JP2007290068A - Straight move link device, robot using the same, and bipedal walking robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a straight move link device excellent in universality, having the shortened shortest link length, and elongating the stroke of the link so as to enlarge a movable range by comprising multi-stage links. <P>SOLUTION: The device is provided with: (a) a first joint 21 comprising a first ball screw shaft 21a, a first ball screw nut 21b rotatably engaged with the first ball screw shaft 21a, and a driven gear 22 formed on or fixed to the outer circumference of the first ball screw nut 21b; (b) a second joint 25 comprising a drive motor 29, a second ball screw shaft 25a rotated by the drive motor 29, and a drive gear 26 provided through the second ball screw shaft 25a, and engaged with the driven gear 22 of the first joint 21; and (c) a third joint 34 comprising a second ball screw nut 34a rotatably engaged with the second ball screw shaft 25a of the second joint 25, and a cylindrical member 34b continuously provided with the second ball screw nut 34a, and combined with the second ball screw shaft 25a of the second joint 25. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multi-stage linear motion link device having a large movable range, a robot using the linear motion link device, and a biped robot using the linear motion link device in a parallel link mechanism.

In recent years, research and development of humanoid robots that are active in human living environments, so-called humanoid robots, have been extensively conducted. Humanoid robots are often used not only as industrial production equipment but also for the purpose of making human life comfortable, such as housework and elderly care, and are unspecified users in an environment created for humans. It is necessary to have a form and function suitable for it. Moreover, it is required to provide a safe and flexible interface without requiring special use training, and there are a great many research subjects. In particular, bipedal walking robots that have two legs as a means of movement and that perform bipedal walking, like humans, have been extensively studied and developed by many research institutions and companies.
(Patent Document 1) filed by the present applicant includes “a base portion, a right foot portion and a left foot portion, a plurality of passive joints disposed on each of the base portion, the right foot portion and the left foot portion, and a base portion. Parallel disposed between the passive joint provided and the passive joint disposed on the right foot, and between the passive joint disposed on the base and the passive joint disposed on the left foot. And a lower body module of a biped walking robot provided with a link mechanism unit ”.
Similarly, (Patent Document 2) and (Patent Document 3) filed by the applicant of the present application are “a walking that creates a walking pattern that allows a biped walking robot device with a parallel link mechanism to perform a stable biped walking. A “pattern creation device” is disclosed.
JP 2003-291080 A JP 2004-82223 A JP 2006-82155 A

The lower body module of the biped robot described in (Patent Document 1) is configured with a parallel link mechanism for the legs, so that the legs can withstand a heavy load, enabling human boarding and transporting heavy objects. In addition to being highly practical and capable of mounting or incorporating a heavy upper body, it has excellent design freedom. By providing the walking pattern creation device described in (Patent Document 2), stable biped walking It was possible to create a walking pattern that can be performed, especially on a flat ground contact surface, which has the effect and effect of excellent stability of walking motion, but the movable range of the parallel link mechanism using a linear link is In order to improve the stability of the movement further, and to realize activities on various terrains, it was desired to expand the range of movement.
In particular,
(1) When moving up and down steps such as stairs or walking with a large stride, in order to stabilize and control the walking motion using, for example, (Patent Document 3), the movable range of the leg is set. There was a problem that the stroke of the linear link of the parallel link mechanism must be increased.
(2) On the other hand, in order for elderly people and persons with walking disabilities to get on and off easily, or to operate in a human living environment where the ceiling height is limited by boarding a human, There has been a problem that the minimum height of the seat surface from the road surface must be reduced by shortening the link length.

  The present invention solves the above-described conventional problems, and by providing a multi-stage link, the provision of a linear motion link device having excellent versatility with a shortest link length is short, and the link stroke is long and the movable range is large. In addition, the shortest link length of legs and arms, etc. is short, the link stroke is long and the movable range is wide, and a robot using a linear link device with excellent versatility is provided, and the shortest link length of the legs is shortened. The minimum height from the road surface to the seating surface can be lowered, and elderly people and people with walking disabilities can easily get on and off, and people can board and operate in a living environment where the ceiling height is limited. It is possible to extend the range of movement of the leg by extending the stroke of the link, and there are irregularities, steps, obstacles etc. using stabilization control that corrects the length of the link in real time Double And an object thereof is to provide a biped walking robot with a linear motion link device a walking in terrain can be stabilized.

In order to solve the above problems, a linear motion link device of the present invention, a robot using the linear motion link device, and a biped walking robot have the following configurations.
The linear motion link device according to claim 1 of the present invention includes: (a) a first ball screw shaft; a first ball screw nut rotatably engaged with the first ball screw shaft; A first node having a driven gear formed or fixed on the outer periphery of one ball screw nut, (b) a drive motor, a second ball screw shaft rotated by the drive motor, and a second ball A second section having a main drive gear penetrating through the screw shaft and meshing with the driven gear of the first section; and (c) threadably engaged with the second ball screw shaft of the second section. A third node comprising: a second ball screw nut that is formed; and a cylindrical body that is connected to the second ball screw nut and that is externally attached to the second ball screw shaft of the second node; It has the composition provided with.
This configuration has the following effects.
(1) The first knuckle is formed on the outer periphery of the first ball screw nut, the first ball screw nut that is rotatably engaged with the first ball screw shaft, and the first ball screw nut. A second driven gear, a second ball screw shaft rotated by the drive motor, and a second ball screw shaft penetrating the second ball screw shaft. A main gear that meshes with the gear, so that the main ball is rotated by rotating the second ball screw shaft by the drive motor, and the first ball screw nut rotates along with the driven gear. However, by constraining the rotation of the first node (first ball screw shaft), the first ball screw shaft slides in the longitudinal direction of the second node without rotating, and the link length Can be changed.
(2) The third section is connected to the second ball screw nut rotatably coupled to the second ball screw shaft of the second section, and the second section is connected to the second ball screw nut. And a cylindrical body extrapolated to the ball screw shaft of the second ball. Therefore, by restricting the rotation of the second ball screw nut of the third node (cylindrical body), the second ball is driven by the drive motor. When the screw shaft is rotated, the second ball screw nut and the cylindrical body of the third node can be slid in the longitudinal direction of the second node and the link length can be changed without rotating. .
(3) Since the first ball screw shaft of the first node and the second ball screw nut of the third node are slidably connected to the second ball screw shaft of the second node, respectively. By simply rotating the second ball screw shaft with a single drive motor, the first and third nodes can be slid simultaneously, two drive motors are not required, and the expansion and contraction operation can be easily controlled. is there.
(4) Since the first section, the second section, and the third section are arranged side by side on different axes, the total stroke of the first section and the third section becomes longer than the shortest link length and is movable. The range can be expanded.
(5) a second ball screw nut in which the third section is rotatably engaged with the second ball screw shaft of the second section, and a cylindrical body connected to the second ball screw nut. Therefore, the second and third nodes can be arranged coaxially, and the second and third nodes can be slidably held with a simple structure.

