JP2019094911A - Linear motion expandable mechanism robot arm mechanism - Google Patents

Abstract

To improve durability of a hinge part, which couples a linear motion expandable mechanism and a top of a robot arm mechanism in a bendable manner.SOLUTION: A linear motion expandable mechanism comprises a plurality of plate-shaped first tops 53 coupled in a bendable manner by a first hinge part 300, and a plurality of second tops 54 coupled in a bendable manner by a second hinge part 400 on a bottom side and having a U-shaped or square-shaped transverse section. The first hinge part 300 has a columnar shaft 60, a bearing part 533 of a shaft provided at a rear end or front end of each first top so as to project rearward or frontward, and a support part 532 of the shaft provided at the front end or rear end of each first top so as to project frontward or rearward. The bearing part comprises needle roller bearings 538-1, 538-2.SELECTED DRAWING: Figure 6

Description

  Embodiments of the present invention relate to a linear motion telescopic mechanism and a robot arm mechanism.

  In recent years, the possibility of working in the vicinity of a worker has been examined for industrial robots as well as nursing robots. If this situation is realized, for example, it may be possible for a disabled person to work as well as a healthy person with the support of a robot. A vertical articulated robot arm mechanism with a linear motion telescopic mechanism that the inventors have realized practical use has no elbow joint and no singular point, so it does not move suddenly at high speed in an unexpected direction The movement of the arm and the end effector can be predicted, the safety of which is very high, and the safety fence is not required to realize the cooperative work between the robot and the worker.

  The linear motion expansion and contraction mechanism has a plurality of flat plate-shaped pieces that are flexibly connected at the hinge portion and a plurality of U-shaped groove-shaped pieces that are similarly connected at the bottom portion side so as to be freely bent at the hinge portion Become. These two types of frames are pressed firmly and joined together by the roller unit. Thus, a columnar arm portion rigidly fixed in a straight line and having a certain rigidity is formed. A linear gear is provided on the back surface of the flat plate-shaped piece, and a drive gear connected to a motor is engaged with the linear gear. When the drive gear rotates forward, the columnar arm portion is sent forward from the roller unit, and when it rotates reversely, it is pulled back. At the rear of the roller unit, the two types of frames are separated and restored to the flexed state. The two types of tops restored to the flexed state are flexed in the same direction and accommodated inside the support. A wrist is attached to the tip of the arm. The wrist is equipped with three articulations with three orthogonal rotation axes in order to arbitrarily change the attitude of the end effector.

  As described above, one of the important parts in the linear motion expansion and contraction mechanism is a large number of flexibly connected pieces, and the bending between the pieces is repeated along with the expansion and contraction of the arm portion. The deformation of the shaft and the bearing due to this causes a bending load of the top, and separates the smooth expansion and contraction movement of the arm portion. Therefore, the frequency of replacement of the shaft and the bearing in the hinge portion is relatively high.

Patent No. 5435679 gazette

  It is an object of the present invention to improve the durability of a linear motion telescopic mechanism and a hinge portion that connects a top of a robot arm mechanism in a bendable manner.

  The linear motion telescopic mechanism according to the present embodiment has a plurality of plate-shaped first frames connected so as to be bendable by the first hinge portion, and a cross-sectionally U-shaped or cross-sectionally connected so as to be bendable by the second hinge portion When the first piece is joined to the plurality of second pieces and the second piece on the surface side opposite to the bottom side, the first and second pieces are rigid due to their bending being restricted. The first and second pieces, which are formed into a columnar body, return to a bent state when separated from each other. The first hinge portion includes a cylindrical shaft, a bearing portion of the shaft provided to project backward or forward at the rear end or front end of each of the first pieces, and the front end or rear end of each of the first pieces. And a support portion of the shaft provided to project forward or backward, and the bearing portion includes a needle roller bearing.

FIG. 1 is a perspective view showing the appearance of a robot arm mechanism equipped with a linear motion telescopic mechanism according to the present embodiment. FIG. 2 is a side view of the robot arm mechanism of FIG. FIG. 3 is a side view showing the internal structure of the robot arm mechanism of FIG. FIG. 4 is a diagram showing the configuration of the robot arm mechanism of FIG. FIG. 5 is a view showing the arm unit of FIG. FIG. 6 is a diagram showing the structure of the first frame of FIG. FIG. 7 is a view showing a structure of a second top in FIG. FIG. 8 is a view showing the structure of the bearing of FIG. FIG. 9 is a view showing the structure of the movable portion of the first hinge portion of FIG.

