JP2020106137A - clutch - Google Patents

Abstract

To provide a clutch which can switch the connection and disconnection between a first shaft member and a second shaft member at arbitrary timing by a simple constitution, and can completely separate the first shaft member and the second shaft member from each other.SOLUTION: In a clutch 100 having a first shaft member 110 and a second shaft member 150, a cam abutment part 111 is arranged at the first shaft member 110, a transmission part 151 is arranged at the second shaft member 150, a transmission cam 120 is arranged between the cam abutment part 111 and the transmission part 151, the cam abutment part 111 and a first face of the transmission cam 120 abut on each other so as to be slidably rotatable while making spiral faces 112, 113, 122 and 128 oppose one another, the transmission cam 120 is constituted so as to be advanceable and retractable in a rotating shaft direction of the first shaft member 110 in conjunction with slide rotation with the cam abutment part 111, and the transmission part 151 and a second face of the transmission cam 120 are constituted so as to be capable of abutting on each other, and separable from each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a clutch that transmits rotation of an input shaft to an output shaft side, and more particularly to a clutch that switches between transmission and disconnection of power from an input shaft to an output shaft by an external operation.

BACKGROUND ART Conventionally, a clutch for transmitting power from an input shaft to an output shaft side is arranged on a transmission path of a driving force of a transmission device of an automobile, a motorcycle, a driving device such as an OA device, and various clutches are known.

For example, the clutch described in Patent Document 1 is a one-way overrunning clutch C1, which includes a first shaft member (annular guide member 50 and force limiting member 180) and a first shaft member (annular guide member 50 and Force limiting member 180) and a second shaft member (drive shaft and tubular body 76) configured to be independently rotatable on the same rotation shaft, and the first shaft member (annular guide member 50 and force). The restricting member 180) is provided with a cam contact portion (spiral guide tooth 52), and the second shaft member (drive shaft and tubular body 76) is provided with a transmitting portion (friction member 70). Between the contact portion (spiral guide tooth 52) and the transmission portion (friction member 70), the first shaft member (annular guide member 50 and force limiting member 180) rotates relatively on the same rotation axis. A transmission cam (intermediate member 90) configured as possible is provided.
Further, the cam contact portion (spiral guide tooth 52) and the first surface (spiral guide tooth 92) of the transmission cam (intermediate member 90) are the first shaft member (annular guide member 50 and force limiting member). 180), the spiral-shaped surfaces centering on the same rotation axis are made to face each other and slidably rotatably abutted to constitute a rotation guide mechanism G, and the transmission cam (intermediate member 90) is a cam abutting portion. The first shaft member (the annular guide member 50 and the force limiting member 180) is configured to be movable forward and backward in the rotational axis direction in conjunction with the sliding rotation with the (spiral guide tooth 52), and the transmission portion (the friction member 70). ) And the second surface (rotational friction surface 104) of the transmission cam (intermediate member 90) are connected to each other to form the guide friction mechanism F1.

In the clutch described in Patent Document 1, the rotation guide mechanism G and the guide friction mechanism F1 both constitute a space wedge mechanism of the one-way overrunning clutch C1, and the first shaft member (annular guide member 50). When the force limiting member 180) is normally rotated, the cam contact portion (spiral guide tooth 52) and the first surface (spiral guide tooth 92) of the transmission cam (intermediate member 90) slide.
As a result, the transmission cam (intermediate member 90) is pressed against the rotary pulling friction surface 72 of the transmission portion (friction member 70), and the force transmission friction surface 74 of the transmission portion (friction member 70) causes the force on the force limiting member 180 side. Since it is pressed against the transmission friction surface 58, a large friction force is generated between the transmission cam (intermediate member 90) and the transmission portion (friction member 70) and between the transmission portion (friction member 70) and the force limiting member 180. Then, the driving force from the first shaft member (annular guide member 50 and force limiting member 180) is transmitted to the second shaft member (drive shaft and tubular body 76) via the transmission portion (friction member 70). be able to.
Further, while the driving force is being transmitted from the first shaft member (the annular guide member 50 and the force limiting member 180) to the second shaft member (the drive shaft and the tubular body 76), the cam contact portion is generated due to the wedge effect. The (spiral guide teeth 52) and the first surface (spiral guide teeth 92) of the transmission cam (intermediate member 90) continue to be engaged with each other.

