TW201733753A - Linear extension and retraction mechanism, and robot arm mechanism - Google Patents

Abstract

The present invention improves the durability of a hinge part that couples together, in a bendable manner, pieces of a linear extension/retraction mechanism and a robot arm mechanism. The linear extension/retraction mechanism comprises: a plurality of first pieces (53) each of which has a plate-like shape and which are coupled together in a bendable manner through a first hinge part (300); and a plurality of second pieces (54) each of which has a U-shaped cross section or a rectangular cross section and which are coupled together, at the bottom surface side, in a bendable manner through a second hinge part (400). The first hinge part (300) includes: a cylindrical shaft (60); a shaft bearing part (533) provided at the rear or front end of each of the first pieces so as to protrude backward or forward; and a shaft support part (532) provided at the front or rear end of each of the first pieces so as to protrude forward or backward. The bearing part is provided with needle roller bearings (538-1, 538-2).

Description

Linear motion retracting mechanism and mechanical arm mechanism

Embodiments of the present invention relate to a linear motion expansion mechanism and a mechanical arm mechanism.

In recent years, there has been a possibility of discussing the situation in which the care robot and the industrial robot operate in the vicinity of the operator. If this is achieved, the obstacle can be operated in the same manner as the healthy person by, for example, the support of the robot. The inventor and the like have realized that the vertical multi-joint type robot arm mechanism with the linear motion expansion mechanism has no elbow joint and no critical point, so that it does not suddenly move at a high speed in an unpredictable direction, and the arm and the end can be predicted. The action of the effector is very safe, and there is no need for a safety fence to achieve the cooperation between the robot and the operator.

The linear motion retracting mechanism has a plurality of flat-plate-shaped links that are flexibly connected by a hinge portion, and a plurality of hinged portions that are bent and freely connected to the bottom side by a hinge portion. The word slot shape is formed by a chain link. The two links are firmly pressed and joined to each other by the roller unit. Thereby, a columnar arm portion which is straight and straight and has a certain rigidity is formed. A linear gear is disposed on a back surface of the plate-shaped chain link, and the linear gear is meshed with a drive gear coupled to the motor. When the drive gear rotates in the forward direction, the arm portion that becomes the columnar body is sent forward from the roller unit, and if it is reversely rotated, it is pulled back toward the rear. After the roller unit, the two links are separated and returned to a bent state. The two links that are restored to the bent state are bent in the same direction and are housed inside the pillar portion. A wrist is attached to the front end of the arm. The wrist is equipped with three joint portions having orthogonal axes of three axes for arbitrarily changing the posture of the end effector.

One of the important parts of the linear motion retractable mechanism is a plurality of links that are flexibly connected, and the bending between the links is repeated with the expansion and contraction of the arm portion. Therefore, the shaft and the bearing caused by the wear of the shaft and the bearing of the hinge portion are caused. The deformation becomes a bending load of the link, and the arm is no longer smoothly telescopically moved. Therefore, the frequency of replacement of the shaft and the bearing of the hinge portion is relatively high.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5435679

An object of the present invention is to improve the durability of a hinge portion in which a link of a linear motion expansion mechanism and a mechanical arm mechanism is bendably coupled.

The linear motion expansion/contraction mechanism according to the present embodiment includes a plurality of first links that are bent in a plate shape by the first hinge portion, and a cross section that is bendably coupled to the bottom surface side by the second hinge portion. When the second link is joined to the first link on the surface side opposite to the bottom surface side, the bending of the first link and the second link is restricted to form a plurality of second links. In the case of the hard straight columnar body, when the first and second link segments are separated from each other, the state is restored to a curved state. The first hinge portion includes a cylindrical shaft, a bearing portion of the shaft that protrudes rearward or forward from the rear end or the front end of the first link, and a front end or a rear end of the first link. Or the support portion of the shaft protruding from the rear, and the bearing portion is provided with a needle roller bearing.

53‧‧‧1st link

531‧‧‧ Body Department

532-1, 532-2‧‧‧ Support Blocks

533‧‧‧ bearing block

534-1, 534-2, 536‧‧‧ shaft holes

535-1‧‧‧Flange bearing department

535-2‧‧‧Circle containment department

537-1, 537-2‧‧‧ Bearing Housing Department

538-1, 538-2‧‧‧ bearing

Fig. 1 is a perspective view showing the appearance of a mechanical arm mechanism equipped with the linear motion stretching mechanism of the embodiment.

