Clutch device

Abstract

[Problem] To provide a clutch device that is incorporated between a drive source and a driven body and is capable of preventing transmission of impact torque from the driven body to the drive source. [Solution] A clutch device 1 comprises a first rotating member 2, a second rotating member 3, a third rotating member 4, an engaging element 5, and a flywheel 6 fixed to the first rotating member 2. When torque is input to the second rotating member 3, a steady rotation state is brought about in which the first rotating member 2 and the flywheel 6 rotate integrally with the second rotating member 3, the third rotating member 4, and the engaging element 5, while the torque is transmitted between the second rotating member 3 and the third rotating member 4. When the torque acting on the third rotating member 4 rapidly increases in the steady rotation state, a torque transmission regulation state is brought about in which the torque transmitted between the second rotating member 3 and the third rotating member 4 is reduced or lost, on the basis of inertia force acting on the flywheel 6.

Description

Clutch device

[0001] The present disclosure relates to a clutch device that is installed between a driving source and a driven body.

[0002] A drive unit for an electric vehicle includes an electric motor as a drive source, a gear-type reduction mechanism, and a differential gear, as described in, for example, Japanese Patent Laid-Open Publication No. 9-226394. When the electric motor is energized to rotate its output shaft, the rotational torque of the output shaft is increased by the reduction mechanism and then transmitted to the differential gear, which then distributes the torque to the left and right drive wheels as the driven bodies.

[0003] Japanese Patent Application Publication No. 9-226394

[0004] The electric vehicle drive device disclosed in Japanese Patent Laid-Open Publication No. 9-226394 has room for improvement in the following respects.

[0005] In the electric vehicle drive device, when the torque input in reverse to the drive wheels is greater than the torque transmitted from the electric motor to the drive wheels via the differential gear and the reduction mechanism, the torque input in reverse from the drive wheels is transmitted to the electric motor via the differential gear and the reduction mechanism.

[0006] For example, when an electric vehicle is traveling on a rough road and the drive wheels lift off the road surface and then touch the ground again, an impulsive torque is input from the drive wheels. If an attempt is made to allow such an impulsive torque to be input in reverse, problems arise such as an increase in the size and weight of the differential gear, the reduction mechanism, and the electric motor.

[0007] An object of the present disclosure is to provide a clutch device that is incorporated between a driving source and a driven body and is capable of preventing the transmission of impulsive torque from the driven body to the driving source.

[0008] A clutch device according to one aspect of the present disclosure comprises: a first rotating member having a first rotating member side engaging portion; a second rotating member having a second rotating member side engaging portion; a third rotating member having a third rotating member side engaging portion; an engager having an engager side first engaging portion engageable with the first rotating member side engaging portion, an engager side second engaging portion engageable with the second rotating member side engaging portion, and an engager side third engaging portion engageable with the third rotating member side engaging portion; and a flywheel fixed to the first rotating member.

[0009] In particular, in a clutch device according to one aspect of the present disclosure, when torque is input to the second rotating member or the third rotating member, the second rotating member side engaging portion engages with the engaging member side second engaging portion, and the third rotating member side engaging portion engages with the engaging member side third engaging portion, thereby transmitting torque between the second rotating member and the third rotating member, and the engaging member side first engaging portion engages with the first rotating member side engaging portion, thereby entering a steady rotation state in which the first rotating member, the flywheel, the second rotating member, the third rotating member and the engaging member rotate integrally.

[0010] Furthermore, in a clutch device according to one aspect of the present disclosure, when the torque acting on the third rotating member suddenly increases in the steady rotation state, the first rotating member side engaging portion presses the engaging member side first engaging portion based on the inertial force acting on the flywheel, causing the engaging member to move the engaging member side third engaging portion in a direction away from the third rotating member side engaging portion, and the contact pressure between the engaging member side third engaging portion and the third rotating member side engaging portion decreases or is lost, thereby entering a torque transmission restricted state in which the torque transmitted between the second rotating member and the third rotating member decreases or is lost.

[0011] A reverse input cutoff clutch according to one aspect of the present disclosure may include a biasing member that elastically biases the engagement element in a direction in which the third rotating member side engagement portion and the engagement element side third engagement portion engage with each other.

[0012] In a clutch device according to one aspect of the present disclosure, the third rotating member may have the third rotating member side engaging portion on its inner peripheral surface, the first rotating member side engaging portion may be arranged radially inward of the third rotating member side engaging portion, the second rotating member side engaging portion may be arranged radially inward of the first rotating member side engaging portion, and the engaging element may have the engaging element side second engaging portion on its radially inner surface and the engaging element side third engaging portion on its radially outer surface, and may be arranged to be able to move in a first direction, which is a direction towards or away from the third rotating member side engaging portion.

[0013] In a clutch device according to one aspect of the present disclosure, the engaging element may be composed of two engaging elements, and the first rotating member side engaging portion may be composed of two first rotating member side engaging portions.

[0014] A clutch device according to one aspect of the present disclosure can be incorporated into a drive system that transmits torque from a drive source to drive wheels.

[0015] According to one aspect of the clutch device of the present disclosure, the clutch device is installed between a driving source and a driven body, and can prevent impulsive torque transmission from the driven body to the driving source.

[0016] FIG. 1 is a schematic diagram showing a portion of a drive system of an electric vehicle incorporating a clutch device according to a first example of an embodiment of the present disclosure. FIG. 2 is a cross-sectional view of the clutch device according to the first example. FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2. FIG. 4 is a cross-sectional view similar to FIG. 3, showing a steady rotation state in which rotational torque input to the second rotating member is transmitted to the third rotating member in the clutch device according to the first example. FIG. 5 is a cross-sectional view similar to FIG. 3, showing a state in which the first rotating member to which the flywheel is fixed rotates relative to the second and third rotating members due to inertial force in the clutch device according to the first example. FIGS. 6(a) to 6(e) are schematic diagrams illustrating the operation of the clutch device according to the first example when an impulsive torque is reversely input from the output side. FIG. 7 is a cross-sectional view similar to FIG. 3, showing a steady rotation state in which rotational torque reversely input to the third rotating member is transmitted to the second rotating member in the clutch device according to the first example. Figures 8(a) to 8(d) are schematic diagrams illustrating the operation of the clutch device of the first example when the torque reversely input from the output side increases. Figure 9 is a schematic diagram showing the drive system of an electric vehicle incorporating a clutch device of a second example embodiment of the present disclosure. Figure 10 is a schematic diagram showing a portion of the drive system of a mechanical device incorporating a clutch device of a third example embodiment of the present disclosure. Figure 11 is a cross-sectional view of a clutch device of a fourth example embodiment of the present disclosure. Figure 12 is a cross-sectional view taken along line B-B of Figure 11.

[0017] First Example A first example of the embodiment of the present disclosure will be described with reference to FIGS. 1 to 8(d).

[0018] The clutch device 1 of this example includes a first rotating member 2, a second rotating member 3, a third rotating member 4, an engaging element 5, and a flywheel 6 fixed to the first rotating member.

