JP2020104232A - Joint mechanism - Google Patents

Abstract

To provide a joint mechanism that can be suppressed from being enlarged in size as a whole even if increasing torque.SOLUTION: The joint mechanism comprises: a torque generation part 7 that has a first arm 3 and a second arm 5 which are a pair of turning members coupled by a turning shaft 13 to be relatively turnable, a main body part 35 joined to the first arm 3 and a shaft part 37 supported rotatably on the main body part 35, which makes the main body part 35 generate torque in the shaft part 37; a large gear part 9, relatively large and provided integrally in the second arm 5, which performs rotation motion in response to turning of the second arm; and a small gear part 11, relatively small and supported in the shaft part 37 of the torque generation part 7 to be integrally rotatable, which engages with the large gear part 9.SELECTED DRAWING: Figure 1

Description

The present invention relates to a joint mechanism used for joints and hinges of various devices.

As a conventional joint mechanism, for example, there is one applied to the body assisting tool described in Patent Document 1.

In this joint mechanism, a first mounting body and a second mounting body, which are a pair of rotating members, are rotatably connected by a rotating shaft, and are connected to the rotating shaft by a damper as a torque generating portion. As a result, a torque is generated by the damper with respect to the relative rotation of the first mounting body and the second mounting body, and it is possible to suppress the occurrence of impact and the like.

In such a joint mechanism, it may be necessary to increase the torque of the damper depending on the application, but if the torque of the damper is increased, the size of the damper may be increased, which may result in an increase in size as a whole.

When the torque generating unit is used as a drive source such as a motor to rotate the pair of rotating members, there is a problem in that the size of the rotating member is increased.

JP, 2018-166928, A

The problem to be solved is that when the torque of the damper is increased, the size of the damper may increase, which may increase the size of the joint mechanism as a whole.

The present invention, in order to suppress an increase in size as a whole even if the torque is increased, a pair of rotating members that are relatively rotatably coupled by a rotating shaft, and the pair of rotating members. A torque generating portion having a main body portion coupled to one of the main body portion and a shaft portion rotatably supported by the main body portion, for generating a torque in the shaft portion by the main body portion, and the other of the pair of rotating members. A relatively large large gear part that is integrally provided and rotates according to the relative rotation of the other of the rotating members with respect to one of the rotating members, and integrally rotates with the shaft part of the torque generating part. The joint mechanism has the main feature that it is provided with a relatively small small gear portion that is supported so as to mesh with the large gear portion.

In the present invention, since the torque can be increased without increasing the size of the torque generating unit by changing the gear ratio between the large gear portion and the small gear portion, it is possible to increase the overall size even if the torque is increased. It becomes possible to suppress. On the contrary, when it is not necessary to increase the torque, it is possible to reduce the size of the torque generating unit and reduce the size as a whole.

Moreover, since the rotation shafts of the pair of rotation members and the shaft portion of the torque generation portion can be displaced without being coaxial with each other, the rotation shafts of the pair of rotation members and the shaft portion of the torque generation portion are arranged. Thinning can be achieved by overlapping the space.

It is a front view which shows the joint mechanism in an extended state (Example 1). It is a front view showing a joint mechanism in a bent state (Example 1). FIG. 3 is a sectional view taken along line III-III of the joint mechanism in FIG. 1 (Example 1). It is a front view which shows the joint mechanism in an extended state (Example 2). 5 is a sectional view taken along line VV of the joint mechanism in FIG. 4 (Example 2). It is a front view which shows the joint mechanism in an extended state (Example 3).

For the purpose of suppressing the increase in size as a whole even if the torque is increased, a small gear portion is provided on the shaft portion of the torque generating portion that is coupled to one of the pair of rotating members, and a pair of rotating members are provided. It was realized by integrally providing a large gear on the other side.