  Hereinafter, the linear motion telescopic mechanism according to the present embodiment will be described with reference to the drawings. In addition, the linear motion expansion-contraction mechanism which concerns on this embodiment can be used as a single mechanism (joint). In the following description, a robot arm mechanism will be described by way of example, in which one of the plurality of joints is a linear motion telescopic mechanism according to the present embodiment. As a robot arm mechanism, here, a vertical articulated robot arm mechanism having a linear motion telescopic mechanism is described, but other types of robot arm mechanisms may be used. In the following description, components having substantially the same function and configuration are given the same reference numerals, and repeated description will be made only when necessary.

FIG. 1 shows the appearance of a robot arm mechanism equipped with a linear motion telescopic mechanism according to this embodiment. FIG. 2 is a side view of the robot arm mechanism of FIG. FIG. 3 is a side view showing the internal structure of the robot arm mechanism of FIG.
The robot arm mechanism includes a base 1, a pivoting portion (supporting portion) 2, an undulating portion 4, an arm portion 5 and a wrist portion 6. The pivoting portion 2, the ups and downs 4, the arm 5 and the wrist 6 are disposed in order from the base 1. The plurality of joints J1, J2, J3, J4, J5, and J6 are disposed in order from the base 1. On the base 1, a pivoting portion 2 which is a cylindrical body is typically installed vertically. The pivoting unit 2 accommodates a first joint J1 as a pivoting joint. The first joint J1 includes a torsional rotation axis RA1. The rotation axis RA1 is parallel to the vertical direction. The pivoting portion 2 has a lower frame 21 and an upper frame 22. One end of the lower frame 21 is connected to the fixed portion of the first joint portion J1. The other end of the lower frame 21 is connected to the base 1. The lower frame 21 is covered by a cylindrical housing 31. The upper frame 22 is connected to the rotating portion of the first joint J1 and rotates about the rotation axis RA1. The upper frame 22 is covered by a cylindrical housing 32. The upper frame 22 rotates with respect to the lower frame 21 with the rotation of the first joint J1, and the arm 5 pivots horizontally. First and second frame trains 51 and 52 of a third joint J3 as a linear motion extension and contraction mechanism described later are accommodated in the hollow of the turning portion 2 forming a cylindrical body.

  At the upper part of the pivoting portion 2, a relief portion 4 for accommodating a second joint portion J2 as a relief rotary joint portion is installed. The second joint J2 is a bending rotary joint. The rotation axis RA2 of the second joint J2 is perpendicular to the rotation axis RA1. The relief portion 4 has a pair of side frames 23 as a fixing portion (supporting portion) of the second joint portion J2. The pair of side frames 23 is connected to the upper frame 22. The pair of side frames 23 is covered by a wedge-shaped cover 33. A cylindrical body 24 is supported by the pair of side frames 23 as a rotating portion of the second joint J2 which also serves as a motor housing. The delivery mechanism 25 is attached to the circumferential surface of the cylindrical body 24. The delivery mechanism 25 is covered by a cylindrical cover 34. The gap between the wedge-shaped cover 33 and the cylindrical cover 34 is covered by a U-shaped bellows cover 14 having a U-shaped cross section. The U-shaped bellows cover 14 expands and contracts following up and down movement of the second joint J2.

  The delivery mechanism 25 holds the drive gear 56, the guide roller 57 and the roller unit 58. The delivery mechanism 25 rotates with the axial rotation of the cylindrical body 24, and the arm portion 5 supported by the delivery mechanism 25 is raised and lowered up and down.

