JP2018089284A - Assisting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve miniaturization and cost reduction in an assisting device.SOLUTION: An assisting device 10 assists a motion of a joint between a first part and a second part in a human body. The device includes: a first member 21 to be mounted on a first part; a second member 22 to be mounted on a second part; and a speed reducer 40 to be provided between the first member 21 and the second member 22. The speed reducer 40 includes: a housing 45 and a motor housing 48 as fixing members to be connected to the first member 21; a spacer 46 and an internal gear 43 as output members to be connected to the second member 22; and a second bearing 47 as a main bearing to be arranged between the housing 45 as a fixing member and the internal gear 43 as an output member. The second bearing 47 as a main bearing is constituted by one single-row roller bearing or a slide bearing.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an assist device that assists movement of a joint.

Development of an assist device that assists the movement of a joint of an elderly person or a disabled person is in progress.
Conventionally, a wearable assist device worn by a user has been proposed (see, for example, Patent Document 1).
This conventional assist device has a waist fastening member to be worn on the user's waist and a leg auxiliary frame suspended from the waist fastening member via a joint.
The leg auxiliary frame is attached to a user's leg, and a motor and a speed reducer are built in the joint.
And rotation operation | movement was provided to the leg part auxiliary | assistant frame from the motor, and the user's walk operation assistance was performed.

JP 2010-75548 A

Since such an assist device is assumed to be worn on the human body, there has been a high demand for miniaturization so as not to burden the user.
In addition, there is a high demand for cost reduction because it is necessary to spread the assist device more widely due to the recent increase in the elderly population.

  An object of the present invention is to reduce the size and cost of an assist device.

  The present invention is an assist device for assisting movement of a joint between a first part and a second part of a human body, the first member being attached to the first part, and the second member being attached to the second part And a speed reducer interposed between the first member and the second member, the speed reducer being connected to the first member and a fixing member connected to the second member An output member, and a main bearing disposed between the fixed member and the output member, and the main bearing is constituted by one single-row rolling bearing.

  According to the present invention, it is possible to reduce the size and cost of the assist device.

1 is an exploded perspective view of an assist device according to an embodiment of the present invention. It is sectional drawing along the joint centerline of a joint unit. It is the front view which looked at the spacer of the reduction gear from the joint centerline direction. It is a perspective view of the spacer of a reduction gear.

[Outline of assist device]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view of an assist device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along a joint centerline O of a joint unit described later.

  The assist device 10 according to the embodiment of the present invention provides torque for performing a rotation operation on a predetermined part of a specific joint of a human body, and assists the rotation operation of the user's joint. Is.

  As shown in FIG. 1, the assist device 10 assists the movement of the left hip joint. The assist device 10 includes a first member 21, a second member 22, and a joint unit 30.

The first member 21 is disposed on the left side of the waist as the first part of the human body.
The first member 21 includes a fixed-side annular portion 211, a first extending portion 212, and a first arc plate 213, which are integrally formed.

  The fixed-side annular portion 211 has a circular annular shape, and the first extending portion 212 described above extends from one end of the outer edge portion toward the radially outer side. The fixed side annular portion 211 has a plurality of counterbore holes penetrating in the thickness direction along the circumferential direction. The fixed-side annular portion 211, the housing 45 described later, and the external gear 42 described later are all concentric with the joint center line O as the center by a plurality of bolts 485 passed through each counterbore. In the state, it is fastened and fixed to the motor housing 48.

The first extending portion 212 is plate-shaped, and a first arc plate 213 is provided at the extending end portion. When the assist device 10 is used, the first extension part 212 is arranged on the left side of the user's waist with the extension end part facing upward.
In addition, as shown in FIG. 2, the first extending portion 212 is bent in a crank shape at the base portion on the fixed-side annular portion 211 side so that the extending end portion approaches the human body. .

  The first arc plate 213 is a plate-like body that is curved in an arc shape when viewed from the extending direction of the first extending portion 212. When the first extending portion 212 is placed along the left side surface of the waist, the inside of the arc of the first arc plate 213 is in close contact with the waist. Then, the first arc plate 213 is fixed to a waist belt (not shown) wound around the waist of the human body, and the first member 21 can be put on.