[0019] In the description of the clutch device 1, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the clutch device 1, unless otherwise specified. The axial direction, radial direction, and circumferential direction of the clutch device 1 coincide with the axial direction, radial direction, and circumferential direction of the first rotating member 2, coincide with the axial direction, radial direction, and circumferential direction of the second rotating member 3, and coincide with the axial direction, radial direction, and circumferential direction of the third rotating member 4. With respect to the clutch device 1, one axial side is the right side in Figures 1 and 2, and the other axial side is the left side in Figures 1 and 2. These points also apply to other embodiments described later.

[0020] The first rotating member 2 has a first rotating member side engaging portion 7 .

[0021] In this example, the first rotating member side engaging portion 7 is provided in a portion radially outwardly spaced from the rotation center O of the first rotating member 2, and has a portion that engages with the engaging element side first engaging portion 15 of the engaging element 5. The first rotating member side engaging portion 7 is configured so that its radially inner surface 9 engages with the radially inner surface 18 of the engaging element side first engaging portion 15 as the first rotating member 2 or the engaging element 5 rotates.

[0022] In this example, the first rotating member 2 has a first shaft portion 8 in addition to the first rotating member side engaging portion 7. The first shaft portion 8 has a stepped cylindrical shape consisting of a small diameter portion on one axial side and a large diameter portion on the other axial side.

[0023] The first rotating member side engaging portion 7 protrudes toward the other axial side from a portion of the end face on the other axial side of the first shaft portion 8 that is radially outwardly spaced from the rotation center O.

[0024] The shape of the first rotating member side engaging portion 7 is not limited as long as it is configured to engage with the engaging element side first engaging portion 15 of the engaging element 5. The number of first rotating member side engaging portions 7 is determined according to the number of engaging elements 5, and when the engaging element 5 is configured with a plurality of engaging elements 5, the first rotating member side engaging portion 7 is also configured with a plurality of first rotating member side engaging portions 7 (the same number as the engaging elements 5).

[0025] In this example, the engaging elements 5 are configured by two engaging elements 5. Therefore, the first rotating member side engaging portion 7 is configured by two first rotating member side engaging portions 7 to match the number of engaging elements 5. The two first rotating member side engaging portions 7 are arranged at two radially opposite positions on the radially outer side of the end face on the other axial side of the first shaft portion 8, and are spaced apart from each other in the radial direction of the first rotating member 2. The first rotating member side engaging portion 7 has a shape that is symmetrical in the circumferential direction.

[0026] In this example, the first rotating-member-side engaging portion 7 has a substantially arch-shaped end face shape when viewed from the axial direction. That is, the radially inner surface 9 of the first rotating-member-side engaging portion 7 is formed as a flat surface perpendicular to a line connecting the rotation center O and the center of the first rotating-member-side engaging portion 7 when viewed from the axial direction. The radially outer surface 55 of the first rotating-member-side engaging portion 7 is formed as a partially cylindrical surface centered on the rotation center O. The side surfaces 56 on both circumferential sides of the first rotating-member-side engaging portion 7 are formed as flat surfaces parallel to a line connecting the rotation center O and the center of the first rotating-member-side engaging portion 7 when viewed from the axial direction. The connection portions between the radially inner surface 9 and the circumferentially opposite side surfaces 56, and the connection portions between the radially outer surface 55 and the circumferentially opposite side surfaces 56, are each formed as convex curved surfaces such as R-chamfered portions.

[0027] The first rotating member 2 can be rotatably supported by a fixed portion (not shown) arranged around the third rotating member 4 or the clutch device 1 .

[0028] The second rotating member 3 has a second rotating member side engaging portion 10 .

[0029] The second rotating member 3 is disposed coaxially with the first rotating member 2 .

[0030] The second rotating member side engaging portion 10 is radially inward of the first rotating member side engaging portion 7, but has a portion that is radially outward from the rotation center O of the second rotating member 3, and this portion is arranged at a position where it can engage with the engaging member side second engaging portion 16 of the engaging member 5. The second rotating member side engaging portion 10 is configured so that this portion engages with the engaging member side second engaging portion 16 as the second rotating member 3 or the engaging member 5 rotates.

[0031] In this example, the second rotating member 3 has a second shaft portion 11 in addition to the second rotating member side engaging portion 10. The second shaft portion 11 has a cylindrical shape.

[0032] The second rotating member side engaging portion 10 protrudes from the center of an end face on one axial side of the second shaft portion 11 toward one axial side.

[0033] The shape of the second rotating member side engaging portion 10 is not limited as long as it is configured to engage with the engaging element side second engaging portion 16. The number of portions of the second rotating member side engaging portion 10 that engage with the engaging element side second engaging portion 16 is determined according to the number of engaging elements 5, and when the engaging elements 5 are configured with a plurality of engaging elements 5, the second rotating member side engaging portion 10 is also configured to have a plurality of engaging portions (the same number as the engaging elements 5).

[0034] In this example, the second rotating member side engaging portion 10 is configured to have portions that engage with two of the engaging element side second engaging portions 16 in accordance with the number of engaging elements 5 .

[0035] In this example, the second rotating member side engaging portion 10 has a substantially rectangular end face shape when viewed in the axial direction, and protrudes toward one axial side from the center of one axial end face of the second shaft portion 11. In other words, the distance from the rotation center O of the second rotating member 3 to the outer circumferential surface of the second rotating member side engaging portion 10, which is the portion that engages with the engaging element side second engaging portion 16, is not constant in the circumferential direction. Therefore, the second rotating member side engaging portion 10 has a cam function.

[0036] More specifically, the outer peripheral surface of the second rotating member side engaging portion 10 is composed of two large flat surfaces 12 that are parallel to each other, two small flat surfaces 13 each having a width dimension smaller than that of the large flat surfaces 12 when viewed in the axial direction, and a convex curved surface such as an R-chamfered portion that connects the large flat surfaces 12 and the small flat surfaces 13. Therefore, the distance from the rotation center O of the second rotating member 3 to the outer peripheral surface of the second rotating member side engaging portion 10 is not constant in the circumferential direction.

[0037] The second rotating member side engaging portion 10 is plane-symmetrical with respect to an imaginary plane that passes through the rotation center O of the second rotating member 3 and is perpendicular to the large flat surface 12. Furthermore, the second rotating member side engaging portion 10 is plane-symmetrical with respect to an imaginary plane that passes through the rotation center O of the second rotating member 3 and is parallel to the large flat surface 12.

[0038] Such a second rotating member side engaging portion 10 is disposed between the two first rotating member side engaging portions 7 .

[0039] The second rotary member 3 can be rotatably supported on the third rotary member 4 or on the fixed part.

[0040] The third rotating member 4 has a third rotating member side engaging portion 14 .

[0041] The third rotating member 4 is arranged coaxially with the first rotating member 2 and the second rotating member 3. In this example, the third rotating member side engaging portion 14 is provided on the inner circumferential surface of the third rotating member 4. In this example, the first rotating member side engaging portion 7 of the first rotating member 2 and the second rotating member side engaging portion 10 of the second rotating member 3 are arranged coaxially radially inside the third rotating member side engaging portion 14, and the engaging element 5 is arranged so as to be movable toward and away from the third rotating member side engaging portion 14. The first rotating member side engaging portion 7, the second rotating member side engaging portion 10, and the engaging element 5 are rotatable radially inside the third rotating member side engaging portion 14. The third rotating member side engaging portion 14 forms a surface that comes into contact with the engaging element side third engaging portion 17 of the engaging element 5 when the engaging element 5 moves in a direction approaching the third rotating member side engaging portion 14.