Here, the link can be expanded and contracted by using a motor capable of forward and reverse rotation as the drive motor. The drive motor may be disposed on the axis of the second ball screw shaft of the second section and directly rotate the second ball screw shaft, or the drive pulley disposed on the motor shaft of the drive motor and the second A driven pulley disposed on the second ball screw shaft may be connected by a timing belt so that the power of the drive motor is transmitted to the second ball screw shaft. In particular, the connection via the timing belt is preferable because the minimum length of the linear motion link device can be further reduced.
The driven gear of the first section may be any one that rotates together with the first ball screw nut, and may be formed on the outer periphery of the first ball screw nut, or may be fixed to the end of the first ball screw nut. You may set up.
By disposing a urethane washer having an outer diameter substantially equal to the inner diameter of the cylindrical body on the lower end side of the second ball screw shaft, even if the linear motion link device is extended beyond the set stroke, the urethane washer Can be stopped by the second ball screw nut, and the second ball screw shaft can be prevented from falling off the cylindrical body.

By providing joints on the upper end side and the lower end side of the linear motion link device, it is possible to connect the two members that are desired to be expanded and contracted. This joint can be appropriately selected depending on its purpose and application.
When the linear link device is used for the parallel link mechanism of the leg of the biped robot, the lumbar side passive joint is a passive joint having two degrees of freedom of rotation, and the foot side passive joint is passive having three degrees of freedom of rotation. A joint is preferred. Since the left and right parallel link mechanisms have 6 degrees of freedom, the left and right feet can perform various movements. For example, Japanese Patent Laid-Open No. 2006-82155 can be used to stabilize and control walking movements. it can.
A universal joint is preferably used as a passive joint having two degrees of freedom of rotation, and a passive joint having three degrees of freedom of rotation is preferably a combination of a universal joint and a rotary joint connected in series or a ball joint. .

The invention according to claim 2 is the linear motion link device according to claim 1, wherein the guide rail disposed in parallel with the first ball screw shaft on the first node, and the second node And a guide portion that slidably guides the guide rail.
With this configuration, in addition to the operation of the first aspect, the following operation is provided.
(1) A guide rail is disposed in the first section in parallel with the first ball screw shaft, and a guide portion for slidably guiding the guide rail is disposed in the second section. When the first ball screw shaft of the first section is slid with respect to the second section, the guide rail of the first section is guided by the guide section of the second section. The first ball screw shaft can be moved parallel to the second node.

  Here, the guide rail is formed to have a length substantially equal to the stroke of the first node, and when the upper end portion of the guide rail and the upper end portion of the first node are connected via the upper end fixing portion, the first ball While restricting the rotation of the screw shaft, the sliding motion of the first ball screw shaft can be reliably guided from the beginning to the end by the guide rail. The cross-sectional shape of the guide rail only needs to be uniform in the longitudinal direction, and can be formed in an arbitrary shape such as a circular shape, a rectangular shape, or a polygonal shape. The guide part may be any as long as it can guide the guide rail slidably. A guide rail that is guided through an insertion hole having the same shape as the cross-sectional shape of the guide rail is preferably used, but at least one protrusion or recess is formed in the longitudinal direction of the guide rail, and the guide portion is formed. It may be guided by engaging with the formed ridges or ridges.

The invention according to claim 3 is the linear motion link device according to claim 1 or 2, wherein the guide rail disposed in parallel with the second ball screw shaft at the second node, And a sliding portion that is disposed in three sections and is guided by the guide rail.
With this configuration, in addition to the operation of the first or second aspect, the following operation is provided.
(1) A guide rail is disposed in the second section in parallel with the second ball screw shaft, and a sliding portion guided by the guide rail is disposed in the third section. When the rotation of the third section is constrained and the third section is slid with respect to the second section, the sliding portion of the third section is guided by the guide rail of the second section, and the cylindrical body of the third section is moved. It can be moved parallel to the second section.

  Here, the guide rail is formed to be approximately the same length as the stroke of the third section, and when the upper end of the guide rail and the upper end of the second section are connected, the sliding movement of the third section is performed. Guide rails can guide you from start to finish. The cross-sectional shape of the guide rail only needs to be uniform in the longitudinal direction, and can be formed in an arbitrary shape such as a circular shape, a rectangular shape, or a polygonal shape. The sliding part should just be a thing which can move slidably along a guide rail. A guide rail that is inserted and moved through an insertion hole having the same shape as the cross-sectional shape of the guide rail is preferably used, but at least one ridge or recess is formed in the longitudinal direction of the guide rail, and the sliding portion You may make it move by engaging with the concave line or convex line formed in this.

A fourth aspect of the present invention is the linear motion link device according to any one of the first to third aspects, wherein the first joint is disposed in the third node in parallel with the cylindrical body. It has the structure provided with the reinforcement cylindrical body in which a ball screw axis is inserted.
With this configuration, in addition to the operation of any one of claims 1 to 3, the following operation is provided.
(1) By arranging the reinforcing cylindrical body in parallel with the cylindrical body of the third section, the rigidity against the compression of the third section can be improved, and the bending moment generated in the third section is reduced. Can do.

  Here, the reinforcing cylindrical body is disposed coaxially with the first ball screw shaft of the first node. A linear motion link device is formed by forming the reinforcing cylindrical body to be substantially the same length as the first ball screw shaft, and connecting the upper end portion of the reinforcing cylindrical body and the upper end portion of the cylindrical body via a connecting portion. The first ball screw shaft is reliably accommodated in the inside of the reinforcing cylindrical body, and the third section can be made compact.