That is, the joint mechanism is rotatably supported by a pair of rotating members that are relatively rotatably coupled by a rotating shaft, a body portion that is coupled to one of the pair of rotating members, and the body portion. And a torque generating portion for generating torque in the shaft portion by the main body portion, and a relative rotation of one of the rotating members with respect to the other of the rotating members, which is integrally provided on the other of the pair of rotating members. A relatively large large gear portion that rotates in response to the rotation and a relatively small small gear portion that is supported by the shaft portion of the torque generating portion so as to rotate integrally and that meshes with the large gear portion are provided.

The rotation shaft of the large gear portion may be configured to rotate with the rotation shaft of the rotation member as the rotation shaft.

In addition, the joint mechanism has a columnar shape in which one of the pair of rotating members is provided with a pair of opposing plates that are opposed to each other with a space therebetween, and the rotation shaft of the rotating member is located between the opposing plates to maintain the space. The small gear portion may be located between the facing plates, and the large gear portion may mesh with the small gear portion between the facing plates.

The large gear part may be a fan-shaped gear according to the turning range of the pair of turning members.

In addition, the joint mechanism may include a stopper that limits the rotation range between the pair of rotation members and maintains the meshing of the large gear portion and the small gear portion.

On the other hand, the joint mechanism may include a limit sensor that detects the limit of the rotation of the pair of rotation members within the rotation range. In this case, the torque generator generates torque according to the detection by the limit sensor, and maintains the meshing of the large gear portion and the small gear portion.

[Structure of joint mechanism]
1 is a front view showing a joint mechanism in an extended state according to a first embodiment of the present invention, FIG. 2 is a front view showing the joint mechanism in the same flexion state, and FIG. 3 is a III-III joint mechanism of FIG. It is a line sectional view.

The joint mechanism 1 of the present embodiment is applicable to various devices that require a joint function, and is applied to, for example, a robot arm, an assist suit, a rehabilitation device, and the like.

As shown in FIGS. 1 to 3, the joint mechanism 1 includes a first arm 3 and a second arm 5 as a pair of rotating members, a torque generating section 7, a large gear section 9, and a small gear section 11. Equipped with. In the following, the axial direction means the axial direction of the joint mechanism 1 in the extended state, the plate thickness direction is the plate thickness direction of the joint mechanism 1, and the rotation axes of the first arm 3 and the second arm 5 The direction along the heart. The width direction is the width direction of the joint mechanism 1 and is a direction orthogonal to the axial direction and the plate thickness direction.

The first arm 3 and the second arm 5 are rotatably connected by a rotation shaft 13. The rotating member does not have to be in the shape of an arm, and may be of any suitable form depending on the device to which the joint mechanism 1 is applied, as long as it is relatively rotatably coupled. ..

The first arm 3 is one of the pair of rotating members of this embodiment, and includes a pair of facing plates 15 and 17 and a first arm body 19.

The facing plates 15 and 17 are plate-shaped and extend in the axial direction, and are formed in the same shape. The facing plates 15 and 17 are arranged to face each other with a gap in the plate thickness direction. In the facing plates 15 and 17 of the present embodiment, both axial end portions 21 and 23 are formed in an arc shape, and one end portion 21 has a smaller radius of curvature than the other end portion 23. Further, between the end portions 21 and 23, both edge portions in the width direction are linearly continuous and are inclined with respect to the axial direction according to the difference in radius of curvature.

Between the facing plates 15 and 17, the rotary shaft 13 is positioned (interposed) on the one end 21 side, and the first arm body 19 and the spacer 25 are positioned (interposed) on the other end 23 side. Thus, the space between them is maintained.

The rotating shaft 13 is formed in a columnar shape, and both ends thereof are in contact with the inner surfaces 15a and 17a of the facing plates 15 and 17, respectively. The rotating shaft 13 is fastened and fixed between the facing plates 15 and 17 by a fastener 27 such as a screw threaded through the facing plates 15 and 17 from the outer surfaces 15b and 17b of the facing plates 15 and 17. Has been done.

The first arm body 19 has a plate shape that extends in the axial direction with respect to the facing plates 15 and 17, and integrally has a base portion 19a located between the facing plates 15 and 17 on the base end side. The base portion 19a is a plate-shaped body formed in a plane arc shape so as to be along the other end portion 23 of the facing plates 15 and 17 while avoiding the small gear portion 11 described later. The planar shape of the base 19a is not particularly limited as long as it is interposed between the facing plates 15 and 17.

