 5 is configured by two engaging elements 5. Therefore, the input side engaging portion 14 is configured by two input side engaging portions 14 in accordance with the number of engaging elements 5. The two input side engaging portions 14 are disposed at two radially opposite positions on the other axial side surface of the input flange portion 16, and are spaced apart from each other in the radial direction of the input member 3. Furthermore, each input side engaging portion 14 has a shape that is symmetrical in the circumferential direction.

[0046] In this example, each input side engaging portion 14 has an end face shape of a substantially sector or trapezoid with a circumferential width increasing radially outward when viewed from the axial direction. The radial inner side surface 17 of each input side engaging portion 14 is composed of flat surfaces parallel to each other, and the radial outer side surface 18 of each input side engaging portion 14 has the same cylindrical contour shape as the outer circumferential surface of the input flange portion 16. The two circumferential side surfaces 19 of each input side engaging portion 14 are composed of flat surfaces that are inclined in a direction away from each other as they move radially outward. The radial inner side surface 17 and the circumferential side surface 19 are connected by a curved surface portion 20 that has a contour shape of a substantially arc when viewed from the axial direction.

[0047] The input member 3 can be rotatably supported by the pressed member 2 or the fixed portion. In this example, the input member 3 is rotatably supported inside the input side element by a radial bearing.

[0048] The output member 4 has an output-side engagement portion 21 arranged radially inward of the pressed surface 7 relative to the input-side engagement portion 14, and is arranged coaxially with the pressed surface 7. That is, the output member 4 is also arranged coaxially with the input member 3. The output member 4 is connected to an output-side mechanism such as a reduction mechanism, and is configured to output a rotational torque to the output-side mechanism as it rotates.

[0049] The output side engaging portion 21 is radially inward from the input side engaging portion 14, but has a portion that is offset radially outward from the rotation center O of the output member 4, and is arranged at a position where the portion can engage with the output side engaged portion 35 of the engager 5. The output side engaging portion 21 is configured so that the portion engages with the output side engaged portion 35 as the output member 4 or the engager 5 rotates.

[0050] In this example, in addition to the output side engagement portion 21, the output member 4 has an output shaft portion 22, an output flange portion 23, and a small diameter shaft portion 24.

[0051] The output shaft portion 22 has a stepped cylindrical shape.

[0052] The output flange portion 23 protrudes radially outward from the outer circumferential surface of one axial end of the output shaft portion 22 over the entire circumference.

[0053] The output side engagement portion 21 protrudes from the center of a side surface on one axial direction side of the output shaft portion 22 toward one axial direction side.

[0054] The shape of the output side engaging portion 21 is not limited as long as it is configured to have a portion that engages with the output side engaged portion 35. Furthermore, the number of portions of the output side engaging portion 21 that engage with the output side engaged portion is determined according to the number of engaging elements 5, and when the engaging element 5 is composed of a plurality of engaging elements 5, the output side engaging portion 21 is also configured to have a plurality of the engaging portions. Note that even when the engaging element is composed of a single engaging element, the output side engaging portion can have a plurality of the engaging portions.

[0055] In this example, the output side engaging portion 21 is configured to have portions that engage with two output side engaged portions 35 in accordance with the number of the engaging elements 5.

[0056] In this example, the output side engaging portion 21 has a substantially rectangular or oval end face shape when viewed in the axial direction, and protrudes from the center of one axial end face of the output shaft portion 22 toward one axial side. That is, the distance from the rotation center O of the output member 4 to the outer circumferential surface of the output side engaging portion 21, which is the portion that engages with the output side engaged portion 35, is not constant in the circumferential direction. Therefore, the output side engaging portion 21 has a cam function.

[0057] More specifically, the outer circumferential surface of the output side engagement portion 21 is composed of two parallel flat surfaces 25 and two convex curved surfaces 26, each of which is a partial cylindrical surface. Therefore, the distance from the rotation center O of the output member 4 to the outer circumferential surface of the output side engagement portion 21 is not constant in the circumferential direction. Each of the two convex curved surfaces 26 is composed of a partial cylindrical surface with the rotation center O of the output member 4 as its center.

[0058] The output-side engagement portion 21 is plane-symmetrical with respect to an imaginary plane that passes through the rotation center O of the output member 4 and is perpendicular to the flat surface 25. Furthermore, the output-side engagement portion 21 is plane-symmetrical with respect to an imaginary plane that passes through the rotation center O of the output member 4 and is parallel to the flat surface 25.

[0059] Such an output side engagement portion 21 is disposed between the two input side engagement portions 14.

[0060] The small diameter shaft portion 24 has a cylindrical shape and protrudes from the center of an end face on one axial side of the output side engagement portion 21 toward one axial side.

[0061] The output member 4 can be rotatably supported by the pressed member 2 or the fixed portion. In this example, the output member 4 is rotatably supported by a radial rolling bearing 27 on the radial inside of the output element 8 of the pressed member 2. The outer ring 28 of the radial rolling bearing 27 is fitted into the small diameter cylindrical surface portion 10 of the output element 8 without rattle, and is axially sandwiched between a side surface on one axial side of the inward flange portion 12 and a retaining ring 29a engaged with an end portion on one axial side of the small diameter cylindrical surface portion 10. The inner ring 30 of the radial rolling bearing 27 is fitted outside the end portion on one axial side of the output shaft portion 22 without rattle, and is axially sandwiched between a side surface on the other axial side of the output flange portion 23 and a retaining ring 29b engaged with an outer peripheral surface of an axial middle portion of the output shaft portion 22.

[0062] In the illustrated example, the radial rolling bearing 27 is configured as a ball bearing using balls as the rolling elements 31. However, the radial rolling bearing for supporting the output member 4 may also be configured as a tapered roller bearing using tapered rollers as the rolling elements or a roller bearing using cylindrical rollers.