The linear motion link device according to claim 5 of the present invention includes: (a) a first node having a drive motor and a cylindrical body connected to the drive motor; and (b) an inner part of the cylindrical body. A splined ball screw having a hollow ball screw that is inserted and rotated along the cylindrical body by being rotated by the drive motor of the first section; and a lower end portion of the hollow ball screw, A second section having a ball screw nut having a thread groove formed in a direction opposite to the winding direction of the thread groove formed on the outer peripheral surface of the hollow ball screw; and (c) the ball screw of the second section And a third node having a ball screw shaft that is rotatably engaged with the nut and inserted into the hollow ball screw.
This configuration has the following effects.
(1) The first node has a drive motor and a cylindrical body connected to the drive motor, and the second node is inserted into the cylindrical body and rotated by the drive motor of the first node. Since the splined ball screw having the hollow ball screw that slides along the cylindrical body is provided, the hollow ball screw of the second node is rotated by driving the drive motor of the first node. It is possible to slide (linearly move) while changing the link length.
(2) A ball screw nut having a thread groove formed in the winding direction opposite to the winding direction of the thread groove formed on the outer peripheral surface of the hollow ball screw is continuously provided at the lower end of the hollow ball screw of the second section. The third section has a ball screw shaft that is rotatably engaged with the ball screw nut of the second section and is inserted into the hollow ball screw, and the lower end portion (ball screw shaft) of the third section is the left and right foot portions. So that when the second motor ball ball screw is rotated by the drive motor, the third screw ball screw shaft does not rotate and the second motor ball ball screw is rotated in the longitudinal direction. The link length can be changed by sliding.
(3) The ball screw with spline of the second node is inserted into the cylindrical body of the first node, and the ball screw shaft of the third node is slidably held with respect to the hollow ball screw of the ball screw with spline. Therefore, the second and third sections can be simultaneously slid by simply rotating the hollow ball screw of the splined ball screw with a single drive motor, eliminating the need for two drive motors. Easy to control expansion and contraction.
(4) Since the first to third sections are coaxially arranged, the mechanism can be simplified and made compact, and the hollow ball screw and the ball screw shaft are not subjected to a bending moment, and are coaxial. It is possible to secure an overwhelmingly large rigidity compared to the configuration that is not, the stability of the sliding movement of the second section and the third section, excellent long life, and a very high human-rigid riding type two feet It can be suitably used for a leg mechanism of a walking robot, and the total stroke of the second and third sections becomes longer than the shortest link length, and the movable range can be expanded.
(5) By adopting a multistage system in which two hollow ball screws of the second section and two ball screw shafts of the third section are arranged in series, the overall expansion / contraction reduction ratio is made constant compared to the case of one ball screw. If this is the case, the number of rotations of the ball screw when performing the same operation becomes small, so that it becomes difficult to reach the critical speed, and a higher speed operation becomes possible.

Here, the mechanism of the ball screw with a spline is conventionally known. For example, when the ball spline outer cylinder is rotated in a state in which the ball screw nut and the ball spline outer cylinder are immovable in the axial direction, The ball spline rolling element rolls along the ball screw groove and the ball spline groove, and the ball screw shaft linearly moves in the axial direction while rotating in the circumferential direction. By making this ball screw shaft a hollow ball screw, the ball screw shaft can be inserted, and the second and third nodes can be arranged coaxially.
There are Σ series (registered trademark) manufactured by NSK, BNS series (registered trademark) manufactured by THK, and the like that can be moved linearly (spiral motion) while rotating the hollow ball screw. From these, an appropriate one can be selected according to the outer diameter and the lead of the ball screw shaft of the third section.
The third section is inserted on the same axis as the second section, and the rotation speed of the hollow ball screw of the second section and the ball screw shaft of the third section is equal, and the linear movement is performed at the same time. The longest stroke is the same as the stroke in Section 2. In this case, it is necessary to set the lead of the ball screw shaft of the third section so that the third section advances by the same stroke by the rotation of the stroke of the second section.

According to a sixth aspect of the present invention, there is provided a robot according to any one of the first to fifth aspects, the fixed base portion connected to one end of the linear motion link device, and the linear motion. And a movable base connected to the other end of the link device.
This configuration has the following effects.
(1) By connecting the fixed base portion and the movable base portion to both ends of the linear motion link device, respectively, the distance between the fixed base portion and the movable base portion can be easily changed by extending and contracting the linear motion link device. Can do.
(2) Since the linear motion link device is a multistage linear motion actuator having the first to third sections, the shortest link length can be shortened and the stroke of the link can be lengthened to move the movable range of the movable base section. Can be expanded, and is highly versatile.

Here, since the linear motion link device can expand and contract the movable base portion with respect to the fixed base portion, the movable range can be expanded by arranging it on the leg portions and arm portions of various robots.
The number and arrangement of the linear motion link devices disposed between the fixed base portion and the movable base portion are appropriately selected according to the size and shape of the fixed base portion and the movable base portion, the purpose and application of the robot, etc. be able to.

In the biped walking robot according to claim 7 of the present invention, the linear motion link device according to any one of claims 1 to 5 is arranged in a V shape as a set of two, and three sets of the linear motion link devices are arranged. A parallel link mechanism formed by an installed Stewart platform, a waist connected to the upper end side of the linear motion link device, and left and right foot portions connected to the lower end side of the linear motion link device. It has a configuration.
This configuration has the following effects.
(1) The parallel link mechanism that expands and contracts the legs of the biped walking robot is composed of a Stewart platform in which two linear motion link devices are arranged in a V-shape and three sets are arranged. Therefore, the stability and rigidity of the leg portion are excellent, and the operation control can be simplified.
(2) Since the linear motion link device of the parallel link mechanism is a multistage linear motion actuator having the first to third sections, the shortest link length of the legs is shortened from the road surface of the seating surface. The minimum height can be lowered, so that elderly people and people with walking disabilities can easily get on and off, and people can board and operate in a living environment where the ceiling height is limited. In addition to being excellent, it can extend the range of movement of the legs by lengthening the stroke of the link, and can stabilize the real time of walking that requires a large range of movement such as walking with large steps or climbing stairs. It can also be used on complex terrain with obstacles, etc., and is highly versatile.

  Here, as described in claim 1, the linear link device is connected between the waist and the left and right feet of the biped walking robot via the waist-side passive joint and the foot-side passive joint. . Since the left and right parallel link mechanisms have 6 degrees of freedom, the walking motion of the biped robot can be stabilized and controlled using, for example, Japanese Patent Application Laid-Open No. 2006-82155.

As described above, according to the linear motion link device of the present invention, the robot using the same, and the biped robot, the following advantageous effects can be obtained.
According to invention of Claim 1, it has the following effects.
(1) By simply rotating the second ball screw shaft of the second node with a single drive motor, the first and third nodes connected to the second ball screw shaft so as to be slidable. It is possible to provide a linear motion link device that can be simultaneously slid, does not require two drive motors, and can easily control expansion and contraction operations.
(2) By arranging the first section, the second section and the third section side by side on different axes, the total stroke of the first section and the third section can be made longer than the shortest link length, and walking It is possible to provide a linear link device excellent in versatility that can improve operational stability.

According to invention of Claim 2, in addition to the effect of Claim 1, it has the following effects.
(1) The guide rail of the first node arranged in parallel with the first ball screw shaft is guided by the guide portion of the second node, and the first ball screw shaft of the first node is surely connected to the second node. It is possible to provide a linear motion link device that can be moved in parallel with each other.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2, it has the following effects.
(1) The sliding portion disposed in the third section is guided by the second section guide rail disposed in parallel with the second ball screw shaft, and the third section cylindrical body is securely connected to the second section. A linear motion link device that can be moved in parallel with the two nodes can be provided.

