Selectable clutch

Abstract

To provide a selectable clutch that enables switching of operation modes with a simple structure, has high responsiveness, can ensure a prescribed torque capacity, has little rattle or noise and can be switched with little force even when transmission torque is large.SOLUTION: A selectable clutch comprises: a first clutch mechanism in which a locking member 150 that moves and / or rotates is arranged between a first rotary element 110 and a second rotary element 120, and that is configured to be capable of transmitting rotation at any rotation angle; a second clutch mechanism configured to be capable of transmitting rotation at a predetermined rotation angle by engaging a first engaging element 131 with a second engaging element 141; and an operation mechanism that switches the operation of at least the first clutch mechanism and / or the second clutch mechanism. The selectable clutch is configured to be capable of switching between transmitting and blocking of relative rotation between a first shaft and a second shaft.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a selectable clutch that includes a clutch mechanism that transmits or interrupts rotation between a first shaft and a second shaft that are coaxially arranged so as to be capable of relative rotation, and an operating mechanism that switches the operation of the clutch mechanism, and that can switch between transmitting and interrupting the relative rotation between the first shaft and the second shaft. [Background technology]

[0002] As a clutch that controls the transmission and interruption of rotation between two shafts, a two-way clutch that can switch between driving and idling in both the forward and reverse directions is known. Although devices consisting of a ratchet clutch or a dog clutch are well known, they are only capable of transmitting rotation at a specified rotation angle, and because they transmit rotation through rigid engagement, they are prone to rattling and produce a lot of noise. Some types of two-way clutches are configured to switch between a locked state, in which relative rotational movement between the inner and outer rings is prohibited (rotational force is transmitted), and a free state, in which relative rotational movement between the inner and outer rings is permitted (rotational force is blocked), by tilting a cam or sprag, making it possible to transmit rotation at any rotational angle (see, for example, Patent Document 1 and Patent Document 2).

[0003] Furthermore, Patent Document 3 describes a two-way clutch equipped with a switching mechanism that can switch between three operating modes, namely, two-way free mode, one-way locked mode, and two-way locked mode, by controlling a retainer that holds a roller, as a power transmission member, in a neutral position or one of the engaged positions of a cam surface formed on the inner circumference of the outer ring, and that can transmit rotation at any rotation angle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-220509 A [Patent Document 2] Japanese Patent Application Publication No. 11-182589 [Patent Document 3] JP 2014-219015 A [Patent Document 4] JP 2020-190255 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the two-way clutch described in Patent Document 1, when the input rotor rotates relative to the output rotor, the sprags tilt in the same direction as the rotational direction of the input rotor, switching between engagement and disengagement between the input rotor and the output rotor, resulting in a time loss when the rotational direction is switched, resulting in poor responsiveness. The two-way clutch described in Patent Document 2 also has the same problem. The two-way clutch described in Patent Document 3 is capable of transmitting power in both directions simultaneously using a leaf spring-like member, but because power is transmitted by friction, there is a problem in that the transmittable torque is small compared to the size of the two-way clutch. Furthermore, in order to solve these problems and provide a cam clutch that has a simple structure, is capable of switching operation modes, has high responsiveness, and can ensure the desired torque capacity, the applicant invented a cam clutch with an operation mode switching mechanism shown in Patent Document 4.

[0006] However, in clutches that lock these cams or rollers by clamping them, the cams and rollers can be locked in any position in each direction, and a slight relative rotation from the start of torque transmission causes the cams or rollers to strongly mesh and transmit torque. Therefore, in two-way lock mode, even if the rotational torque is eliminated, the slight relative rotation when one cam or roller is released from its engagement will cause the other cam or roller to mesh, and the cams and rollers in both directions will remain engaged. In order to switch to two-way free mode or one-way free mode in this state, a force is required to release the engagement of the cams and rollers. Since the larger the transmitted torque, the greater the engagement, it was necessary to have a switching mechanism with a structure capable of generating a large force when transmitting a large torque.