[0042] In this example, the third rotating member side engaging portion 14 has an annular shape when viewed in the axial direction, and although not limited to this, in this example it has a cylindrical surface shape whose inner diameter does not change in the axial direction.

[0043] In this example, the third rotating member 4 is rotatably supported by at least one of the first rotating member 2, the second rotating member 3, and the fixed portion. The shape of the third rotating member 4 is not limited as long as it has the third rotating member side engaging portion 14 on its inner circumferential surface.

[0044] In this example, the third rotating member 4 includes at least a cylindrical portion having a third rotating member side engaging portion 14 on its inner circumferential surface.

[0045] The engaging element 5 has an engaging element side first engaging portion 15 that can engage with the first rotating member side engaging portion 7, an engaging element side second engaging portion 16 that can engage with the second rotating member side engaging portion 10, and an engaging element side third engaging portion 17 that can engage with the third rotating member side engaging portion 14.

[0046] In this example, the engaging piece 5 is arranged so as to be movable in a first direction, which is a direction toward or away from the third rotating member side engaging portion 14 .

[0047] In the clutch device 1, when torque is input to the second rotating member 3 or the third rotating member 4, the second rotating member side engaging portion 10 engages with the engaging member side second engaging portion 16, and the third rotating member side engaging portion 14 engages with the engaging member side third engaging portion 17, thereby transmitting torque between the second rotating member 3 and the third rotating member 4 via the engaging member 5, and as the engaging member 5 rotates, the engaging member side first engaging portion 15 engages with the first rotating member side engaging portion 7, thereby entering a steady rotation state in which the first rotating member 2 and the flywheel 6 rotate integrally with the second rotating member 3, the third rotating member 4, and the engaging member 5.

[0048] In the clutch device 1, when the torque input in reverse to the third rotating member 4 suddenly increases while operating in the steady rotation state, the inertial force acting on the flywheel 6 causes the first rotating member side engaging portion 7 to press the engaging member side first engaging portion 15, causing the engaging member 5 to move the engaging member side third engaging portion 17 in a direction away from the third rotating member side engaging portion 14, and the contact pressure between the engaging member side third engaging portion 17 and the third rotating member side engaging portion 14 decreases or is lost, resulting in a torque transmission restriction state in which the torque transmitted between the second rotating member 3 and the third rotating member 4 decreases or is lost.

[0049] The engagement element 5 may be configured with one engagement element 5 or two or more engagement elements 5, as long as the steady rotation state and the torque transmission restricted state can be realized.

[0050] 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 arrow B in FIG. 3). The configuration of each engaging element 5 will be described below.

[0051] In this example, the radial direction with respect to the engaging element 5 is the direction of approach or distance of the engaging element side third engaging portion 17 relative to the third rotating member side engaging portion 14, and corresponds to the direction indicated by arrow A in Fig. 3. The width direction with respect to the engaging element 5 is the direction perpendicular to both the direction of approach or distance of the engaging element side third engaging portion 17 relative to the third rotating member side engaging portion 14 and the axial direction of the third rotating member side engaging portion 14, and corresponds to the direction indicated by arrow B in Fig. 3. In this example, the radial direction with respect to the engaging element 5 corresponds to the first direction.

[0052] The engaging element-side third engaging portion 17 is provided on the radially outer surface of the engaging element 5 facing the third rotating member-side engaging portion 14. In this example, the engaging element-side third engaging portion 17 is composed of two engaging element-side third engaging portions 17 provided at two positions spaced apart from each other in the circumferential direction on the radially outer surface of the engaging element 5. Each engaging element-side third engaging portion 17 is composed of a partially cylindrical convex curved surface having a radius of curvature smaller than the radius of curvature of the third rotating member-side engaging portion 14.

[0053] When viewed from the axial direction, the portions of the radially outer surface of the engaging member 5 that are circumferentially displaced from the two engaging member-side third engaging portions 17 are located radially inward of an imaginary circle that is centered on the rotation center O of the first rotating member 2 and that is tangent to the two engaging member-side third engaging portions 17. In other words, when the two engaging member-side third engaging portions 17 are in contact with the third rotating member-side engaging portion 14, the portions that are circumferentially displaced from the two engaging member-side third engaging portions 17 do not contact the third rotating member-side engaging portion 14.

[0054] The third engaging portion 17 on the engaging member side preferably has a surface property that has a higher coefficient of friction with the third rotating member side engaging portion 14 than the other portions of the engaging member 5. The third engaging portion 17 on the engaging member side may be formed integrally with the other portions of the engaging member 5, or may be formed by the surface of a friction material fixed to the other portions of the engaging member 5 by adhesion or the like.

[0055] In this example, the first engaging portion 15 on the engaging member side is provided at a radially intermediate portion of the widthwise center portion of the engaging member 5. The shape of the first engaging portion 15 on the engaging member side is not limited as long as it is configured to be able to engage with the first rotating member side engaging portion 7.

[0056] In this example, the first engagement portion 15 on the engagement element side has an approximately arched opening shape when viewed from the axial direction, and is configured as a through hole that penetrates the radial middle portion of the engagement element 5 at the center position in the width direction in the axial direction.

[0057] The engaging element-side first engaging portion 15 has a size that allows the first rotating-member-side engaging portion 7 to be loosely inserted therein. Therefore, when the first rotating-member-side engaging portion 7 is inserted inside the engaging element-side first engaging portion 15, gaps exist between the first rotating-member-side engaging portion 7 and the inner surface of the engaging element-side first engaging portion 15 in both the width direction and the radial direction of the engaging element 5. Therefore, the first rotating-member-side engaging portion 7 is displaceable relative to the engaging element-side first engaging portion 15 in the rotational direction of the first rotating member 2, and the engaging element-side first engaging portion 15 is displaceable in the radial direction of the engaging element 5 relative to the first rotating-member-side engaging portion 7. In this example, of the inner surface of the engaging element-side first engaging portion 15, a radially inner surface 18 facing radially outward is configured as a flat surface perpendicular to the first direction.

[0058] In this example, the engaging element-side second engaging portion 16 is provided at the center in the width direction of the radially inner surface of the engaging element 5. The shape of the engaging element-side second engaging portion 16 is not limited as long as it is configured to be able to engage with the second rotating member-side engaging portion 10.

[0059] In this example, the engaging element 5 has, on its radially inner surface, a flat surface portion 19 that is perpendicular to the radial direction of the engaging element 5. The engaging element 5 has a central recess 20 formed in the center of the width direction of the flat surface portion 19 so as to be recessed radially outward, and also has approximately rectangular guide recesses 21 formed at two positions on both sides of the flat surface portion 19 in the width direction so as to be recessed radially outward.