According to invention of Claim 4, in addition to the effect of any one of Claims 1 thru | or 3, it has the following effects.
(1) By arranging the reinforcing cylindrical body in parallel with the cylindrical body of the third node, the rigidity against the compression of the third node can be improved, and when the foot part comes in contact with the ground, its own weight is reduced. It is possible to provide a linear link device excellent in durability that can be supported and can reduce a bending moment generated in the third section.

According to invention of Claim 5, it has the following effects.
(1) A third ball screw held slidably with respect to the hollow ball screw only by rotating the hollow ball screw of the second-line splined ball screw with a single drive motor. It is possible to provide a linear link device that can slide the shafts at the same time, does not need two drive motors, and can easily control expansion and contraction operations.
(2) By arranging the first to third sections on the same axis, the mechanism can be simplified and made compact, and the bending moment is not applied to the hollow ball screw or the ball screw shaft, and the configuration is not coaxial. Compared to a human-riding biped robot that can secure an overwhelmingly large rigidity, has excellent sliding stability and long life in the second and third sections, and has a very high required rigidity. It can be suitably used for a leg mechanism, and the total stroke of the second and third sections can be made longer than the shortest link length to widen the movable range, and in particular the stability of the walking motion of a biped robot Therefore, it is possible to provide a linear link device excellent in versatility.

According to invention of Claim 6, it has the following effects.
(1) Since the linear motion link device is a multistage linear motion actuator having the first to third sections, the shortest link length can be shortened and the link stroke is long and the legs and arms can be moved. A robot with a wide range and excellent versatility can be provided.

According to invention of Claim 7, it has the following effects.
(1) Since the linear motion link device of the parallel link mechanism is a multistage linear motion actuator with a shortest link length and a long stroke, the seating surface when the passenger gets on and off can be lowered. It is easy for people with walking disabilities to get on and off, and can be operated in human living environments where the ceiling height is limited by boarding humans, and it is safe and widens the range of movement of the legs. Enables real-time stabilization of walking that requires a large range of movement, such as walking with large steps or moving up and down stairs, and stabilizes walking activity even in complex terrain with irregularities, steps, obstacles, etc. It is possible to provide a biped walking robot with excellent versatility.

(Embodiment 1)
A linear motion link device according to Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view showing a linear motion link device according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view showing an extended state of the linear motion link device according to Embodiment 1 of the present invention.
1 and 2, 1 is a linear motion link device in the first embodiment, 20 a is an upper end fixing portion of the linear motion link device 1, 20 b is a lower end fixing portion of the linear motion link device 1, and 21 is a linear motion link device 1. The first section 21a is connected to a first ball screw shaft of the first section 21 fixed to the upper end fixing section 20a at the upper end, and 21b is connected to a second section 25, which will be described later. The first ball screw nut of the first joint 21 disposed on the connecting portion 20c to be fixed and screwed to the first ball screw shaft 21a so as to be rotatable, and 22 is an end of the first ball screw nut 21b. The driven gear of the first joint 21 that rotates together with the first ball screw nut 21b, 23a is a urethane washer disposed at the lower end of the first ball screw shaft 21a, and 23b is the first ball screw. Urethane washer 23a disposed at the lower end of shaft 21a The bearing nut 24 to be fixed is fixed at both ends of the upper end fixing portion 20a at the upper end portion, and the guide rail of the first joint 21 disposed in parallel with the first ball screw shaft 21a, and 25 is fixed by the connecting portion 20c. The second joint 25a of the linear motion link device 1 arranged in parallel with the first joint 21 is a second ball screw shaft of the second joint 25 held rotatably by the connecting portion 20c, and 26 is a second ball. A main driving gear that is provided on the upper end side of the screw shaft 25a and meshes with the driven gear 22 of the first joint 21, 27 is a driven pulley disposed on the second ball screw shaft 25a, and 28a is a second ball screw shaft. A urethane washer disposed at the lower end of 25a, 28b is a bearing nut disposed at the lower end of the second ball screw shaft 25a and fixes the urethane washer 28a, and 29 is a second joint fixed to the connecting portion 20c. 25 drive motors 30 is a drive pulley disposed on the motor shaft of the drive motor 29, 31 is a timing belt for connecting the drive pulley 30 and the driven pulley 27 and transmitting the power of the drive motor 29 to the second ball screw shaft 25a, and 32 is connected. A guide portion of the second joint 25 is provided on both sides of the portion 20c and slidably guides the guide rail 24 by the guide groove 32a, and 33 is a second ball on the side of the connecting portion 20c on the first joint 21 side. A guide rail 34 of the second joint 25 disposed in parallel with the screw shaft 25a, and a coupling portion 20d disposed at the lower end of the second joint 25 are coaxial with the second ball screw shaft 25a of the second joint 25. The third joint 34a of the linear motion link device 1 provided on the upper side is rotatably screwed to the second ball screw shaft 25a of the second joint 25 and fixed to the connecting portion 20d. The second ball screw nut, 34b is the second ball screw. The cylindrical body of the third joint 34, which is connected to the nut 34a and is externally inserted into the second ball screw shaft 25a of the second joint 25, has an upper end portion and a lower end portion connected to the connecting portion 20d and the lower end fixing portion 20b, respectively. A reinforcing cylindrical body of the third joint 34, which is fixed and arranged in parallel with the cylindrical body 34b and into which the first ball screw shaft 21a of the first joint 21 is inserted, 36 is on the first joint 21 side of the connecting portion 20d. It is a sliding part of the third joint 34 arranged on the side and guided to the guide rail 33 of the second joint 25 by a guide groove (not shown).

Urethane washers 23a and 28a having outer diameters substantially equal to the inner diameters of the reinforcing cylindrical body 35 and the cylindrical body 34b are disposed on the lower ends of the first ball screw shaft 21a and the second ball screw shaft 25a. Thereby, even if the linear motion link device 1 tries to extend beyond the set stroke, the urethane washers 23a, 28a stop at the first ball screw nut 21b, the second ball screw nut 34a, and the first ball screw shaft. The 21a and the second ball screw shaft 25a can be prevented from falling off from the connecting portion 20c and the cylindrical body 34b.
The guide rails 24 and 33 were formed to have substantially the same length as the stroke of the first joint 21 and the stroke of the third joint 34, respectively. Thus, the sliding motion of the first joint 21 and the third joint 34 can be reliably guided from the beginning to the end by the guide rails 24 and 33.
In the present embodiment, the guide rails 24 and 33 are formed to have a substantially rectangular cross-sectional shape, but the present invention is not limited to this, and the guide rails 24 and 33 can be formed in an arbitrary shape such as a circular shape or a polygonal shape. Moreover, the guide part 32 and the sliding part 36 should just be slidable with respect to the guide rails 24 and 33, and it is the insertion hole of the same shape as the cross-sectional shape of the guide rails 24 and 33 instead of forming the guide groove 32a. May be formed.
The reinforcing cylindrical body 35 of the third node 34 is formed to have a length substantially equal to that of the first ball screw shaft 21 and is arranged coaxially with the first ball screw shaft 21 a of the first node 21. Thereby, when the linear motion link device 1 is contracted, the first ball screw shaft 21a is reliably accommodated in the reinforcing cylindrical body 35, and the third joint 34 can be made compact.