Figure 2 is a side elevational view of the robotic arm mechanism of Figure 1.

Fig. 3 is a side view showing the internal structure of the mechanical arm mechanism of Fig. 1.

Fig. 4 is a view showing the configuration of the mechanical arm mechanism of Fig. 1 by the symbol representation.

Fig. 5 is a view showing the arm of Fig. 3.

Fig. 6 is a view showing the structure of the first link of Fig. 5;

Fig. 7 is a view showing the structure of the second link of Fig. 5;

Fig. 8 is a view showing the structure of the bearing of Fig. 6.

Fig. 9 is a view showing the structure of a movable portion of the first hinge portion of Fig. 5;

Hereinafter, the linear motion expansion mechanism of this embodiment will be described with reference to the drawings. Further, the linear motion expansion mechanism of the present embodiment can be used as a separate mechanism (joint). In the following description, a mechanical arm mechanism including a linear motion expansion mechanism of the present embodiment, in which one of the plurality of joint portions is formed, will be described as an example. As the mechanical arm mechanism, a vertical multi-joint type mechanical arm mechanism having a linear motion expansion mechanism will be described here, but other types of mechanical arm mechanisms may be used. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and the description thereof will be repeated only when necessary.

Fig. 1 shows the appearance of a mechanical arm mechanism equipped with the linear motion stretching mechanism of the present embodiment. Figure 2 is a side elevational view of the robotic arm mechanism of Figure 1. Fig. 3 is a side view showing the internal structure of the mechanical arm mechanism of Fig. 1.

The arm mechanism includes a base 1, a turning portion (pillar portion) 2, a undulation portion 4, an arm portion 5, and a wrist portion 6. The turning portion 2, the undulation portion 4, the arm portion 5, and the wrist portion 6 are sequentially disposed from the susceptor 1. A plurality of joint portions J1, J2, J3, J4, J5, and J6 are sequentially disposed from the susceptor 1. The turning portion 2 forming the cylindrical body on the susceptor 1 is typically provided vertically. The turning portion 2 houses the first joint portion J1 as a turning joint portion. The first joint portion J1 includes a torsion rotation axis RA1. The rotating shaft RA1 is parallel to the vertical direction. The turning 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 casing 31. The upper frame 22 is connected to the rotating portion of the first joint portion J1, and pivots about the rotation axis RA1. The upper frame 22 is covered by a cylindrical casing 32. Accompanied by the first When the joint portion J1 rotates, the upper frame 22 rotates relative to the lower frame 21, whereby the arm portion 5 is horizontally rotated. The first and second link rows 51 and 52 of the third joint portion J3 which is a linear motion expansion mechanism which will be described later are accommodated in the inside of the turning portion 2 in which the cylindrical body is formed.

An undulation portion 4 that accommodates the second joint portion J2 that is the undulating rotary joint portion is provided on the upper portion of the turning portion 2. The second joint portion J2 is a curved joint. The rotation axis RA2 of the second joint portion J2 is perpendicular to the rotation axis RA1. The undulations 4 have one side frame 23 as one of the fixing portions (support portions) of the second joint portion J2. The pair of side frames 23 are coupled to the upper frame 22. The pair of side frames 23 are covered by a saddle-shaped outer cover 33. A cylindrical body 24 serving as a rotating portion of the second joint portion J2 that also serves as a motor housing is supported by the pair of side frames 23. A delivery mechanism 25 is attached to the circumferential surface of the cylindrical body 24. The delivery mechanism 25 is covered by a cylindrical outer cover 34. The gap between the saddle cover 33 and the cylindrical outer cover 34 is covered by a U-shaped bellows outer cover 14 having a U-shaped cross section. The U-shaped corona cover 14 is stretched and contracted following the undulating movement of the second joint portion J2.

The delivery mechanism 25 holds the drive gear 56, the guide roller 57, and the roller unit 58. As the shaft of the cylindrical body 24 rotates, the delivery mechanism 25 rotates to support the arm portion 5 supported by the delivery mechanism 25 up and down.

