JP2016186322A - Lock type bidirectional clutch equipped with planetary gear and eccentric mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make actuation smooth, and to prevent the generation of noise and the like, in a lock typ bidirectional clutch which transmits rotations from an input side and prevents rotation transmission from an output side.SOLUTION: In the inside of a housing 1 equipped with an input shaft 2 and an output shaft 3, a planetary gear mechanism which has a planetary gear PG revolving and rotating around a fixed sun gear SG, and an eccentric mechanism which has an eccentric gear EG are installed in parallel in an axial direction. The planetary gear PG is engaged with the eccentric gear EG, and a center shaft of the eccentric gear EG is fitted in an eccentric hole of the output shaft 3 to configure a bidirectional clutch. Rotations in a normal/reversed direction from the input shaft 2 are transmitted to the output shaft 3 at constant speed, through the planetary movement of the planetary gear PG. On the other hand, when driven from the output shaft 3 side, rotation transmission from the eccentric gear EG eccentrically installed to the planetary gear PG is impossible, and the output shaft 3 is locked to prevent power transmission.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a clutch device that changes a power transmission state between an input shaft and an output shaft, and in particular, transmits power of normal / reverse rotation from the input shaft (drive side) and from the output shaft (driven side). The power transmission relates to a lock-type bidirectional clutch that shuts off the output shaft as being unrotatable.

  In a power transmission system that drives work equipment or the like from a drive source such as a motor, for example, an elevating device that moves an article up and down by a motor, when the article reaches a predetermined position, the article is automatically In some cases, an operation to maintain the position is required. For this reason, there is known a device that uses a lock-type bidirectional clutch having an input shaft and an output shaft to connect the input shaft to a motor that can rotate forward and reverse, and to move the article up and down by rotating the output shaft. . In the bidirectional clutch of this device, when the input shaft is rotated forward / reversely by the motor, the output shaft is linked forward / reversely to move the article up / down while the output shaft is rotated forward / reversely. The shaft is locked to prevent the article from falling.

  An outline of an elevating device using a lock type bidirectional clutch and an example of the structure of the bidirectional clutch will be described with reference to FIGS. FIG. 7 shows a cross-sectional AA structure of a lifting device that moves an article up and down by a belt and a pulley and a bidirectional clutch provided in the driving device. FIG. 8A shows an output shaft as an input shaft. FIG. 8B shows a cross section AA in a state where the article is moved up and down in conjunction with each other, and FIG. 8B shows a cross section AA in a state where the output shaft is locked to prevent the article from falling.

  The lifting device of FIG. 7 is a device in which a belt B is stretched between pulleys P1 and P2 arranged above and below, and an article W to be transferred to the belt B is fixed, and the upper pulley P1 is rotationally driven. A motor M that can rotate forward and backward is coupled via a bidirectional clutch DC. The bidirectional clutch DC includes an input shaft IS that is continuous with the motor M, an output shaft OS that is continuous with the pulley P1, and a fixed housing HG. As shown in the cross-sectional arrow A-A view, in the housing HG of the bidirectional clutch DC, the input shaft IS is divided into a plurality of sector parts, and the output shaft OS is fitted inside the sector part. The output shaft OS is provided with a protrusion that enters between adjacent fan-shaped portions of the input shaft IS, and a roller R is provided between the V-shaped recess formed at the tip of the protrusion and the housing HG. Intervened.

As shown in FIG. 8A, when the input shaft IS is rotated by the motor M, the side surface of the fan-shaped portion of the input shaft IS and the side surface of the protruding portion of the output shaft OS abut, and the output shaft OS Rotates at the same speed in the same direction as pushed by the IS. The same is true when the input shaft IS rotates in the reverse direction. In the lifting device of FIG. 7, when the motor M is rotated forward / reversely, the article W fixed to the belt B can be raised or lowered.
On the other hand, when the output shaft OS rotates, as shown in FIG. 8 (b), the roller R is pushed up to the inclined surface of the V-shaped recess by the slight rotation, and moves outward, and the housing HG. And the projection of the output shaft OS. As a result, the output shaft OS is locked and stopped at that position, and rotation is not transmitted to the input shaft IS. That is, in the lifting device of FIG. 7, even if the driving by the motor M is stopped, the article W can be automatically prevented from falling due to its own weight. Such a lock-type bidirectional clutch is disclosed in Japanese Patent No. 4850653, which is a prior application of the present applicant.

