JP4772438B2 - Link actuator - Google Patents

Description

  The present invention relates to a link operating device used for a link mechanism such as a parallel link mechanism or a robot joint that performs complicated processing or article handling in a three-dimensional space at high speed and precisely.

  For example, there is a working device equipped with a parallel link mechanism that performs high-speed and precise operations such as complicated processing and article handling in a three-dimensional space (see, for example, Patent Document 1).

  This working apparatus includes a parallel link mechanism that changes the position and posture of the traveling plate with respect to the base plate by cooperatively expanding and contracting a plurality of links connecting the base plate and the traveling plate. By attaching a tool to the traveling plate of this parallel link mechanism and rotatably arranging a table to hold the workpiece, the position and posture of the tool with respect to the workpiece on the table can be freely changed. It enables complex processing and handling of articles in the space.

In the parallel link mechanism, the mass of the movable part can be reduced, and the positioning error of each link is averaged at the tip, and complicated work in three-dimensional space and handling of articles are performed. It has great features in executing at high speed and precision.
JP 2000-94245 A JP 2004-9276 A

  However, in the parallel link mechanism described above, since the operating angle of each link is small, if the operating range of the traveling plate is set to be large, the link length becomes long, which increases the overall size of the mechanism and increases the size of the device. There was a problem of inviting. There is also a problem that the rigidity of the entire mechanism is low and the weight of the tool mounted on the traveling plate, that is, the loadable weight of the traveling plate is limited to a small one.

  In order to solve this problem, the present applicant has previously proposed a link actuating device having a link mechanism having a high rigidity and a large portable weight (see, for example, Patent Document 2).

  In this link actuating device, the end link members are rotatably connected to the link hubs provided on the input member and the output member, and the end link members on the input side and the output side are connected to the central link member. 3 or more link mechanisms connected in a rotatable manner, the input side and the output side are geometrically identical with respect to the cross section at the center of each link mechanism, and the rotation of each link mechanism connected to the input member Among the kinematic pairs, two or more sets of link mechanisms are provided with a stationary mechanism for stopping the output member at an arbitrary position on the rotating part of one or more rotating pairs of each group.

  However, in this link operating device, there are many members constituting the link mechanism, and it is difficult to make the entire device compact due to interference of the link mechanism, and the rotating portion of the rotating pair of the link mechanism has a highly rigid bearing structure. Therefore, the entire apparatus becomes expensive.

  Accordingly, the present invention has been proposed in view of the above-mentioned problems, and an object of the present invention is to provide a link operating device that is simple in structure and lightweight and compact.

As a technical means for achieving the above-mentioned object, the present invention provides a movable member with respect to a stationary member and circumferentially equidistant positions of three receiving portions in a radial direction from the axis center within a plane perpendicular to the axis. The spherical member is arranged in each cylindrical groove of the movable member so as to be slidable in the radial direction, and the projection position onto the stationary member at the center of the spherical member is held at the circumferentially equidistant position to hold the respective PCR positions. The spherical member is provided on the stationary member so as to be slidable in the axial direction, and the movable member is stationary in a predetermined posture with respect to the stationary member between the spherical member and the stationary member or between the spherical member and the movable member. Is provided . Here, the “projection position of the center of the spherical member onto the stationary member” means a position on a plane perpendicular to the axis of the spherical member when the stationary member and the movable member are not at an angle.

In this link actuating device, the movable member with respect to the stationary member is provided with three receiving portions at circumferentially equidistant positions in the radial direction from the axis center within a plane perpendicular to the axis thereof, and a spherical surface is provided at each receiving portion of the movable member. The members are arranged so as to be slidable in the radial direction, and the spherical member can be slid in the axial direction so that the projection position onto the stationary member at the center of the spherical member holds the respective PCR positions at circumferentially equidistant positions. The structure is simple and lightweight by providing a mechanism for stopping the movable member in a predetermined position with respect to the stationary member between the spherical member and the stationary member or between the spherical member and the movable member. It can be realized a compact link actuator, the movable member relative to the stationary member, a predetermined posture, i.e., Ru can be fixed at any inclination state only spaced locations given distance from the stationary member.

The receiving portion in the above-described link operating device is a cylindrical groove provided on the movable member at a circumferentially equidistant position in the radial direction from the center of the axis within a plane perpendicular to the axis thereof. A spherical ring with a spherical surface and a cylindrical hole on the inner diameter. The spherical ring is attached to three axes that are fixed to each PCR position at the circumferentially equidistant position of the stationary member and arranged parallel to each other. The movable member can be mounted so as to be movable in the axial direction, and a mechanism for stopping the movable member in a predetermined posture with respect to the stationary member can be used as a stopper screw provided on the movable member.