The operation of the linear motion link device configured as described above will be described.
In FIG. 1, when the drive motor 29 is rotated, the rotation of the drive pulley 30 disposed on the motor shaft is transmitted to the driven pulley 27 via the timing belt 31, and the second ball screw shaft 25a of the second node 25 is transmitted. Rotates. As a result, the main driving gear 26 rotates together with the second ball screw shaft 25a, so that the driven gear 22 of the first joint 21 meshed with the main driving gear 26 and the first ball screw nut 21b fixed to the driven gear 22 are provided. Rotates. At this time, the upper end portion of the first ball screw shaft 21a that is rotatably engaged with the first ball screw nut 21b is fixed to the upper end fixing portion 20a, and the rotation is restricted. The first joint 21 and the second joint 25 move relatively linearly (slide). At the same time, the second ball screw nut 34a of the third knot 34 that is rotatably engaged with the second ball screw shaft 25a and the cylindrical body 34b connected thereto are connected to the connecting portion 20d and the lower end. Since the rotation is restrained by being fixed to the fixing portion 20b, the second joint 25 and the third joint 34 are relatively linearly moved (slid) by the screw pair.
By selecting the rotation direction of the drive motor 29, these linear movement (sliding) directions can be switched.

Next, the case where the linear motion link device in Embodiment 1 of the present invention is applied to a biped walking robot will be described.
FIG. 3 is a schematic perspective view showing a biped walking robot using the linear motion link device according to Embodiment 1 of the present invention, and FIG. 4 is a bipedal device including the linear motion link device according to Embodiment 1 of the present invention. It is a model plane perspective view of a walking robot. In FIG. 3, for convenience of explanation, a part of the parallel link mechanism is omitted.
In FIGS. 3 and 4, 1, 1 ', 1a, 1a', 1b, 1b ', 1c, 1c' are linear link devices in the first embodiment, and 100 is a linear link in the first embodiment of the present invention. Biped robots 101a, 101b using the devices 1, 1 ', 1a, 1a', 1b, 1b ', 1c, 1c' (hereinafter referred to as linear motion link devices 1-1c ') The parallel link mechanism of the left leg, 102 is the waist of the biped robot 100, 103a and 103b are the right and left legs of the biped robot 100, and 104a and 104b are the right and left legs 103a and 103b, respectively. Fixing plates arranged on the upper surface, 106, 106 ', 106a, 106a', 106b, 106b ', 106c, 106c' are waist-side passive joints, 107, 107a, 107b, 107c are foot portions It is a passive joint.
Since each part of the parallel link mechanism 101b on the left leg is symmetrical and identical in configuration with the parallel link mechanism 101a on the right leg, the description thereof is omitted.

Here, the waist-side passive joints 106 a and 106 a ′ are disposed on the right rear side of the lower surface of the waist 102. The foot side passive joint 107a is disposed on the right rear side of the right foot 103a. The linear motion link device 1a has an upper end connected to the waist-side passive joint 106a and a lower end connected to the foot-side passive joint 107a. The linear link device 1a ′ has an upper end connected to the waist-side passive joint 106a ′ and a lower end connected to the foot-side passive joint 107a.
The waist-side passive joints 106 b and 106 b ′ are disposed on the front right side of the lower surface of the waist 102. The foot side passive joint 107b is disposed on the right front side of the right foot 103a. The linear link device 1b has an upper end connected to the waist-side passive joint 106b and a lower end connected to the foot-side passive joint 107b. The linear link device 1b 'has an upper end connected to the waist-side passive joint 106b' and a lower end connected to the foot-side passive joint 107b.
The waist-side passive joints 106 c and 106 c ′ are disposed at the right center portion of the lower surface of the waist 102. The foot side passive joint 107c is disposed at the right center portion of the right foot portion 103a. The linear motion link 1c has an upper end connected to the waist-side passive joint 106c and a lower end connected to the foot-side passive joint 107c. The linear link device 1c ′ has an upper end connected to the waist-side passive joint 106c ′ and a lower end connected to the foot-side passive joint 107c.
The right leg parallel link mechanism 101a and the left leg parallel link mechanism 101b are symmetrically disposed on both sides of the center of the waist 102.

Lumbar side passive joints 106, 106 ', 106a, 106a', 106b, 106b ', 106c, 106c' (hereinafter referred to as lumbar side passive joints 106-106c ') are longitudinal directions of the linear motion link devices 1-1c'. And two degrees of freedom that rotate in the axial direction of two axes orthogonal to each other.
The foot-side passive joints 107, 107a, 107b, and 107c (hereinafter referred to as foot-side passive joints 107 to 107c) are in the vertical axis direction with respect to the bottom of the foot and the longitudinal direction of the linear motion link devices 1 to 1c ′ as will be described later. It is formed with three degrees of freedom to rotate in the axial direction of two axes orthogonal to each other and orthogonal to each other.

Next, the structure of the waist-side passive joint will be described in detail with reference to the drawings. FIG. 5 is a perspective view of an essential part of the waist-side passive joint. Since the waist-side passive joints 106 to 106c ′ have the same structure, the waist-side passive joint 106 will be described.
In FIG. 5, 113 is a U-shaped waist-side upper joint fixed to the lower portion of the waist 102, 113a is an upper joint shaft that is pivotally supported between opposed pieces of the waist-side upper joint 113, and 114 is a straight joint. A U-shaped waist-side lower joint 114 a fixed to the upper end fixing portion 20 a of the dynamic link device 1 is pivotally supported between opposed pieces of the waist-side lower joint 114, and the waist-side lower joint 114 is rotatable. A lower joint shaft 115 is pivotally supported by the upper joint shaft 113a and a lower joint shaft 114a.
As shown in FIG. 5, the waist-side lower joint 114 rotates in the axial direction of the upper joint shaft 113 a and the lower joint shaft 114 a with respect to the waist-side upper joint 113. As a result, the waist-side passive joint 106 has two degrees of freedom in the circumferential direction of the upper joint shaft 113a and the lower joint shaft 114a orthogonal to the longitudinal direction of the linear motion link device 1, so that the linear motion link device 1 can be expanded and contracted. Follow and follow smoothly without interfering with this.