The third joint portion J3 is provided by a linear motion expansion mechanism. The linear motion expansion mechanism has a newly developed structure by the inventors and the like, and is clearly distinguished from the so-called previous direct motion joint from the viewpoint of the movable range. The arm portion 5 of the third joint portion J3 is freely bendable, but the bending is restricted when the feed mechanism 25 from the root portion of the arm portion 5 is fed forward along the center axis (the telescopic center axis RA3) to ensure linear rigidity. When the arm portion 5 is pulled back toward the back, the bending is resumed. The arm portion 5 has a first link row 51 and a second link row 52. The first link row 51 includes a plurality of first links 53 that are connected to each other in a flexible manner. The first link 53 is formed in a substantially flat plate shape. The first link 53 is connected to the first hinge portion 300 at the end portion so as to be bendable. The second chain link row 52 includes a plurality of second link segments 54. The second link 54 is configured as a cross section a groove-shaped body of a word shape or a cylindrical body of a square shape. The second link 54 is flexibly coupled by the second hinge portion 400 at the end portion of the bottom plate. The bending of the second chain link row 52 is restricted at a position where the end faces of the side plates of the second link 54 abut each other. At this position, the second chain link row 52 is linearly arranged. Details of the first and second hinge portions 300 and 400 will be described later. The first link 53 at the foremost end of the first link row 51 and the second link 54 at the foremost end of the second link row 52 are connected by the joint link 55. For example, the joint link 55 has a shape in which the first link 53 and the second link 54 are combined.

The first and second link rows 51 and 52 are pressed and joined to each other by the roller 59 when passing through the roller unit 58 of the delivery mechanism 25. The first and second link rows 51 and 52 are linearly rigid by joining, and constitute a columnar arm portion 5. Immediately after the roller unit 58, the 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 inner surface of the first link 53, that is, the surface on the side joined to the second link 54. When the plurality of first links 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 guide roller 57 to be pressed Linear gear 539 of the first link 53. The linearly connected linear gear 539 is combined with the drive gear 56 to constitute a rack and pinion mechanism. When the drive gear 56 rotates in the forward direction, the first and second link rows 51 and 52 are sent forward from the roller unit 58. When the drive gear 56 rotates in the reverse direction, the first and second link rows 51, 52 are pulled back toward the roller unit 58. The first and second link rows 51 and 52 that are pulled back are separated from each other between the roller unit 58 and the drive gear 56. The first and second link rows 51 and 52 after separation are restored to a bendable state. The first and second link rows 51 and 52 that have been restored to the bendable state are all bent in the same direction (inside), and are vertically housed inside the turning portion 2. At this time, the first link row 51 is accommodated in a substantially aligned state substantially in parallel with the second link row 52.

A wrist portion 6 is attached to the front end of the arm portion 5. The wrist 6 is equipped with the fourth to sixth joint portions J4 to J6. The fourth to sixth joint portions J4 to J6 each have a three-axis orthogonal rotation axis RA4 to RA6. The fourth joint portion J4 is a torsion joint that is centered on the fourth rotation axis RA4 that substantially coincides with the expansion and contraction center axis RA3, and the end effector swings and rotates by the rotation of the fourth joint portion J4. The fifth joint portion J5 is a curved rotary joint centering on the fifth rotation axis RA5 disposed perpendicular to the fourth rotation axis RA4, and the end effector is tilted back and forth by the rotation of the fifth joint portion J5. The sixth joint portion J6 is a torsion rotation joint centering on the sixth rotation axis RA6 disposed perpendicular to the fourth rotation axis RA4 and the fifth rotation axis RA5, and the end effector shaft is rotated by the rotation of the sixth joint portion J6. .

The end effector (end effector) is attached to the adapter 7 provided at the lower portion of the rotating portion of the sixth joint portion J6 of the wrist portion 6. End effector The robot is directly applied to a part of the function of the work object (workpiece), for example, there are a holding portion, a vacuum suction portion, a nut fastener, a welding gun, a spray gun, and the like, and various tools exist depending on the task. The end effector is moved to an arbitrary position by the first, second, and third joint portions J1, J2, and J3, and is disposed in any posture by the fourth, fifth, and sixth joint portions J4, J5, and J6. . In particular, the length of the telescopic distance of the arm portion 5 of the third joint portion J3 allows the end effector to reach a wide range of objects from the proximal position of the base 1 to the remote position. The third joint portion J3 is characterized in that the linear telescopic movement realized by the linear motion expansion mechanism constituting the third joint portion J3 and the length of the telescopic distance thereof are different from those of the previous direct motion joint.

