JP6202351B2 - Actuator for motion assist device and motion assist device - Google Patents

Description

  The disclosed embodiment relates to an actuator for a motion assist device and a motion assist device.

  In Patent Document 1, a driving motor is fixed to a wearer's torso, and a rotational driving force output from the driving motor is transmitted to a driving mechanism such as a speed reducer provided in the vicinity of a joint via a flexible shaft to be driven. The brace is described.

JP 2009-213671 A

  However, when the flexible shaft is arranged outside the body over a long range, there is room for improvement in terms of operation performance because it easily interferes with an external obstacle. Even when the drive motor is provided in the vicinity of the joint, when a large drive motor capable of outputting the required torque is installed, the outer diameter of the drive motor is large, so that it is also greatly increased from the wearer's body to the outside side. Protrudes and easily interferes with other obstacles. Further, in order to improve the operation accuracy, it is desirable to remove backlash as much as possible in the reduction gear included in the drive mechanism.

  The present invention has been made in view of such problems, and an object thereof is to provide an actuator for an operation assisting device and an operation assisting device capable of achieving both large torque, avoidance of external interference, and removal of backlash. To do.

In order to solve the above problems, according to one aspect of the present invention, there is provided an actuator for an operation assisting device for driving an operation assisting device for assisting a rotation operation in any joint of a wearer's limb, In the vicinity of the auxiliary joint, the drive shaft and the rotation shaft are arranged so as to be substantially coaxial, and the output shaft provided with the worm pinion is arranged in substantially the same direction. and two drive motors configured to mesh with the worm gear body, was closed, the two drive motors, removably cooperative control behavior auxiliary backlash between each of said worm pinion relative to the worm gear body A device actuator is applied.

  According to another aspect of the present invention, there is provided an operation assisting device actuator for driving an operation assisting device for assisting a rotation operation in any joint of a wearer's limb, wherein In the vicinity, the worm gear main body configured so that the drive shaft and the rotation shaft are arranged substantially coaxially and the output shaft provided with the worm pinion respectively mesh with the worm gear main body so as to face each other in substantially the same direction. Two drive motors configured to be arranged so that the two drive motors are substantially parallel to any one of the two body parts that rotate relative to each other via the joint to be supported Then, an actuator for a motion assisting device configured to be fixed to the motion assisting device is applied.

  According to another aspect of the present invention, any one of the above-described motion assisting device actuators may be provided, and the motion of any one of the limbs of the wearer may be rotated by driving the motion assisting device actuator. An assisting operation assisting device is applied.

  According to the present invention, it is possible to achieve both large torque, avoidance of external interference, and removal of backlash.

It is a figure showing the wearer's whole body which mounted | wore the movement assistance apparatus to the left knee. It is an enlarged plan view and an arrow IIb-IIb sectional view of an actuator for a knee joint.

  Hereinafter, an embodiment will be described with reference to the drawings. In the following description, “front”, “back”, “upper”, “lower”, “left”, and “right” refer to “front”, “rear”, “upper”, “lower”, “left”, and “right”, respectively, shown in FIG. Refers to the noted direction. These directions are only used in a unified manner corresponding to the direction seen from the wearer wearing the motion assist device in a normal standing posture.For example, when the wearer rotates the limb, What is necessary is just to change suitably according to it.

  The motion assisting device provided with the actuator for motion assisting device of the present embodiment is an example that assists the rotation operation of the knee joint of the wearer M, and FIG. 1 shows that the motion assisting device is mounted on the left knee. Represents the whole body of the wearer M. In FIG. 1, the motion assisting device 1 includes a trunk device 2, a hip joint hinge 3, a thigh arm 4, a thigh device 5, a shin device 6, and a shin device. The arm 7, the ankle joint hinge 8, the shoe portion 9, and the knee joint actuator 10 are provided.

  The torso equipment 2 is an equipment to be worn around the torso of the wearer M so as to be wound around the torso, and the torso of the wearer M is stably attached at the position of the thinnest waist.

  The hip joint hinge 3 is a hinge provided between the torso brace 2 and a later-described thigh arm 4, and rotates in accordance with the rotation operation of the hip joint by the wearer M itself. In the illustrated example, the hip hinge 3 is not provided with a drive mechanism that actively assists the turning operation.

  The thigh arm 4 is a beam-like structure, and its upper end is fixed to the hip joint hinge 3 and its lower end is fixed to a thigh orthosis 5 described later.