Next, the structure of the foot side passive joint will be described in detail with reference to the drawings. FIG. 6 is a perspective view of an essential part of the foot side passive joint. Since the foot side passive joints 107 to 107c have the same structure, the foot side passive joint 107 will be described.
In FIG. 6, reference numeral 116 denotes a first foot upper joint connected to the lower end fixing portion 20b of the linear motion link device 1, and 116 'denotes a second foot connected to the lower end fixing portion 20b of the linear motion link device 1'. Upper joints 116a and 116b are side shaft support plates disposed on opposite sides of the first foot upper joint 116, and 116a 'and 116b' are second foot upper joints 116 '. Side shaft support plates 117 disposed opposite to each other on both sides have a ball housing portion 117a having a spherical inner wall surface inside, and a side shaft support plate with a joint shaft 117b projecting on both sides. 116a, 116b, 116a ', 116b' is pivotally supported by a ball holding portion that connects the first foot upper joint 116 and the second foot upper joint 116 ', and 117c is provided at both ends of the joint shaft 117b. Screwed side shaft support plates 116a, 116b, 116a ' A lock nut 119 for preventing the 116b 'from coming off is provided on a foot side base 118 fixed on the fixing plate 104b, and a ball joint 119a in which a ball portion 119a to be received in the ball receiving portion 117a is formed at the upper end portion. Is the axis.

As shown in FIG. 6, the first foot upper joint 116 and the second lower member lower joint 116 ′ rotate with respect to the ball holding portion 117 in the axial direction of the joint shaft 117 b. Further, the ball holding portion 117 rotates in an arbitrary direction with respect to the foot side base portion 118. Accordingly, the foot side passive joint 107 has two degrees of freedom of one degree of freedom in the axial direction of the joint shaft 117b and the axial direction of the ball joint shaft 119, and at least the joint shaft 117b and the ball joint shaft 119 Since there is one degree of freedom in the axial direction of the axis orthogonal to the linear link device 1, 1 'follows the expansion and contraction of the linear motion link devices 1 and 1' and smoothly follows without obstructing this.
In this way, the foot-side passive joint 107 has a structure using a ball joint, so that the number of fastening points is smaller than that in which a universal joint and a rotary joint are connected in series, rattling is reduced, and the operation accuracy is reduced. The stability and rigidity of the control can be improved, and a stable walking motion can be performed at high speed.

As described above, since the parallel link mechanism portions 101a and 101b are each formed with six degrees of freedom, the right and left foot portions 103a and 103b have front and rear, left and right, up and down, front and rear directions, left and right directions, and up and down directions. Operation in the axial direction of the axis is possible, various operations can be performed, and walking can be performed smoothly.
The right leg parallel link mechanism 101a and the left leg parallel link mechanism 101b are symmetrically disposed on both sides of the center of the waist 102, and each parallel link mechanism 101a, 101b has six degrees of freedom. Therefore, it is possible to perform walking control so that no moment is applied in the circumferential direction of the axis of the biped walking robot 100, that is, the axis that passes through the center of the waist 102 and is orthogonal to the waist 102 during the walking motion. Thereby, the stable walking is possible, without falling down, without the waist part 102 rotating in the axial direction of a waist axis at the time of walking.

In the present embodiment, the case where the linear link device 1 is applied to the biped walking robot 100 has been described. However, the present invention is not limited to this.
The number and arrangement of the linear motion link device 1 and the legs 103a and 103b can be selected as appropriate according to the size and shape of the waist 102, the purpose and use of the walking robot, etc., and four or more legs The present invention can also be applied to a multi-legged robot having a part.
Further, by connecting the fixed base portion and the movable base portion to both ends of the linear motion link device 1 and expanding and contracting the linear motion link device 1, the movable base portion is moved in the vertical direction and the horizontal direction with respect to the fixed base portion. Therefore, it can be arranged on various robot arms other than the legs to widen the movable range, and can be used for robots other than walking robots.

As described above, the linear motion link device according to Embodiment 1 has the following effects.
(1) The first knuckle 21 includes a first ball screw shaft 21a, a first ball screw nut 21b that is rotatably engaged with the first ball screw shaft 21a, and a first ball screw nut 21. A second gear 25, a second ball screw shaft 25a rotated by the drive motor 29, and a second ball screw shaft. And the main gear 26 that is engaged with the driven gear 22 of the first joint 21. The main gear 26 is rotated by rotating the second ball screw shaft 25 a with the drive motor 29. Then, the first ball screw nut 21b is rotated together with the driven gear 22 by being driven, but the upper end portion of the first ball screw shaft 21a is fixed to the upper end fixing portion 20a. The shaft 21a does not rotate and the second joint 25 Slides longitudinally, it is possible to change the link length.
(2) The third joint 34 is connected to the second ball screw nut 34a that is rotatably engaged with the second ball screw shaft 25a of the second joint 25, and the second ball screw nut 34a. A cylindrical body 34b extrapolated to the second ball screw shaft 25a of the second joint 25, and the rotation of the second ball screw nut 34a is restricted, and the upper end and lower end of the cylindrical body 34b. Since the respective parts are fixed by the connecting part 20d and the lower end fixing part 20b, when the second ball screw shaft 25a is rotated by the drive motor 29, the second ball screw nut 34a of the third node 34 and The cylindrical body 34b can slide in the longitudinal direction of the second joint 25 without rotating, and the link length can be changed.
(3) The first ball screw shaft 21a of the first joint 21 and the second ball screw nut 34a of the third joint 34 are slidable with respect to the second ball screw shaft 25a of the second joint 25. Since they are continuously provided, the first joint 21 and the third joint 34 can be simultaneously slid by simply rotating the second ball screw shaft 25a with one drive motor 29, and the expansion and contraction motion can be controlled. Easy and excellent in operational stability.
(4) Since the first node 21, the second node 25, and the third node 34 are arranged on different axes, the total stroke of the first node 21 and the third node 34 is less than the shortest link length. Can be extended, and the range of motion can be expanded.
(5) The third joint 34 is connected to the second ball screw nut 34a, which is rotatably engaged with the second ball screw shaft 25a of the second joint 25, and the second ball screw nut 34a. Since the second joint 25 and the third joint 34 are arranged coaxially, the second joint 25 and the third joint 34 can be slidably held with a simple structure. it can.
(6) A guide rail 24 is disposed in the first joint 21 in parallel with the first ball screw shaft 21a, and a guide portion 32 for slidably guiding the guide rail 24 is disposed in the second joint 25. As a result, the rotation of the first joint 21 and the second joint 25 is restrained, and when the first ball screw shaft 21a of the first joint 21 is slid with respect to the second joint 25, the first joint 21 guides. The rail 24 can be guided by the guide portion 32 of the second joint 25 and the first ball screw shaft 21a can be moved in parallel with the second joint 25.
(7) The guide rail 33 is disposed in the second joint 25 in parallel with the second ball screw shaft 25a, and the sliding portion 36 guided by the guide rail 33 is disposed in the third joint 34. When the rotation of the second joint 25 and the third joint 34 is restrained and the third joint 34 is slid with respect to the second joint 25, the sliding portion 36 of the third joint 34 is guided by the guide of the second joint 25. The cylindrical body 34 b of the third joint 34 can be moved in parallel with the second joint 25 by being guided by the rail 33.
(8) By arranging the reinforcing cylindrical body 35 in parallel with the cylindrical body 34b of the third section 34, the rigidity of the third section 34 against compression can be improved, and the bending generated in the third section 34 can be improved. The moment can be reduced.