Fig. 4 is a view showing the configuration of the mechanical arm mechanism by the symbol representation. In the arm mechanism, three positional degrees of freedom are realized by the first joint portion J1, the second joint portion J2, and the third joint portion J3 which constitute the three axes of the root portion. Further, three posture degrees of freedom are realized by the fourth joint portion J4, the fifth joint portion J5, and the sixth joint portion J6 which constitute the three axes of the wrist. As shown in FIG. 4, the rotation axis RA1 of the first joint portion J1 is provided in the vertical direction. The rotation axis RA2 of the second joint portion J2 is provided in the horizontal direction. The second joint portion J2 is shifted in the two directions of the rotation axis RA1 and the axis orthogonal to the rotation axis RA1 with respect to the first joint portion J1. The rotation axis RA2 of the second joint portion J2 does not intersect the rotation axis RA1 of the first joint portion J1. The movement axis RA3 of the third joint portion J3 is oriented perpendicular to the rotation axis RA2. The third joint portion J3 is shifted in the two directions of the rotation axis RA1 and the axis orthogonal to the rotation axis RA1 with respect to the second joint portion J2. The rotation axis RA3 of the third joint portion J3 does not intersect the rotation axis RA2 of the second joint portion J2. Will have multiple joints J1-J6 One of the three axes of the root portion is replaced with the linear motion joint portion J3, and the second joint portion J2 is displaced in the two directions with respect to the first joint portion J1, and the third joint portion J3 is opposed to the first joint portion J3. The joint portion J2 is shifted in the two directions, whereby the mechanical arm mechanism of the robot apparatus of the present embodiment structurally eliminates the critical point posture.

Fig. 5 is a view showing the arm portion 5 of Fig. 3. Fig. 6 is a view showing the structure of the first link 53 of Fig. 5. Fig. 7 is a view showing the structure of the second link 54 of Fig. 5. Fig. 8 is a view showing the configuration of the bearing 538-1 of Fig. 6. Fig. 9 is a view showing the structure of a movable portion of the first hinge portion 300 of Fig. 5;

(1st link 53)

As shown in FIG. 5, the front and rear first links 53 are connected to each other by bending the first hinge portion 300 at the end portion. The first hinge portion 300 has a shaft 60, a support portion at the front end of the first link 53, and a bearing portion at the rear end of the first link 53.

As shown in FIG. 6, the first link 53 as a whole is a substantially flat body. The first link 53 has a body portion 531 of a rectangular flat plate. As the support portion at the front end of the first link 53, a pair of support blocks 532-1, 532-2 are protruded forward on both sides of the front end of the main body portion 531. The pair of support blocks 532-1 and 532-2 penetrate the pair of shaft holes 534-1 and 534-2 in parallel with the width direction of the first link 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 to be described later, or a diameter slightly larger than the inner diameters of the bearings 538-1 and 538-2. On the outer side of the bearing block 532-1, a flange receiving portion 535 that receives the flange portion 61 of the shaft 60 to be described later is provided. 1. A ring accommodating portion 535-2 that accommodates a locking ring 65 that engages a groove portion 63 at a front end of a shaft 60, which will be described later, is provided on the outer surface of the other bearing block 532-2.