A spacer 25 is laminated on the base portion 19 a of the first arm body 19. The spacer 25 has the same planar shape as the base portion 19 a, and is interposed between the base portion 19 a and the counter plate 17. In this state, the base portion 19a and the spacer 25 are fastened and fixed between the facing plates 15 and 17 by the fastener 29. Although the base portion 19a of the first arm body 19 and the spacer 25 are formed as separate bodies, they can be formed integrally.

The second arm 5 is the other of the pair of rotating members of this embodiment. The second arm 5 includes a plate-shaped second arm body 31 that extends in the axial direction with respect to the facing plates 15 and 17 of the first arm 3. The second arm body 31 integrally includes a base portion 31a on the base end side. The second arm body 31 of this embodiment has the same shape as the first arm body 19, but is longer than the first arm body 19 in the axial direction.

The base portion 31 a of the second arm body 31 has a planar shape that bulges in a substantially arc shape with respect to the second arm body 31, and is arranged between the facing plates 15 and 17 of the first arm 3. The base portion 31a of the second arm main body 31 is provided with a hole portion 31b in the plate thickness direction at the center thereof, and the boss portion 9a of the large gear portion 9 described later is fitted into the hole portion 31b. The rotation shaft 13 on the first arm 3 side is inserted into the hole 9b of the boss 9a. As a result, the second arm 5 is rotatable with respect to the first arm 3, and the first arm 3 is also rotatable with respect to the second arm 5.

The tip of the boss portion 9a of the large gear portion 9 is flush with the surface of the base portion 31a of the second arm body 31, and the washer 32 is provided between the counter plate 15 and the opposite plate 15. A washer 32 is also provided between the large gear portion 9 and the counter plate 17.

Further, a stopper 33 is provided on the base portion 31 a of the second arm body 31. The stopper 33 is provided on the protruding portion 31c of the base portion 31a. The protrusion 31c is located outside the facing plates 15 and 17 of the first arm 3 in the extended state of the joint mechanism 1.

The stopper 33 has a columnar shape protruding from the protruding portion 31c of the base portion 31a of the second arm body 31 in the plate thickness direction, and contacts the outer edge of the facing plate 15 when the joint mechanism 1 is in the extended state.

Therefore, the stopper 33 limits the rotation range of the first arm 3 and the second arm 5, and maintains the meshing state of the large gear portion 9 and the small gear portion 11, which will be described later. The stopper 33 can also be provided on the first arm 3.

For this reason, the stopper 33 is provided between the first arm 3 and the second arm 5 which are rotating members, limits the rotation range between the first arm 3 and the second arm 5, and prevents the large gear portion 9 and the second gear 5 from rotating. It is configured to maintain the meshing of the small gear portion 11. The large gear portion 9 is attached to the base portion 31 a of the second arm body 31.

The torque generator 7 generates torque (load torque or drive torque) with respect to the rotation between the first arm 3 and the second arm 5. The torque generation unit 7 may be any unit that generates at least one of the load torque and the drive torque, and may be, for example, a motor, an electromagnetic clutch, a rotary damper, or the like.

Further, the torque generator 7 is preferably configured to generate torque for the rotation of the first and second arms 3 and 5 through the energization control, but the torque generator 7 may be configured to generate torque by, for example, a one-way clutch. The torque may be generated when the first and second arms 3 and 5 rotate in one direction.

The torque generator 7 has a main body 35 and a shaft 37. The main body portion 35 is a portion that causes the shaft portion 37 to generate a torque, and is formed in a cylindrical shape having a torque generating mechanism (not shown) inside. The body 35 of the torque generator 7 is coupled to the first arm 3.

The body portion 35 can be directly or jointly coupled to the first arm 3. In this embodiment, the main body 35 of the torque generator 7 is attached to the counter plate 17 and directly coupled to the first arm 3. When indirectly coupled to the first arm 3, the main body portion 35 of the torque generator 7 is coupled to another member that is coupled to the first arm 3 so as to rotate integrally.