The biped walking robot using the linear motion link device in the first embodiment has the following actions.
(1) The parallel link mechanism portions 101a and 101b for extending and contracting the legs of the biped robot 100 include two linear motion link devices 1, 1 '(1a, 1a', 1b, 1b ', 1c, 1c'). Are arranged in a V-shape as a set, and the Stewart platform is provided with three sets of them, so that the stability and rigidity of the legs are excellent and the operation control can be simplified.
(2) Since the linear motion link devices 1 to 1c ′ of the parallel link mechanism portions 101a and 101b are multistage linear motion actuators having the first joint 21 to the third joint 34, the shortest link length of the legs is reduced. The seating surface can be lowered by shortening it so that passengers can easily get on and off, and they can ride in humans and operate in a living environment where the ceiling height is limited. The stroke can be extended to widen the range of movement of the legs, improving the stability of walking motion, and can be active even in complex terrain with irregularities, steps, obstacles, etc., and is excellent in versatility.

(Embodiment 2)
FIG. 7 is a perspective view showing a linear motion link device according to Embodiment 2 of the present invention, and FIG. 8 is a perspective view showing an extended state of the linear motion link device according to Embodiment 2 of the present invention.
7 and 8, 40 is a linear motion link device according to the second embodiment of the present invention, 40a is an upper end fixing portion for attaching a joint such as a waist-side passive joint 106 to the upper end portion of the linear motion link device 40, and 40b. Is a lower end fixing portion for attaching a joint such as the foot side passive joint 107 to the lower end portion of the linear motion link device 40, and 41 is connected to a joint such as the lumbar side passive joint 106 via the upper end fixing portion 40a at the upper end portion. The first node 41a of the linear motion link device 40 is a cylindrical body of the first node 41 fixed to the upper end fixing portion 40a at the upper end portion, and 42 is connected to the cylindrical body 41a via the connecting portion 40c. The drive motor of the first joint 41, 43 is a drive pulley disposed on the motor shaft of the drive motor 42, and 44 is a second of the linear motion link device 40 disposed coaxially with the cylindrical body 41 a of the first joint 41. section 45 is a ball screw with a spline of the second node 44 that is inserted in the cylindrical body 41a and slides along the cylindrical body 41a while the hollow ball screw 45b rotates as the spline outer cylinder 45a rotates. Is a driven pulley of the second node 44 that is fixed to the spline outer cylinder 45a and rotates together with the spline outer cylinder 45a, 47 connects the driving pulley 43 and the driven pulley 46, and transmits the power of the driving motor 42 to the splined ball screw 45. The timing belt 48 is connected to the lower end of the hollow ball screw 45b, and a thread groove (not shown) is formed in the winding direction opposite to the winding direction of the thread groove 45c formed on the outer peripheral surface of the hollow ball screw 45b. The ball screw nut 49 is arranged coaxially with the hollow ball screw 45b of the second joint 44 and is inserted into the hollow ball screw 45b so that the lower end fixing portion 40b is at the lower end. The third joint 49a of the linear motion link device 40 connected to a joint such as the foot side passive joint 107 via the outer circumferential surface is opposite to the winding direction of the thread groove 45c formed on the outer circumferential surface of the hollow ball screw 45b. This is a ball screw shaft of a third joint 49 formed with a screw groove 49b in the winding direction and rotatably engaged with a ball screw nut 48 of the second joint 44.

  The mechanism of the splined ball screw 45 of the second joint 44 is conventionally known. In the present embodiment, in consideration of the shaft diameter of the ball screw shaft 49a of the third joint 49, etc., the THK BNS series ( BNS1616A was selected from registered trademark) and used. The third joint 49 is inserted on the same axis as the second joint 44, and the number of rotations of the hollow ball screw 45b of the second joint 44 and the ball screw shaft 49a of the third joint 49 are equal, and the linear motion is performed simultaneously. Yes. At this time, by setting the lead of the ball screw shaft 49a of the third joint 49 so that the third joint 49 advances by the same stroke by the rotation of the stroke of the second joint 44, the stroke of the third joint 49 is set. Is the longest and is the same as the stroke of the second knot 44.

The operation of the linear motion link device configured as described above will be described.
In FIG. 7, when the drive motor 42 is rotated, the rotation of the drive pulley 43 disposed on the motor shaft is transmitted to the driven pulley 46 via the timing belt 47. Thereby, the spline outer cylinder 45a rotates with the driven pulley 46. At this time, the hollow ball screw 45b screwed into the spline outer cylinder 45a rotates (slids) in the longitudinal direction while rotating. At the same time, the ball screw shaft 49a of the third joint 49, which is rotatably engaged with the ball screw nut 48 of the second joint 44, is a foot-side passive joint 107 disposed on the lower end fixing portion 40b. Since it is fixed to the foot part etc. which are connected via joints, etc. and rotation is restricted, it moves straight (sliding) in the longitudinal direction by a screw pair.
By selecting the rotation direction of the drive motor 42, these linear movement (sliding) directions can be switched.