  The thigh device 5 is a device that is mounted so as to be wound around the thigh of the wearer M. In the illustrated example, the thigh device 5 is stably mounted at a position immediately above the knee joint.

  The shin device 6 is a device that is mounted so as to be wound around the shin portion of the wearer M, and is stably mounted at a position just below the knee joint in the illustrated example.

  The shin part arm 7 is a beam-like structure, and its upper end is fixed to the shin part orthosis 6 and its lower end is fixed to an ankle joint hinge 8 described later.

  The ankle joint hinge 8 is a hinge provided between the above-mentioned shin part arm 7 and a shoe part 9 to be described later, and rotates in accordance with the rotation operation of the ankle joint by the wearer M itself. In the illustrated example, the ankle joint hinge 8 is not provided with a drive mechanism that actively assists the turning operation.

  The shoe portion 9 is a shoe-like brace that is worn so that the foot of the wearer M is inserted therein, and is stably worn so as to restrain the posture of the foot. Further, the vicinity of the ankle of the shoe portion 9 is fixed to the ankle joint hinge 8.

  The knee joint actuator 10 (actuator for motion assisting device) has a speed reducer 11 having two worm gears and two drive motors 12 as shown in FIG. 2 to be described later. In this example, the main body of the speed reducer 11 Is fixed to the thigh device 5 (first device) on the outer surface side of the knee joint, and the drive shaft of the speed reducer 11 is fixed to the shin device 6 (second device). The two drive motors 12 are arranged so as to be sandwiched in the front-rear direction of the speed reducer 11, and each of the rotating shafts has a lower end in a direction toward the extending direction of the thigh arm 4 (substantially above the state in the drawing). Is connected to the speed reducer 11. That is, the two drive motors 12 are substantially parallel to the thighs of the thighs and shins (two body parts) that rotate with each other via the knee joint, which is an assisting object in this example. It is fixed to the motion assisting device 1 by arrangement.

  The rotational driving forces of these two drive motors 12 are decelerated by the speed reducer 11 to increase the torque and output to the drive shaft. As a result, the shin part orthosis 6 and the shin part arm 7 perform a relative rotation operation around the drive shaft with respect to the thigh orthosis 5 and the thigh arm 4. Since the position of the drive shaft is arranged so as to substantially coincide with the knee joint of the wearer M, the knee joint actuator 10 can assist the rotational operation coaxially with the knee joint of the wearer M. Although not particularly illustrated, the speed reducer 11 may be fixed to the shin device 6 and the drive shaft may be fixed to the thigh device 5. In this case, the direction of the relative rotation operation is reversed, but switching between forward rotation and reverse rotation of the drive motor 12 may be controlled in reverse.

  The configuration of the knee joint actuator 10 will be described in detail. FIG. 2A shows an enlarged plane of the knee joint actuator 10, and FIG. 2B shows a cross section taken along the arrow IIb-IIb in FIG. 2A. The inside of the machine 11 is shown through. In FIG. 2, the knee joint actuator 10 includes a speed reducer main body 21, a worm gear main body 22, two worm pinions 23, and two drive motors 12.

  The worm gear main body 22 is a gear on the driven side of the worm gear, and most of the worm gear is rotatably housed inside the speed reducer main body 21, and only the drive shaft 22 a serving as the center of rotation is viewed from the right side surface of the speed reducer main body 21. It protrudes. As a result, the worm gear main body 22 is disposed in the vicinity of the rotation shaft of the assisting knee joint in this example so that the axial directions of the drive shaft 22a and the rotation shaft are substantially parallel to each other.

  The two worm pinions 23 are gears on the main drive side of the worm gear, and are coupled to the output shafts of two drive motors 12 described later, and mesh with the outer peripheral gear teeth of the worm gear body 22 inside the speed reducer body 21. doing. These two worm pinions 23 have tooth surfaces formed in opposite directions, and mesh with the worm gear main body 22 so as to face each other with a phase difference of about 180 ° around the drive shaft 22a. The reduction gear body 21, the worm gear main body 22, and the two worm pinions 23 constitute the reduction gear 11.

  In the example of this embodiment, the two drive motors 12 are constituted by direct current motors, and output shafts of the two drive motors 12 are coupled to the two worm pinions 23 inside the speed reducer main body 21. These two drive motors 12 mesh with the worm gear body 22 in such a manner that output shafts provided with the worm pinions 23 are directed in substantially the same direction (downward in the illustrated posture). Further, the stators corresponding to the main bodies of the two drive motors 12 are respectively fixed to the speed reducer main body 21 so as to be arranged in substantially the same direction (upward in FIG. 2A). The reduction gear main body and the main body (stator) of the two drive motors 12 are set to have substantially the same thickness dimension in the axial direction of the drive shaft 22a (vertical direction in FIG. 2B). .