[0060] The central recess 20 has a size and shape that allows half of the second rotating member side engaging portion 10 in the short direction (vertical direction in FIG. 3 ) to be loosely positioned inside it. Specifically, the central recess 20 has an opening width that is greater than the dimension of the second rotating member side engaging portion 10 in the longitudinal direction (horizontal direction in FIG. 3 ) and a radial depth that is less than half the dimension of the second rotating member side engaging portion 10 in the short direction. The bottom surface of the central recess 20 is formed by a flat surface that is perpendicular to the radial direction of the engaging piece 5. In this example, the engaging piece side second engaging portion 16 is formed by the bottom surface of the central recess 20.

[0061] In this example, the two engaging elements 5 are arranged radially inward of the third rotating-member-side engaging portion 14 so as to be movable in the first direction, with the engaging element-side third engaging portions 17 of the two engaging elements 5 facing radially opposite directions and with the flat surface portions 19 facing each other. Furthermore, the two first rotating-member-side engaging portions 7 of the first rotating member 2 are axially inserted into the engaging element-side first engaging portions 15 of the two engaging elements 5, and the second rotating-member-side engaging portion 10 of the second rotating member 3 is axially inserted between the engaging element-side second engaging portions 16 of the two engaging elements 5. In other words, the two engaging elements 5 are arranged so that the second rotating-member-side engaging portion 10 is sandwiched from the radially outer side by the respective engaging element-side second engaging portions 16.

[0062] The inner diameter dimension of the third rotating member side engaging portion 14 and the radial dimension of the engaging element 5 are regulated so that when the two engaging elements 5 are positioned radially inside the third rotating member side engaging portion 14, a gap exists in at least one of the portions between the third rotating member side engaging portion 14 and the engaging element side third engaging portion 17, and between the flat surface portions 19 of the two engaging elements 5.

[0063] The flywheel 6 is fixed to the first rotating member 2 .

[0064] The flywheel 6 is fixed to the first rotating member 2 to form a combined body together with the first rotating member 2, and is a member for ensuring a large mass of the combined body. There are no limitations on the shape and size of the flywheel 6, as long as it is possible to avoid interference with objects disposed around it.

[0065] The mass of the flywheel 6 is adjusted appropriately according to the magnitude of the impulsive torque that should be restricted from being transmitted from the third rotating member 4 to the second rotating member 3 .

[0066] Specifically, when the clutch device 1 is incorporated into the drive system of a vehicle, the mass of the flywheel 6 is adjusted to a size that prevents an impulsive torque that is reversely input to the third rotating member 4 based on an impulsive torque applied to the drive wheel when the drive wheel lifts off the road surface and then touches the ground again while the vehicle is traveling, or when the vehicle is rear-ended by a following vehicle, from being transmitted to the second rotating member 3. However, from the viewpoint of reducing loss when the second rotating member 3 is rotationally driven by the drive source 23 and reducing the weight of the clutch device 1, it is preferable to make the mass of the flywheel 6 as small as possible within a range that can restrict the transmission of the impulsive torque from the third rotating member 4 to the second rotating member 3.

[0067] In this example, the flywheel 6 has a generally circular disk shape, and is fixed to one axial end of the first shaft portion 8 in a state where it is disposed coaxially with the first rotating member 2 .

[0068] The clutch device 1 of this example further includes, as an optional component, a biasing member 22. The biasing member 22 elastically biases the engaging element 5 in a direction in which the third rotating member side engaging portion 14 and the engaging element side third engaging portion 17 engage with each other, i.e., in a direction in which the engaging element side third engaging portion 17 approaches the third rotating member side engaging portion 14 with respect to the first direction. The shape and number of the biasing member 22 are not particularly limited as long as it has such a function.

[0069] In this example, the biasing member 22 is configured with two biasing members 22 arranged between the two engaging members 5. Each of the two biasing members 22 is configured with a compression coil spring. The compression coil spring constituting each biasing member 22 is held by inserting both axial ends thereof into guide recesses 21 provided in the two engaging members 5. When implementing the present disclosure, the biasing member may be configured with various springs other than compression coil springs, such as a leaf spring disposed between the second rotating member and the engaging members.

[0070] In this example, the biasing member 22 elastically biases the engaging members 5 in a direction that moves the engaging member-side third engaging portions 17 closer to the third rotating member-side engaging portion 14 in the first direction, so it is possible to synchronize the attitudes of the two engaging members 5 and stabilize the attitudes of each engaging member 5, thereby enabling each engaging member 5 to accurately move toward or away from the third rotating member-side engaging portion 14 in the radial direction. Furthermore, the engaging member-side third engaging portions 17 of the two engaging members 5 can be pressed against the third rotating member-side engaging portion 14, except when the engaging members 5 move in a direction that moves the engaging member-side third engaging portions 17 away from the third rotating member-side engaging portion 14 due to the inertial rotational force of the first rotating member 2 and the flywheel 6, based on the first rotating member-side engaging portion 7 engaging with the engaging member-side first engaging portion 15.

[0071] In this example, the clutch device 1 is incorporated into the drive system (drive device) of an electric vehicle, as shown in Figure 1. However, the use of the clutch device of the present disclosure is not limited to this. The clutch device of the present disclosure can be incorporated and used between the drive source and the driven body of various mechanical devices.

[0072] The drive system of the electric vehicle in this example comprises a drive source 23, a rotating shaft 24 connected to the driven body, i.e., the drive wheel, via another driving member so as to be able to transmit torque, and a clutch device 1 incorporated between the drive source 23 and the rotating shaft 24.

[0073] The drive source 23 is configured by an electric motor. In this example, the second shaft portion 11 (see FIG. 2) of the second rotating member 3 that constitutes the clutch device 1 is provided at the tip end of the output shaft 25 of the drive source 23 either integrally with the output shaft 25 or connected to the tip end of the output shaft 25 so as to be able to transmit torque.

[0074] In this example, the third rotating member 4 constituting the clutch device 1 has a gear portion 26 (shown only in FIG. 1 ) on its outer circumferential surface. The rotating shaft 24 has a gear portion 27 at its base end, which meshes with the gear portion 26 of the third rotating member 4. This allows torque to be transmitted between the third rotating member 4 and the rotating shaft 24.

[0075] The operation of the clutch device 1 of this example will be described with reference to Figures 4, 5, 6(a) to 6(e), 7, and 8(a) to 8(d). Figures 4, 5, and 7 exaggerate the radial gaps between the first rotating member 2 and the second rotating member 3 and the two engaging elements 5. Figures 6(a) to 6(e) and 8(a) to 8(d) are schematic cross-sectional views of the same locations as in Figures 4, 5, and 7.

[0076] In a drive system incorporating the clutch device 1 of this example, when torque is input to the second rotating member 3 by rotating the output shaft 25 of the drive source 23, the second rotating member side engaging portion 10 rotates in the rotational direction of the second rotating member 3 (clockwise in the example of FIG. 4 ) between the engaging member side second engaging portions 16 of the two engaging elements 5, regardless of the rotational direction of the second rotating member 3. Then, the engaging member side second engaging portion 16 is pressed radially outward by the connecting portion (corner portion) between the large flat surface 12 and the small flat surface 13 on the outer circumferential surface of the second rotating member side engaging portion 10, and the engaging member side third engaging portions 17 of the two engaging elements 5 are pressed against the third rotating member side engaging portion 14 to frictionally engage them.