[0063] Further, the small diameter shaft portion 24 of the output member 4 is supported by a sliding bearing (sleeve) 32 on the inside of the input member 3 so as to be freely rotatable relative to the input member 3.

[0064] The engaging element 5 has a pressing surface 33 facing the pressed surface 7, an input side engaged portion 34 engageable with the input side engaging portion 14, and an output side engaged portion 35 engageable with the output side engaging portion 21, and is arranged so as to be able to move in a first direction, which is the direction towards or away from the pressed surface 7.

[0065] When a rotational torque is input to the input member 3, the engagement element 5 moves in the first direction away from the pressed surface 7 based on the engagement of the input side engaging portion 14 with the input side engaged portion 34, and transmits the rotational torque input to the input member 3 to the output member 4 by engaging the output side engaged portion 35 with the output side engaging portion 21. Conversely, when a rotational torque is input in the reverse direction to the output member 4, the engagement of the output side engaging portion 21 with the output side engaged portion 35 presses the pressing surface 33 against the pressed surface 7, frictionally engaging the pressing surface 33 with the pressed surface 7.

[0066] The engaging element 5 may be configured by one engaging element 5 having such a configuration, or may be configured by two or more engaging elements 5.

[0067] In this example, the engaging element 5 is composed of two engaging elements 5. Each engaging element 5 functions as 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 (the direction indicated by the arrow B in FIG. 5). The configuration of each engaging element 5 will be described below.

[0068] In this example, the radial direction with respect to the engaging element 5 is the direction in which the pressing surface 33 approaches or approaches the pressed surface 7, and corresponds to the direction indicated by the arrow A in Fig. 5. The width direction with respect to the engaging element 5 is the direction perpendicular to both the direction in which the pressing surface 33 approaches or approaches the pressed surface 7 and the axial direction of the input member 3, and corresponds to the direction indicated by the arrow B in Fig. 5. In this example, the radial direction with respect to the engaging element 5 corresponds to the first direction, and the width direction with respect to the engaging element 5 corresponds to the second direction.

[0069] The pressing surface 33 is provided on the radially outer surface of the engaging element 5 facing the pressed surface 7. In this example, the pressing surface 33 is composed of two pressing surfaces 33 provided at two positions spaced apart from each other in the circumferential direction on the radially outer surface of the engaging element 5. Each pressing surface 33 is composed of a partially cylindrical convex curved surface having a radius of curvature smaller than the radius of curvature of the pressed surface 7.

[0070] Of the radially outer surface of the engagement element 5, a portion that is circumferentially offset from the two pressing surfaces 33 is located radially inward of an imaginary circle that is centered on the central axis O of the input member 3 and is tangent to the two pressing surfaces 33, when viewed from the axial direction. In other words, when the two pressing surfaces 33 are in contact with the pressed surface 7, the portion that is circumferentially offset from the two pressing surfaces 33 does not contact the pressed surface 7.

[0071] It is preferable that the pressing surface 33 has a surface property that has a larger coefficient of friction with the pressed surface 7 than the other parts of the engaging element 5. The pressing surface 33 can be formed integrally with the other parts of the engaging element 5, or can be formed of the surface of a friction material fixed to the other parts of the engaging element 5 by sticking, bonding, or the like.

[0072] In this example, the input-side engaged portion 34 is provided at a radially intermediate portion of the widthwise center portion of the engaging element 5. More specifically, although not limited thereto, the input-side engaged portion 34 has a substantially arch-shaped opening shape when viewed from the axial direction, and is configured as a through-hole that axially passes through a radially intermediate portion at the widthwise center position of the engaging element 5.

[0073] The input side engaged portion 34 has a size that allows the input side engaging portion 14 to be loosely inserted therein. Therefore, with the input side engaging portion 14 inserted inside the input side engaged portion 34, there are gaps in the width direction and radial direction of the engaging element 5 between the input side engaging portion 14 and the inner surface of the input side engaged portion 34. Therefore, the input side engaging portion 14 can be displaced relative to the input side engaged portion 34 in the rotational direction of the input member 3, and the input side engaged portion 34 can be displaced relative to the input side engaging portion 14 in the radial direction of the engaging element 5.

[0074] As long as the input side engaged portion 34 is configured to be able to engage with the input side engaging portion 14, there are no limitations on its shape.

[0075] In this example, the radially inner side surface 36 facing the radially outward among the inner surfaces of the input-side engaged portion 34 is configured by a flat surface perpendicular to the first direction, and the radially outer side surface 37 facing the radially inward among the inner surfaces of the input-side engaged portion 34 is configured by a composite surface having a substantially V-shaped contour shape when viewed from the axial direction. Specifically, the radially outer side surface 37 has a concave curved surface portion 38 of a partial cylindrical surface in a middle portion in the width direction of the engaging element 5, and has two inclined surface portions 39 on both sides in the width direction of the engaging element 5 that are inclined in a direction toward the inside in the radial direction of the engaging element 5 as they move away from each other in the width direction of the engaging element 5. The circumferential side surface 40 connecting both ends in the second direction of the radially inner side surface 36 and both ends in the second direction of the radially outer side surface 37 is configured by a concave curved surface of a partial cylindrical surface.

[0076] In this example, the output-side engaged portion 35 is provided at the center in the width direction of the radially inner surface of the engagement element 5. The shape of the output-side engaged portion 35 is not limited as long as it is configured to be able to engage with the output-side engaging portion 21.