In addition, the driving force is sufficiently transmitted to the second shaft member (the drive shaft and the tubular body 76), and the first shaft member (the annular guide member 50 and the force limiting member 180) moves to the second shaft member (the drive shaft and the tubular body). When rotating in the opposite direction relative to the body 76), the cam contact portion (helical guide tooth 52) and the first surface (helical guide tooth 92) of the transmission cam (intermediate member 90) are caught. Since the disengagement and transmission cam (intermediate member 90) gradually slides toward the cam contact portion (spiral guide tooth 52) side, the pressing force on the transmission portion (friction member 70) decreases, and the transmission cam ( The intermediate member 90) and the transmission portion (friction member 70) slide out to cancel the transmission of the driving force.
The transmission cam (intermediate member 90) is urged toward the transmission portion (friction member 70) by an urging member (torsion spring 150), and the transmission cam (intermediate member 90) is retransmitted when the driving force is retransmitted. It is possible to maintain the position where the wedges are preliminarily wedged so as to be immediately pressed against the transmission portion (friction member 70).

Patent No. 5679469

However, there is still room for improvement in the clutches known in the above patent documents and the like.

That is, the clutch known in Patent Document 1 and the like is a one-way clutch, and automatically connects and disconnects the first shaft member and the second shaft member depending on the direction of torque, so that the first shaft can be switched at any timing. There is a possibility that the transmission of the driving force from the member to the second shaft member cannot be switched.
Furthermore, since the transmission cam is constantly biased toward the transmission portion by the biasing member, it is difficult to completely cancel the transmission of the driving force from the first shaft member to the second shaft member, and the transmission force is transmitted. There is a risk that the sliding time between the working cam and the transmission portion increases, and the wear of each portion may easily progress.
Further, since the transmission cam is biased by the biasing member toward the transmission portion and maintains the position where it is wedged in advance, the first shaft member and the second shaft member are completely separated at the start of the driving force transmission. There is a problem that it is difficult to use in a situation where the driving force is not separated and an operation for transmitting the driving force at an arbitrary timing is required.

The present invention solves these problems and is capable of generating a large frictional force by a wedge effect with a simple configuration, and connecting and disconnecting the first shaft member and the second shaft member at will. It is an object of the present invention to provide a clutch that can be switched at the timing, and that can completely separate the first shaft member and the second shaft member.

A clutch of the present invention is a clutch having a first shaft member and a second shaft member that is independently rotatable on the same rotation shaft as the first shaft member, and the first shaft member includes A cam contact portion is provided at a position facing the second shaft member, and a transmission portion is provided at a position facing the cam contact portion on the second shaft member, A transmission cam is provided between the transmission portion and the first shaft member so as to be rotatable relative to the first shaft member, and the cam contact portion and the first surface of the transmission cam are provided. Are in contact with each other so that their spiral surfaces centering on the same rotation axis as the first shaft member face each other so as to be slidably rotatable, and the transmission cam is interlocked with sliding rotation with the cam abutting portion. The first shaft member is configured to be movable back and forth in the rotation axis direction, and the transmission portion and the second surface of the transmission cam are configured to be contactable with and removable from each other. To do.

In the clutch of the invention according to claim 1, the first shaft member is provided with a cam contact portion at a position facing the second shaft member, and the second shaft member is provided at a position facing the cam contact portion. A transmission portion is provided, and a transmission cam is provided between the cam contact portion and the transmission portion, and the cam contact portion and the first surface of the transmission cam are the same as the rotation shaft of the first shaft member. The spiral-shaped surfaces centering on each other are in contact with each other so as to be slidably rotatable, and the transmission cam can move forward and backward in the rotational axis direction of the first shaft member in conjunction with the sliding rotation with the cam abutting portion. Since the transmission portion and the second surface of the transmission cam can be brought into contact with and separated from each other when the transmission portion and the second surface of the transmission cam are brought into contact with each other, the first shaft member The driving force is transmitted between the second transmission member and the second shaft member, and the transmission cam has a wedge effect of forming an angle between the spiral surface and the second surface as a wedge angle. It is possible to generate a large frictional force with the surface, prevent the transmission portion and the second surface of the transmission cam from slipping, and prevent the driving force transmission efficiency from decreasing.
Further, by completely disconnecting the transmission portion and the transmission cam, it is possible to completely separate the first shaft member and the second shaft member.
Furthermore, since the switching of the transmission of the driving force can be switched by the contact and the disengagement of the transmission portion and the transmission cam regardless of the magnitude and direction of the torque, the first shaft member and the second shaft can be switched at any timing. The transmission of the driving force with the member can be switched, and the driving force can be transmitted with respect to both forward and reverse rotations.
Further, it is possible to adjust the wedge angle of the spiral-shaped surface centering on the same rotation axis as the first shaft member, which is the contact surface between the cam contact portion and the first surface of the transmission cam, and the friction material on the surface. Then, the characteristics of the clutch can be changed, for example, by making the transmission portion and the transmission cam slidably contact each other and gradually transmitting the driving force.