The second member 22 is disposed on the left side of the thigh as the second part of the human body.
The second member 22 includes a movable-side annular portion 221, a second extending portion 222, and a second arc plate 223, which are integrally formed.

  The movable-side annular portion 221 has a circular annular shape, and the second extending portion 222 described above extends from one end of the outer edge portion toward the radially outer side. As shown in FIG. 2, the movable-side annular portion 221 has a plurality of counterbore holes penetrating in the thickness direction along the circumferential direction. The movable side annular portion 221 and a spacer 46 described later are connected in a concentric state with the joint center line O as the center by a plurality of bolts 464 passed through each counterbore.

The second extending portion 222 is plate-shaped, and a second arc plate 223 is provided at the extending end portion. When the assist device 10 is used, the second extending portion 222 is disposed on the left side surface of the user's thigh with the extending end directed downward.
Further, as shown in FIG. 2, the second extending portion 222 is disposed on the human body side in the direction along the joint centerline O with respect to the first extending portion 212 described above, and therefore the first extending portion 222 Like the projecting portion 212, it extends straight without being bent into a crank shape.

  The second arc plate 223 is a plate-like body that is curved in an arc shape when viewed from the extending direction of the second extending portion 222. When the second extending portion 222 is placed along the left side surface of the thigh, the inner side of the arc of the second arc plate 223 is in close contact with the thigh. And the 2nd circular arc board 223 is fixed to the thigh belt (not shown) wound around the thigh of a human body, and can make the 2nd member 22 into a mounting state.

[Details of joint unit]
As described above, the fixed-side annular portion 211 of the first member 21 and the movable-side annular portion 221 of the second member 22 are both concentrically connected to the joint unit 30 so that the joint center line O is the center. ing.
Then, the joint unit 30 gives the second member 22 a turning operation around the joint centerline O. Thereby, in a state where the assist device 10 is mounted on the human body, the second member 22 can be relatively rotated in the front-rear direction of the human body. That is, with respect to the pelvis, which is the upper skeleton part of the left hip joint of the human body, the second member 22 is arranged with respect to the first member 21 in a direction in which the skeleton part of the thigh bends and extends back and forth around the hip joint. Relative rotation is possible.

  The joint unit 30 includes a hollow motor 31 and a speed reducer 40 in order to apply a torque of relative rotation between the first member 21 and the second member 22 described above.

  The hollow motor 31 includes an output shaft 311 (an input shaft of the speed reducer 40) on the joint center line O, and a disc-shaped mounting plate for coupling to the speed reducer 40 is provided at the tip of the output shaft 311. 312 is integrally formed.

The speed reducer 40 is a so-called flexibly meshing gear device, and reduces the rotational output of the hollow motor 31 and transmits it to the second member 22.
As shown in FIG. 2, the speed reducer 40 includes an eccentric cam 41 as a vibrating body, an external gear 42 as a bending gear, an internal gear 43, a first bearing 44, a housing 45, and a spacer 46. A second bearing 47 as a main bearing, and a motor housing 48. The motor housing 48 can be regarded as a constituent member of the hollow motor 31 instead of the speed reducer 40.

The motor housing 48 includes a cylindrical sleeve 481 that houses the hollow motor 31, and a bottom plate 482 that closes one end of the sleeve 481. The sleeve 481 and the bottom plate 482 are connected by a plurality of bolts 483.
The hollow motor 31 is fastened and fixed to the bottom plate 482 with bolts 484. The output shaft 311 of the hollow motor 31 is stored so as to face the opening end side (the side opposite to the bottom plate 482) of the motor housing 48.

The internal gear 43 is a cylindrical gear having rigidity, and a plurality of tooth portions are formed on the inner circumference along the entire circumference. The internal gear 43 has a perfect circle shape on both the inner periphery (the pitch circle of the gear) and the outer periphery.
Inside the internal gear 43, an external gear 42, a first bearing 44, and an eccentric cam 41 are arranged in order toward the inside, and these are all centered (axial center) on the joint center line O. Are concentric to be located.