[0077] In this example, the engaging element 5 has a flat surface portion 41 on its radially inner surface that is perpendicular to the radial direction of the engaging element 5, and the flat surface portion 41 has two protruding portions 42 that protrude radially inward at two positions in the width direction of the engaging element 5. The output side engaged portion 35 is formed by a portion of the flat surface portion 41 that is between the two protruding portions 42 in the width direction. In this example, the width dimension of the output side engaged portion 35, i.e., the distance between the two protruding portions 42, is larger than the width dimension of the flat surface 25 of the output side engaging portion 21.

[0078] In the reverse input cutoff clutch 1 of this example, the pressing surfaces 33 of the two engaging elements 5 are oriented in opposite directions in the radial direction, and the flat surface portions 41 are opposed to each other, and each engaging element 5 is arranged radially inside the pressed member 2 so as to be movable in a first direction, which is the radial direction of each engaging element 5 and corresponds to the approaching direction of the pressing surface 33 relative to the pressed surface 7. In addition, the two input side engaging portions 14 of the input member 3 arranged on one axial side are axially inserted into the input side engaged portions 34 of the two engaging elements 5, and the output side engaging portion 21 of the output member 4 arranged on the other axial side is axially inserted between the output side engaged portions 35 of the two engaging elements 5. That is, the two engaging elements 5 are arranged so that the output side engaging portions 21 are sandwiched from the radially outer side by the output side engaged portions 35.

[0079] The inner diameter dimension of the pressed member 2 and the radial dimension of the engaging elements 5 are regulated so that, when the two engaging elements 5 are positioned radially inside the pressed member 2, a gap exists in at least one of the portions between the pressed surface 7 and the two pressing surfaces 33, and between the tip faces of each of the two combinations of convex portions 42 formed by the two convex portions 42 of the two engaging elements facing each other.

[0080] The leaf spring 6 has two clamped portions 43 arranged on either side of the input side engaging portion 14 in the second direction and elastically clamped between the input side engaging portion 14 and the input side engaged portion 34, and a base 44 connecting the two clamped portions 43 to each other.

[0081] The two held portions 43 impart an elastic force to the input side engaging portion 14, the elastic force having a component in a direction facing each other in the second direction and a component facing outward in the radial direction of the engaging element 5. The two held portions 43 also impart an elastic force to the engaging element 5, the elastic force having a component in a direction away from each other in the second direction and a component facing inward in the radial direction of the engaging element 5.

[0082] In this example, each clamped portion 43 has a discontinuous portion at one circumferential position of the clamped portion 43 itself, and has a notched cylindrical shape with a radius of curvature of the outer circumferential surface slightly smaller than the circumferential side surface 40 of the input-side engaged portion 34. Note that, although not limited to this, in the illustrated example, each clamped portion 43 has an end face shape that is approximately 3 / 4 arc-shaped when viewed from the axial direction.

[0083] The base 44 is positioned between the radial outer surface 18 of the input side engaging portion 14 and the radial outer surface 37 of the input side engaged portion 34, and connects the base ends of the two clamped portions 43, i.e., the ends on both sides of the two clamped portions 43 in the circumferential direction that are farthest from each other in the second direction.

[0084] In this example, the base 44 has a substantially V-shaped end face shape when viewed from the axial direction. Specifically, the base 44 has a partially cylindrical curved portion 45 in the middle in the second direction, and two inclined plate portions 46 on both sides in the second direction that are inclined in a direction away from the pressed surface 7 in the first direction as they move away from each other in the second direction.

[0085] The leaf spring 6 is disposed inside the input-side engaged portion 34 with the base 44 elastically deformed so as to bring the two held portions 43 closer to each other, and each held portion 43 is sandwiched between the circumferential side surface 19 of the input-side engaging portion 14 and the circumferential side surface 40 of the input-side engaged portion 34 in an elastically compressed (diameter-reduced) state. Therefore, the outer circumferential surface near the tip of the held portion 43 is elastically pressed against the circumferential side surface 19 of the input-side engaging portion 14 based on the elastic restoration of each held portion 43 so as to expand in diameter.

[0086] In addition, based on the base 44 attempting to elastically restore in a direction moving the two clamped portions 43 away from each other and each clamped portion 43 attempting to elastically restore in such a way that it expands in diameter, the portion of the outer surface of each clamped portion 43 that abuts against the circumferential side surface 19 and the portion that is located approximately opposite in the radial direction of the clamped portion 43 are elastically pressed against the circumferential side surface 40 of the input side engaged portion 34.

[0087] With the leaf spring 6 disposed inside the input-side engaged portion 34, at least one position of the radially outer side surface of the base portion 44 is in contact with the radially outer side surface 37 of the input-side engaged portion 34 facing radially inward. In this example, the radially outer side surface of the curved portion 45 is in contact with the concave curved surface portion 38 of the radially outer side surface 37 of the input-side engaged portion 34.

[0088] In this example, the leaf spring 6 has a symmetrical shape with respect to the second direction. Therefore, the spring characteristics of the two clamped portions 43 are the same. In addition, the width dimensions in the axial direction of the two clamped portions 43 and the width dimensions in the axial direction of the base portion 44 are the same. Furthermore, the width dimensions in the axial direction of the two clamped portions 43 and the width dimensions in the axial direction of the base portion 44 are approximately the same as the axial thickness of the engaging element 5.

[0089] However, the axial width dimension of the two held parts and the axial width dimension of the base part may be made smaller or larger than the axial thickness of the engaging part. Also, the axial width dimension of the two held parts and the axial width dimension of the base part may be made different from each other.

[0090] The leaf spring 6 further has a restricting portion 47 that restricts relative displacement with respect to the engaging element 5 in the axial direction.

[0091] The regulating portion 47 is bent from both axial ends of the two clamped portions 43 or the base portion 44, and has bent pieces 48 that are arranged on both axial sides of the peripheral portion of the input side engaged portion 34 of the engaging element 5.