According to the configuration of claim 2, the clutch has a transmission switching member, and the transmission switching member rotates the transmission cam forward and backward relative to the first shaft member to thereby transfer the transmission cam. Is configured to be movable back and forth in the rotation axis direction of the first shaft member, so that the second surface of the transmission cam can be easily brought into and out of contact with the transmission portion only by operating the transmission switching member. Therefore, the transmission of the driving force between the first shaft member and the second shaft member can be switched.
In addition, the cam contact portion and the first surface of the transmission cam are slidably rotated with the spiral surfaces having the same rotation axis as the first shaft member as the center facing each other so as to be slidably rotated, thereby transmitting the transmission cam and the transmission cam. When the frictional force is generated by pressing against the transmission part, this frictional force causes the transmission cam to be drawn into the wedge area between the transmission member and the wedge effect, which is larger than the force applied to the transmission cam by the transmission switching member. A frictional force can be generated, and the force for operating the transmission switching member can be suppressed only to the force required to switch between contact and disconnection of the transmission cam with the transmission portion.
According to the configuration of claim 3, the transmission cam has the switching engagement portion, the transmission switching member has the engaged portion engageable with the switching engagement portion, and the transmission shaft has the first shaft member. It is configured so as to rotate integrally with the first shaft member and to move back and forth in the rotation axis direction of the first shaft member, and the transmission cam rotates forward and backward with respect to the first shaft member by movement of the transmission switching member in the rotation axis direction. Since it is configured to be possible, the forward and backward movements of the transmission cam can be easily performed only by moving the transmission switching member forward and backward.

According to the structure of claim 4, the clutch is provided with the urging member for urging the transmission switching member in the direction in which the transmission cam is disengaged from the transmission portion. Even if the transmission switching member cannot be operated, the transmission cam can be detached from the transmission portion by the biasing member, and the first shaft member and the second shaft member are completely separated, and the safe state is automatically established. Can be transferred.
According to the configuration of claim 5, the transmission cam has the limiting piece that limits the movement of the first shaft member in the radial direction from the rotation shaft, so that the transmission cam can move in the radial direction during rotation of the clutch. Even if vibration or a large force is applied unexpectedly, the driving force can be reliably transmitted without shifting the position of the transmission cam or the center of rotation.

According to the configuration of claim 6, at least one of the first shaft member and the second shaft member is centered on the rotation axis of the first shaft member, and the other of the first shaft member and the second shaft member. A restricting member having a circumferential wall extending toward the side is provided, and the radially inner peripheral side of the restricting piece has a restricting arc-shaped portion along the peripheral wall of the restricting member. It can be prevented more reliably.
According to the configuration of claim 7, a plurality of transmission cams are provided in the circumferential direction around the rotation shaft of the first shaft member, and at least one transmission cam is arranged in the opposite direction to the cam contact portion. Since it is arranged so as to be slidably rotated with respect to the first shaft member and the second shaft member, the transmission cam is brought into contact with the transmission member to transmit the driving force regardless of whether the rotation directions of the first shaft member and the second shaft member are normal or reverse. it can.