  The eccentric cam 41 is a plate-like rigid body having rigidity, and has a cam surface eccentric about the joint center line O on the outer periphery thereof. The cam surface has a curvature that is eccentric in the circumferential direction around the joint centerline O, but has no curvature in the axial direction of the joint centerline O. The cross-sectional shape perpendicular to the axis of the cam surface is, for example, a shape close to an ellipse having a major axis and a minor axis. The midpoint of the long axis and the midpoint of the short axis intersect on the joint centerline O. The long shaft has a length for meshing the external gear 42 and the internal gear 43, while the short shaft has a length for separating the external gear 42 and the internal gear 43 so as not to mesh.

  The eccentric cam 41 is connected by a plurality of bolts 313 to the mounting plate 312 provided on the output shaft 311 of the hollow motor 31 described above. As a result, the eccentric cam 41 is rotated by the hollow motor 31 around the joint centerline O.

  The external gear 42 is a flexure gear that bends and deforms and meshes with the internal gear 43, and is configured to be flexibly deformable in a direction in which the curvature in the circumferential direction is changed. The external gear 42 is integrally formed with a cylindrical base portion 421, a flange portion 422 that extends radially outward from one end portion of the base portion 421, and an annular attachment portion 423 provided on the outer periphery of the flange portion 422. ing. In other words, the speed reducer 40 constitutes a so-called top hat type flexure meshing gear device in which the external gear 42 has a top hat shape.

The base portion 421 and the flange portion 422 have flexibility by thinning, and the attachment portion 423 has rigidity that does not easily deform due to a certain thickness.
On the outer periphery of the cylindrical base portion 421, a plurality of teeth are formed along the entire periphery, and the eccentric cam 41 is disposed inside the base portion 421 via the first bearing 44. When the eccentric cam 41 rotates relatively inside the base portion 421, a plurality of teeth on the outer periphery of both ends of the long axis can mesh with the teeth of the internal gear 43. Further, the plurality of teeth around the outer ends of both ends of the short shaft of the eccentric cam 41 do not reach the teeth of the internal gear 43 and cannot be engaged with each other.

The attachment portion 423 has a perfect circular shape, and the inner diameter and the outer diameter thereof substantially coincide with the inner diameter and the outer diameter of the sleeve 481 of the motor housing 48.
A plurality of through holes penetrating in the thickness direction are formed in the attachment portion 423 along the circumferential direction. The attachment portion 423 is fixed to the sleeve 481 of the motor housing 48 in a fastening state by the bolts 485 that are passed through the through-holes together with the stationary-side annular portion 211 of the first member 21 and the housing 45 described above. That is, the housing 45 and the motor housing 48 function as a “fixing member connected to the first member”.

  The base portion 421 of the external gear 42 is bent so as to follow the outer peripheral shape of the eccentric cam 41, while the attachment portion 423 is fixed to the motor housing 48 and is not deformed. The flange portion 422 acts so that the mounting portion 423 does not hinder the bending of the base portion 421 due to its flexibility.

The first bearing 44 is interposed between the external gear 42 and the eccentric cam 41 and regulates the base portion 421 of the external gear 42 to a shape along the eccentric cam surface of the eccentric cam 41, while the external gear. This is to realize the relative rotational movement between the cam 42 and the eccentric cam 41 with a small resistance.
The first bearing 44 is, for example, a deep groove ball bearing, and includes a cylindrical outer ring 441, a plurality of balls 442, and a cage 443 that holds the intervals between the plurality of balls 442. The outer peripheral cam surface of the eccentric cam 41 is in contact with the inner side of the first bearing 44, and the inner peripheral surface of the base portion 421 of the external gear 42 is in contact with the outer side of the first bearing 44.

The outer ring 441 has a high hardness with respect to a force compressing in the thickness direction, and is formed of a member that can be elastically deformed in a direction in which the circumferential curvature is changed. The outer ring 441 comes into contact with the inner peripheral surface of the base portion 421 of the external gear 42 and bends and deforms integrally with the base portion 421, and rotates integrally with the external gear 42 when the external gear 42 rotates.
The first bearing 44 may have an inner ring that is elastically deformable between the plurality of balls 442 and the eccentric cam 41.
The first bearing 44 is not limited to a deep groove ball bearing, and may be another bearing such as a roller bearing or a needle roller bearing.