[0092] In this example, the restricting portion 47 has four bent pieces 48 that are bent from both axial ends of each of the inclined plate portions 46 constituting the base portion 44 toward the radial outside of the engaging element 5 and are arranged on both axial sides of a portion of the engaging element 5 that is located radially outside the inclined surface portion 39. In other words, the bent pieces 48 clamp the portion of the engaging element 5 that is located radially outside the inclined surface portion 39 from both axial sides, thereby restricting the axial relative displacement of the leaf spring 6 with respect to the engaging element 5.

[0093] Such a leaf spring 6 is made as a whole by performing punching and bending processes using a press on a metal plate having elasticity, such as a steel plate.

[0094] The reverse input cutoff clutch 1 of this example further includes, as optional components, a biasing member 49, two spacers 50, and a stopper member 51.

[0095] The biasing member 49 is provided between the output side engaging portion 21 of the output member 4 and the engaging element 5, and elastically biases the engaging element 5 in a direction that brings the pressing surface 33 closer to the pressed surface 7 in the first direction. In this example, the biasing member 49 is composed of two biasing members 49 that are respectively arranged between the radial inner surfaces of the two engaging elements 5 and the output side engaging portion 21 of the output member 4.

[0096] Each of the biasing members 49 is composed of a leaf spring having two arms 52 and two connection parts 53. Each of the arms 52 has a notch that opens at the tip, and has a substantially U-shaped planar shape when viewed in the plate thickness direction (radial direction of the engaging element 5). Each connection part 53 is composed of a rectangular flat plate that connects the axially opposite ends of the base ends of the two arms 52.

[0097] Each of the urging members 49 is supported by the engagement element 5 by engaging notches formed in the two arm portions 52 with the two protrusions 42 of the engagement element 5. In this example, regardless of the positional relationship between each of the engagement elements 5 and the output side engagement portion 21, specifically, the radial position of each of the engagement elements 5 and the rotational phase of the output side engagement portion 21 relative to each of the engagement elements 5, the output side engagement portion 21 is adapted to elastically abut against the two connection portions 53 constituting each of the urging members 49. This suppresses rattling between the output side engagement portion 21 and the output side engaged portion 35.

[0098] The shape of the biasing member is not particularly limited as long as it can elastically bias the engagement elements in a direction that brings the pressing surface closer to the pressed surface, and can quickly switch to the locked state or the semi-locked state when a rotational torque is input inversely to the output member. For example, the biasing member can be formed of a torsion coil spring that is held in an elastically compressed state between the radially inner surfaces of the two engagement elements.

[0099] Each spacer 50 is formed in a flat plate shape and has an end face shape that is generally oval or generally rectangular when viewed in the axial direction. Each spacer 50 has a through hole 54 through which the output side engagement portion 21 can be inserted without rattle. Each spacer 50 is disposed on both axial sides of the two engagement elements 5 with the output side engagement portion 21 inserted into the respective through hole 54 without rattle.

[0100] The stopper member 51 is configured by a snap ring having a partially cut circular shape. That is, the stopper member 51 has a substantially C-shaped end face shape when viewed from the axial direction.

[0101] The stopper member 51 is engaged with the end portion on the other axial side of the small diameter shaft portion 24. This prevents the spacer 50 on one axial side of the two spacers 50 from being displaced toward one axial side. In this example, the biasing member 49 supported by the two engagement elements 5 is axially sandwiched between the side surface on one axial side of the output flange portion 23 and the stopper member 51 via the two spacers 50, thereby preventing the two engagement elements 5 from being displaced relative to the output member 4 in the axial direction.

[0102] <Operation explanation of reverse input cutoff clutch> The operation of the reverse input cutoff clutch 1 of this embodiment will be described with reference to Figures 6 and 7. In Figures 6 and 7, the leaf spring 6 and the biasing member 49 are omitted, and the radial gaps between the input member 3 and the output member 4 and the two engagement elements 5 are exaggerated.

[0103] When a rotational torque is input to the input member 3, the two engaging elements 5 move in a direction away from the pressed surface 7, regardless of the rotational direction of the input member 3. More specifically, as shown in Fig. 6, the input-side engaging portion 14 rotates in the rotational direction of the input member 3 (counterclockwise in the example of Fig. 6) inside the input-side engaged portion 34 while elastically compressing the clamped portion 43 arranged in front of the input-side engaging portion 14 in the rotational direction of the input member 3, against the resistance force applied to the input-side engaging portion 14 from the clamped portion 43 arranged on the front side of the input-side engaging portion 14 in the rotational direction of the input member 3, among the two clamped portions 43 arranged on both sides of the input-side engaging portion 14 in the second direction.

[0104] This reduces the gap between the radial inner surface 17 of the input side engaging portion 14 and the radial inner surface 36 of the input side engaged portion 34, and brings the radial inner surface 17 of the input side engaging portion 14 into contact with the radial inner surface 36 of the input side engaged portion 34.

[0105] When the input member 3 rotates further from this state, the radial inner surface 17 of the input side engaging portion 14 presses the radial inner surface 36 of the input side engaged portion 34 radially inward, and the engaging element 5 moves in a direction away from the pressed surface 7. That is, the two engaging elements 5 move radially inward, that is, in a direction approaching each other, based on their engagement with the input member 3, and the radial inner surfaces of the two engaging elements 5 approach each other, and the output side engaging portion 21 of the output member 4 is sandwiched from both radial sides by the output side engaged portions 35 of the two engaging elements 5.

[0106] In this manner, while rotating the output member 4 so that the flat surface 25 of the output side engaging portion 21 is parallel to the flat surface portion 41 of the engaging element 5, the output side engaging portion 21 and the output side engaged portion 35 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 is output from the output member 4.