  The third joint J3 is provided by a linear motion telescopic mechanism. The linear motion telescopic mechanism has a structure newly developed by the inventors, and is clearly distinguished from a so-called conventional linear joint in view of the movable range. The arm 5 of the third joint J3 is bendable, but when it is fed forward from the delivery mechanism 25 at the base of the arm 5 along the central axis (the telescopic central axis RA3), the bending is restricted, and linear rigidity Is secured. When the arm 5 is pulled back, the bending is recovered. The arm unit 5 has a first frame train 51 and a second frame train 52. The first top row 51 is composed of a plurality of first tops 53 connected in a flexible manner. The first top 53 is formed in a substantially flat plate shape. The first cotter 53 is flexibly connected by the first hinge 300 at the end. The second frame sequence 52 is composed of a plurality of second frames 54. The second cotter 54 is configured as a groove-like body having a U-shaped cross section or a cylindrical body having a U-like shape. The second top 54 is flexibly connected by the second hinge 400 at the bottom plate end. The bending of the second frame 52 is limited at the position where the end faces of the side plates of the second frame 54 abut. At that position, the second frame train 52 is linearly arranged. Details of the first and second hinges 300 and 400 will be described later. The leading first frame 53 of the first frame sequence 51 and the leading second frame 54 of the second frame sequence 52 are connected by a combined frame 55. For example, the combined top 55 has a shape in which the first top 53 and the second top 54 are combined.

  When passing through the roller unit 58 of the delivery mechanism 25, the first and second frame trains 51 and 52 are mutually pressed by the roller 59 and joined. By joining, the first and second frame rows 51 and 52 exert linear rigidity to constitute a columnar arm portion 5. At the rear of the roller unit 58, a drive gear 56 is disposed together with the guide roller 57. The drive gear 56 is connected to a motor unit (not shown). The motor unit generates power for rotating the drive gear 56. A linear gear 539 is formed along the connecting direction at the center of the width of the inner surface of the first top 53, ie, the surface on the side to be joined to the second top 54. When the plurality of first tops 53 are linearly aligned, the adjacent linear gears 539 are linearly connected to form a long linear gear. The drive gear 56 is engaged with the linear gear 539 of the first frame 53 pressed by the guide roller 57. The linear gear 539 connected in a straight line form a rack and pinion mechanism together with the drive gear 56. When the drive gear 56 rotates forward, the first and second frame trains 51 and 52 are fed forward from the roller unit 58. When the drive gear 56 reversely rotates, the first and second frame trains 51 and 52 are pulled back to the rear of the roller unit 58. The pulled back first and second frame trains 51 and 52 are separated from each other between the roller unit 58 and the drive gear 56. The separated first and second frame trains 51 and 52 respectively return to the bendable state. The first and second frame trains 51 and 52 returned to the bendable state are both bent in the same direction (inner side), and are vertically stored inside the turning portion 2. At this time, the first frame train 51 is stored substantially in parallel with the second frame train 52.

  The wrist 6 is attached to the tip of the arm 5. The wrist portion 6 is equipped with the fourth to sixth joint portions J4 to J6. The fourth to sixth joint portions J4 to J6 respectively have rotation axes RA4 to RA6 of three orthogonal axes. The fourth joint J4 is a torsional rotary joint centered on a fourth rotation axis RA4 substantially coinciding with the telescopic central axis RA3. The rotation of the fourth joint J4 causes the end effector to swing. The fifth joint J5 is a bending and rotating joint centered on the fifth rotation axis RA5 disposed perpendicularly to the fourth rotation axis RA4, and rotation of the fifth joint J5 causes the end effector to tilt and rotate back and forth. Be done. The sixth joint portion J6 is a torsional rotary joint centering on the sixth rotation axis RA6 disposed perpendicularly to the fourth rotation axis RA4 and the fifth rotation axis RA5, and rotation of the sixth joint portion J6 The end effector is pivoted.

  The end effector (hand effect device) is attached to an adapter 7 provided at the lower part of the rotating portion of the sixth joint portion J6 of the wrist portion 6. The end effector is a portion having a function of causing the robot to directly act on a work target (work), and various tools exist depending on tasks such as a gripping unit, a vacuum suction unit, a nut clamp, a welding gun and a spray gun. The end effector is moved to an arbitrary position by the first, second and third joints J1, J2 and J3, and is placed in an arbitrary posture by the fourth, fifth and sixth joints J4, J5 and J6. In particular, the extension distance of the arm 5 of the third joint J3 enables the end effector to reach a wide range of objects from the proximity position of the base 1 to the remote position. The third joint portion J3 is a characteristic point that the linear expansion and contraction operation realized by the linear motion expansion and contraction mechanism constituting the third joint portion J3 and the length of the expansion and contraction distance thereof are different from those of the conventional linear motion joint.