The perspective view which shows each component before the assembly of the clutch 100 which concerns on one Embodiment of this invention. The side view which shows the state where the transmission cam 120 has disengaged from the transmission part 151 of the clutch 100 which concerns on one Embodiment of this invention. FIG. 3 is a side view of the clutch 100 according to the embodiment of the present invention, in which a transmission switching member 140 is removed in a state in which a transmission cam 120 is disengaged from a transmission portion 151. The side view which shows the state which the transmission cam 120 is contacting the transmission part 151 of the clutch 100 which concerns on one Embodiment of this invention. FIG. 6 is a side view of the clutch 100 according to the embodiment of the present invention, in which the transmission switching member 140 is removed, with the transmission cam 120 being in contact with the transmission portion 151. The schematic perspective view which shows each component before the assembly of the clutch 200 which concerns on one Embodiment of this invention. The schematic perspective view which shows each component before the assembly of the clutch 300 which concerns on one Embodiment of this invention.

Hereinafter, a clutch 100 according to an embodiment of the present invention will be described with reference to the drawings.
For the sake of explanation, FIGS. 3 and 5 do not show the transmission switching member 140.

As shown in FIG. 1, a clutch 100, which is an embodiment of the present invention, includes a first shaft member 110 and a second shaft member that is independently rotatable about the same rotation shaft as the first shaft member 110. 150, and between the first shaft member 110 and the second shaft member 150, a transmission cam 120 configured to be relatively rotatable on the same rotation shaft as the first shaft member 110. An annular transmission switching member 140 configured to be engageable from the side surface of the transmission cam 120 is provided.

The first shaft member 110 is provided with a cam contact portion 111 at a position facing the second shaft member 150, and the cam contact portion 111 has a forward spiral surface 112 and the first shaft member 110. It has a reverse spiral-shaped surface 113 which is formed in the opposite direction with the rotating shaft interposed therebetween.
Further, at the center of the first shaft member 110, a through hole 114 penetrating in the rotation axis direction of the first shaft member 110 is provided.

On the second shaft member 150, a transmission portion 151 formed in a flat plate shape at a position facing the cam contact portion 111, and a circumferential wall protruding from the center of the transmission portion 151 toward the cam contact portion 111 side. A regulating member 152 having 153 is provided.

The transfer cam 120 has a fan-shaped positive cam having a forward spiral slide surface 122 corresponding to the forward spiral surface 112 on the first surface and a flat plate surface 123 corresponding to the transfer portion 151 on the second surface. A fan-shaped reverse direction transfer cam having a direction transfer cam 121, a reverse spiral slide surface 128 corresponding to the reverse spiral surface 113, and a flat plate surface 129 corresponding to the transfer portion 151 on the second surface. 127 are provided so as to face each other with respect to the rotation axis of the first shaft member 110.
Forward direction spiral engaging portions 124 and reverse direction spiral engaging portions 130 are provided on the outer peripheral surfaces of the forward direction transmitting cam 121 and the reverse direction transmitting cam 127, respectively. On the inner peripheral surface side of the transmission cam 127, there are provided restriction pieces 125 and 131 which are formed in a disc shape along the inner peripheral surfaces of the cams 127 and are arranged so as to be displaced in the rotation axis direction of the first shaft member 110. The restriction pieces 125, 131 are provided at their central portions with restriction through holes 126, 132 penetrating the restriction pieces 125, 131 in the rotation axis direction of the first shaft member 110.

The transmission switching member 140 is fixed in a position in the rotation direction relative to the first shaft member 110, and the forward spiral engaging portion 124 and the reverse spiral engaging member are provided on the inner peripheral surface of the transmission switching member 140. A forward direction engaged portion 141 and a reverse direction engaged portion 142 which are slidably engageable are formed corresponding to the joining portions 130, respectively.
The transmission switching member 140 is always biased by a biasing member (not shown) in the direction from the second shaft member 150 side toward the first shaft member 110 side.
The restriction member 152 restricts the movement of the through hole 114 in the radial direction and the axial direction and is slidable only in the rotation direction, and does not move in the radial direction of the restriction through holes 126 and 132. It is formed so as to be slidable in the rotational direction and the axial direction while restricting only the movement.

Next, the operation of each part of the clutch 100 of the present invention when switching the driving force transmission from the first shaft member 110 to the second shaft member 150 will be described with reference to FIGS. 2 to 5.