The attachment of the body portion 35 to the counter plate 17 is performed by a fastener 29 such as a screw. The fastener 29 is inserted through the facing plate 15, the first arm body 19 of the first arm 3, the spacer 25, and the facing plate 17, and is screwed into the body portion 35 of the torque generating unit 7.

The shaft portion 37 is rotatably supported with respect to the main body portion 35, and is connected so as to interlock with a torque generating mechanism inside the main body portion 35. The shaft portion 37 reaches between the facing plates 15 and 17 through the through hole 17c of the facing plate 17 to which the main body portion 35 is attached. The small gear portion 11 is attached to the shaft portion 37 between the facing plates 15 and 17.

The large gear portion 9 is meshed with the small gear portion 11, and torque is applied to the rotation of the first arm 3 and the second arm 5 via the small gear portion 11 and the large gear portion 9.

The large gear portion 9 is a relatively large gear that is provided integrally with the second arm 5 and that performs a rotational operation according to the relative rotation of the second arm 5 with respect to the first arm 3. The large gear portion 9 of the present embodiment is formed separately from the second arm 5 and is attached to the second arm 5 by a fastener 39 such as a screw. However, the large gear portion 9 can also be formed integrally with the second arm 5.

The large gear portion 9 of this embodiment rotates about the rotation shafts 13 of the first arm 3 and the second arm 5 as rotation shafts.

That is, the large gear portion 9 has the boss portion 9a in the central portion, and the boss portion 9a is fitted into the hole portion 31b of the second arm 5 as described above. The rotation shaft 13 on the first arm 3 side is inserted through the hole 9b of the boss 9a as described above.

As a result, the large gear portion 9 rotates around the rotation shaft 13. With this configuration, the rotation axis of the large gear portion 9 and the rotation axis of the second arm 5 can be aligned with each other, or the deviation between the rotation axis and the rotation axis can be suppressed. The boss 9a may be provided on the second arm 5, and the large gear 9 may be provided with a hole 9b into which the boss 9a is fitted.

Further, the large gear portion 9 of the present embodiment is a sector gear according to the rotation range of the first arm 3 and the second arm 5.

The large gear portion 9 meshes with the small gear portion 11 between the facing plates 15 and 17 of the first arm 3.

The small gear portion 11 is a relatively small gear that is supported by the shaft portion 37 of the torque generating portion 7 so as to rotate integrally therewith and meshes with the large gear portion 9. The small gear portion 11 of this embodiment is a cylindrical gear.

According to the gear ratio between the small gear portion 11 and the large gear portion 9, the torque generated in the shaft portion 37 of the torque generating portion 7 is decelerated and transmitted to the second arm 5.

[Motion of joint mechanism]
The joint mechanism 1 of the present embodiment has a damping operation when the first arm 3 and the second arm 5 relatively rotate, and a first arm 3 and a second arm 5 when the torque generator 7 is a motor or the like. It is possible to perform a driving operation of relatively rotating the.

During the damping operation, a load torque is generated by the torque generator 7 with respect to the rotation of the first arm 3 and the second arm 5 by the external force. Note that the load torque is generated, for example, during the transition from the extended state of FIG. 1 to the bent state of FIG. 2, the transition of the bent state of FIG. 2 to the extended state of FIG. Can be done. These may be appropriately set according to the device to which the joint mechanism 1 is applied.

When the first arm 3 and the second arm 5 rotate relative to each other when the load torque is generated, the large gear portion 9 rotates in response to the rotation of the second arm 5, and the large gear portion 9 is rotated. The rotation operation of 9 causes the small gear portion 11 to rotate together.

Therefore, the load torque of the torque generator 7 is decelerated from the shaft 37 via the small gear 11 and the large gear 9, so that the second arm 5 brakes the relative rotation with respect to the first arm 3. Entered in.

Therefore, in the joint mechanism 1 of this embodiment, if a small load torque corresponding to the gear ratio of the small gear portion 11 and the large gear portion 9 is generated in the torque generation portion 7, the first arm 3 and the second arm 5 are connected. Rotation can be damped.