  FIG. 4 shows the configuration of the robot arm mechanism in a pictorial representation. In the robot arm mechanism, three positional freedoms are realized by the first joint portion J1, the second joint portion J2 and the third joint portion J3 constituting the three axes of roots. Further, three posture freedoms are realized by the fourth joint portion J4, the fifth joint portion J5, and the sixth joint portion J6 that constitute the three wrist axes. As shown in FIG. 4, the rotation axis RA1 of the first joint J1 is provided in the vertical direction. The rotation axis RA2 of the second joint J2 is provided in the horizontal direction. The second joint J2 is offset with respect to the first joint J1 in two directions of the rotation axis RA1 and the axis orthogonal to the rotation axis RA1. The rotation axis RA2 of the second joint J2 does not intersect the rotation axis RA1 of the first joint J1. The movement axis RA3 of the third joint J3 is provided in a direction perpendicular to the rotation axis RA2. The third joint J2 is offset with respect to the second joint J2 in two directions of the rotation axis RA1 and the axis orthogonal to the rotation axis RA1. The rotation axis RA3 of the third joint J3 does not intersect the rotation axis RA2 of the second joint J2. The bending joint of one of the root three axes of the plurality of joints J1-J6 is replaced with the linear motion expansion joint J3, and the second joint J2 is offset in two directions with respect to the first joint J1, By offsetting the third joint J3 in two directions with respect to the second joint J2, the robot arm mechanism of the robot apparatus according to the present embodiment structurally eliminates the singularity posture.

  FIG. 5 is a view showing the arm unit 5 of FIG. FIG. 6 is a view showing the structure of the first top 53 shown in FIG. FIG. 7 is a view showing the structure of the second top 54 shown in FIG. FIG. 8 is a view showing the structure of the bearing 538-1 of FIG. FIG. 9 is a view showing the structure of the movable portion of the first hinge 300 of FIG.

(1st piece 53)
As shown in FIG. 5, the front and rear first tops 53 are flexibly connected by the first hinges 300 at end portions. The first hinge portion 300 has a shaft 60, a support portion at the front end of the first top 53, and a bearing portion at the rear end of the first top 53.
As shown in FIG. 6, the first top 53 is a substantially flat plate as a whole. The first top 53 has a main body portion 531 of a rectangular flat plate. Here, a pair of support blocks 532-1 and 532-2 is provided to project forward on both sides of the front end of the main body portion 531 as a support portion of the front end of the first top 53. A pair of shaft holes 534-1 and 534-2 are penetrated in the pair of support blocks 532-1 and 532-2 in parallel with the width direction of the first top 53. The pair of shaft holes 534-1 and 534-2 have a diameter equivalent to the inner diameter of the bearings 538-1 and 538-2 described later, or slightly larger than the inner diameter of the bearings 538-1 and 538-2. The outer surface of one bearing block 532-1 is provided with a hook receiving portion 535-1 which receives a hook portion 61 of a shaft 60 described later. A ring accommodating portion 535-2 is provided on the outer side surface of the other bearing block 532-2 to accommodate a locking ring 65 fitted in a groove 63 at the tip of a shaft 60 described later.

  As a bearing portion at the rear end of the first top 53, a bearing block 533 is provided at the center of the rear end of the main body 531 so as to protrude rearward. The total width of the width of the bearing block 533 of the first top 53 and the width of the pair of support blocks 532-1 and 532-2 is substantially equivalent to the width of the first top 53. The width of the bearing block 533 of the first top 53 is wider than the total width of the pair of support blocks 532-1 and 532. The bearing block 533 includes a bearing that rotatably supports the shaft 60 with respect to the bearing block 533, here, a pair of bearings 538-1 and 538-2. Specifically, an axial hole 536 is penetrated in the bearing block 533 in parallel with the width direction of the first cotter 53. The axial hole 536 has a diameter substantially equivalent to the inner diameter of bearings 538-1 and 538-2 described later. At both ends of the shaft hole 536, a pair of bearing accommodating portions 537-1 and 537-2 are provided. The pair of bearings 538-1 and 538-2 are fitted in the pair of bearing accommodating portions 537-1 and 537-2. As shown in FIG. 8, the bearings 538-1 and 538-2 are particularly needle bearings (needle roller bearings) as roller bearings provided with “rollers” in line contact with the surface of the shaft as rolling elements. ). A bearing provided with a rolling element in line contact with the surface of the shaft has a high load capacity and is advantageous against vibration and impact load as compared to a ball bearing in point contact with the surface of the shaft. In needle bearings (needle roller bearings), the diameter of rolling elements is very short compared to the length, and many rolling elements can be arranged on the circumference of the bearing, so vibration and impact load can be achieved compared to ball bearings. It is further advantageous.