  The knee joint actuator 10 configured as described above is configured so that the drive shaft 22a of the worm gear main body 22 is controlled by rotating the two drive motors 12 in opposite directions by power supply control from a control unit (not shown). It can be rotationally driven with a desired torque and a desired rotational direction. Further, by coordinating the rotational drive of the two drive motors 12, backlash in the worm gear can be removed.

  According to the embodiment described above, the following effects are obtained. That is, in the knee joint actuator 10 of the present embodiment, a worm gear is used as the speed reducer 11 and is driven by the two drive motors 12. Specifically, a worm gear main body 22 and a worm pinion 23 are provided in the vicinity of the rotation shaft of the knee joint to be supported so that the drive shaft 22a and the rotation shaft are arranged substantially coaxially. And two drive motors 12 that mesh with the worm gear main body 22 in an arrangement in which the output shafts are directed in substantially the same direction.

  With this configuration, the two drive motors 12 are arranged so that their output shaft directions (rotational axis directions) are directed in substantially the same direction on a plane substantially orthogonal to the rotation axis of the knee joint. The installation space area of the entire 10 can be reduced. In addition, since the required drive torque can be shared by the two drive motors 12, the individual outer diameters can be reduced. For this reason, the thickness dimension of the entire knee joint actuator 10 with respect to the rotation axis direction of the knee joint (left and right direction in the figure) can be reduced (thinned), and interference with an external obstacle can be avoided. Smooth operation is possible.

  Further, each drive motor 12 can improve the drive torque by extending the axial length of the rotor and stator (extending in the direction of arrow E in the figure) without increasing the outer diameter. The driving force can be improved while the entire actuator is thinned in the left-right direction. Further, since the two drive motors 12 are engaged with the same worm gear main body 22 by the worm pinion 23, the backlash in the worm gear can be removed by their cooperative control. As a result, it is possible to realize an actuator for an operation assisting device that can achieve both large torque, avoidance of external interference, and removal of backlash.

  In the present embodiment, in particular, the two drive motors 12 are either one of two body parts (thighs and shins) that rotate with each other via the assisting knee joint (in the illustrated example). The movement assisting device 1 is fixed in an arrangement substantially parallel to the thigh). Thus, no matter what angle the knee joint rotates, the two drive motors 12 do not protrude from the body part of the wearer M on the plane orthogonal to the rotation axis of the knee joint. Smooth operation can be ensured by avoiding interference.

  In the above embodiment, the two drive motors 12 are fixed in an arrangement substantially parallel to the thigh. However, the present invention is not limited to this. For example, the two drive motors 12 may be fixed in an arrangement substantially parallel to the shin part. In this case, the reduction gear 11 is fixed to the shin device 6 and the drive shaft 22a is fixed to the thigh device 5, so that the two drive motors 12 can be prevented from protruding.

  Further, the present embodiment is particularly suitable for application to a knee joint in which the rotation axis is fixed in one direction, not a joint that rotates in a multiaxial manner such as a hip joint or a shoulder joint. Note that the application of the motion assisting device actuator is not limited to the knee joint, and can also be applied to assisting the rotational motion of the ankle joint and elbow joint whose rotational axis is fixed in one direction. Also, for example, a joint that can be rotated in two axial directions (front-rear direction and left-right direction) such as a hip joint is limited to rotation in one axial direction (for example, front-rear direction rotation in a normal walking motion). Then, an operation assisting device actuator may be applied to assist the rotation operation.

  Further, in the present embodiment, interference between the two legs can be avoided by disposing the knee joint actuator 10 not on the inner surface of the knee joint but on the outer surface.

  In the present embodiment, in particular, the two drive motors 12 are constituted by DC motors. A general DC motor has a configuration in which two permanent magnets are disposed opposite to the center of the rotation axis inside the stator on the outer peripheral side (not shown). For this reason, the whole axis orthogonal cross section of each drive motor 12 can be flattened (flattened so as to increase in diameter in the front-rear direction and in the left-right direction in the illustrated orientation), and thinning is facilitated. If the outer diameter is sufficiently small, another type of motor other than the DC motor may be used for the drive motor 12.