  The lock-type bidirectional clutch can be applied to, for example, an elevating device that transfers a paper table on which a paper is placed, or an elevating device that raises and lowers a window blind of a building in a finisher of a copying machine. When this is used, automatic power transmission can be controlled by a simple device, and the use of electric power or the like is unnecessary, as in the case of electrical control by providing a brake mechanism, for example. When there is an unexpected reverse input from the output shaft side, the motor of the drive source can be protected.

Japanese Patent No. 4850653

  As described above, the lock-type two-way clutch shown in FIG. 7 is a compact machine part that can reliably control power transmission, but there is still room for improvement depending on the application. The present invention solves the following problems of a bidirectional clutch.

In order to achieve the function of the bidirectional clutch having the structure shown in FIG. 7, it is necessary to provide a gap between the fan-shaped portion of the input shaft IS and the protruding portion of the output shaft OS. To do. Further, when this bidirectional clutch is applied to the lifting device of FIG. 7, there is no problem when the motor W is rotated forward to raise the article W, but when the motor M is reversed and the article W is lowered, the article W The speed of the output shaft OS repeatedly fluctuates slightly due to the gravity, and vibrations and abnormal noise may occur. This is due to the following reason.
When the motor M is rotated in reverse to lower the article W, the output shaft OS may rotate (overrun) faster than the input shaft IS due to gravity acting on the article W. When overrun occurs, 8B, the roller R and the housing HG are engaged with each other, and the output shaft OS is locked. This locked state is released when the roller R is pushed by the rotation of the input shaft IS, but the repetition of the biting and the release gives a fine fluctuation to the speed of the output shaft OS. In order to release the locked state, it is necessary to apply a torque (moment) that overcomes the frictional force acting on the roller. This is also the case when the article W in the stopped state is raised. In addition to the load torque that raises the article W, a torque for releasing the biting is also required.

In view of the above problems, the present invention constitutes a lock-type bidirectional clutch by combining a planetary gear mechanism and an eccentric mechanism without using a biting roller, and prevents the occurrence of abnormal noise or the like due to operation, When stopping the output shaft, the locked state is surely maintained. That is, the present invention
“A non-rotatable housing, a rotation center shaft having a common input shaft and output shaft, forward and reverse rotations from the input shaft are transmitted to the output shaft and from the output shaft to the input shaft The rotation transmission is a lock-type two-way clutch that is cut off with the output shaft being unrotatable,
A planetary gear mechanism having a sun gear fixed to the housing, a planetary gear that revolves and rotates around the sun gear while meshing with the sun gear, and a carrier that pivotally supports the planetary gear; and The sun gear is placed in parallel in the axial direction and meshes with the planetary gear, and the sun gear is provided with an eccentric gear having a different number of teeth,
The carrier is connected to the input shaft, and the eccentric gear is connected to the output shaft so as to rotate about an eccentric shaft different from the common rotation center shaft. ''
This is a lock type two-way clutch.

The lock type two-way clutch of the present invention has a non-rotatable housing, and an input shaft and an output shaft installed at the center thereof. The input shaft and the output shaft have a common rotation center shaft, and a planetary gear mechanism having a fixed sun gear and a planetary gear that performs planetary motion is installed between them and meshes with the planetary gear. However, an eccentric gear that rotates around an eccentric shaft is installed. Although the sun gear and the eccentric gear are meshed with the same planetary gear, the eccentric gear is eccentric, so the diameter and the number of teeth of both gears are different.
The input shaft is connected to a carrier that supports the planetary gear, and an eccentric gear is fitted to the output shaft so as to rotate around an axis (an eccentric amount e) that is eccentric from the center axis. That is, when the output shaft rotates, the center axis of the eccentric gear moves on the circumference of the radius e centering on the common rotation center axis (see FIG. 2 described later).