  With the bearing block 533 at the rear end of the other first cotter 53 fitted between the pair of support blocks 532-1 and 532-2 at the front end of the first cotter 53, the pair of shaft holes 534-1, 531 534-2 and the axial hole 537 connect continuously. The shaft 60 is inserted through the continuously connected through holes. The shaft 60 inserted into the continuously connected through hole is rotatably supported by the bearings 538-1 and 538-2 provided in the bearing block 533 of the first top 53, whereby the front and rear first tops 53 are The shafts 60 are rotatably connected to each other. As shown in FIG. 9, the shaft 60 has a cylindrical main body portion 62 having a diameter substantially equivalent to the inner diameter of the bearings 538-1 and 538-2. At the rear end of the main body portion 62, a collar portion 61 having a non-circular shape, here, a D-shaped cross section is provided. A groove 63 is provided at the tip of the main body 62 along the circumference of the main body 62. The locking ring 65 is fitted into the groove 63. The length from the rear end to the front end of the shaft 60 is approximately equal to the width of the first top 53 or slightly shorter than the width of the first top 53. Thus, the shaft 60 rotates with the inner ring of the bearings 538-1 and 538-2 in a state where the shaft 60 is inserted into the bearings 538-1 and 538-2, and the axial movement of the shaft 60 The portion 535-1 receives the hook portion 61, and the ring accommodation portion 535-2 is locked by receiving the locking ring 65.

  As described above, the bearing block at the center of the rear end of the first cotter 53 includes a pair of bearings 538-1 and 538-2. The width of the bearing block 533 at the center of the rear end of the first top 53 is made wider than the total width of the support blocks 532-1 and 532-2 on both sides of the top end of the first top 53. It is realized to adopt a needle bearing at 538-2. Of course, in the case where the width of the first top 53 is sufficiently wider than the length of the needle bearing, the width of the bearing block 533 is shorter than or equal to the total width of the pair of support blocks 532-1 and 532. May be

  Adopting a needle bearing with high load performance as compared to a ball bearing as the bearings 538-1 and 538-2 rotatably supporting the shaft 60 connecting the front and rear first pieces 53 Improve endurance performance. The improvement of the durability performance of the first hinge portion 300 suppresses rattling between the front and rear first pieces 53 and realizes not only the smooth expansion and contraction movement of the arm portion 5 but also the shaft 60 and the bearing 538-1 , 538-2, and the first frame 53 is reduced.

  The pair of bearings 538-1 and 538-2 may not be needle bearings, but may be other bearings provided with rolling elements in linear contact with the surface of the shaft, such as cylindrical roller bearings. Also, although the bearing block 533 is herein provided with a pair of needle bearings 538-1, 538-2, the bearing block 533 may be provided with a wide single needle bearing. In addition, although the bearing block 533 at the center of the rear end of the first top 53 is herein provided with the pair of needle bearings 538-1 and 538-2, the pair of support blocks 532-1 and 531-2 on both sides of the front end of the first top 53 532-2 may include a pair of needle bearings 538-1, 538-2. Furthermore, the structure of the first hinge 300 is not limited thereto. For example, the structure of the front and rear ends of the first top 53 described above may be reversed. That is, a bearing block may be provided so as to protrude forward at the center of the front end of the first top 53, and a support block may be provided protruding rearward on both sides of the rear end of the first top 53. In addition, a first bearing block may be provided on the front right side of the front end of the first top 53 so as to protrude forward, and a second bearing block may be provided on the rear left side of the first top 53 so as to protrude rearward. At this time, the first and second bearing blocks are equipped with a pair of needle bearings.