The housing 45 is a rigid cylinder, and from the side far from the opening end of the sleeve 481 of the motor housing 48, the fixed-side annular portion 211 of the first member 21, the housing 45, and the attachment portion 423 of the external gear 42. The bolts 485 are fastened and fixed in this order.
The housing 45 has an internal gear 43 on the inner side in the radial direction, and is rotatably supported through one second bearing 47.

  The second bearing 47 is composed of a single-row deep groove ball bearing including an inner ring, an outer ring, a plurality of balls, and a ball cage (not shown). Both the inner ring and the outer ring have moderate rigidity that is not easily bent. And the inner periphery of an inner ring | wheel is attached to the outer periphery of the internal gear 43, and these rotate together. Moreover, the outer periphery of the outer ring is attached to the inner periphery of the housing 45, and these are integrated in the rotation direction. Therefore, the relative rotation of the internal gear 43 with respect to the housing 45 is smoothly performed by the second bearing 47.

  A ring-shaped oil seal 49 is provided between the housing 45 and the internal gear 43 and outside the second bearing 47 in the direction (axial direction) along the joint centerline O (on the second member 22 side). Is inserted.

3 is a front view of the spacer 46 as viewed from the direction of the joint centerline O (on the hollow motor 31 side), and FIG. 4 is a perspective view.
As shown in the figure, the spacer 46 has a cylindrical main body 461 whose one end is closed, and a flange 462 extending radially outward from one end of the main body 461, which are integrated. Is formed.
The main body 461 is formed with a plurality of through-holes penetrating along the center line direction (axial direction) of the spacer 46 in the circumferential direction, and the spacer 46 is formed by bolts 463 passed through the through-holes. It is connected to the outside (human body side) of the internal gear 43 in a concentric state with the tooth gear 43.

  The flange portion 462 is formed with a plurality of screw holes penetrating along the center line direction of the spacer 46 (coincident with the direction of the joint center line O) in the circumferential direction. The movable-side annular portion 221 of the two members 22 is concentrically connected to the outer side (human body side) of the flange portion 462. That is, the spacer 46 and the internal gear 43 that are integrally connected to the second member 22 on the output side function as “an output member that is connected to the second member”.

In addition, in the innermost peripheral portion of the flange portion 462, two thin portions 465 and two punch holes 466 are alternately formed in the circumferential direction.
The thin portion 465 is formed to have a thinner thickness in the direction along the joint center line O than the periphery, for example, other portions of the flange portion 462 or the main body portion 461.
The punch hole 466 is a long hole that penetrates the flange portion 462 in a direction along the joint centerline O.
The thin-walled portion 465 and the punched hole 466 are both arc-shaped when viewed from the joint center line O, and surround the main body 461 by the two thin-walled portions 465 and the two punched holes 466.

The two thin portions 465 and the two through holes 466 constitute a “fragile portion that is easily broken by an external load smaller than other portions of the speed reducer”.
The external load here refers to a moment around the joint centerline O acting on the spacer 46 applied from the second member 22 side and a moment acting around the diameter direction around the joint centerline O.
If the load resistance strength of the fragile portion composed of the thin portion 465 and the two through holes 466 is exceeded by these moments, the thin portion 465 is broken or broken. On the other hand, each of the components other than the spacer 46 of the speed reducer 40 has a high load bearing strength based on the moment, and thus can be prevented from being damaged.

[Technical significance of the second bearing]
For example, in the case of a general speed reducer incorporated in the joint of a robot arm of an industrial robot, it is highly likely to receive an external load from the output side, and supports a member that is integrally connected to the configuration on the output side. The bearing is required to have durability against an external load.
The load acting on the bearing due to the external load from the output side includes radial load (in the radial direction of the bearing), axial load (in the direction of the center of rotation of the bearing), and moment load (in the direction of rotation about the diameter of the bearing's rotation). ).
In order to make the moment load durable, it is only necessary to support the member integrally connected to the output side configuration with two bearings separated from each other in the rotation center line direction. Large size in the axial direction occurs.
On the other hand, special and expensive bearings such as cross roller bearings are required to provide durability for all of the above radial load, axial load, and moment load with a single bearing, avoiding an increase in cost of the reducer. I can't.