When the input shaft is rotated by being driven by a motor or the like, the planetary gear supported by the carrier is rotated while revolving around a common rotation center shaft while meshing with the fixed sun gear. The planetary gear meshes with an eccentric gear arranged eccentrically, and when the planetary gear revolves around a common rotation center axis, the center axis of the eccentric gear is a circumference of a radius e centered on the common rotation center axis. Move up. In other words, the center of the eccentric gear having a different number of teeth (the pitch circle diameter is also different) from the sun gear is on a straight line connecting the center of the sun gear and the planetary gear, and the same angular velocity as the revolution angular velocity of the planetary gear. To revolve around the circle. An eccentric gear having a different number of teeth from the sun gear also rotates due to the planetary motion of the planetary gear due to the difference in the number of teeth.
The output shaft into which the eccentric gear is eccentrically fitted rotates as a result of the central axis of the eccentric gear moving on the circumference of the radius e, so that it rotates around the common rotation center axis. And constant speed. That is, in the lock type bidirectional clutch of the present invention, when the input shaft rotates, the rotation is transmitted to the output shaft, and the output shaft rotates at the same rotation speed.

  On the other hand, when transmitting rotation from the output shaft to the input shaft, first, the eccentric gear that is eccentrically fitted to the output shaft needs to rotate while revolving around a common rotation center axis. At this time, the eccentric gear meshes with the planetary gear, and the planetary gear meshes simultaneously with the sun gear having a different number of teeth from the eccentric gear, so that rotation and rotation of the planetary gear via the eccentric gear is caused by rotation of the output shaft. It is virtually impossible to make a movement and the output shaft is locked.

  Thus, in the lock type bidirectional clutch of the present invention, the planetary gear mechanism and the eccentric mechanism are used to transmit the rotational power from the input shaft to the output shaft and cut off the power transmission in the opposite direction. Since the rotation transmission from the output shaft is blocked by setting the planetary gear mechanism in a locked state, even when the reverse torque acting on the output shaft is large, it is possible to reliably hold the stop. Further, since the planetary gear mechanism is locked immediately when it is driven from the output shaft side via the eccentric mechanism (eccentric gear), the impact sound of the roller is generated during operation unlike the bidirectional clutch of FIG. There is no occurrence of a change in the speed of the output shaft due to the repeated engagement and release of the rollers.

It is a figure which shows the Example of the lock type bidirectional | two-way clutch of this invention. It is a figure explaining the action | operation of the bidirectional | two-way clutch of FIG. FIG. 2 is an exploded view of a single part such as a housing constituting the bidirectional clutch of FIG. 1. FIG. 2 is an exploded view of components such as an input shaft constituting the bidirectional clutch of FIG. 1. It is a general view which shows another Example of the lock type bidirectional | two-way clutch of this invention. FIG. 6 is an exploded view of parts such as an input shaft constituting the bidirectional clutch of FIG. 5. It is a figure which shows an example of the conventional lock type bidirectional clutch. It is a figure explaining the action | operation of the lock type bidirectional | two-way clutch of FIG.

  Hereinafter, the lock type bidirectional clutch of the present invention will be described with reference to the drawings. First, FIG. 1 shows the overall structure of a bidirectional clutch according to one embodiment of the present invention, and FIG. 3 and 4 are exploded views showing components of the lock type bidirectional clutch of the embodiment of FIG.

  As shown in the central longitudinal sectional view of FIG. 1 (see also FIGS. 3 and 4 in which each part is shown as a single item), the bidirectional clutch of this embodiment has an input shaft 2 and an output at the center of a fixed housing 1. In this structure, the shafts 3 are respectively arranged. The input shaft 2 and the output shaft 3 have a common rotation center axis o and are not shown, but the input shaft 2 is connected to the drive side of a motor or the like (as shown in FIG. The cross section is D-shaped, and a drive shaft such as a motor is inserted in such a manner that relative rotation is impossible.), And the output shaft 3 is connected to a driven side such as a lifting device. A lid 1C that is a part of the housing 1 is press-fitted and shielded at the end of the housing 1, and the lid 1C also serves as a bearing for the input shaft 2 that passes therethrough. A rolling bearing BG is provided between the output shaft 3 and the housing 1.

  Inside the housing 1 are a planetary gear mechanism (cross section AA) constituted by a fixed sun gear SG, a planetary gear PG and a carrier 21 formed integrally with the housing 1, and an eccentric gear EG arranged eccentrically. Are arranged in parallel in the axial direction. Here, although the center of the fixed sun gear SG exists on the common rotation center axis o of the input shaft 2 and the output shaft 3, the eccentric gear EG has its rotation center axis o ′ from the common rotation center axis o. The output shaft 3 is fitted so as to be separated by an eccentric amount e. Therefore, the number of teeth of the eccentric gear EG is larger than the number of teeth of the sun gear SG. In this embodiment, the number of teeth of the eccentric gear EG is 17, the number of teeth of the sun gear SG is 15, and the number of teeth of the planetary gear PG. Is 12.