In addition, after the rotation of the first arm 3 and the second arm 5 is stopped or when the stopped state continues (for example, when the first arm 3 and the second arm 5 stop in the bent state of FIG. 2), the damping operation is performed. It is also possible to lock the first arm 3 and the second arm 5 so as not to rotate them.

Further, when the bent state of FIG. 2 is changed to the extended state of FIG. 1, the stopper 33 of the second arm 5 contacts the first arm 3 so that the large gear portion 9 is a sector gear and the small gear. The engagement with the portion 11 can be maintained.

On the other hand, in the case of the driving operation, the torque generating section 7 causes the main body section 35 to generate the driving torque by the energization control. The generated drive torque causes the small gear portion 11 to rotate via the shaft portion 37 of the torque generation portion 7. The rotation operation of the small gear portion 11 causes the large gear portion 9 to rotate in association with each other, and the second arm 5 rotates with respect to the first arm 3 in accordance with the rotation of the large gear portion 9.

Therefore, in the joint mechanism 1 of the present embodiment, if a small driving torque corresponding to the gear ratio of the small gear portion 11 and the large gear portion 9 is generated by the torque generating portion 7, the first arm 3 and the second arm 5 are separated from each other. It can be driven and rotated.

During such a damping operation and a driving operation, the large gear portion 9 rotates about the rotation shaft 13 of the second arm 5 as a rotation axis, so that an unreasonable force acts on the engagement between the large gear portion 9 and the small gear portion 11. Instead, the small gear portion 11 can be smoothly rotated in conjunction with the large gear portion 9.

[Effect of Example 1]
The joint mechanism 1 of this embodiment is connected to the first arm 3 and a first arm 3 and a second arm 5 which are a pair of rotating members that are relatively rotatably connected by a rotating shaft 13. The main body portion 35 and the shaft portion 37 rotatably supported by the main body portion 35 are provided, and the torque generation portion 7 that causes the shaft portion 37 to generate a torque by the main body portion 35 and the second arm 5 are integrally provided. A relatively large large gear portion 9 that rotates in response to the rotation of the second arm, and a relatively large gear portion 9 supported by the shaft portion 37 of the torque generating portion 7 so as to rotate integrally therewith and meshed with the large gear portion 9. And a small small gear portion 11.

Therefore, in the present embodiment, the torque (load torque or drive torque) generated in the torque generating unit 7 can be increased according to the gear ratio between the large gear unit 9 and the small gear unit 11, so that the torque is increased. However, it is possible to suppress the increase in size of the joint mechanism 1 as a whole.

On the contrary, when it is not necessary to increase the torque, the size of the joint mechanism 1 as a whole can be reduced by reducing the size of the torque generating unit 7 while maintaining the gear ratio between the large gear unit 9 and the small gear unit 11. Is possible.

Further, in the joint mechanism 1 of the present embodiment, the rotating shaft 13 of the first arm 3 and the second arm 5 and the shaft portion 37 of the torque generating portion 7 can be displaced without being coaxial with each other. 3 and the rotation shaft 13 of the second arm 5 and the shaft portion 37 of the torque generating portion 7 can overlap each other to reduce the thickness.

In addition, in the joint mechanism 1 of the present embodiment, since the large gear portion 9 rotates about the rotation shaft 13 of the first arm 3 and the second arm 5, the rotation of the first arm 3 and the second arm 5 is performed. By using the shaft 13 as the rotation shaft of the large gear portion 9 as well, it is possible to suppress the increase in size.

Moreover, it is possible to suppress the deviation between the rotation axis of the first arm 3 and the second arm 5 and the rotation axis of the large gear portion 9, and to rotate the large gear portion 9 and the large gear portion 9 and the small gear. Unreasonable force does not act on the meshing operation with the portion 11, and the large gear portion 9 and the small gear portion 11 can smoothly rotate in association with each other.