[0007] The present invention is devised to solve these problems, and aims to provide a selectable clutch that has a simple structure, is capable of switching operating modes, is highly responsive, can ensure the desired torque capacity, has little backlash or noise, and can be switched with a light force even when the transmitted torque is large. [Means for solving the problem]

[0008] The present invention solves the above-mentioned problems by providing a selectable clutch that includes a first clutch mechanism and a second clutch mechanism that transmit / cut off rotation of a first shaft and a second shaft that are coaxially arranged so as to be capable of relative rotatability, and an operating mechanism that switches the operation of at least the first clutch mechanism and / or the second clutch mechanism, and that can switch between transmitting / cutting the relative rotation between the first shaft and the second shaft, wherein the first clutch mechanism is configured to be able to transmit rotation at any rotation angle by disposing a locking member that moves and / or rotates between a first rotating element and a second rotating element, and the second clutch mechanism is configured to be able to transmit rotation at a predetermined rotation angle by engagement between a first engagement element and a second engagement element. Effect of the Invention

[0009] According to the invention of claim 1, the first clutch mechanism is configured so that a locking member that moves and / or rotates is arranged between the first rotating element and the second rotating element, and the second clutch mechanism is configured so that it can transmit rotation at any rotation angle, and the second clutch mechanism is configured so that it can transmit rotation at a predetermined rotation angle by engagement between the first engagement element and the second engagement element.Since the first clutch mechanism can transmit rotation at any rotation angle, rotation can be transmitted in both directions without any backlash in the two-way lock mode, and the second clutch mechanism does not become engaged due to the relative rotation when the rotational torque is eliminated and the engagement of the first clutch mechanism is released, so that switching operation can be performed with a light force even if the transmission torque is large. Furthermore, by disengaging the second clutch mechanism and operating the one-way free mode using the first clutch mechanism, relative rotation with extremely little noise and rotational resistance is possible.

[0010] According to the configurations of claims 2 and 3, the first clutch mechanism is configured as a so-called cam clutch, which makes it possible to switch the operating mode of the first clutch mechanism with a simple structure while ensuring high responsiveness and the desired torque capacity. According to the invention as defined in claim 4, the second clutch mechanism is configured as a so-called ratchet type one-way clutch, so that high responsiveness and a desired torque capacity can be ensured. According to the configuration of claim 5, the first engagement element and the second engagement element are arranged opposite each other in the axial direction, and the operating mechanism is configured to be able to move the first engagement element or the second engagement element in the axial direction, thereby making it possible to switch the operating mode of the second clutch mechanism with a simple structure. According to the configuration of claim 6, the first engagement element is composed of a plurality of ratchet pawls provided on the end face of the outer ring, and the second engagement element is composed of ratchet teeth arranged to extend from the end face of the inner ring toward the outer periphery, thereby making it possible to achieve a simple and compact structure. [Brief description of the drawings]

[0011] [Figure 1]1 is a cross-sectional perspective view of a selectable clutch according to an embodiment of the present invention; [Diagram 2] 2 is a cross-sectional perspective view of the selectable clutch shown in FIG. 1, as viewed from another direction. [Diagram 3] FIG. 2 is an exploded explanatory view of the selectable clutch shown in FIG. 1. [Figure 4] FIG. 2 is a side view of the selectable clutch shown in FIG. [Diagram 5] FIG. 2 is a side cross-sectional view of the selectable clutch shown in FIG. [Figure 6] FIG. 2 is a front view of the selectable clutch shown in FIG. [Figure 7] FIG. 2 is a rear view of the selectable clutch shown in FIG. 1. [Figure 8] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Examples of the present invention will be described with reference to Figures 1 to 7. However, the present invention is not limited to these embodiments. EXAMPLES

[0013] As shown in Figures 1 to 7, a selectable clutch 100 according to one embodiment of the present invention comprises a first clutch mechanism and a second clutch mechanism which transmit and interrupt rotation of a first shaft and a second shaft which are coaxially arranged so as to be rotatable relative to each other, and an operating mechanism which switches the operation of the first clutch mechanism and the second clutch mechanism. The first clutch mechanism is a cam clutch in which cam 150, which is a rotating locking member, is disposed between inner ring 120 which is a first rotating element and outer ring 110 which is a second rotating element, and which is configured to be able to transmit rotation at any rotation angle.