  The input shaft 2 is connected to the carrier 21 so as to be formed integrally with the disk-shaped carrier 21, and the planetary gear PG is rotatable on a support shaft 22 erected on one surface of the carrier 21. It is inserted. As will be described in detail later, an input shaft reinforcing plate 23 that is in contact with the end plate of the housing 1 and rotates with the carrier 21 is installed so that the planetary gear PG rotates stably. It couple | bonds with the hole of the board 23 (refer FIG. 4). The planetary gear PG meshes with the sun gear SG formed in the housing 1 as shown in the section AA, and rotates and revolves around the common rotation center axis o as the input shaft 2 rotates. Do. The planetary gear PG is a gear that is relatively long in the axial direction, and meshes with an eccentric gear EG that is eccentrically fitted to the output shaft 3 as shown in a cross section BB.

The operation of the lock type bidirectional clutch of the embodiment of FIG. 1 will be described with reference to FIG.
As shown in the longitudinal sectional view in the upper center of FIG. 2, when a rotational torque in the clockwise direction (viewed from the right in the figure) is applied to the input shaft 2, the planetary gear PG supported on the carrier 21 is Move (revolve) clockwise around a common rotation center axis o. As shown in the upper cross section AA of FIG. 2, the planetary gear PG meshes with the fixed sun gear SG, so that the planetary gear PG rotates in the clockwise direction simultaneously with the revolution.

As shown in the upper section BB, the planetary gear PG is also meshed with the eccentric gear EG arranged eccentrically, and is in a state where the pitch circles of both gears having different diameters are in contact with each other. The rotation center axis o ′ of the EG is separated from the common rotation center axis o by an eccentric amount e. When the planetary gear PG revolves around the rotation center axis o in this state, the rotation center axis o ′ of the eccentric gear EG is always the center of the rotation center axis o (the center axis of the sun gear SG) and the planetary gear PG. It exists on a straight line connecting PGo. Therefore, the center of the eccentric gear EG moves (revolves) on the circumference of the radius e at the same angular velocity as the revolution angular velocity of the planetary gear PG. Since the number of teeth of the eccentric gear EG is different from the number of teeth of the fixed sun gear SG, the eccentric gear EG also rotates due to the planetary motion of the planetary gear PG due to the difference in the number of teeth.
The output shaft 3 into which the eccentric gear EG is eccentrically fitted is input around the common rotation center axis o as a result of the central axis of the eccentric gear EG moving on the circumference of the radius e at the revolution angular velocity of the planetary gear PG. It rotates at the same speed as the shaft 2. That is, in the lock type bidirectional clutch of the present invention, when the input shaft 2 rotates in the forward / reverse direction, the output shaft 3 rotates at the same rotational speed in the same direction.

  On the other hand, as shown in the longitudinal sectional view in the lower center of FIG. 2, when transmitting rotation from the output shaft 3 to the input shaft 2, first, the eccentric gear EG that is eccentrically fitted to the output shaft 3 is inserted. , It must rotate while revolving around a common rotation center axis o. However, the center shaft of the eccentric gear EG is merely fitted into the output shaft 3 so as to revolve while sliding, and the planetary gear PG meshed with the eccentric gear EG is also meshed with the sun gear SG having a different number of teeth. Therefore, it is substantially impossible to cause the planetary gear PG to perform revolution and rotation through the eccentric gear EG by the rotation of the output shaft 3, and the output shaft 3 is locked without rotating.

  As described above, in the lock type bidirectional clutch of the present invention, the rotation of the input shaft 2 from the carrier 21 side is transmitted to the output shaft 3 side at a constant speed, but the reverse power from the output shaft 3 side is transmitted. Transmission is interrupted because the output shaft 3 cannot rotate. Since the rotation transmission from the output shaft 3 is blocked by setting the planetary gear mechanism in a locked state, there is no need for a gap for operation, such as a bidirectional clutch for engaging the roller. Therefore, the impact sound and intermittent behavior of the roller are not generated during operation, and no extra torque is required to release the roller.