(2nd piece 54)
The second top 54 is flexibly connected by the second hinge 400 at the bottom plate end. The second hinge portion 400 has a shaft 70, a support portion at the front end of the second top 54, and a bearing portion at the rear end of the second top 54.

  The second hinge 400 has the same structure as the first hinge 300 of the first top 53. As shown in FIG. 7, the second top 54 is a groove-like body or a U-shaped tubular body that is generally U-shaped in cross section. The second top 54 has a groove-shaped (wedge-shaped) main body. The main body portion is formed by connecting a pair of side plates 540-1 and 540-2 of the same size and the same shape in parallel by the bottom plate 541. A pair of support blocks 542-1 and 542-2 are provided to project forward on both sides of the front end of the bottom plate 541 as support portions of the front end of the second top 54. A pair of axial holes 544-1 and 544-2 are penetrated in a pair of support blocks 542-1 and 542-2 in parallel with the width direction of the second top 54. The pair of shaft holes 544-1 and 544-2 have a diameter equivalent to the inner diameter of the bearings 548-1 and 548-2 described later, or slightly larger than the inner diameter of the bearings 548-1 and 548-2. The outer surface of one bearing block 542-1 is provided with a hook receiving portion 545 for receiving the hook portion 71 of the shaft 70. On the outer side surface of the other bearing block 542-2, a ring accommodating portion 545-2 for accommodating the locking ring 75 fitted in the groove portion 73 at the tip of the shaft 70 is provided.

  A bearing block 543 is provided to project rearward at the center of the rear end of the bottom plate 541 as a bearing portion at the rear end of the second top 54. The total width of the width of the bearing block 543 of the second top 54 and the width of the pair of support blocks 542-1 and 542-2 is substantially equivalent to the width of the second top 54. The width of the bearing block 543 of the second top 54 is wider than the total width of the pair of support blocks 542-1 and 542. The bearing block 543 includes bearings, in this case a pair of bearings 548-1 and 548-2 that rotatably support the shaft 70 with respect to the bearing block 543. Specifically, an axial hole 546 is penetrated in the bearing block 543 in parallel with the width direction of the second top 54. The axial hole 546 has a diameter substantially equivalent to the inner diameter of the bearings 548-1 and 548-2. A pair of bearing accommodating portions 547-1 and 547-2 are provided at both ends of the shaft hole 546. A pair of bearings 548-1 and 548-2 are fitted in the pair of bearing accommodating portions 547-1 and 547-2. The bearings 548-1 and 548-2 are preferably the same type and the same size as the bearing 538-1 provided in the first top 53.

  With the bearing block 543 at the rear end of the other second cotter 54 fitted between the pair of support blocks 542-1 and 542-2 at the front end of the second cotter 54, the pair of shaft holes 544-1, 544-2 and the axial hole 547 connect continuously. In a state where the shaft 70 is inserted into the continuously connected through hole, the locking ring 75 is fitted in the groove portion at the tip of the shaft 70. The shaft 70 and the locking ring 75 are preferably of the same kind and size as the shaft 60 of the first piece 53 and the locking ring 65. The shaft 70 inserted into the continuously connected through hole is rotatably supported by bearings 548-1 and 548-2 provided in the bearing block 543 of the second top 54, whereby the front and rear second tops 54 are The shafts 70 are rotatably connected to each other.

  As described above, according to the structure of the second hinge portion 400, the same effect as the first hinge portion 300 is exerted. That is, by adopting needle bearings with high load performance compared to ball bearings, bearings 548-1 and 548-2 rotatably supporting the shaft 70 connecting the front and rear second pieces 54, the second hinge portion The durability performance of 400 is improved. The improvement of the durability performance of the second hinge portion 400 suppresses the rattling between the front and rear second tops 54, and realizes not only the smooth expansion and contraction of the arm portion 5, but also the shaft 70 and the bearings 548-1. , 548-2, and the second frame 54 is reduced in frequency.