A bearing block 533 is protruded rearward from the center of the rear end of the main body portion 531 as a bearing portion at the rear end of the first link 53. The width of the bearing block 533 of the first link 53 and the total width of the pair of support blocks 532-1 and 532-2 are substantially equivalent to the width of the first link 53. The width of the bearing block 533 of the first link 53 is larger than the total width of the pair of support blocks 532-1, 532-2. The bearing block 533 is provided with a bearing that rotatably supports the shaft 60 with respect to the bearing block 533, and here is a pair of bearings 538-1 and 538-2. Specifically, the bearing block 533 has a shaft hole 536 penetrating in parallel with the width direction of the first link 53 . The shaft hole 536 has a diameter substantially equivalent to the inner diameter of the bearings 538-1 and 538-2 which will be described later. A pair of bearing receiving portions 537-1, 537-2 are provided at both ends of the shaft hole 536. A pair of bearings 538-1 and 538-2 are fitted into the pair of bearing housing portions 537-1 and 537-2. As shown in Fig. 8, the bearings 538-1 and 538-2 are a plurality of types of bearings, and have a "roller" in contact with the surface of the shaft as a rolling element roller bearing, particularly a needle bearing (needle roller). Sub-bearing). A bearing having a rolling element in contact with the surface of the shaft has a high load capacity and is advantageous in terms of vibration and impact load as compared with a ball bearing that is in point contact with the surface of the shaft. The needle roller bearing (needle roller bearing) has a very small diameter compared to the rolling element, and a large number of rolling elements can be disposed on the circumference of the bearing, so that it is more advantageous in terms of vibration and impact load than the ball bearing.

The state of the bearing block 533 at the rear end of the other first link 53 is embedded between the support block 532-1, 532-2 at one of the front ends of the first link 53 Next, the pair of shaft holes 534-1, 534-2 are continuously connected to the shaft hole 537. A shaft 60 is inserted into the continuously connected through hole. The shaft 60 into which the continuous through-holes are inserted is rotatably supported by the bearings 538-1 and 538-2 of the bearing block 533 of the first link 53, whereby the first link 53 before and after the shaft 60 is a shaft that is rotatably coupled to each other. As shown in Fig. 9, the shaft 60 has a cylindrical body portion 62 having a diameter substantially equivalent to the inner diameter of the bearings 538-1, 538-2. A flange portion 61 having a non-circular shape and a cross-sectional shape D is provided at a rear end of the main body portion 62. A groove portion 63 is provided along the circumference of the body portion 62 at a front end portion of the body portion 62. A locking ring 65 is fitted in the groove portion 63. The length from the rear end to the front end of the shaft 60 is substantially equivalent to the width of the first link 53 or slightly shorter than the width of the first link 53. Thereby, the shaft 60 rotates together with the inner wheels of the bearings 538-1, 538-2 in the state of being inserted into the bearings 538-1, 538-2, and the axis movement of the shaft 60 is convex by the first link 53 The edge receiving portion 535-1 receives the flange portion 61 and the ring housing portion 535-2 receives the locking ring 65 and is locked.

As described above, the bearing block at the center of the rear end of the first link 53 is provided with 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 link 53 is larger than the total width of the support blocks 532-1, 532-2 on both sides of the front end of the first link 53, so that a pair of bearings 538-1, 538- 2 uses needle bearings. Of course, when the width of the first link 53 is sufficiently larger than the length of the needle bearing, the width of the bearing block 533 may be equivalent to the total width of the pair of support blocks 532-1, 532-2 or may be shorter than the total width. .

The shaft 60 of the first link 53 before and after the connection is rotatably supported The bearings 538-1 and 538-2 use a needle bearing having a higher load performance than a ball bearing, and the durability of the first hinge portion 300 is improved. When the durability of the first hinge portion 300 is improved, the looseness between the front and rear first links 53 is suppressed, and not only the smooth telescopic movement of the arm portion 5 but also the shaft 60, the bearings 538-1, 538-2, and the like are reduced. And the frequency of replacement of the first link 53.

Further, the pair of bearings 538-1 and 538-2 may not be needle bearings, but may be other bearings including rolling elements that are in line contact with the surface of the shaft, such as cylindrical roller bearings. Further, the bearing block 533 here is provided with a pair of needle bearings 538-1 and 538-2, but the bearing block 533 may be provided with a wide single needle roller bearing. Further, the bearing block 533 at the center of the rear end of the first link 53 has a pair of needle bearings 538-1 and 538-2, but one of the two sides of the front end of the first link 53 is opposed to the support blocks 532-1 and 532. -2 can also be equipped with a pair of needle bearings 538-1, 538-2. Further, the structure of the first hinge portion 300 is not limited to this. For example, the configuration of the front end of the first link 53 described above may be reversed. In other words, a bearing block may be provided so as to protrude forward in the center of the front end of the first link 53, and a support block may be provided on both sides of the rear end of the first link 53 so as to protrude rearward. Further, the first bearing block may be provided so as to protrude forward on the right side of the front end of the first link 53, and the second bearing block may be provided to protrude rearward from the rear end of the first link 53 at the rear side. At this time, a pair of needle bearings are provided in the first and second bearing blocks.