Therefore, in the present embodiment, even when the torque of the torque generator 7 is increased by the large gear portion 9 and the small gear portion 11, the accuracy and smoothness of the operation of the joint mechanism 1 can be ensured and the durability can be improved. The deterioration of sex can be suppressed.

Further, the joint mechanism 1 of the present embodiment is provided with a pair of facing plates 15 and 17 in which the first arm 3 is arranged to face each other with a gap, and the rotating shafts 13 of the first arm 3 and the second arm 5 face each other. It is located between the plates 15 and 17 and has a columnar shape for maintaining a space, the small gear portion 11 is located between the facing plates 15 and 17, and the large gear portion 9 is located between the facing plates 15 and 17 with respect to the small gear portion 11. Mesh with each other.

Therefore, in the joint mechanism 1 of the present embodiment, the meshing portions of the large gear portion 9 and the small gear portion 11 can be protected by the facing plates 15 and 17. Moreover, since the space between the facing plates 15 and 17 is held by using the rotary shaft 13, the structure can be simplified. Further, in the present embodiment, the small gear portion 11 and the large gear portion 9 can be provided by utilizing the space between the facing plates 15 and 17 on which the rotating shafts 13 of the first arm 3 and the second arm 5 are arranged. Therefore, it is possible to more reliably realize thinning and miniaturization.

Since the large gear portion 9 is a fan-shaped gear corresponding to the rotation range of the first arm 3 and the second arm 5, the joint mechanism 1 can be more reliably downsized.

Since the joint mechanism 1 of this embodiment includes the stopper 33 between the first arm 3 and the second arm 5 that limits the rotation range and maintains the meshing of the large gear portion 9 and the small gear portion 11, the large gear portion is provided. Even if 9 is a sector gear, meshing between the large gear portion 9 and the small gear portion 11 can be maintained, and the stability of operation can be ensured.

FIG. 4 is a front view showing the joint mechanism in the extended state according to the second embodiment of the present invention, and FIG. 5 is a sectional view taken along line VV of the joint mechanism of FIG. Since the basic structure of the second embodiment is the same as that of the first embodiment, the corresponding components are designated by the same reference numerals and the duplicate description will be omitted.

In the joint mechanism 1 of the present embodiment, the large gear portion 9 meshes with the small gear portion 11 via the intermediate gear portion 41. Further, in the present embodiment, the rotating shaft 13 has the boss portion 13a, and the main body portion 35 of the torque generating portion 7 has the fitting portion 35a. Others are the same as those in the first embodiment.

The boss portion 13a of the rotary shaft 13 is provided so as to project from both sides of the rotary shaft 13, and is fitted into the fitting holes 15c and 17c of the counter plates 15 and 17, respectively. Therefore, in this embodiment, the positioning accuracy of the rotary shaft 13 can be improved. As a result, the interlocked rotation of the large gear portion 9 and the small gear portion 11 can be performed more reliably and smoothly. The boss portion 13a can be applied to the rotating shaft 13 of the first embodiment.

The fitting portion 35 a of the torque generating portion 7 is formed in a boss shape integral with the main body portion 35 on the base side of the shaft portion 37. The outer circumference of the fitting portion 35a is fitted to the inner circumference of the through hole 17c of the counter plate 17 of the first arm 3. As a result, the small gear portion 11 can be reliably positioned with respect to the large gear portion 9. The fitting portion 35a can also be applied to the torque generator 7 of the first embodiment.

The intermediate gear portion 41 is rotatably supported by a rotary shaft 43 at an axial intermediate portion of the facing plates 15 and 17 of the first arm 3. The rotating shaft 43 has support shaft portions 43a protruding from both sides. The rotary shaft 43 is supported by fitting the support shaft portions 43a on both sides into the support hole portions 15d and 17d of the facing plates 15 and 17, respectively.

The intermediate gear portion 41 integrally includes an intermediate small gear portion 45 that meshes with the large gear portion 9 and an intermediate large gear portion 47 that meshes with the small gear portion 11.

Therefore, in the second embodiment, since the intermediate gear portion 41 is provided between the large gear portion 9 and the small gear portion 11, a higher gear ratio can be obtained, and the torque of the torque generating portion 7 is increased or the torque is increased. It is possible to further reduce the size of the generation unit 7.