  In the above description, although the bearing is a needle bearing (needle roller bearing) 538-1, 538-2, 548-1, and 548-2 as a rolling bearing, load capacity, vibration, and impact load can be tolerated. In this case, it does not completely deny that it is a cylindrical slide bearing made of a self-lubricating resin such as polyacetal (POM), polyamide (PA), polytetrafluoroethylene (PTFE; fluorocarbon resin), etc. .

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

  53 first frame 531 main body 532-1 532-2 support block 533 bearing block 534-1 534-2, 536 axial hole 535-1 wedge receiver 535 2 ... ring accommodating part, 537-1, 537-2 ... bearing accommodating part, 538 -1, 538-2 ... bearings.

Claims (4)

A plurality of plate-shaped first frames connected so as to be bendable by the first hinge portion;
On the bottom side, a plurality of second pieces having a cross section U-shape or B-shape connected so as to be bendable by a second hinge part, and the second pieces are joined on the surface side opposite to the bottom side And the first and second pieces are structured in the shape of a rigid column whose bending is restrained, and the first and second pieces are returned to the bent state when separated from each other. ,
The first hinge portion includes a cylindrical shaft, a bearing portion of the shaft provided to project backward or forward at the rear end or front end of each of the first pieces, and the front end or rear end of each of the first pieces. And a support portion of the shaft provided to project forward or backward,
The linear motion telescopic mechanism characterized in that the bearing portion comprises needle roller bearings. A plurality of plate-shaped first frames connected so as to be bendable by the first hinge portion;
On the bottom side, a plurality of second pieces having a cross section U-shape or B-shape connected so as to be bendable by a second hinge part, and the second pieces are joined on the surface side opposite to the bottom side And the first and second pieces are structured in the shape of a rigid column whose bending is restrained, and the first and second pieces are returned to the bent state when separated from each other. ,
The second hinge portion includes a cylindrical shaft, a bearing portion of the shaft provided to project backward or forward at the rear end or front end of each of the second pieces, and the front end or rear end of each of the second pieces. And a support portion of the shaft provided to project forward or backward,
The linear motion telescopic mechanism characterized in that the bearing portion comprises needle roller bearings. A supporting column having a pivoting rotation joint is supported on a base, a relief having a rising and lowering rotation joint is mounted on the support, and the relief has a linear motion stretchable arm. A linear motion extension mechanism is provided, and a tip of the arm is equipped with a wrist capable of mounting an end effector, and the wrist has at least one rotation joint for changing the attitude of the end effector In the equipped robot arm mechanism,
The linear motion telescopic mechanism is
A plurality of plate-shaped first frames connected so as to be bendable by the first hinge portion;
On the bottom side, a plurality of second pieces having a cross section U-shape or B-shape connected so as to be bendable by a second hinge part, and the second pieces are joined on the surface side opposite to the bottom side And the first and second pieces are structured in the shape of a rigid column whose bending is restrained, and the first and second pieces are returned to the bent state when separated from each other. ,
The first hinge portion includes a cylindrical shaft, a bearing portion of the shaft provided to project backward or forward at the rear end or front end of each of the first pieces, and the front end or rear end of each of the first pieces. And a support portion of the shaft provided to project forward or backward,
The robot arm mechanism characterized in that the bearing portion comprises a needle roller bearing. A supporting column having a pivoting rotation joint is supported on a base, a relief having a rising and lowering rotation joint is mounted on the support, and the relief has a linear motion stretchable arm. A linear motion extension mechanism is provided, and a tip of the arm is equipped with a wrist capable of mounting an end effector, and the wrist has at least one rotation joint for changing the attitude of the end effector In the equipped robot arm mechanism,
The linear motion telescopic mechanism is
A plurality of plate-shaped first frames connected so as to be bendable by the first hinge portion;
On the bottom side, a plurality of second pieces having a cross section U-shape or B-shape connected so as to be bendable by a second hinge part, and the second pieces are joined on the surface side opposite to the bottom side And the first and second pieces are structured in the shape of a rigid column whose bending is restrained, and the first and second pieces are returned to the bent state when separated from each other. ,
The second hinge portion includes a cylindrical shaft, a bearing portion of the shaft provided to project backward or forward at the rear end or front end of each of the second pieces, and the front end or rear end of each of the second pieces. And a support portion of the shaft provided to project forward or backward,
The robot arm mechanism characterized in that the bearing portion comprises a needle roller bearing.

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