[0077] As a result, torque input to the second rotating member 3 is transmitted to the third rotating member 4 via the two engaging elements 5. As a result, when the second rotating member 3, the two engaging elements 5, and the third rotating member 4 begin to rotate integrally, the radially inner surfaces 18 of the engaging element-side first engaging portions 15 of the two engaging elements 5 engage with the radially inner surfaces 9 of the two first rotating member-side engaging portions 7, as shown in Figures 4 and 6(a) . As a result, the first rotating member 2 and the flywheel 6 rotate integrally with the second rotating member 3, the two engaging elements 5, and the third rotating member 4. In other words, a steady rotation state is reached in which the first rotating member 2 and the flywheel 6 rotate integrally with the second rotating member 3, the third rotating member 4, and the two engaging elements 5 while forward torque is transmitted from the second rotating member 3 to the third rotating member 4. In Figures 6(a) to 6(e), the solid arrows attached to the respective members indicate the rotation direction of the members, and the length of the solid arrows indicates the rotation speed.

[0078] In the steady rotation state in which the forward torque is transmitted, the torque transmitted from the second rotating member 3 to the third rotating member 4 via the two engaging members 5 is transmitted to the rotating shaft 24 via the meshing portion between the gear section 26 and the gear section 27, and is further transmitted from the rotating shaft 24 to the drive wheel via the other drive member.

[0079] On the other hand, when the accelerator is released and the vehicle is coasting, torque is input in reverse from the road surface via the drive wheels to the third rotating member 4, causing the two engaging elements 5 to rotate integrally with the third rotating member 4 regardless of the rotational direction of the third rotating member 4. That is, in a neutral state in which no torque is applied to the second rotating member 3 or the third rotating member 4, the third rotating member 4 and the two engaging elements 5 are in a state in which the engaging element-side third engaging portion 17 is pressed against the third rotating member-side engaging portion 14 by the elastic biasing force of the biasing member 22, and the third rotating member-side engaging portion 14 and the engaging element-side third engaging portion 17 are frictionally engaged with each other. Therefore, when torque is input in reverse to the third rotating member 4, the two engaging elements 5 rotate integrally with the third rotating member 4 regardless of the rotational direction of the third rotating member 4.

[0080] When the two engaging members 5 rotate integrally with the third rotating member 4, as shown in Figures 7 and 8(a), the second engaging portion 16 on the engaging member side engages with the connection portion (corner portion) between the large flat surface 12 and the small flat surface 13 on the outer surface of the second rotating member side engaging portion 10.

[0081] As a result, torque input to the third rotating member 4 is transmitted to the second rotating member 3 via the two engaging elements 5. As a result, when the second rotating member 3, the two engaging elements 5, and the third rotating member 4 begin to rotate integrally, the radially inner surfaces 18 of the engaging element-side first engaging portions 15 of the two engaging elements 5 engage with the radially inner surfaces 9 of the two first rotating member-side engaging portions 7, as shown in Figures 7 and 8(a). As a result, the first rotating member 2 and the flywheel 6 rotate integrally with the second rotating member 3, the two engaging elements 5, and the third rotating member 4. In other words, a steady rotation state is reached in which the first rotating member 2 and the flywheel 6 rotate integrally with the second rotating member 3, the third rotating member 4, and the two engaging elements 5 while torque is transmitted in the reverse direction from the third rotating member 4 to the second rotating member 3. In Figures 8(a) to 8(d), the solid arrows attached to each member indicate the rotation direction of that member, and the length of the solid arrow indicates the rotation speed.

[0082] In the steady rotation state in which the torque is transmitted in the reverse direction, the torque transmitted from the third rotating member 4 to the second rotating member 3 via the two engaging members 5 is transmitted to the output shaft 25 of the drive source 23, and the electric motor constituting the drive source 23 enters a regenerative state.

[0083] In this example, when the torque acting on the third rotating member 4 suddenly increases during the steady rotation state, the clutch device 1 enters a torque transmission restriction state in which the torque transmitted from the third rotating member 4 to the second rotating member 3 is reduced or lost.

[0084] In the steady rotation state in which the forward torque is transmitted, for example, when a vehicle jumps in a rally or the like, causing the drive wheels to leave the road surface and lose grip, and then the drive wheels contact the road surface again and regain grip, or when a vehicle runs from a dry road onto an icy or snowy road and loses grip, and then the vehicle runs back onto a dry road and regains grip, the torque applied to the drive wheels suddenly decreases and then increases rapidly. As a result, the torque input in the reverse direction to the third rotating member 4 suddenly decreases and then increases rapidly.

[0085] The clutch device 1 of this example can prevent the impulsive torque that is reversely input to the third rotating member 4, based on the impulsive torque applied to the driving wheel at the moment the grip force of the driving wheel is restored, from being transmitted to the second rotating member 3 in the following manner.

[0086] First, in the steady rotation state in which the forward torque is transmitted as shown in Figures 4 and 6(a), if the grip force of the drive wheel decreases or is lost, the resistance to rotation of the third rotating member 4 connected to the drive wheel decreases, and as a result, as shown in Figure 6(b), the rotational speed of the entire clutch device 1, i.e., the integrated rotational speed of the first rotating member 2 and flywheel 6, and the second rotating member 3, third rotating member 4, and engaging element 5, increases.

[0087] Thereafter, when the grip force of the drive wheel is restored, the frictional force acting between the drive wheel and the road surface increases rapidly, the torque applied to the drive wheel increases rapidly, and the rotational speed of the drive wheel decreases rapidly. As a result, as shown in Figure 6(c), the torque input in reverse to the third rotating member 4 increases rapidly, and the rotational speed of the third rotating member 4 decreases rapidly. As for the two engaging elements 5, since the engaging element-side third engaging portions 17 of each engaging element are frictionally engaged with the third rotating member-side engaging portions 14, the rotational speed also decreases in the same way as the third rotating member 4.

[0088] In contrast, the combined body of the first rotating member 2 and the flywheel 6 tends to continue rotating at the original rotational speed due to its inertial force, and rotates forward in the rotational direction (clockwise in the example of FIG. 6(c)) relative to the two engaging members 5. As a result, as shown in FIGS. 6(c) and 6(d), the radially inner surface 9 of the first rotating member-side engaging portion 7 presses against the radially inner surface 18 of the engaging member-side first engaging portion 15.

[0089] As a result, the two engaging members 5 overcome the radially outward biasing forces of the two biasing members 22 and move radially inward, which is a direction that moves the engaging member-side third engaging portion 17 away from the third rotating member-side engaging portion 14. Then, the contact pressure between the engaging member-side third engaging portion 17 and the third rotating member-side engaging portion decreases, or, as shown in Figures 5 and 6(d), the engaging member-side third engaging portion 17 and the third rotating member-side engaging portion 14 separate, and the contact pressure between the engaging member-side third engaging portion 17 and the third rotating member-side engaging portion 14 is lost. This results in a torque transmission restricted state in which the torque transmitted from the third rotating member 4 to the second rotating member 3 is reduced or lost.