In addition, also in the second embodiment, the same operational effect as that of the first embodiment can be obtained.

FIG. 6 is a front view showing the joint mechanism in the extended state according to the third embodiment of the present invention. Since the basic structure of the third embodiment is the same as that of the first embodiment, the same reference numerals are given to the corresponding configurations and the duplicated description will be omitted.

The joint mechanism 1 according to the present embodiment includes a limit sensor 49 for rotating the first arm 3 and the second arm 5. Accordingly, in this embodiment, the stopper 33 of the second arm 5 and the protrusion 31c of the base 31a are omitted. Others are the same as those in the first embodiment.

The limit sensor 49 detects the limit of the rotation of the first arm 3 and the second arm 5 within the rotation range. The limit within the rotation range here is a limit at which the large gear portion 9 and the small gear portion 11 can maintain meshing. The limit sensor 49 is composed of, for example, a limit switch, and the circuit closes at or near the limit of the rotation range of the first arm 3 or the second arm 5. Note that FIG. 6 conceptually shows only the vicinity of the second arm 5 of the joint mechanism 1 in the extended state.

The torque generator 7 generates torque according to the detection by the limit sensor 49 to maintain the meshing of the large gear portion 9 and the small gear portion 11. For example, when transitioning from the flexed state to the extended state, the energization of the torque generating unit 7 is controlled by the detection by the limit sensor 49, and the rotation between the first arm 3 and the second arm 5 is stopped or the second arm 5 is stopped. The arm 5 is returned to the first arm 3 in the bending direction.

On the other hand, even if an abnormality occurs in the limit sensor 49, the engagement between the large gear portion 9 and the small gear portion 11 is disengaged so that unintended torque is prevented from occurring between the first arm 3 and the second arm 5. be able to.

In addition, also in the third embodiment, the same operational effect as that of the first embodiment can be obtained.

1 Joint Mechanism 3 First Arm (One of Rotating Members)
5 Second arm (other side of rotating member)
7 Torque Generating Section 9 Large Gear Section 11 Small Gear Section 13 Rotating Shafts 15, 17 Opposing Plate 33 Stopper 35 Main Body Section (Torque Generating Section)
37 Shaft (torque generator)
49 limit sensor

Claims (6)

A pair of rotating members that are relatively rotatably coupled by a rotating shaft;
A torque generating unit that has a main body unit coupled to one of the pair of rotating members and a shaft unit that is rotatably supported by the main body unit, and that generates torque in the shaft unit by the main body unit
A relatively large large gear portion that is integrally provided on the other of the pair of rotating members and that performs a rotating operation according to the relative rotation of the other of the rotating members with respect to one of the rotating members;
A relatively small gear part which is supported by the shaft part of the torque generating part so as to rotate integrally and meshes with the large gear part;
A joint mechanism characterized by having. The joint mechanism according to claim 1, wherein
The large gear portion rotates about a rotation shaft of the rotation member as a rotation shaft,
A joint mechanism characterized in that The joint mechanism according to claim 2, wherein
One of the pair of rotating members includes a pair of facing plates that are arranged to face each other with a gap,
The rotating shaft of the rotating member is a pillar that is located between the facing plates and holds the gap,
The small gear portion is located between the facing plates,
The large gear portion meshes with the small gear portion between the facing plates,
A joint mechanism characterized in that The joint mechanism according to any one of claims 1 to 3,
The large gear portion is a fan-shaped gear corresponding to the rotation range of the pair of rotation members,
A joint mechanism characterized in that The joint mechanism according to claim 4, wherein
A stopper for limiting the rotation range between the pair of rotation members to maintain meshing of the large gear portion and the small gear portion,
A joint mechanism characterized in that The joint mechanism according to claim 4, wherein
A limit sensor for detecting a limit within the rotation range for rotation of the pair of rotation members,
The torque generation unit generates the torque according to the detection by the limit sensor to maintain the meshing of the large gear unit and the small gear unit,
A joint mechanism characterized in that

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