As described above, the linear motion link device according to Embodiment 2 has the following effects.
(1) The first node 41 has a drive motor 42 and a cylindrical body 41a connected to the drive motor 42. The second node 44 is inserted into the cylindrical body 41a and the first node 41 is inserted. Since the splined ball screw 45 having the hollow ball screw 45b that slides along the cylindrical body 41a by being rotated by the drive motor 42 is provided, the drive motor 42 of the first joint 41 is driven. Thus, the hollow ball screw 45b of the second joint 44 can be slid (directly moved) while rotating, and the link length can be changed.
(2) A ball screw nut 48 in which a thread groove is formed in the winding direction opposite to the winding direction of the thread groove 45c formed on the outer peripheral surface of the hollow ball screw 45b at the lower end of the hollow ball screw 45b of the second joint 44. The third joint 49 has a ball screw shaft 49a that is rotatably engaged with the ball screw nut 48 of the second joint 44 and is inserted into the hollow ball screw 45b. Since the lower end portion of the screw shaft 49a) is connected to the foot portion or the like via a joint such as the foot side passive joint 107 disposed on the lower end fixing portion 40b, the drive motor 42 uses the hollow ball screw of the second joint 44. When the shaft 45b is rotated, the ball screw shaft 49a of the third joint 49 is slid in the longitudinal direction together with the hollow ball screw 45b of the second joint 44, and the link length can be changed. .
(3) The ball screw 45 with the spline of the second node 44 is inserted into the cylindrical body 41a of the first node 41, and the ball screw shaft of the third node 49 with respect to the hollow ball screw 45b of the ball screw 45 with the spline. Since 49a is slidably held, the second knot 44 and the third knot 49 can be simultaneously slid by simply rotating the hollow ball screw 45b of the splined ball screw 45 with one drive motor 42. Therefore, two drive motors are not necessary, and the expansion and contraction operation can be easily controlled.
(4) Since the first joint 41 to the third joint 49 are arranged coaxially, the mechanism can be simplified and made compact, and a bending moment is applied to the hollow ball screw 45b and the ball screw shaft 49. Therefore, it is possible to secure an overwhelmingly large rigidity compared to the non-coaxial configuration, and it has excellent sliding stability and long life of the second joint 44 and the third joint 49, and has a very high required rigidity. It can be suitably used for a leg mechanism of a high human-carrying bipedal walking robot, and the total stroke of the second joint 44 and the third joint 49 becomes longer than the shortest link length, and the movable range of the leg can be reduced. Can be spread.

  According to the biped walking robot using the linear motion link device in the second embodiment, it has the same operation as that obtained in the first embodiment.

  The present invention provides a linear link device that has a short link length, a short link length, a long link stroke, a large movable range, and excellent versatility by using a multistage link. Provide a robot using a linear link device with a short link length, long link stroke and wide range of motion and excellent versatility, and shortening the shortest link length of the legs to minimize the minimum height from the road surface to the seat surface The height can be lowered, and elderly people and people with walking disabilities can easily get on and off, and they can operate in a human living environment where the ceiling height is limited by boarding humans, and the stroke of the link can be reduced. Longer movement range of legs can be extended, and stabilization control that corrects link length in real time stabilizes walking motion in complex terrain with irregularities, steps, obstacles, etc. A biped walking robot using a linear motion link device that can be operated can be provided, and is suitable for activities in a human living environment, in particular, a human boarding type biped walking robot and a heavy object loading The spread of bipedal robots can be promoted.

The perspective view which shows the linear motion link apparatus in Embodiment 1 of this invention. The perspective view which shows the expansion | extension state of the linear motion link apparatus in Embodiment 1 of this invention The schematic perspective view which shows the biped walking robot using the linear motion link apparatus in Embodiment 1 of this invention Schematic plan perspective view of a biped walking robot provided with the linear motion link device in Embodiment 1 of the present invention Perspective view of the main part of the lumbar side passive joint Perspective view of essential parts of passive joint on the foot side The perspective view which shows the linear motion link apparatus in Embodiment 2 of this invention. The perspective view which shows the expansion | extension state of the linear motion link apparatus in Embodiment 2 of this invention

Explanation of symbols

1, 1 ', 1a, 1a', 1b, 1b ', 1c, 1c', 40 Linear motion link device 20a, 40a Upper end fixing part 20b, 40b Lower end fixing part 20c, 20d, 40c Connection part 21, 41 Section 1 21a First ball screw shaft 21b First ball screw nut 22 Driven gear 23a, 28a Urethane washer 23b, 28b Bearing nut 24, 33 Guide rail 25, 44 Second section 25a Second ball screw shaft 26 Main drive gear 27, 46 Driven pulley 29, 42 Drive motor 30, 43 Drive pulley 31, 47 Timing belt 32 Guide part 32a Guide groove 34, 49 Third section 34a Second ball screw nut 34b Cylindrical body 35 Reinforcing cylindrical body 36 Sliding part 41a Tubular body 45 Ball screw with spline 45a Spline outer cylinder 45b Hollow ball screw 45c, 49b Thread groove 48 Ball screw nut 49a Ball screw shaft 100 Biped robot 101a, 101b Parallel link mechanism part 102 Lumbar part 103a, 103b Foot part 104a, 104b Fixing plate 106, 106 ', 106a, 106a', 106b, 106b ′, 106 c, 106 c ′ Lumbar side passive joint 107, 107 a, 107 b, 107 c Foot side passive joint 113 Lumbar side upper joint 113 a Upper joint shaft 114 Lumbar side lower joint 114 a Lower joint shaft 115 Connecting rotation portion 116 First foot Upper joint 116 'Second foot upper joint 116a, 116b, 116a', 116b 'Side shaft support plate 117 Ball holding portion 117a Ball housing portion 117b Joint shaft 117c Locking nut 118 Foot side base 119 Ball joint shaft 119 Ball portion

Claims (7)

(A) a first ball screw shaft, a first ball screw nut rotatably engaged with the first ball screw shaft, and a follower formed or fixed on the outer periphery of the first ball screw nut A first node having a gear; (b) a drive motor; a second ball screw shaft that is rotated by the drive motor; and a second ball screw shaft penetrating through the second ball screw shaft. And a second ball screw nut rotatably engaged with the second ball screw shaft of the second node, and the second ball. A linear link device comprising: a third section having a cylindrical body that is connected to a screw nut and that is externally attached to the second ball screw shaft of the second section. A guide rail disposed in the first section parallel to the first ball screw shaft; and a guide section disposed in the second section for slidably guiding the guide rail. The linear motion link device according to claim 1, wherein A guide rail disposed in parallel with the second ball screw shaft in the second section; and a sliding portion disposed in the third section and guided by the guide rail. The linear motion link device according to claim 1 or 2. 4. The reinforcing cylinder according to any one of claims 1 to 3, further comprising a reinforcing cylinder disposed in parallel with the cylinder at the third node and into which the first ball screw shaft is inserted. The linear motion link device described. (A) a first node having a drive motor and a cylindrical body connected to the drive motor; (b) inserted into the cylindrical body and rotated by the drive motor of the first node. A splined ball screw having a hollow ball screw that slides along the cylindrical body, and a winding direction of a thread groove formed on the outer peripheral surface of the hollow ball screw connected to the lower end of the hollow ball screw A second node having a ball screw nut in which a thread groove is formed in a direction opposite to the winding direction, and (c) the second ball screw nut of the second node being rotatably engaged with the hollow ball screw. A linear link device comprising: a third node having a ball screw shaft inserted therein. 6. The linear motion link device according to claim 1, a fixed base portion connected to one end portion of the linear motion link device, and an operation base connected to the other end side of the linear motion link device. And a robot characterized by comprising: A parallel link mechanism formed by a Stewart platform in which the linear motion link device according to any one of claims 1 to 5 is arranged in a V shape as a set of two, A biped walking robot comprising: a base portion connected to an upper end side of the linear motion link device; and left and right foot portions connected to a lower end side of the linear motion link device.

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