  In the case of a robot arm, it is necessary to support the weight of the tip part from the joint, and a load based on the weight of the tool or the object to be transported is generated from the arm tip part. Since the posture can be taken, a large load can be generated for all of the radial load, the axial load, and the moment load.

  However, in the case of the speed reducer 40 incorporated in the joint of the assist device 10, it is only necessary to support the weight of the second member 22 on the distal end side (output side) from the joint. No heavy load is mounted, and the orientation and posture of the joint are almost constant. For this reason, the load acting on the bearing is exclusively a radial load, and the axial load and moment load are much smaller than this. Moreover, the radial load is also small.

In the speed reducer 40, the spacer 46 corresponds to “a member integrally connected to the configuration on the output side (output member)”, and the second bearing 47 serves as the “bearing (main bearing) for supporting the member”. Is applicable.
As described above, since the load acting on the second bearing 47 is small, one single-row rolling bearing can be used mainly for the purpose of supporting rotation. An example of a single row rolling bearing is a deep groove ball bearing.

As the single row type rolling bearing, in addition to the single row deep groove ball bearing, a single row cylindrical roller bearing, a single row needle roller bearing and the like are suitable.
It does not include double-row bearings, expensive angular bearings, tapered roller bearings, self-aligning bearings, and cross roller bearings. Also, general thrust bearings are not included.
In addition to a single row rolling bearing, a sliding bearing may be used. The sliding bearing is not required to be an independent member as a single bearing. For example, the outer peripheral surface of the internal gear 43 is in direct sliding contact with the inner peripheral surface of the housing 45, and the sliding bearing is provided between them. The case where it comprises is also included. In this case, it is preferable to apply a lubricant such as grease to the sliding surface of both.

[Operation of assist device]
Next, the operation of the assist device 10 will be described.
On the left side of the user's waist, the first arc plate 213 is fixed to the waist of the human body with a waist belt with the first extension 212 facing upward and the second extension 222 facing downward. The second arc plate 223 is fixed to the thigh of the human body with a thigh belt and attached.
Then, the joint unit 30 gives the second member 22 a turning operation around the joint center line O by driving the hollow motor 31. As a result, the second member 22 is rotated in the front-rear direction of the user, and the skeletal portion of the thigh is bent and extended back and forth around the hip joint with respect to the human pelvis to assist the user's walking motion and the like. can do.

  At this time, in the speed reducer 40, when the eccentric cam 41 rotates by driving the hollow motor 31, the movement of the eccentric cam 41 is transmitted to the base portion 421 of the external gear 42 via the first bearing 44. Since the base 421 of the external gear 42 is fixed to the housing 45 and the motor housing 48 so as not to rotate, the external gear 42 does not rotate following the rotation of the eccentric cam 41, and the external gear 42. The base portion 421 can obtain a movement in which the bulging position of the long axis portion goes around following the outer peripheral shape of the rotating eccentric cam 41. The cycle of this rotation is proportional to the high-speed rotation cycle of the eccentric cam 41.

As described above, when the base 421 of the external gear 42 is deformed by the rotation of the eccentric cam 41, the meshing position of the external gear 42 and the internal gear 43 changes in the rotation direction according to the rotation of the long axis of the eccentric cam 41. . Here, if there is a difference in the number of teeth between the external gear 42 and the internal gear 43, the tooth portion of the external gear 42 and the tooth portion of the internal gear 43 that are meshed each time the meshing position makes one round. Since the correspondence relationship shifts, relative rotation occurs between the external gear 42 and the internal gear 43. Here, since the external gear 42 is fixed, the internal gear 43 rotates.
For example, if the number of teeth of the internal gear 43 is 102 and the number of teeth of the external gear 42 is 100, the rotational motion of the eccentric cam 41 is decelerated at a reduction ratio 102: 2 and transmitted to the internal gear 43. .
As a result, the second member 22 is given a decelerated turning motion.