[0014] The second clutch mechanism is a ratchet-type one-way clutch configured to be able to transmit rotation at a predetermined rotation angle by engagement between ratchet teeth 141 provided on a ratchet tooth holding member 140, which is the first engagement element, and ratchet pawl 131 provided on a ratchet pawl holding member 130, which is the second engagement element. The ratchet pawl 131 is configured to engage with the ratchet teeth 141 during relative rotation in one direction, and to pass over the ratchet teeth 141 as the relative distance therebetween changes during relative rotation in the other direction. In this embodiment, the ratchet pawl 131 has the same shape as the ratchet tooth 141, and is configured so that the ratchet pawl holding member 130 and the ratchet tooth holding member 140 move axially relative to each other when climbing over a wall, but each ratchet pawl 131 itself may be configured to be swingable relative to the ratchet pawl holding member 130. The ratchet pawl holding member 130 is fixed to the end face of the outer ring 110, and the ratchet tooth holding member 140 is fixed to the inner ring 120 and arranged to extend from the end face of the inner ring 120 toward the outer periphery, with the ratchet pawl 131 and ratchet tooth 141 arranged to face each other in the axial direction. Further, a side plate 151 is attached to the outer ring 110, and the axial position of a cam 150 that constitutes the first clutch mechanism is defined between the ratchet pawl holding member 140 and the side plate 151.

[0015] The operation mechanism for switching the operation of the first clutch mechanism has a selector member 160 that is fitted onto the inner race 120 and is axially slidable on the selector sliding surface 122 of the inner race 120 . Further, an inner ring stopper plate 123 is disposed at the end of the inner ring 120 to restrict the movement of the selector member 160 and prevent it from falling off. In the first clutch mechanism, as shown in FIG. 8, a spring 170 is wrapped around a pressing portion 152 of a cam 150, which is biased toward the inner ring 120 and biased to rotate in the direction of the arrow shown, thereby coming into contact with both the inner ring 120 and the outer ring 110. This allows relative rotation between the inner ring 120 and the outer ring 110 in one direction and blocks the transmission of rotational torque, and the relative rotation between the inner ring 120 and the outer ring 110 in the other direction is prevented by the cam 150 rotating slightly in the direction of the arrow and becoming wedged between the cam sliding surfaces 111, 121 of the inner ring 120 and the outer ring 110, thereby transmitting the rotational torque. The selector member 160 slides axially on the selector sliding surface 122 of the inner ring 120 and is inserted below the pressing portion 152, and is configured to maintain the cam 150 in a position where it receives no force from either the inner ring 120 or the outer ring 110 against the biasing force of the spring 170, thereby allowing free relative rotation in both directions between the inner ring 120 and the outer ring 110 and blocking the transmission of rotational torque in both directions.

[0016] The operating mechanism for switching the operation of the second clutch mechanism is configured to change the distance between the ratchet teeth 141 provided on the ratchet tooth holding member 140 and the ratchet pawl 131 provided on the ratchet pawl holding member 130 by moving the inner wheel 120 itself axially relative to the outer wheel 110, thereby switching between a state in which the ratchet mechanism is operable and transmits rotation in only one direction, and a state in which the ratchet pawl 131 is not in contact with the ratchet teeth 141 and the transmission of rotational torque in both directions is blocked. Incidentally, the inner ring stopper plate 123 and the selector member 160 described above regulate excessive sliding of the inner ring 120 during this switching operation.

[0017] The operation of the selectable clutch 100 configured as above will now be described. The state shown in Figures 1, 2, 4, and 5 is the two-way free mode, in which the selector member 160 abuts against the pressing portion 152 of the cam 150, freeing the first clutch mechanism, and the inner ring 120 slides to a state in which the ratchet pawl 131 does not contact the ratchet teeth 141, freeing the second clutch mechanism as well. From this state, when the selector member 160 is slid to release the contact of the selector member 160 with the pressing portion 152 of the cam 150, the first clutch mechanism operates as a one-way clutch and the one-way free mode is established. Furthermore, when the selector member 160 is slid, the selector member 160 abuts against the inner wheel retaining plate 123 and the inner wheel 120 slides together with it, enabling the ratchet pawl 131 and the ratchet teeth 141 to engage with each other. The second clutch mechanism operates as a one-way clutch for rotation in the opposite direction to the first clutch mechanism, resulting in a two-way lock mode in which rotation is transmitted in both directions. This action may be achieved by directly sliding the inner ring 120 .

[0018] In this embodiment, the selector member 160 of the first clutch mechanism is configured to be able to abut against the pressing portion 152 of the cam 150 only at the position of the inner wheel 120 where the second clutch mechanism is free. When the first clutch mechanism is switched from the two-way free mode by the selector member 160, it is possible to switch the second clutch mechanism by sliding the inner wheel 120 with the same operation, and it is possible to directly switch to the two-way locked mode. When switching from the two-way locked mode, the selector member 160 is slid, and the inner ring 120 also slides at the same time, so that the first clutch mechanism and the second clutch mechanism are set in a free state, resulting in the two-way free mode shown in FIGS. Furthermore, when switching the first clutch mechanism from the two-way free mode with the selector member 160, if the operation is stopped at a position where the inner ring 120 does not slide, the second clutch mechanism is kept free and the one-way free mode is entered.