Put that accept portion of the aforementioned link actuating device, the movable member has a cylindrical groove provided circumferentially equidistant positions in the radial direction from the shaft center in a plane perpendicular to the axis, the spherical member , A spherical ring having a spherical outer peripheral surface and a cylindrical hole on the inner diameter, and fixed to each PCR position at the circumferentially equidistant position on the stationary member, and the spherical surface on the three axes arranged in parallel to each other A movable member is installed so as to be movable in the axial direction via the ring, and the shaft is used as a ball screw shaft, and a nut member screwed into the ball screw shaft is provided in the spherical ring, and the movable member is mounted on the stationary member. A structure in which the mechanism that is stationary in a predetermined posture is a motor connected to the shaft end of the ball screw shaft is possible.

Further, the receiving portion in the above-described link actuating device is a spherical holding block provided on the movable member at a circumferentially equidistant position in the radial direction from the axis center within a plane perpendicular to the axis thereof. Is composed of a spherical portion and a rod portion extending from the spherical portion, and a spherical receiving holder for receiving the spherical portion of the spherical rod is arranged on each spherical holding block of the movable member so as to be slidable in the radial direction. so that the projection position of the center of the stationary member to hold the respective PCR position at the circumference equidistant positions, and So設slidably stationary member rod portion of the spherical rod axially stationary member movable member On the other hand, it is possible to adopt a structure in which the mechanism that is stationary in a predetermined posture is a linear actuator connected to the end of the rod portion.

Furthermore, the receiving part in the above-described link operating device is a cylindrical groove provided on the movable member at a circumferentially equidistant position in the radial direction from the axis center within a plane perpendicular to the axis thereof. A spherical rod having a spherical portion and a rod portion extending from the spherical portion, the rod portion of the spherical rod being mounted on the stationary member so as to be slidable in the axial direction, and the movable member being in a predetermined posture with respect to the stationary member It is possible to adopt a structure in which the stationary mechanism is a motor coupled with a rack portion provided on the rod portion of the spherical rod with a gear.

According to the present invention, the movable member with respect to the stationary member is provided with three receiving portions at circumferentially equidistant positions in the radial direction from the center of the axis within a plane perpendicular to the axis thereof, and a spherical surface is provided at each receiving portion of the movable member. The members are arranged so as to be slidable in the radial direction, and the spherical member can be slid in the axial direction so that the projection position onto the stationary member at the center of the spherical member holds the respective PCR positions at circumferentially equidistant positions. The structure is simple and lightweight by providing a mechanism for stopping the movable member in a predetermined position with respect to the stationary member between the spherical member and the stationary member or between the spherical member and the movable member. It can be realized a compact link actuator, the movable member relative to the stationary member, a predetermined posture, i.e., Ru can be fixed at any inclination state only spaced locations given distance from the stationary member.

  Each embodiment of the link actuator according to the present invention will be described in detail below. 1 to 4 illustrate the first embodiment, FIGS. 5 and 6 illustrate the second embodiment, FIGS. 7 to 9 illustrate the third embodiment, and FIGS. 10 to 14 illustrate the fourth embodiment. Is to do.

  [First embodiment]

  The link actuating device in the first embodiment shown in FIG. 1 to FIG. 3 suspends three shafts 2 at the same PCR position at circumferentially equidistant positions on a circular stationary base 1 as a stationary member, A structure in which the upper end portions of these shafts 2 are connected and integrated by a reinforcing ring 3 is provided. The three shafts 2 on the stationary table 1 are arranged in parallel. Here, the PCR position means the distance (pitch circle radius) from the center of the stationary table 1 to the center of the shaft 2. Further, by connecting and integrating the upper end portions of the respective shafts 2 with the reinforcing ring 3, the parallelism of the three shafts 2 is ensured to increase the rigidity.

  A movable table 4 as a movable member is disposed above the stationary table 1 and is connected to each shaft 2 suspended on the stationary table 1 through a spherical ring 5 as a spherical member. The movable table 4 includes a disk-like boss portion 4a and a connecting portion 4b protruding integrally in the radial direction from a circumferentially equidistant position on the outer periphery of the boss portion 4a. A cylindrical groove 6, which is a receiving portion extending in the radial direction at the circumferentially equidistant position of the movable table 4, is formed in the connecting portion 4 b of the movable table 4. The cylindrical groove 6 has a groove surface in which the cross section parallel to the radial direction of the movable table 4 is straight, and the cross section perpendicular to the radial direction is arc-shaped.