[0090] As a result, the application of an impact torque from the drive wheel to the drive source 23 is prevented.

[0091] As shown in Figures 6(c) and 6(d), the inertial rotational force of the combination of the first rotating member 2 and the flywheel 6 causes the radial inner surface 9 of the first rotating member side engaging portion 7 to press against the radial inner surface 18 of the engaging member side first engaging portion 15. This phenomenon occurs immediately after the grip force of the drive wheel is restored, and then the inertial force decreases and the radially outward biasing forces of the two biasing members 22 exceed the inertial force, causing the engaging member side third engaging portion 17 and the third rotating member side engaging portion 14 to strongly abut against each other. As a result, the rotational speed of the combination of the first rotating member 2 and the flywheel 6 and the rotational speed of the third rotating member 4 become the same, and the system returns to a steady rotational state in which forward torque is transmitted, as shown in Figure 6(e).

[0092] On the other hand, in the steady rotation state in which the torque in the reverse direction is being transmitted, if the vehicle is rear-ended by a following vehicle, for example, the torque input in reverse from the road surface to the drive wheels increases rapidly, and as a result, the torque input in reverse to the third rotating member 4 also increases rapidly.

[0093] In the clutch device 1 of this example, regardless of the direction of torque transmission between the second rotating member 3 and the third rotating member 4, if an impact torque is input in reverse to the third rotating member 4 in the steady rotation state, for example, when the vehicle is rear-ended by another vehicle, the impact torque can be prevented from being transmitted to the second rotating member 3 as follows.

[0094] For example, in the steady rotation state shown in Figures 7 and 8(a) in which the torque is transmitted in the reverse direction, if the torque input in reverse to the third rotating member 4 suddenly increases, as shown in Figure 8(b), the rotation speed of the third rotating member 4 suddenly increases.

[0095] In contrast, the combined body of the first rotating member 2 and the flywheel 6 tends to continue rotating at the original rotational speed due to its inertial force, and rotates relatively rearward in the rotational direction relative to the two engaging members 5. As a result, as shown in Figures 8(b) and 8(c), the radially inner surface 9 of the first rotating member side engaging portion 7 presses against the radially inner surface 18 of the engaging member side first engaging portion 15. The dashed arrow in Figure 8(c) indicates the direction of the inertial force of the combined body of the first rotating member 2 and the flywheel 6.

[0096] As a result, the two engaging members 5 overcome the biasing forces of the two biasing members 22 directed radially outward and move radially inward, which is a direction that moves the engaging member-side third engaging portion 17 away from the third rotating member-side engaging portion 14. Then, the contact pressure between the engaging member-side third engaging portion 17 and the third rotating member-side engaging portion decreases, or, as shown in Figure 8(c) , the engaging member-side third engaging portion 17 and the third rotating member-side engaging portion 14 separate, and the contact pressure between the engaging member-side third engaging portion 17 and the third rotating member-side engaging portion 14 is lost. This results in a torque transmission restricted state in which the torque transmitted between the third rotating member 4 and the second rotating member 3 is reduced or lost.

[0097] As a result, the application of an impact torque from the drive wheel to the drive source 23 is prevented.

[0098] As shown in Figure 8(c), the inertial rotational force of the combined body of the first rotating member 2 and the flywheel 6 causes the radial inner surface 9 of the first rotating member side engaging portion 7 to press against the radial inner surface 18 of the engaging member side first engaging portion 15. This phenomenon occurs immediately after a sudden increase in the torque input in reverse to the third rotating member 4. Thereafter, the inertial rotational force decreases, and the radially outward biasing forces of the two biasing members 22 exceed the inertial rotational force, causing the engaging member side third engaging portion 17 and the third rotating member side engaging portion 14 to strongly abut against each other. As a result, the rotational speed of the combined body of the first rotating member 2 and the flywheel 6 becomes the same as the rotational speed of the third rotating member 4, and the system returns to a steady rotational state in which torque is transmitted in the reverse direction, as shown in Figure 8(d).

[0099] In the clutch device 1 of this example, in addition to the cases described above, for example, in a steady rotation state in which the forward torque is transmitted, if the vehicle is rear-ended by a following vehicle, the torque input in reverse to the third rotating member 4 suddenly increases, causing the rotation speed of the third rotating member 4 to suddenly increase, and the rotation of the first rotating member 2 will be delayed, causing the engaging element 5 to be pressed radially inward, and the device may switch to the torque transmission restriction state.

[0100] In any of the above cases, the rate of increase in torque acting on the third rotating member 4, which is required to transition from the steady rotation state to the torque transmission restriction state, is determined by the mass of the flywheel 6 fixed to the first rotating member 2. In other words, the rate of increase in torque acting on the third rotating member 4, which is required to transition from the steady rotation state to the torque transmission restriction state, becomes smaller as the mass of the flywheel 6 increases.

[0101] The clutch device 1 of this example can prevent impact torque from being applied from the drive wheels to the drive source 23, thereby making it possible to reduce the size and weight of each component that makes up the drive system of an electric vehicle.

[0102] Second Example A second example of the embodiment of the present disclosure will be described with reference to FIG.

[0103] In this example, the clutch device 1a is incorporated into the drive system (drive device) of an electric vehicle having a three-shaft transaxle structure.

[0104] The drivetrain of the electric vehicle of this example includes a drive source 23a formed by an electric motor, a power transmission mechanism 28, a differential gear 29, two drive shafts 30, and a clutch device 1a. The drivetrain amplifies torque generated by the drive source 23a using the power transmission mechanism 28, transmits it to the differential gear 29, and distributes it to the two drive shafts 30 using the differential gear 29. This rotates and drives drive wheels 54 supported on the ends of the two drive shafts 30 via suspensions.

[0105] In this example, the power transmission mechanism 28 is configured with a gear-type reducer. The power transmission mechanism 28 includes a drive gear 31, an intermediate shaft 32, an intermediate gear 33, and a final reduction gear 34. The drive gear 31 is fixed to the tip of the output shaft 25a (first shaft) of the drive source 23a. The intermediate shaft 32 (second shaft) is disposed parallel to the output shaft 25a of the drive source 23a and rotatably supported by a gear housing (not shown). The intermediate gear 33 has a greater number of teeth than the drive gear 31 and is fixed to one axial side (right side in FIG. 9 ) of the intermediate shaft 32. The intermediate gear 33 meshes with the drive gear 31. The final reduction gear 34 has a smaller number of teeth than the intermediate gear 33 and is fixed to the other axial side (left side in FIG. 9 ) of the intermediate shaft 32.

[0106] The differential device 29 includes a differential case 35 , two pinion gears 57 , and two side gears 37 .

[0107] The differential case 35 has a central axis that is arranged parallel to the output shaft 25a of the drive source 23a and is supported so as to be rotatable about the central axis. The differential case 35 has a ring gear 36 on its radially outer side. The ring gear 36 has a greater number of teeth than the final reduction gear 34 and is in mesh with the final reduction gear 34. The differential case 35 has a support shaft 58 on its radially inner side that is perpendicular to the central axis of the differential case 35.