First, as shown in FIGS. 2 and 3, in the clutch 100 of the present invention, the forward transmission cam of the transmission cam 120 is mounted on the forward spiral surface 112 and the reverse spiral surface 113 of the first shaft member 110. 121 and the reverse direction transmission cam 127 are slidably brought into contact, and the restriction member 152 of the second shaft member 150 is inserted into the through hole 114 of the first shaft member 110 and the restriction through holes 126 and 132 of the transmission cam 120. Then, the second shaft member 150 is arranged with the distance between the cam contact portion 111 and the transmission portion 151 fixed, and the forward direction engaged portion 141 and the reverse direction engaged portion 142 of the transmission switching member 140 are arranged. The transmission cam 120 is slidably engaged with the forward spiral engagement portion 124 and the reverse spiral engagement portion 130.

At this time, the transmission switching member 140 is moved to the first shaft member 110 side by the biasing member (not shown).
Further, since the transmission switching member 140 is fixed in the rotational position relative to the first shaft member 110, the forward transmission cam 121 and the reverse transmission cam 127 are fixed in the forward direction of the transmission switching member 140. By rotating the forward direction spiral engagement portion 124 and the reverse direction spiral engagement portion 130 while being slid on the engaged portion 141 and the reverse direction engaged portion 142, respectively, the forward direction spiral surface 112 is rotated. And, while rotating with sliding on the reverse spiral surface 113, the state of being separated from the transmission portion 151 of the second shaft member 150 is maintained.

In this state, since the first shaft member 110 and the second shaft member 150 are not in physical contact with each other, the driving force is transmitted to the second shaft member 150 side even if the first shaft member 110 is rotated. There is no.

Next, when the transmission switching member 140 is moved in the direction from the first shaft member 110 side toward the second shaft member 150 side, the forward direction transmission cam 121 and the reverse direction transmission cam 127 are moved to the forward direction of the transmission switching member 140. The direction-direction engaged portion 141 and the reverse-direction engaged portion 142 are rotated while being slid on the forward spiral engagement portion 124 and the reverse spiral engagement portion 130, respectively. While rotating with the reverse spiral surface 113, the flat surfaces 123 and 129 of the transmission cam 120 come into contact with the transmission portion 151 of the second shaft member 150.
At this time, when the first shaft member 110 is rotating in the forward direction, the forward-direction transmitting cam 121 receives a force that further slides in the forward direction between the cam contact portion 111 and the transmitting portion 151. As a result, a wedge effect is generated, and the wedge force is further pushed toward the transmission portion 151 side to increase the frictional force between the forward direction transmission cam 121 and the transmission portion 151.

As described above, since the driving force is transmitted using the pressing force due to the wedge effect, the force for moving the transmission cam 120 to the transmission portion 151 side can be suppressed to a very small level, and the transmission switching member 140 is used. It is not necessary to strongly press the transmission cam 120 toward the transmission portion 151 side.
That is, for example, as compared with a general electromagnetic clutch, an electromagnet that can generate only a small electromagnetic force can be used for the operation of the transmission switching member 140, which leads to power saving and downsizing of the device configuration. You can
The engagement characteristic of the clutch 100 due to the wedge effect is that the spiral-shaped surfaces 112 and 113, the spiral sliding surfaces 122 and 128, the flat plate surfaces 123 and 129, and the transmission portion 151 are in contact with each other with their parallel surfaces facing each other. Since it is sliding, it is determined by the angle between the spiral sliding surfaces 122 and 128 and the flat plate surfaces 123 and 129, which are wedge angles.

If the frictional force is sufficiently large immediately after the forward direction transmission cam 121 and the transmission portion 151 are in contact with each other, the transmission cam 120 instantly rotates integrally with the transmission portion 151 without slipping, and the The driving force can be transmitted to the second shaft member 150.
At this time, since the flat plate surfaces 123 and 129 of the transmission cam 120 and the transmission portion 151 are in surface contact with each other in a wide plane, it is possible to suppress wear and deformation as compared with line contact such as a roller type clutch.

Further, even when the friction material is used for the flat plate surfaces 123, 129 and the transmission portion 151, since a general material used for the flat surface can be used, it is possible to reduce the material and cost required for processing.
Further, since the spiral-shaped surfaces 112 and 113 of the cam contact portion 111 and the spiral sliding surfaces 122 and 128 of the transmission cam 120 are in contact with each other with their parallel surfaces facing each other, they are worn during sliding. At this time, the parallel relationship between the spiral-shaped surfaces 112 and 113 and the spiral sliding surfaces 122 and 128 that face each other does not change, the wedge angle does not change, and the engagement characteristic of the clutch 100 does not change.