[Spacer replacement]
As described above, the spacer 46 of the speed reducer 40 includes the thin portion 465 and the punched hole 466 that are fragile portions. Therefore, when a large external load is applied from the second member 22, the thin portion 465 is damaged or broken.
When the thin portion 465 is broken and the main body portion 461 and the flange portion 462 of the spacer 46 are completely separated, the spacer 46 is replaced by the following procedure.
(1) Unfasten the waist belt and remove the first member 21 from the user's waist. Thereby, components other than the flange part 462 of the spacer 46 of the 1st member 21, the hollow motor 31, and the reduction gear 40 are removed.
(2) Next, the thigh belt is unwound and the second member 22 is removed from the user's thigh. Thereby, the flange part 462 of the 2nd member 22 and the spacer 46 is removed.
(3) Next, all bolts 464 are loosened and removed, and the flange portion 462 of the spacer 46 is removed from the second member 22.
(4) Next, all the bolts 463 are loosened and removed, and the main body 461 of the spacer 46 is removed from the internal gear 43.
(5) Next, all bolts 463 are fastened, and a new spacer 46 is attached to the internal gear 43.
(6) Next, all the bolts 464 are fastened, and the second member 22 is attached to the new spacer 46. Thereby, the replacement work of the spacer 46 is completed, and the assist device 10 can be used again.

If the thin portion 465 is damaged but is not broken and the main body portion 461 and the flange portion 462 of the spacer 46 are not separated, the spacer 46 is replaced by the following procedure.
(1) Unfasten the thigh belt and remove the second member 22 from the user's thigh. However, since the spacer 46 is not broken, the second member 22 is still connected to the joint unit 30.
(2) Next, the waist belt is unwound and the first member 21 is removed from the user's waist. Thereby, the whole structure of the assist apparatus 10 is removed.
(3) Next, all the bolts 463 are loosened and removed, the spacer 46 is separated from the internal gear 43, and the spacer 46 and the second member 22 are removed.
(4) Next, all the bolts 464 are loosened and removed, and the damaged spacer 46 is removed from the second member 22.
(5) Next, all the bolts 464 are fastened and a new spacer 46 is attached to the second member 22.
(6) Next, all the bolts 463 are fastened, the new spacer 46 is connected to the internal gear 43, and the second member 22 and the spacer 46 are attached. Thereby, the replacement work of the spacer 46 is completed, and the assist device 10 can be used again.

[Technical effects of assist device]
The speed reducer 40 of the assist device 10 is disposed between a housing 45 that constitutes a fixed member connected to the first member 21 and an internal gear 43 that constitutes an output member connected to the second member 22. The second bearing 47 is constituted by one single row type rolling bearing.
In the case of the assist device, since the acting load is very small, the rotation can be stably supported by one single row type rolling bearing.

Furthermore, since the second bearing 47 is constituted by one single row type rolling bearing, it is possible to reduce the size of the speed reducer 40 and consequently the size of the assist device 10 as a whole.
Further, since the second bearing 47 is constituted by one single-row rolling bearing, a special and expensive bearing can be eliminated, and the cost of the assist device 10 can be reduced. In particular, when the second bearing 47 is formed of a deep groove ball bearing that is more widely used in the world, the ease of manufacturing the assist device 10 can be improved due to further cost reduction and availability.
Further, the same effect as described above can be obtained when the second bearing 47 is constituted by a single sliding bearing.

  Further, since the speed reducer 40 of the assist device 10 is composed of a flexure meshing gear device, unlike the speed reducer made of a spur gear, it is easy to downsize, and the assist device can be further downsized. It becomes possible. Further, the backlash can be reduced by the gears, and a highly accurate and smooth assist operation can be realized.

Furthermore, since the speed reducer 40 of the assist device 10 is provided with the thin portion 465 and the punched hole 466 as weak portions in the spacer 46, when an external load is applied from the second member 22 side, Vulnerable parts are destroyed with priority. For this reason, an external load is prevented from being applied to the configuration inside the spacer 46 in the speed reducer 40, and each configuration of the speed reducer 40 can be protected.
In particular, in the case where the speed reducer 40 is configured by a flexure meshing gear device, a gear having flexibility is provided inside, and each gear may be processed with high accuracy. It is possible to effectively protect the spacer 46 from an external load by the weakened portion.