[0108] The two pinion gears 57 are disposed radially inside the differential case 35 and are supported on both axial sides of the support shaft 58 so as to be rotatable relative to the support shaft 58 .

[0109] The two side gears 37 are arranged coaxially with the differential case 35 and rotatably relative to the differential case 35 at both axially opposite radially inner portions of the differential case 35, and are meshed with two pinion gears 57. The two side gears 37 are fixed to the base ends of the two drive shafts 30 (third shafts).

[0110] In this example, the clutch device 1a is attached to an intermediate portion of the output shaft 25a of the drive source 23a. That is, in this example, the output shaft 25a includes a base-side shaft portion 38 and a tip-side shaft portion 39 that are coaxially arranged with each other. The clutch device 1a is attached between the base-side shaft portion 38 and the tip-side shaft portion 39.

[0111] More specifically, the second shaft portion 11 of the second rotating member 3 constituting the clutch device 1a is provided at the tip end of the base end side shaft portion 38 either integrally with the base end side shaft portion 38 or connected to the tip end of the base end side shaft portion 38 so as to be able to transmit torque. The third rotating member 4a constituting the clutch device 1a is provided at the base end of the tip end side shaft portion 39 either integrally with the tip end side shaft portion 39 or connected to the base end of the tip end side shaft portion 39 so as to be able to transmit torque.

[0112] In the clutch device 1a of this example, the first shaft portion 8a of the first rotating member 2a and the flywheel 6a each have a through-hole that penetrates in the axial direction at the radial center, and the second shaft portion 11 or the base-end shaft portion 38 of the second rotating member 3 is inserted into this through-hole. By adopting this configuration, it is possible to assemble the clutch device 1a coaxially with the rotating shaft (in this example, the output shaft 25a) at the intermediate portion of the rotating shaft.

[0113] In this example, the clutch device of the present disclosure is mounted on the first shaft (output shaft of the drive source) in a drivetrain having a three-shaft transaxle structure. However, when implementing the present disclosure, the clutch device of the present disclosure can also be mounted on the second shaft (intermediate shaft) or the third shaft (at least one of the two drive shafts, preferably both).

[0114] The other configurations and effects of the second example are the same as those of the first example.

[0115] Third Example A third example of the embodiment of the present disclosure will be described with reference to FIG.

[0116] In this example, in the drive system of various mechanical devices, the third rotating member 4 constituting the clutch device 1 is arranged on the side of the drive source 40 that generates torque, and the second rotating member 3 constituting the clutch device 1 is arranged on the side of the driven body.

[0117] More specifically, in this example, the rotating shaft 24 is provided integrally with the output shaft 41 at the tip of the output shaft 41 of the driving source 40, or is connected to the tip of the output shaft 41 in a manner allowing torque to be transmitted thereto. In other words, the torque generated by the driving source 40 is input to the third rotating member 4 via the meshing portions of the two gear portions 26, 27. The second shaft portion 11 of the second rotating member 3 is connected to the driven body in a manner allowing torque to be transmitted thereto directly or via a gear transmission device or the like.

[0118] In the structure of this example, the principle explained using FIGS. 6(a) to 6(e) and 8(a) to 8(d) prevents impact torque from being applied from the driving source 40 to the driven body.

[0119] The other configurations and effects of the third example are the same as those of the first example.

[0120] Fourth Example A fourth example of the embodiment of the present disclosure will be described with reference to FIGS. 11 and 12. FIG.

[0121] In this example, the structure of the clutch device 1b is different from that of the first example.

[0122] The clutch device 1 b of this example includes a first rotating member 42 , a second rotating member 43 , a third rotating member 44 , an engaging element 45 , a flywheel 6 b , and a biasing member 46 .

[0123] The first rotating member 42 is disposed on one axial side (right side in FIG. 11 ) of the clutch device 1 b, and has a first shaft portion 47 and a first cylindrical portion 48 extending toward the other axial side from the radially outer end of the end portion on the other axial side (left side in FIG. 11 ) of the first shaft portion 47. The first cylindrical portion 48 has retaining holes 49 penetrating radially at a plurality of locations at equal circumferential intervals in an axially intermediate portion. The first cylindrical portion 48 has first rotating member-side engaging portions 50 between circumferentially adjacent retaining holes 49.

[0124] The second rotating member 43 is configured as a shaft member arranged coaxially with the first rotating member 42 on the other axial side of the clutch device 1b. The second rotating member 43 has second rotating member side engaging portions 51 configured as flat surfaces at multiple locations (the same number as the first rotating member side engaging portions 50) that are equally spaced circumferentially on the outer peripheral surface of an end portion on one axial side. The end portion on one axial side of the second rotating member 43 is inserted radially inside the first cylindrical portion 48 that constitutes the first rotating member 42 via a radial gap. In this state, the second rotating member side engaging portions 51 and the retaining hole 49 are arranged at approximately the same position in the circumferential direction.

[0125] The third rotating member 44 is cylindrical and is coaxially disposed around the first rotating member 42 and the second rotating member 43. The third rotating member 44 has a third rotating member side engaging portion 52 formed of a cylindrical surface at an axially intermediate portion of its inner circumferential surface. With the third rotating member side engaging portion 52 disposed around the first cylindrical portion 48 of the first rotating member 42, the third rotating member 44 is rotatably supported at both axial ends relative to the first rotating member 42 and the second rotating member 43 by two rolling bearings 53 a, 53 b. The distance between the second rotating member side engaging portion 51 and the third rotating member side engaging portion 52 gradually decreases toward both circumferential ends.

[0126] The engaging elements 45 are made up of a plurality of engaging elements 45, each made up of a cylindrical roller. The engaging elements 45 are held two by two inside the retaining holes 49 that make up the first rotating member 42, and are arranged radially between the second rotating member side engaging portion 51 and the third rotating member side engaging portion 52. The outer circumferential surface of the engaging element 45 has a portion that engages with the first rotating member side engaging portion 50 as an engaging element side first engaging portion, a portion that engages with the second rotating member side engaging portion 51 as an engaging element side second engaging portion, and a portion that engages with the third rotating member side engaging portion 52 as an engaging element side third engaging portion.

[0127] The flywheel 6b is coaxially fixed to one axial end of a first shaft portion 47 that constitutes the first rotating member 42.

[0128] The biasing member 46 is made up of a plurality of biasing members 46, each made up of a spring member. One biasing member 46 is disposed between each pair of engaging elements 45 held inside the holding hole 49. The two engaging elements 45 are elastically biased by the biasing members 46 in directions away from each other.

[0129] 12 shows the first rotating member 42, the second rotating member 43, the third rotating member 44, the engaging elements 45, and the biasing member 46 in a neutral position. The two engaging elements 45 held in the retaining holes 49 are pressed in directions away from each other by the biasing member 46, so that each engaging element 45 is lightly engaged in a wedge-like manner with both circumferential sides between the second rotating member-side engaging portion 51 and the third rotating member-side engaging portion 52. In this state, a circumferential gap exists between each engaging element 45 and the first rotating member-side engaging portion 50 adjacent to that engaging element 45.