  In the present embodiment, in particular, the motion assisting device 1 includes a thigh orthosis and a tibial orthosis 6 that are respectively attached to a thigh and a shin that rotate relative to each other via a knee joint to be assisted. Have. The knee joint actuator 10 has a speed reducer main body 21, the speed reducer main body 21 is fixed to the thigh orthosis 5, and the drive shaft 22 a is fixed to the tibial orthosis 6. Thereby, the knee joint actuator 10 reliably rotates the knee joint between the thigh and the shin by rotating the speed reducer main body 21 and the drive shaft 22a relatively by driving the drive motor 12. Can assist.

  In the present embodiment, in particular, the thigh orthosis 5 and the tibial orthosis 6 are mounted so as to wind around the body part (thigh and thigh), respectively. As a result, the thigh orthosis 5 and the tibial orthosis 6 are fixedly attached to the body part, and the knee joint actuator 10 reliably rotates the knee joint between the thigh and the shin. Can assist. As described above, when the motion assisting device actuator is applied to assist the rotation of the ankle joint, one body part via the ankle joint is the foot of the wearer M. In this case, the shoe part 9 is fixedly mounted by storing the foot part 9 so that the foot is inserted into the shoe part 9 and can reliably assist the rotation of the ankle joint.

  The motion assisting device 1 of the above embodiment can be used for rehabilitation when the knee joint has a paralysis disorder, and can also be used for assisting work such as transporting heavy objects when worn by a healthy person.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  In addition, although not illustrated one by one, the above-mentioned embodiment and each modification are implemented with various modifications within a range not departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 Operation assistance apparatus 2 Torso orthosis 3 Hip joint hinge 4 Thigh arm 5 Thigh orthosis (1st orthosis)
6 Thigh orthosis (second orthosis)
7 Arm for shin part 8 Hinge for ankle joint 9 Shoe part 10 Actuator for knee joint (actuator for motion assist device)
DESCRIPTION OF SYMBOLS 11 Reduction gear 12 Drive motor 21 Reduction gear main body 22 Worm gear main body 22a Drive shaft 23 Warm pinion M Wearer

Claims (9)

An actuator for an operation assisting device for driving an operation assisting device for assisting a rotation operation in any joint of a wearer's limb,
A worm gear main body configured so that the drive shaft and the rotation shaft are arranged substantially coaxially in the vicinity of the auxiliary joint,
Two drive motors configured to mesh with the worm gear body in an arrangement in which output shafts each provided with a worm pinion are directed in substantially the same direction;
I have a,
The operation assisting device actuator , wherein the two drive motors are cooperatively controlled so as to remove backlash between the worm gear main body and each of the worm pinions .   The two drive motors are configured to be fixed to the motion assisting device in an arrangement that is substantially parallel to any one of two body parts that rotate relative to each other via the auxiliary target joint. The actuator for a motion assisting device according to claim 1.   3. The motion assisting device actuator according to claim 1, wherein the motion assisting device is configured to assist a turning motion in the knee joint of the wearer. 4.   4. The motion assisting device actuator according to claim 3, wherein the motion assisting device actuator is configured to be disposed on an outer surface of the knee joint.   5. The motion assisting device actuator according to claim 1, wherein the two drive motors are constituted by DC motors. 6. Furthermore, it has a reducer body,
The worm gear main body is housed inside the speed reducer main body so that only the drive shaft projects from the speed reducer main body and is rotatable about the drive shaft.
The two worm pinions have tooth surfaces formed in directions opposite to each other, and mesh with each other so as to face the outer peripheral gear teeth of the worm gear body with a phase difference of about 180 ° centered on the drive shaft,
The two drive motors are axially connected to the worm pinions corresponding to the output shafts, and the stators are fixed to the speed reducer main body in an arrangement in which the stators are directed in substantially the same direction.
6. The reduction gear main body and the stator of the two drive motors are both set to have substantially the same thickness dimension in the axial direction of the drive shaft. Actuator for operation auxiliary equipment given in the clause. It has an actuator for a movement auxiliary device according to any one of claims 1 to 6,
A motion assisting device, wherein the motion assisting device assists a turning motion in any joint of a wearer's limb by driving the motion assisting device actuator. Furthermore, it has a first brace that is attached to any one of the two body parts that rotate relative to each other via the auxiliary joint, and a second brace that is attached to the other.
The operation assisting device actuator has a speed reducer body,
8. The motion assisting device according to claim 7, wherein one of the speed reducer main body and the drive shaft is fixed to the first device, and the other is fixed to the second device. 9. The motion assisting device according to claim 8, wherein the first orthosis and the second orthosis are each mounted so as to be wound or housed around a body part.

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