[0107] When a rotational torque is input in reverse to the output member 4, the two engaging elements 5 move in a direction approaching the pressed surface 7, regardless of the rotational direction of the output member 4. More specifically, as shown in Fig. 7, the output-side engaging portion 21 rotates inside the output-side engaged portions 35 of the two engaging elements 5 in the rotational direction of the output member 4 (clockwise in the example of Fig. 7). The output-side engaged portions 35 are pressed radially outward by the connection portion (corner portion) between the flat surface 25 and the convex curved surface 26 of the outer circumferential surface of the output-side engaging portion 21, and the two engaging elements 5 move in a direction approaching the pressed surface 7.

[0108] That is, based on engagement with the output member 4, the two engagement elements 5 move radially outward, that is, in directions away from each other, and the pressing surfaces 33 of the two engagement elements 5 come into contact with the pressed surface 7 and frictionally engage with the pressed surface 7.

[0109] As a result, the rotational torque inputted inversely to the output member 4 is either completely blocked and not transmitted to the input member 3, or only a portion of the rotational torque inputted inversely to the output member 4 is transmitted to the input member 3 and the remainder is blocked.

[0110] In order to completely block the rotational torque input in reverse 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 portion 21 and the pressed member 2 so that the pressing surface 33 of the engaging element 5 does not slide (rotate relative to) against the pressed surface 7, and the output member 4 is locked.

[0111] In order to transmit only a portion of the rotational torque input inversely to the output member 4 to the input member 3 and block the remainder, the engaging element 5 is braced (clamped) between the output side engaging portion 21 and the pressed member 2 so that the pressing surface 33 of the engaging element 5 slides against the pressed surface 7, and the output member 4 is semi-locked.

[0112] In the reverse input cutoff clutch 1 of this embodiment, the size of the gap between each component is adjusted so that the above operation is possible. In particular, in a positional relationship in which the pressing surfaces 33 of the two engaging elements 5 are in contact with the pressed surfaces 7, a gap is set to exist between the radially inner surface 17 of the input side engaging portion 14 and the radially inner surface 36 of the input side engaged portion 34.

[0113] This prevents the input side engagement portion 14 from blocking the radially outward movement of the engagement element 5 when a rotational torque is input in reverse to the output member 4, and even after the pressing surface 33 comes into contact with the pressed surface 7, the surface pressure acting on the contact portion between the pressing surface 33 and the pressed surface 7 changes depending on 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 semi-locked.

[0114] According to the reverse input cutoff clutch 1 of this example, for reasons similar to those of the reverse input cutoff clutch described in WO 2019 / 026794, the axial dimension can be shortened and the number of parts can be reduced.

[0115] The reverse input cutoff clutch 1 of this example converts the rotation of each of the input member 3 and the output member 4 into radial movement of the engagement element 5. By converting the rotation of the input member 3 and the output member 4 into radial movement of the engagement element 5 in this way, the engagement element 5 is engaged with the output member 4 located radially inside the engagement element 5, and the engagement element 5 is pressed against the pressed member 2 located radially outside the engagement element 5.

[0116] In this way, the reverse input blocking clutch 1 of this example can be switched between an unlocked state in which rotational torque can be transmitted from the input member 3 to the output member 4, and a locked state in which rotation of the output member 4 is prevented or a semi-locked state in which rotation of the output member 4 is suppressed, based on the radial movement of the engaging member 5 controlled by the rotation of the input member 3 and / or the output member 4, thereby shortening the axial dimension of the entire device of the reverse input blocking clutch 1.

[0117] Moreover, the engaging element 5 has both the function of transmitting the rotational torque input to the input member 3 to the output member 4 and the function of locking or semi-locking the output member 4. This makes it possible to reduce the number of parts in the reverse input cutoff clutch 1, and also makes the operation more stable compared to a case in which the function of transmitting the rotational torque and the function of locking or semi-locking are provided in separate members.

[0118] For example, if the function of transmitting rotational torque and the function of locking or semi-locking are provided in separate members, there is a possibility that the timing of unlocking or semi-locking may differ from the timing of starting to transmit the rotational torque. In this case, if a rotational torque is input in reverse to the output member between unlocking or semi-locking and starting to transmit the rotational torque, the output member will be locked or semi-locked again.

[0119] In this embodiment, the engagement element 5 has both the function of transmitting rotational torque to the output member 4 and the function of locking or semi-locking the output member 4, so that such inconvenience can be prevented.

[0120] In addition, since the direction of the force acting from the input member 3 to the engagement member 5 and the direction of the force acting from the output member 4 to the engagement member 5 are opposite to each other, the movement direction of the engagement member 5 can be controlled by regulating the magnitude relationship between the two forces. Therefore, the switching operation of the output member 4 between the locked state or semi-locked state and the unlocked state can be performed stably and reliably.

[0121] In particular, in the reverse input cutoff clutch 1 of this example, the two clamped portions 43 constituting the leaf spring 6 are disposed on both sides of the input side engaging portion 14 in the second direction, and are elastically clamped between the input side engaging portion 14 and the input side engaged portion 34. For this reason, when the input member 3 rotates, of the two clamped portions 43, the clamped portion 43 disposed on the front side of the input side engaging portion 14 in the rotational direction of the input member 3 needs to be elastically compressed against the resistance force applied from the torsion coil spring 6 to the input side engaging portion 14.

[0122] Therefore, even if a certain amount of circumferential gap is secured between the input side engaging portion 14 and the input side engaged portion 34 in order to ensure the ease of assembly of the reverse input cutoff clutch 1, it is possible to suppress rattling of the input member 3 relative to the engager 5. Therefore, according to the reverse input cutoff clutch 1 of this example, even during unlocking or half-unlocking, it is possible to prevent the input side engaging portion 14 and the input side engaged portion 34 from colliding forcefully, and to prevent the generation of harsh noises due to the collision between the input side engaging portion 14 and the input side engaged portion 34.