[0130] In this example, the second rotating member 43 constituting the clutch device 1b is provided at the tip end of the output shaft 25 (see FIG. 1) of the drive source 23 either integrally with the output shaft 25 or connected to the tip end of the output shaft 25 so as to be able to transmit torque. The third rotating member 44 constituting the clutch device 1b has a gear portion 26 (see FIG. 1) on its outer circumferential surface. The gear portion 26 meshes with a gear portion 27 (see FIG. 1) provided at the base end of the rotating shaft 24.

[0131] 12 is input to the second rotating member 43, the clockwise rear one of the two engaging elements 45 tightly engages in a wedge shape with the clockwise rear end between the second rotating member side engaging portion 51 and the third rotating member side engaging portion 52. That is, the second rotating member side engaging portion 51 engages with the engaging element side second engaging portion of the clockwise rear engaging element 45, and the engaging element side third engaging portion 17 of the clockwise rear engaging element 45 engages with the third rotating member side engaging portion 14, thereby transmitting torque between the second rotating member 43 and the third rotating member 44.

[0132] As a result, when the second rotating member 43, the two engaging elements 45, and the third rotating member 44 start to rotate integrally, the engaging element-side first engaging portion of the clockwise front engaging element 45 engages with the clockwise front first rotating member-side engaging portion 50. This results in a steady rotation state in the forward direction in which the first rotating member 42 and the flywheel 6b rotate integrally with the second rotating member 43, the two engaging elements 45, and the third rotating member 44.

[0133] In this example, in the forward steady rotation state, when the grip force of the drive wheel is reduced or lost and then recovered, an impact torque is input from the drive wheel to the third rotating member 44 in reverse, causing the rotation speed of the third rotating member 4 and the two engaging members 5 to drop sharply.

[0134] In contrast, the combined body of the first rotating member 42 and the flywheel 6b tends to continue rotating at the original rotational speed due to its inertial force, and rotates clockwise relative to the two engaging members 5. As a result, the inertial rotational force of the combined body of the first rotating member 42 and the flywheel 6b causes the first rotating member-side engaging portion 50 on the clockwise rear side to press the engaging member-side first engaging portion of the clockwise rear engaging member 45 in the circumferential direction.

[0135] As a result, the clockwise rear engaging element 45 moves toward the circumferential center between the second rotating member side engaging portion 51 and the third rotating member side engaging portion 52, i.e., to the portion where the gap between the second rotating member side engaging portion 51 and the third rotating member side engaging portion 52 is wide, and the contact pressure between the engaging element side third engaging portion of the engaging element 45 and the third rotating member side engaging portion 52 decreases or is lost. This results in a torque transmission restricted state in which the torque transmitted between the second rotating member 43 and the third rotating member 44 decreases or is lost.

[0136] As a result, it is possible to prevent impact torque from being applied from the drive wheels to the drive source 23. The other configurations and effects of the fourth example are the same as those of the first example.

[0137] The reverse input cutoff clutch of the present disclosure can be implemented by appropriately combining the structures of the first to fourth examples within a range that does not cause contradictions.

[0138] 1, 1a, 1b Clutch device 2, 2a First rotating member 3 Second rotating member 4, 4a Third rotating member 5 Engagement piece 6, 6a, 6b Flywheel 7 First rotating member side engagement portion 8, 8a First shaft portion 9 Radial inner surface 10 Second rotating member side engagement portion 11 Second shaft portion 12 Large flat surface 13 Small flat surface 14 Third rotating member side engagement portion 15 Engagement piece side first engagement portion 16 Engagement piece side second engagement portion 17 Engagement piece side third engagement portion 18 Radial inner surface 19 Flat surface portion 20 Central recess 21 Guide recess 22 Urging member 23, 23a Drive source 24 Rotating shaft 25, 25a Output shaft 26 Gear portion 27 Gear portion 28 Power transmission mechanism 29 Differential device 30 Drive shaft 31 Drive gear 32 Intermediate shaft 33 Intermediate gear 34 Final reduction gear 35 Differential case 36 Ring gear 37 Side gear 38 Base end side shaft portion 39 Tip end side shaft portion 40 Drive source 41 Output shaft 42 First rotating member 43 Second rotating member 44 Third rotating member 45 Engagement element 46 Urging member 47 First shaft portion 48 First cylindrical portion 49 Retaining hole 50 First rotating member side engagement portion 51 Second rotating member side engagement portion 52 Third rotating member side engagement portion 53a, 53b Rolling bearing 54 Drive wheel 55 Radial outer surface 56 Side surface 57 Pinion gear 58 Support shaft

Claims

1. A first rotating member having a first rotating member side engaging portion, a second rotating member having a second rotating member side engaging portion, a third rotating member having a third rotating member side engaging portion, an engager having a first engaging portion on an engager side engageable with the first rotating member side engaging portion, a second engaging portion on an engager side engageable with the second rotating member side engaging portion, and a third engaging portion on an engager side engageable with the third rotating member side engaging portion, and a flywheel fixed to the first rotating member, When torque is input to the second rotating member or the third rotating member, the second rotating member side engaging portion engages with the engaging member side second engaging portion, and the third rotating member side engaging portion engages with the engaging member side third engaging portion, thereby transmitting torque between the second rotating member and the third rotating member, and the engaging member side first engaging portion engages with the first rotating member side engaging portion, thereby establishing a steady rotation state in which the first rotating member, the flywheel, the second rotating member, the third rotating member, and the engaging member rotate integrally, When the torque acting on the third rotating member suddenly increases in the steady rotation state, the first rotating member side engaging portion presses the engager side first engaging portion based on the inertial force acting on the flywheel, causing the engager to move the engager side third engaging portion in a direction away from the third rotating member side engaging portion, and the contact pressure between the engager side third engaging portion and the third rotating member side engaging portion decreases or is lost, resulting in a torque transmission restricted state where the torque transmitted between the second rotating member and the third rotating member is reduced or lost.

2. A clutch device according to claim 1, further comprising a biasing member for elastically biasing said engaging element in a direction in which said third rotating member side engaging portion and said engaging element side third engaging portion engage with each other.

3. A clutch device as described in claim 1 or 2, wherein the third rotating member has the third rotating member side engaging portion on its inner surface, the first rotating member side engaging portion is arranged radially inward of the third rotating member side engaging portion, the second rotating member side engaging portion is arranged radially inward of the first rotating member side engaging portion, and the engaging member has the engaging member side second engaging portion on its radially inner surface and the engaging member side third engaging portion on its radially outer surface, and is arranged to be capable of moving in a first direction, which is a direction toward or away from the third rotating member side engaging portion.

4. A clutch device according to any one of claims 1 to 3, wherein the engaging element is made up of two engaging elements, and the first rotating member side engaging portion is made up of two first rotating member side engaging portions.

5. A clutch device according to any one of claims 1 to 4, which is incorporated into a drive system that transmits torque from a drive source to drive wheels.

Images