Further, in the speed reducer 40 of the assist device 10, the output member is composed of a plurality of members including the spacer 46 and the internal gear 43, and the weakened portion is provided in the spacer 46 directly connected to the second member 22 among them. ing.
For this reason, when an external load is applied from the second member 22 to the speed reducer 40, the spacer 46 located near the outside of the speed reducer 40 is damaged or broken, so that the replacement work can be easily performed. Thus, it is possible to improve the maintainability.

[Others]
In the above embodiment, the assist device 10 used for the left hip joint portion of the human body is illustrated, but the application part of the human body is not limited to this, and the speed reducer is also characteristic for the assist device used for other joint portions of the human body. It is possible to apply 40.

  Moreover, although the hollow motor 31 was illustrated as a drive source of the joint unit 30, not only this but the various motors which perform rotational drive can be utilized.

  Moreover, although the case where the output member of the reduction gear 40 was comprised with the internal gear 43 and the spacer 46 was illustrated, you may integrate these and comprise with one member. Alternatively, a new spacer may be interposed between the internal gear 43 and the spacer 46 and integrally connected with a bolt or the like, and the output member may be configured by more members.

Similarly, although the case where the fixing member of the reduction gear 40 is configured by the housing 45 and the motor housing 48 is illustrated, these may be integrated and configured by one member. In that case, the external gear 42 is fixed inside the integrated member, and the first member 21 is fixed outside.
Further, a new member (for example, a spacer or the like) may be inserted between the motor housing 48 and the first member 21, and the fixing member may be configured by more members.

In addition, although the case where the reduction gear 40 was comprised with the bending meshing type gear apparatus was illustrated, it is possible to use all the reduction gears which can decelerate the rotational output of the hollow motor 31. FIG.
For example, as a speed reducer, besides a flexure meshing gear device, a speed reducer using a simple planetary gear or an eccentric rocking type speed reducer may be used. Moreover, even if it is a bending meshing type gear apparatus, not only a top hat type but a cup type and a cylinder type may be sufficient.

  Moreover, the structure of the weak part provided in the spacer 46 is not limited to the case where the thin part 465 and the punched hole 466 are configured. For example, you may comprise only a thin part and may comprise only a punch hole. Further, a number of finer holes may be arranged around the main body portion 461.

  In addition, the details shown in the embodiments can be changed as appropriate without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 10 Assist apparatus 21 1st member 22 2nd member 30 Joint unit 31 Hollow motor 40 Reduction gear (flexible meshing type gear apparatus)
41 Eccentric cam 42 External gear 43 Internal gear (output member)
44 First bearing 45 Housing (fixing member)
46 Spacer (Output member)
47 Second bearing (main bearing, deep groove ball bearing)
48 Motor housing (fixing member)
463, 464 Bolt 465 Thin part (fragile part)
466 Punched hole (fragile part)
O Joint center line

Claims (5)

An assist device for assisting movement of a joint between a first part and a second part of a human body,
A first member mounted on the first portion;
A second member attached to the second part;
A speed reducer interposed between the first member and the second member,
The speed reducer has a fixed member connected to the first member, an output member connected to the second member, and a main bearing disposed between the fixed member and the output member,
The main bearing is an assist device configured by a single-row rolling bearing or a sliding bearing.   2. The reduction gear is a flexure meshing gear device comprising a vibration generator, an external gear that is bent and deformed by the vibration generator, and an internal gear that meshes with the external gear. The assist device described.   The assist device according to claim 1, wherein the single-row rolling bearing is a deep groove ball bearing.   The assist device according to any one of claims 1 to 3, wherein the output member has a fragile portion that is easily broken by an external load smaller than other portions of the speed reducer. The output member is configured to connect a plurality of members,
The assist device according to claim 4, wherein the fragile portion is provided on a member directly connected to the second member among the plurality of members constituting the output member.

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