Further, by adjusting the engagement characteristic of the clutch 100, it is possible to gradually transmit the driving force while sliding each other immediately after the contact between the transmission cam 120 and the transmission portion 151. Even when the differential rotation between the first shaft member 110 and the second shaft member 150 is large, the impact torque can be suppressed and the driving force can be transmitted, and damage to the clutch 100 and peripheral components can be suppressed.
When the transmission switching member 140 is moved to the first shaft member 110 side, the transmission cam 120 can rotate while sliding on the spiral-shaped surfaces 112 and 113 so as to be separated from the transmission portion 151. The transmission of the driving force to the second shaft member 150 can be quickly released even while the member 110 is rotating.

Further, even when the first shaft member 110 is rotating in the reverse direction, the reverse direction transmitting cam 127 performs the same operation in the opposite direction to the forward direction transmitting cam 121 at the time of forward rotation. The driving force can be transmitted from the member 110 to the second shaft member 150.
Further, when the transmission cam 120 abuts on the transmission portion 151 and rotates, the transmission cam 120 is strongly pressed against the transmission portion 151 by the wedge effect, so that the second shaft member 150 is rotated to move from the second shaft member 150. The driving force can also be transmitted to the first shaft member 110.

Further, the regulation member 152 regulates the movement of the through hole 114 in the radial direction and the axial direction of the through hole 114 and is slidable only in the rotational direction, and is in the radial direction of the limited through holes 126 and 132. Since only the movement is restricted and the member is slidable in the rotation direction and the axial direction, even if each member receives a force in the radial direction of the rotation shaft due to vibration or the like when the clutch 100 rotates, the rotation shaft of each member Does not significantly deviate from the radial direction of the rotation axis of the first shaft member, and can operate stably.
Further, the limiting pieces 125 and 131 provided on the forward direction transmission cam 121 and the reverse direction transmission cam 127 are formed in a disk shape along the inner peripheral surfaces of each other, and the rotation shaft of the first shaft member 110. Since they are displaced in the direction, the rotation shafts of the forward direction transmission cam 121 and the reverse direction transmission cam 127 are not further displaced from the rotation axis of the first shaft member 110, and stable operation is possible.
In addition, since the transmission switching member 140 is always biased toward the first shaft member 110 by the biasing member (not shown), the transmission switching member 140 can be operated when a failure such as a power failure occurs during the transmission of the driving force. The transmission cam 120 can be reliably separated from the transmission portion 151 by moving in the direction of the first shaft member 110, and the connection between the first shaft member 110 and the second shaft member 150 can be automatically released.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.

In addition, in the above-described embodiment, the transmission cam has the rotation shaft of the first shaft member in the state where the forward direction transmission cam and the reverse direction transmission cam shift the limiting piece in the rotation axis direction of the first shaft member. However, the arrangement of the transmission cams is not limited to this, and, for example, as shown in FIG. 6, the outer circumference is centered around the rotation axis of the first shaft member. The forward direction transmission cam may be provided on the side, and the reverse direction transmission cam may be provided on the inner peripheral side.
Further, in the above-described embodiment, the configuration in which the driving force can be transmitted in the forward direction and the reverse direction has been described, but the transmission direction of the driving force is not limited to this. For example, as shown in FIG. May be provided only in one of the forward and reverse directions so that the driving force can be transmitted in only one direction.

Further, in the above-described embodiment, the transmission switching member is described as being constantly biased by the biasing member in the direction from the second shaft member side to the first shaft member side, but the configuration of the transmission switching member is The present invention is not limited to this. For example, the transmission switching member may be always biased toward an intermediate position in the movable range between the second shaft member and the first shaft member, and there is no biasing member. Good.
Further, in the above-described embodiment, the spiral engaging portion and the engaged portion are described as being in contact with each other in surface contact, but the engagement relationship between the transmission cam and the transmission switching member is not limited to this. However, for example, a round rod-shaped pin engageable with the spiral engagement portion may be formed so as to project on the inner peripheral side of the transmission switching member.