(2nd link 54)

The second link 54 is flexibly coupled by the second hinge portion 400 at the end portion of the bottom plate. The second hinge portion 400 has a shaft 70 and a second chain The support portion at the front end of the segment 54 and the bearing portion at the rear end of the second link 54.

The second hinge portion 400 has the same structure as the first hinge portion 300 of the first link 53 . As shown in FIG. 7, the second link 54 is a cross section as a whole. a grooved body of a glyph or a tubular body of a square shape. The second link 54 has a body portion of a groove shape (saddle shape). The main body portion is formed by connecting one of the same size and the same shape to the side plates 540-1 and 540-2 in parallel by the bottom plate 541. As a support portion at the front end of the second link 54, a pair of support blocks 542-1 and 542-2 are provided to protrude forward on both sides of the front end of the bottom plate 541. The pair of support blocks 542-1 and 542-2 penetrate the pair of shaft holes 544-1 and 544-2 in parallel with the width direction of the second link 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 to be described later, or a diameter slightly larger than the inner diameters of the bearings 548-1 and 548-2. A flange receiving portion 545 that receives the flange portion 71 of the shaft 70 is provided on the outer side of the bearing block 542-1. A ring accommodating portion 545-2 for accommodating the locking ring 75 of the groove portion 73 of the front end of the shaft 70 is provided on the outer surface of the other bearing block 542-2.

As a bearing portion at the rear end of the second link 54, a bearing block 543 is protruded rearward at the center of the rear end of the bottom plate 541. The width of the bearing block 543 of the second link 54 and the total width of the pair of support blocks 542-1 and 542-2 are substantially equal to the width of the second link 54. The width of the bearing block 543 of the second link 54 is greater than the total width of the pair of support blocks 542-1, 542-2. The bearing block 543 is provided with a bearing that rotatably supports the shaft 70 with respect to the bearing block 543, and here is a pair of bearings 548-1 and 548-2. Specifically, the bearing block 543 has a shaft hole 546 penetrating in parallel with the width direction of the second link 54 . Shaft hole 546 has bearing 548-1, 548-2 The inner diameter is roughly equivalent to the diameter. 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 to the pair of bearing housing portions 547-1 and 547-2. The bearings 548-1 and 548-2 are preferably of the same type and the same size as the bearing 538-1 of the first link 53.

a pair of shaft holes 544-1, in a state in which one of the front ends of the second link 54 is between the support blocks 542-1 and 542-2 and the bearing block 543 at the rear end of the other second link 54 is fitted. The 544-2 is continuously connected to the shaft hole 547. In a state in which the shaft 70 is inserted into the continuously connected through hole, the locking ring 75 is fitted into the groove portion at the front end of the shaft 70. The shaft 70 and the locking ring 75 are preferably of the same type and the same size as the shaft 60 and the locking ring 65 of the first link 53. The shaft 70 into which the continuous through-holes are inserted is rotatably supported by the bearings 548-1 and 548-2 of the bearing block 543 of the second link 54, whereby the second link 54 before and after the shaft 70 is a shaft that is rotatably coupled to each other.

As described above, the same effect as that of the first hinge portion 300 is exhibited in accordance with the structure of the second hinge portion 400. In other words, the bearings 548-1 and 548-2 which are rotatably supported by the shaft 70 of the second link 54 before and after the connection are used, and the needle bearing having higher load performance than the ball bearing is used, thereby lifting the second hinge portion 400. Durability. When the durability of the second hinge portion 400 is improved, the looseness between the front and rear second links 54 is suppressed, and not only the smooth telescopic movement of the arm portion 5 but also the shaft 70, the bearings 548-1, 548-2, and the like are reduced. And the frequency of replacement of the second link 54.

In the above description, the bearing system is described as a needle bearing (needle roller bearing) 538-1, 538-2, 548-1, and 548-2 as a rolling bearing, but when load capacity, vibration, and impact load are allowed. Not completely impossible A cylindrical sliding bearing made of a self-lubricating resin such as polyacetal (POM), polyamide (PA) or polytetrafluoroethylene (PTFE: fluororesin) is used.