[0123] In this example, as described above, the leaf spring 6 for suppressing rattle of the input member 3 is made as a whole by applying punching and bending processes to an elastic metal plate. Therefore, the number of parts can be reduced compared to, for example, a case in which two torsion coil springs are disposed on each side of the input side engagement part in the second direction, and the manufacturing cost of the reverse input cutoff clutch 1 can be easily reduced.

[0124] In the reverse input cutoff clutch 1 of this example, the two clamped parts 43 apply elastic force having components that face each other in the second direction to the input side engaging part 14. Furthermore, the two clamped parts 43 have the same spring characteristics, such as the spring constant and free length. Therefore, in a neutral state in which no torque is applied to either the input member 3 or the output member 4, the input side engaging part 14 can be positioned at the center position of the input side engaged part 34 in the second direction.

[0125] In other words, the circumferential gap between the input side engaging portion 14 and the input side engaged portion 34 can be made the same regardless of the rotational direction of the input member 3. Therefore, when the direction of the rotational torque input to the input member 3 is reversed, the circumferential gap between the input side engaging portion 14 and the input side engaged portion 34 can be prevented from becoming large, and the rattle of the input member 3 can be prevented from becoming large.

[0126] However, in cases where high responsiveness is required only for rotation in one direction of the input member 3 and not for rotation in the other direction, the spring characteristics of the two clamped parts arranged between the input side engaging part and the input side engaged part that engage with each other can be made different from each other.

[0127] By making the spring characteristics of the two clamped parts different, in a neutral state where no torque is applied to either the input member or the output member, the gap in the circumferential direction between the input side engaging part and the input side engaged part when the input member rotates in one direction can be made smaller than the gap in the front when the input member rotates in the other direction, thereby improving responsiveness when the input member rotates in one direction.

[0128] Furthermore, according to the reverse input cutoff clutch 1 of this embodiment, the workability of the assembly work can be improved.

[0129] When assembling the reverse input cutoff clutch 1, first, the input member 3 is rotatably supported inside the input element, and the output member 4 is rotatably supported inside the output element 8 by the radial rolling bearing 27. Furthermore, the leaf spring 6 is attached to the inside of the input side engaged portion 34 of the engagement element 5, and the biasing member 49 is attached to the radially inner end of the engagement element 5.

[0130] Next, the small diameter shaft portion 24 and the output side engagement portion 21 of the output member 4 are inserted into the through hole 54 of the spacer 50 on the other axial side from the other axial side, and the side surface of the other axial side of the spacer 50 on the other axial side is abutted against the axial side surface of the output flange portion 23.

[0131] Next, the two engagement elements 5 to which the leaf spring 6 and the biasing member 49 are assembled are disposed between the output side engagement portion 21 of the output member 4 and the pressed surface 7 provided on the inner circumferential surface of the output side element 8.

[0132] Then, with the two input side engaging portions 14 of the input member 3 rotatably supported inside the input side element and the input side engaged portions 34 of the two engagers 5 aligned in the circumferential phase, the input member 3 and the input side element, and the output member 4 and the output side element 8 are displaced in the axial direction in a direction approaching each other. This causes the input side element to fit into the output side element 8 without any rattle, and the two input side engaging portions 14 are inserted into the respective input side engaged portions 34. The input side element and the output side element 8 are then coupled to each other by a coupling member, thereby assembling the reverse input cutoff clutch 1.

[0133] In the reverse input cutoff clutch 1 of this example, at least one position of the radially outer side surface of the base portion 44 constituting the leaf spring 6 is brought into contact with the radially outer side surface 37 of the input side engaged portion 34 facing radially inward. Specifically, in this example, the radially outer side surface of the curved portion 45 is brought into contact with the concave curved surface portion 38 of the radially outer side surface 37 of the input side engaged portion 34. Therefore, before the input side engaging portion 14 of the input member 3 is inserted into the input side engaged portion 34, the leaf spring 6 can be positioned inside the input side engaged portion 34. Therefore, the input side engaging portion 14 can be easily inserted into the input side engaged portion 34, and the workability of the assembly work of the reverse input cutoff clutch 1 can be improved.

[0134] It should be noted that the procedures for assembling the reverse input cutoff clutch 1 can be interchanged or performed simultaneously as long as no contradiction occurs.

[0135] The reverse input cutoff clutch 1 of this example includes a biasing member 49 that elastically biases the engagement element 5 in a direction that brings the pressing surface 33 closer to the pressed surface 7 in the first direction. Therefore, the reverse input cutoff clutch 1 of this example can quickly switch to a locked state or a semi-locked state when a rotational torque is reversely input to the output member 4. In other words, the reverse input cutoff clutch of this example can ensure good locking performance.

[0136] In the reverse input cutoff clutch 1 of this example, the elastic force applied to the engaging element 5 by the two clamped portions 43 includes a component in a direction moving the pressing surface 33 away from the pressed surface 7 in the first direction. However, in this example, the component of the elastic force applied to the engaging element by the biasing member 49 in the direction moving the pressing surface 33 closer to the pressed surface 7 in the first direction is made larger than the component of the elastic force applied to the engaging element 5 by the two clamped portions 43 in the direction moving the pressing surface 33 away from the pressed surface 7 in the first direction. Therefore, even when the leaf spring 6 is provided, in a neutral state in which no torque is applied to either the input member 3 or the output member 4, the engaging element 5 can be elastically biased in a direction moving the pressing surface 33 closer to the pressed surface 7 in the first direction.