Here, the structure of the housing, the input / output shaft, etc. in the lock type bidirectional clutch of the embodiment of FIG.
FIG. 3 is a diagram showing the housing 1 as a stationary part, the output shaft 3 as a rotating part, and the eccentric gear EG eccentrically fitted to the output shaft 3 as a single item. The housing 1 is a cup-shaped fixing member including an end plate 11 and a circumferential wall 12. A lid 1 </ b> C (see FIG. 1) is press-fitted on the opposite side of the end plate 11 to seal the inside. A boss portion 13 projects from the inner central portion of the end plate 11, and a fixed sun gear SG of the planetary gear mechanism is formed on the outer periphery of the boss portion 13. 3 through-holes are formed.

The output shaft 3 is provided with an eccentric hole 31 at a position eccentric from the rotation center axis o by a distance e, and the central shaft of the eccentric gear EG is rotatably fitted in the eccentric hole 31. When the output shaft 3 in this state is assembled to the housing 1, the eccentric gear EG and the sun gear SG having different numbers of teeth are adjacent to each other in the axial direction.
By adopting such a structure for the housing 1 and the like, the overall structure of the lock type bidirectional clutch of the present invention can be simplified, and a small and compact bidirectional clutch can be obtained. In addition, the installation of the fixed sun gear SG is facilitated, and at the same time, the assembly of rotating parts such as the output shaft 3 is simplified, and the eccentric gear EG of the output shaft 3 and the sun gear SG of the housing 1 are connected to the same planetary gear PG. It becomes easy to mesh with.

  FIG. 4 is a diagram showing the carrier 21 integrated with the input shaft 2, the planetary gear PG supported by the carrier 21, and the input shaft reinforcing plate 23 as a single item. The carrier 21 has a disc shape, and a support shaft 22 is erected on one surface, and the planetary gear PG is rotatably supported by the support shaft 22. Further, three connecting pieces 24 extending in the axial direction are erected on the peripheral edge portion of the carrier 21, and a corresponding notch portion of the input shaft reinforcing plate 23 is fitted into the tip of the connecting piece 24, and the carrier 21 and the input shaft reinforcing plate 23 are assembled. At this time, the tip of the support shaft 22 is inserted into the hole 23H of the input shaft reinforcing plate 23, and the planetary gear PG is supported from both sides.

  As shown in FIG. 3, the input shaft assembly including the carrier 21, the planetary gear PG, and the input shaft reinforcing plate 23 is combined with the housing 1 from the back of the output shaft 3. As a result, the planetary gear PG can be easily meshed with the sun gear SG and the eccentric gear EG, and the input shaft reinforcing plate 23 comes into contact with the end plate 11 of the housing 1 to support the support shaft 22 of the planetary gear PG. Therefore, the planetary gear PG can perform a smooth planetary motion.

  Next, another embodiment of the lock type bidirectional clutch of the present invention will be described with reference to FIGS. The two-way clutch of another embodiment is based on the lock type two-way clutch of the embodiment of FIG. 1, and an idle planetary gear is added to stabilize the operation. FIG. FIG. 6 shows an exploded view of the input shaft assembly. In these drawings, parts corresponding to the parts in the embodiment of FIG.

  As shown in the longitudinal cross-sectional view, cross-section AA, and cross-section BB of FIG. 5, the bidirectional clutch of another embodiment is similar to that of the embodiment of FIG. The basic structure of the present invention is provided in combination with an eccentric mechanism (cross section BB) including an eccentric gear EG. The input shaft 2 is integrated with the carrier 21 of the planetary gear PG, the planetary gear PG is meshed with the sun gear SG and the eccentric gear EG formed in the housing 1, and the rotation center axis of the eccentric gear EG is It is the same as that of the lock type bidirectional clutch of the embodiment of FIG.

  The difference between the embodiment of FIG. 5 and the embodiment of FIG. 1 is that, as can be seen from the sections AA and BB in FIG. Two idle planetary gears are attached together with the gear PG, and these are arranged at equal intervals in the circumferential direction. As each set of idle planetary gears, there are two idle planetary gears IG1 (cross section AA) meshing with the fixed sun gear SG and second idle planetary gears IG2 (cross section BB) meshing with the eccentric gear. Gears are provided separately. As shown in FIG. 6, the first idle planetary gear IG <b> 1 and the second idle planetary gear IG <b> 2 are axially supported in parallel with the support shaft of the carrier 21 in the axial direction.