The embodiments of the present invention have been described, but the embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments can be implemented in various other forms, and various omissions, substitutions and changes can be made without departing from the scope of the invention. The scope of the invention and the scope of the invention are intended to be included in the scope of the invention and the equivalents thereof.

531‧‧‧ Body Department

532-1, 532-2‧‧‧ Support Blocks

533‧‧‧ bearing block

534-1, 534-2, 536‧‧‧ shaft holes

535-1‧‧‧Flange bearing department

535-2‧‧‧Circle containment department

537-1, 537-2‧‧‧ Bearing Housing Department

538-1, 538-2‧‧‧ bearing

Claims (4)

A linear motion expansion and contraction mechanism comprising: a plurality of first links that are bent in a plate shape by a first hinge portion; and a cross section that is bendably coupled to the bottom surface side by a second hinge portion When the second link is joined to the first link on the surface side opposite to the bottom surface side, the bending of the first link and the second link is restricted to form a plurality of second links. a rigid straight columnar body that returns to a curved state when the first and second links are separated from each other; and the first hinge portion has a cylindrical axis, and the rear end or the front end of the first link is rearward or A bearing portion of the shaft protruding from the front side and a support portion of the shaft projecting forward or rearward at a front end or a rear end of each of the first link portions, wherein the bearing portion includes a needle roller bearing. A linear motion expansion and contraction mechanism comprising: a plurality of first links that are bent in a plate shape by a first hinge portion; and a cross section that is bendably coupled to the bottom surface side by a second hinge portion When the second link is joined to the first link on the surface side opposite to the bottom surface side, the bending of the first link and the second link is restricted to form a plurality of second links. a rigid straight columnar body that returns to a curved state when the first and second links are separated from each other; and the second hinge portion has a cylindrical axis, and the rear end or the front end of the second link is rearward or a bearing portion of the shaft protruding from the front side and a support portion of the shaft projecting forward or rearward at a front end or a rear end of each of the second link portions, wherein the bearing portion includes a needle roller bearing. A mechanical arm mechanism for supporting a strut portion having a convoluted rotary joint portion on a pedestal, wherein an undulating portion having an undulating rotary joint portion is placed on the struts, and a straight portion having a linear motion is provided on the undulation portion The telescopic mechanism is provided with a wrist portion to which an end effector can be attached to the front end of the arm portion, and at least one rotating joint portion for modifying the posture of the end effector is provided on the wrist portion, wherein The linear motion expansion mechanism includes a plurality of first links that are bent in a plate shape by the first hinge portion, and a cross section that is bendably coupled to the bottom surface side by the second hinge portion When the second link is joined to the first link on the surface side opposite to the bottom surface side, the bending of the first link and the second link is restricted to form a plurality of second links. a rigid straight columnar body that returns to a curved state when the first and second links are separated from each other; and the first hinge portion has a cylindrical axis, and the rear end or the front end of the first link is rearward or A bearing portion of the shaft protruding from the front side and a support portion of the shaft projecting forward or rearward at a front end or a rear end of each of the first link portions, wherein the bearing portion includes a needle roller bearing. A mechanical arm mechanism for supporting a strut portion having a convoluted rotary joint portion on a pedestal, wherein an undulating portion having an undulating rotary joint portion is placed on the struts, and a straight portion having a linear motion is provided on the undulation portion The telescopic mechanism is provided with a wrist portion to which an end effector can be attached to the front end of the arm portion, and at least one rotating joint portion for modifying the posture of the end effector is provided on the wrist portion, wherein The linear motion expansion mechanism includes a plurality of first links that are bent in a plate shape by the first hinge portion, and a cross section that is bendably coupled to the bottom surface side by the second hinge portion When the second link is joined to the first link on the surface side opposite to the bottom surface side, the bending of the first link and the second link is restricted to form a plurality of second links. a rigid straight columnar body that returns to a curved state when the first and second links are separated from each other; the second hinge portion has a cylindrical axis, and the rear end or the front end of the second link is rearward or forward The bearing portion of the shaft that protrudes and the support portion of the shaft that protrudes forward or rearward at a front end or a rear end of each of the second link portions, and the bearing portion includes a needle roller bearing.