[0137] In this example, the input-side engaged portion 34 provided on the engaging element 5 is configured as a through hole that passes through the engaging element 5 in the axial direction, but when implementing this disclosure, for example, the input-side engaged portion 34a can also be configured as a notch that opens onto the radially outer surface of the engaging element 5a as shown in Fig. 12. Alternatively, the input-side engaged portion can be configured as a bottomed hole that opens onto only one axial side surface of the engaging element.

[0138] When implementing the present disclosure, the materials of the input member, output member, pressed member, and engaging element are not particularly limited. For example, as these materials, metals such as iron alloys, copper alloys, and aluminum alloys, as well as synthetic resins mixed with reinforcing fibers as necessary, can be used. In addition, the same material can be used for each of the input member, output member, pressed member, and engaging element, or different materials can be used.

[0139] In implementing the present disclosure, as long as the condition that the output member is locked or semi-locked when a rotational torque is input in reverse to the output member is satisfied, a lubricant can be applied to the portions where the input member, output member, pressed member, and engaging member contact each other. Alternatively, at least one of the input member, output member, pressed member, and engaging member can be made of oil-retaining metal.

[0140] [Example 2] A second example of the embodiment of the present disclosure will be described with reference to Figures 13 and 14. In this example, the opening shape of the input side engaged portion 34b of the engagement element 5b and the shape of the leaf spring 6a are different from those in the first example.

[0141] In this example, among the inner surfaces of the input-side engaged portion 34b, the radially inner side surface 36 facing the radially outward is configured with a flat surface perpendicular to the first direction. Also, among the inner surfaces of the input-side engaged portion 34b, the radially outer side surface 37a facing the radially inward has a partially cylindrical concave curved surface portion 38a in the second direction intermediate portion, and has flat surface portions 55 perpendicular to the radial direction of the engaging element 5 in second both side portions of the engaging element 5b. The circumferential side surface 40 connecting both ends of the radially inner side surface 36 in the second direction and both ends of the radially outer side surface 37a in the second direction is configured with a partially cylindrical concave curved surface.

[0142] The leaf spring 6a has two clamped portions 43a, a base portion 44a, and a restricting portion 47a.

[0143] Each of the clamped portions 43a has an end face shape that is substantially a half-circular arc when viewed from the axial direction. Each of the clamped portions 43a is clamped between the circumferential side surface 19 of the input-side engaging portion 14 and the circumferential side surface 40 of the input-side engaged portion 34b in a state in which the diameter of the clamped portion 43a is elastically contracted.

[0144] The base portion 44 a has a curved portion 56 , two flat plate portions 57 , and two inclined plate portions 58 .

[0145] The curved portion 56 is curved in a partially cylindrical shape so that the outer side in the radial direction of the engaging element 5b is convex.

[0146] The flat plate portions 57 are provided in portions adjacent to both sides of the curved portion 56 in the second direction, and are formed of rectangular flat plates perpendicular to the first direction.

[0147] Each inclined plate portion 58 is bent at an obtuse angle from the end portions of the two flat plate portions 57 that are farther from each other in the second direction toward a direction away from the pressing surface 7 in the first direction.

[0148] The regulating portion 47a is bent radially outward from both axial ends of each inclined plate portion 58, and has four bent pieces 48a arranged on both axial sides of the portion of the engaging element 5b that is located around the circumferential side surface 40.

[0149] The leaf spring 6a is disposed inside the input-side engaged portion 34b in a state in which the curved portion 56 of the base portion 44a is elastically deformed so as to bring the two held portions 43a closer to each other, and each held portion 43a is sandwiched between the circumferential side surface 19 of the input-side engaging portion 14 and the circumferential side surface 40 of the input-side engaged portion 34b in an elastically compressed state. Therefore, the outer circumferential surface near the tip of each held portion 43a is elastically pressed against the circumferential side surface 19 of the input-side engaging portion 14 based on the elastic restoration of each held portion 43a so as to expand in diameter. In addition, because the curved portion 56 attempts to elastically restore in a direction moving the two clamped portions 43a away from each other and because each clamped portion 43a attempts to elastically restore in such a way that it expands in diameter, the portion of the outer surface of each clamped portion 43a that abuts against the circumferential side surface 19 and the portion that is located approximately opposite in the radial direction of the clamped portion 43a are elastically pressed against the circumferential side surface 40 of the input side engaged portion 34b.

[0150] In this example, with the leaf spring 6a assembled inside the input side engaged portion 34b, the radially outer surface of the flat plate portion 57 elastically abuts against the flat surface portion 55 of the radially outer surface 37a of the input side engaged portion 34b. Therefore, the leaf spring 6a can be positioned inside the input side engaged portion 34b before the input side engaging portion 14 of the input member 3 is inserted into the input side engaged portion 34b. The configurations and effects of the other parts are the same as those of the first example.

[0151] [Example 3] A third example of the embodiment of the present disclosure will be described with reference to FIG.

[0152] In this example, the two clamped portions 43b constituting the leaf spring 6b apply an elastic force to the input side engaging portion 14 of the input member 3 consisting only of components facing each other in the second direction, and also apply an elastic force to the engaging element 5 consisting only of components moving away from each other in the second direction.

[0153] In other words, the elastic force imparted by the two clamped portions 43b to the input side engagement portion 14 does not include a component in the first direction, and the elastic force imparted by the two clamped portions 43b to the engagement element 5 does not include a component in the first direction.

[0154] According to this example, the leaf spring 6b does not prevent the biasing member 49 from biasing the engaging element 5 in the direction in which the pressing surface 33 approaches the pressed surface 7 in the first direction, so the elasticity of the biasing member 49 can be kept small. Therefore, the minimum torque required to unlock or semi-lock the reverse input cutoff clutch 1 (see Figures 1 to 4, etc.) can be kept small, and the unlocking performance of switching the reverse input cutoff clutch 1 from the locked or semi-locked state to the unlocked state can be ensured satisfactorily. The configuration and effects of the other parts are the same as those of the first example.