Since the first idle planetary gear IG1 meshes with the sun gear SG concentric with the common rotation center axis o, the pitch diameter and the number of teeth are the same as the planetary gear PG, but the second idle planetary gear IG2 is eccentric. In relation to meshing with the eccentric gear EG, the pitch diameter and the number of teeth are smaller than that of the planetary gear PG, and the number of teeth of the second idle planetary gear IG2 of this another embodiment is nine.
Since the first idle planetary gear IG1 and the second idle planetary gear IG2 are separate and there is no torque transmission between them, the idle planetary gear contributes to the power transmission from the input shaft 2 to the output shaft 3. do not do. However, when these idle planetary gears are installed, the rotational balance of the input shaft 2 and the carrier 21 is improved, and vibration during rotation of the bidirectional clutch due to the unbalanced inertia force can be prevented. Moreover, since the radial wobbling of the eccentric gear EG can be suppressed by the second idle planetary gear IG2, the power transmission from the input shaft 2 to the output shaft 3 can be performed more smoothly.

  As described above in detail, the lock-type bidirectional clutch of the present invention is a lock that blocks reverse power transmission from the output shaft side by combining a planetary gear that rotates and rotates and an eccentric mechanism that includes an eccentric gear. It constitutes a type bidirectional clutch. Since the power transmission is not interrupted by using the biting of the roller, it is possible to prevent the generation of abnormal noise or the like due to the operation or the intermittent operation. In the above embodiment, the rotary shaft provided in the eccentric gear is fitted in the eccentric hole of the output shaft, but conversely, the center hole of the eccentric gear may be fitted in the eccentric shaft formed in the output shaft. . It is obvious that various modifications can be made to the above-described embodiment, such as integrating the input shaft and the carrier separately with a fastener, and manufacturing the gear part of the sun gear separately and assembling it with the housing. It is.

DESCRIPTION OF SYMBOLS 1 Housing 1C Lid 2 Input shaft 21 Carrier 23 Input shaft reinforcement board 3 Output shaft SG Sun gear PG Planetary gear EG Eccentric gear IG1 1st idle planetary gear IG2 2nd idle planetary gear

Claims (5)

A non-rotatable housing, a rotation center shaft having a common input shaft and output shaft, forward and reverse rotations from the input shaft are transmitted to the output shaft, and from the output shaft to the input shaft Transmission of rotation is a lock-type two-way clutch that is shut off with the output shaft being unrotatable,
A planetary gear mechanism having a sun gear fixed to the housing, a planetary gear that revolves and rotates around the sun gear while meshing with the sun gear, and a carrier that pivotally supports the planetary gear; and The sun gear is placed in parallel in the axial direction and meshes with the planetary gear, and the sun gear is provided with an eccentric gear having a different number of teeth,
The lock type bi-directional, wherein the carrier is connected to the input shaft, and the eccentric gear is connected to the output shaft so as to rotate about an eccentric shaft different from the common rotation center shaft. clutch. The lock-type bidirectional clutch according to claim 1, wherein an eccentric hole centered on the eccentric shaft is formed in the output shaft, and a rotation shaft of the eccentric gear is fitted into the eccentric hole. The housing is a cup-shaped fixing member including a circumferential wall and an end plate, and a central hole through which the output shaft passes and the fixed sun gear are formed in a central portion of the end plate. The lock type bidirectional clutch according to claim 1 or 2. The carrier has a disc shape, and a support shaft that pivotally supports the planetary gear is provided on one surface, and a tip of the support shaft abuts on an end plate of the housing and rotates together with the carrier. The lock-type bidirectional clutch according to claim 3, wherein the lock-type bidirectional clutch is coupled to an input shaft reinforcing plate. The planetary gear mechanism includes a first idle planetary gear that meshes with the sun gear and a second idle planetary gear that meshes with the eccentric gear, and the first idle planetary gear and the second idle planetary gear are connected to the carrier. The lock-type bidirectional clutch according to any one of claims 1 to 4, wherein the lock-type bidirectional clutch is axially supported in parallel with each other.