Further, in the above-described embodiment, the restricting member provided on the second shaft member is formed so as to be slidable only in the rotational direction with respect to the through hole provided in the first shaft member, and serves as a limiting piece of the transmission cam. The limiting through hole provided is described as being formed so as to be slidable in the rotational direction and the axial direction, but the configuration of each member is not limited to this, and for example, the first shaft member is provided with the regulating member. The second shaft member may be provided with a through hole, or the limiting piece may be provided with an arcuate limiting arcuate portion along the circumferential wall without providing the limiting through hole. The regulating member may not be provided.
In the above-described embodiment, the first shaft member and the second shaft member are not in physical contact with each other when the transmission switching member is separated from the transmission unit. The relationship with the two shaft members is not limited to this. For example, by connecting the restricting member and the through hole via the radial bearing and the thrust bearing, the first shaft member and the second shaft member transmit the driving force. The first shaft member and the second shaft member are in contact with each other so as not to transmit the driving force by connecting the restriction member and the restriction through hole with a sliding bearing structure. Good.

100, 200, 300... Clutch 110, 210, 310... 1st shaft member 111... Cam contact part 112, 212, 312... Forward spiral surface 113, 213... Reverse direction Helical surface 114 ・・・ Through hole 120 ・・・ Transmission cams 121, 221, 321 ・・・ Forward direction transmission cams 122, 222, 322 ・・・ Forward spiral slide surface 123, 129 ・・・ Flat plate Surface 124... Forward direction spiral engaging portion 125, 131... Limiting piece 126, 132... Limiting through hole 127, 227... Reverse direction transmitting cam 128, 228... Reverse direction spiral sliding Moving surface 130 ... Reverse direction spiral engagement part 140 ... Transmission switching member 141 ... Forward direction engaged part 142 ... Reverse direction engaged part 150, 250, 350 ... 2nd Shaft member 151 ・・・Transmission part 152 ・・・Regulating member 153 ・・・Circular wall

Claims (7)

A clutch having a first shaft member and a second shaft member configured to be independently rotatable on the same rotation shaft as the first shaft member,
A cam contact portion is provided on the first shaft member at a position facing the second shaft member,
A transmission portion is provided on the second shaft member at a position facing the cam contact portion,
A transmission cam is provided between the cam contact portion and the transmission portion, and the transmission cam is configured to be relatively rotatable on the same rotation shaft as the first shaft member.
The cam abutting portion and the first surface of the transmitting cam are slidably rotatably abutting on each other with their spiral surfaces centering around the same rotation axis as the first shaft member facing each other.
The transmission cam is configured to be capable of advancing and retreating in the rotation axis direction of the first shaft member in conjunction with sliding rotation with the cam contact portion.
A clutch, wherein the transmission portion and the second surface of the transmission cam are configured to be capable of abutting and disengaging. The clutch has a transmission switching member,
The transmission switching member is configured to move the transmission cam forward and backward in the rotation axis direction of the first shaft member by rotating the transmission cam forward and backward relative to the first shaft member. The clutch according to claim 1, wherein the clutch is provided. The transmission cam has a switching engagement portion on the outer peripheral surface,
The transmission switching member has an engaged portion that is engageable with the switching engaging portion, rotates integrally with the first shaft member, and advances and retreats in the rotation axis direction of the first shaft member. Configured to be movable,
The clutch according to claim 2, wherein the transmission cam is configured to be rotatable in the forward and reverse directions with respect to the first shaft member by movement of the transmission switching member in a rotation axis direction. The clutch according to claim 2 or 3, wherein the clutch is provided with a biasing member that biases the transmission switching member in a direction in which the transmission cam is disengaged from the transmission portion. The clutch according to any one of claims 1 to 4, wherein the transmission cam has a restricting piece that restricts movement of the first shaft member in a radial direction from a rotation shaft. At least one of the first shaft member and the second shaft member has a circumferential wall extending around the rotation axis of the first shaft member and extending to the other side of the first shaft member and the second shaft member. A regulating member having is provided,
The clutch according to claim 5, wherein a radially inner side of the limiting piece has a limiting arcuate portion along the circumferential wall of the regulating member. A plurality of the transmission cams are provided in the circumferential direction around the rotation shaft of the first shaft member, and at least one transmission cam is arranged so as to be slidably rotated in the opposite direction to the cam contact portion. The clutch according to any one of claims 1 to 6, wherein:

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