[0155] [Example 4] A fourth example of the embodiment of the present disclosure will be described with reference to FIG.

[0156] In this example, the two clamped portions 43c that constitute the leaf spring 6c impart to the input side engaging portion 14 of the input member 3 an elastic force having a component facing each other in the second direction and a component in a direction moving the pressing surface 33 away from the pressed surface 7 in the first direction, and also impart to the engaging piece 5 an elastic force having a component in a direction moving away from each other in the second direction and a component in a direction moving the pressing surface 33 closer to the pressed surface 7 in the first direction.

[0157] According to this example, the two clamped portions 43c constituting the leaf spring 6c can elastically urge the engaging element 5 in a direction that brings the pressing surface 33 closer to the pressed surface 7 in the first direction. Therefore, the urging member 49 can be omitted or the elastic force of the urging member 49 can be reduced. The configurations and effects of the other parts are the same as those of the first example. [Explanation of symbols]

[0158] 1 Reverse input cutoff clutch 2 Pressurized member 3 Input member 4 Output member 5, 5a, 5b engager 6, 6a, 6b, 6c Leaf springs 7 Pressed surface 8 Output side element 9 Large diameter cylindrical surface 10 Small diameter cylindrical surface part 11 Connection surface 12 Inward flange 13 Screw hole 14 Input side engagement portion 15 Input shaft 16 Input flange 17 Radial inner surface 18 Radial outer surface 19 Circumferential side 20 Curved section 21 Output side engagement portion 22 Output shaft 23 Output flange 24 Small diameter shaft 25 flat surface 26 Convex curved surface 27 Radial Rolling Bearing 28 Outer Ring 29a, 29b Retaining ring 30 Inner Circle 31 Rolling elements 32 Plain bearings 33 Pressing surface 34, 34a, 34b Input side engaged part 35 Output side engaged part 36 Radial inner surface 37, 37a Radial outer surface 38, 38a Concave curved part 39 Slope section 40 Circumferential side 41 Flat surface part 42 Convex 43, 43a, 43b, 43c Clamped part 44, 44a base 45 Curved section 46 Inclined plate section 47, 47a Regulatory Department 48 Bent piece 49 Pressing member 50 Spacer 51 Stopper member 52 Arm 53 Connection 54 Through hole 55 Flat surface part 56 Curved section 57 Flat plate part 58 Inclined plate section

Claims

1. A pressed member having a pressed surface on an inner circumferential surface thereof; an input member having an input side engaging portion arranged radially inside the pressed surface and arranged coaxially with the pressed surface; an output member having an output side engaging portion disposed radially inward of the input side engaging portion on the radial inner side of the pressed surface and disposed coaxially with the pressed surface; an engaging element having a pressing surface facing the pressed surface, an input side engaged portion engageable with the input side engaging portion, and an output side engaged portion engageable with the output side engaging portion, the engaging element being arranged to be movable in a first direction which is a direction in which the pressing surface approaches or moves away from the pressed surface; a leaf spring including two clamped portions disposed on both sides of the input side engaging portion in a second direction perpendicular to the central axis of the input member and the first direction, the two clamped portions being elastically clamped between the input side engaging portion and the input side engaged portion, and a base portion connecting the two clamped portions to each other; Equipped with When a rotational torque is input to the input member, the engaging element moves in a direction away from the pressed surface in the first direction based on the engagement of the input side engaging portion 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, whereas when a rotational torque is input in reverse to the output member, the output side engaging portion engages with the output side engaged portion, and presses the pressing surface against the pressed surface, thereby frictionally engaging the pressing surface with the pressed surface. Reverse input cut-off clutch.

2. 2. The reverse input cut-off clutch according to claim 1, wherein the two clamped portions impart an elastic force to the input side engagement portion having a component in a direction facing each other with respect to the second direction and a component in a direction that brings the pressing surface closer to the pressed surface with respect to the first direction.

3. a biasing member that elastically biases the engaging element in a direction that brings the pressing surface closer to the pressed surface in the first direction, 3. The reverse input cut-off clutch according to claim 2, wherein a component of the elastic force applied to the engaging element by the biasing member in a direction that moves the pressing surface closer to the pressed surface in the first direction is greater than a component of the elastic force applied to the engaging element by the two clamped portions in a direction that moves the pressing surface away from the pressed surface in the first direction.

4. 2. The reverse input cutoff clutch according to claim 1, wherein the two clamped portions apply to the input side engaging portion a resilience having only a component in a direction facing each other with respect to the second direction.

5. 2. The reverse input cut-off clutch according to claim 1, wherein the two clamped portions impart to the input side engagement portion an elastic force having a component in a direction facing each other with respect to the second direction and a component in a direction moving the pressing surface away from the pressed surface with respect to the first direction.

6. 2. The reverse input cutoff clutch according to claim 1, wherein the leaf spring has a restricting portion that restricts relative axial displacement with respect to the engaging element.

7. 7. The reverse input cut-off clutch according to claim 6, wherein the regulating portion has bent pieces that are bent from both axial ends of the two clamped portions or the base portion, and that are arranged on both axial sides of a peripheral portion of the input side engaged portion of the engaging element.

8. 2. The reverse input cutoff clutch according to claim 1, wherein at least one position of said base portion abuts against a portion of an inner surface of said input side engaged portion that faces radially inward.

9. 2. The reverse input cutoff clutch according to claim 1, wherein the engaging element is made up of two engaging elements, and the input side engaging portion is made up of two input side engaging portions.

Images