[0019] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made without departing from the present invention described in the claims. In the above embodiment, the selector member 160 of the first clutch mechanism is configured to be able to abut against the pressing portion 152 of the cam 150 only at the position of the inner wheel 120 where the second clutch mechanism is in a free state, but the configuration may be such that each can be switched independently, with only the second clutch mechanism operating as a one-way clutch but having a one-way free mode in the opposite direction, thereby making it possible to switch between four modes.

[0020] In addition, in the above embodiment, the operating mechanism of the first clutch mechanism has a selector member 160 that is axially slidable, and the operating mechanism of the second clutch mechanism is one that is operated by sliding the inner ring 120. Alternatively, other known switching mechanisms may be used. In addition, in the above embodiment, cam 150 serving as the first clutch mechanism may have a different shape depending on the required torque resistance, etc., and is described as a cam clutch having a first clutch mechanism, but it may also be a clutch configured so that a roller or the like moves slightly and becomes engaged between two rotating elements, thereby being able to transmit rotation at any rotation angle. In the above embodiment, the second clutch mechanism is configured with the ratchet pawl 131 and the ratchet teeth 141 that face each other in the axial direction, but it may be configured to face each other in the radial direction. Furthermore, when the one-way free mode in the reverse direction is not provided as in the above embodiment, the second clutch mechanism may be in the form of a dog clutch that does not have the function of a one-way clutch. The cam may have different shapes depending on its required torque resistance etc. [Explanation of symbols]

[0021] 100 ··· Selectable clutch 110 Outer ring (first rotating element) 111 Cam sliding surface 120 Inner ring (second rotating element) 121 Cam sliding surface 122 Selector sliding surface 123 Inner wheel stopper plate 130 Ratchet claw holding member 131 Ratchet claw (first engagement element) 140 Ratchet tooth retaining member 141 Ratchet teeth (second engagement element) 150 ··· Cam (locking member) 151 Side panel 152 Pressing section 160 Selector member 170 Spring (urging means)

Claims

1. A selectable clutch comprising: a first clutch mechanism and a second clutch mechanism for transmitting and interrupting rotation between a first shaft and a second shaft that are coaxially and relatively rotatable; and an operation mechanism for switching operation of at least the first clutch mechanism and / or the second clutch mechanism, the selectable clutch being capable of switching between transmitting and interrupting the relative rotation between the first shaft and the second shaft, The first clutch mechanism is configured such that a locking member that moves and / or rotates is disposed between the first rotating element and the second rotating element, and the first clutch mechanism is capable of transmitting rotation at any rotation angle; A selectable clutch, wherein the second clutch mechanism is configured to be able to transmit rotation at a predetermined rotation angle by engagement between a first engagement element and a second engagement element.

2. The first rotating element and the second rotating element are configured with an outer ring and an inner ring arranged in an axially overlapping position, The locking member is a cam.

2. The selectable clutch according to claim 1, wherein the first clutch mechanism has a plurality of cams provided in a circumferential direction between the outer ring and the inner ring, and a biasing means for biasing the plurality of cams.

3. 3. The selectable clutch according to claim 2, wherein the operation mechanism has a selector member capable of switching between allowing and preventing rotation of the cam.

4. 2. The selectable clutch according to claim 1, wherein the first engaging element and the second engaging element are disposed opposite each other, one having ratchet teeth and the other having a ratchet pawl.

5. The first engagement element and the second engagement element are disposed opposite to each other in an axial direction, 5. The selectable clutch according to claim 4, wherein the operation mechanism is configured to be able to move the first engagement element or the second engagement element in an axial direction. The selectable clutch according to claim 1.

6. The first rotating element and the second rotating element are configured with an outer ring and an inner ring arranged in an axially overlapping position, The first engagement element and the second engagement element are disposed opposite to each other in an axial direction, The first engagement element is composed of a plurality of ratchet pawls provided on an end surface of the outer ring, 2. The selectable clutch according to claim 1, wherein the second engagement element is formed of ratchet teeth arranged to extend from an end face of the inner ring toward an outer periphery thereof.

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