  The spherical ring 5 has a spherical outer diameter, and the shaft 2 is inserted through a cylindrical hole having an inner diameter. The spherical ring 5 is disposed in the cylindrical groove 6 of the connecting portion 4b so as to be slidable in the radial direction. Therefore, the outer diameter of the spherical ring 5 is made substantially equal to the inner diameter of the cylindrical groove 6 so that the cylindrical groove 6 can slide in the radial direction. The spherical ring 5 is perpendicular to the surface of the stationary table 1 so that the projection positions of the spherical ring 5 on the stationary table 1 hold the same PCR position at the circumferentially equidistant positions of the movable table 4. The structure is supported by the shaft 2 so as to be slidable.

  In this link actuating device, the movable base 4 can be moved with respect to the stationary base 1 with two degrees of freedom (X-axis direction and Y-axis direction) in the tilt direction and one degree of freedom (Z-axis direction) in the vertical direction. In order to maintain the posture of the movable table 4, a stopper screw 7 as a stationary mechanism of the movable table 4 is screwed into the spherical ring 5 from the outside in the radial direction of the movable table 4, and the tip of the stopper screw 7 is connected to the spherical ring 5. It can be pressed against the shaft 2 of the inner diameter.

  Accordingly, the movable table 4 is tilted in the XY-axis direction with respect to the stationary table 1 and moved in the Z-axis direction (vertical direction), and when the predetermined posture is reached, the above-described three stopper screws 7 are attached to the spherical ring 5. If the spherical ring 5 is fixed to the shaft 2 by screwing in, the movable base 4 can be made stationary with respect to the stationary base 1 in a predetermined posture.

  The stopper screw 7 is provided with a groove 8 parallel to the shaft 2 so as not to rotate around the axis together with the spherical ring 5 (see FIG. 2), and the tip of the stopper screw 7 enters the groove 8 of the shaft 2 when the stopper screw 7 is screwed. Thus, both the stopper screw 7 and the spherical ring 5 are prevented from rotating.

  The stationary mechanism including the stopper screw 7 is provided between the spherical ring 5 and the shaft 2, but can also be provided between the movable table 4 and the spherical ring 5. If a stationary mechanism is provided at two places between the spherical ring 5 and the shaft 2 and between the movable base 4 and the spherical ring 5, or at two or more places, the support rigidity when the movable base 4 is stationary. It is easy to increase the value.

  FIG. 4 shows another example of the structure of the stationary mechanism. The spherical ring 5 ′ has a notch 5a ′ at a part in the circumferential direction, and the forked end of the connecting portion 4b ′ of the movable base 4 ′. A stopper screw 7 'is screwed onto the shaped part in a direction perpendicular to the radial direction. A rotation stopper 8 'is provided between the spherical ring 5' and the shaft 2 so that the spherical ring 5 'does not rotate about the axis.

  In this stationary mechanism, the spherical ring 5 ′ is reduced in diameter by screwing the stopper screw 7 ′ into the connecting portion 4 b ′ of the movable base 4 ′, thereby narrowing the interval between the bifurcated portions of the connecting portion 4 b ′. If the spherical ring 5 ′ is deformed and fixed to the shaft 2, the movable table 4 ′ can be firmly fixed in a predetermined posture with respect to the stationary table 1.

  [Second Embodiment]

  5 and 6, the link actuating device according to the second embodiment has three shafts 12 arranged at equal circumferential positions on a circular stationary base 11 as a stationary member, as in the first embodiment described above. Are provided at the same PCR position, and the upper ends of the shafts 12 are connected and integrated by the reinforcing ring 13. The three shafts 12 on the stationary table 11 are arranged in parallel. A movable table 14 as a movable member is arranged above the stationary table 11 and is connected to each shaft 12 suspended on the stationary table 11 via a spherical ring 15 as a spherical member. The movable table 14 includes a disk-shaped boss portion 14a and a connecting portion 14b that protrudes integrally in the radial direction from a circumferentially equidistant position on the outer periphery of the boss portion 14a. A cylindrical groove 16 is formed in the connecting portion 14 b of the movable table 14 as a receiving portion extending in the radial direction at a circumferentially equidistant position of the movable table 14. The cylindrical groove 16 has a groove surface in which the cross section parallel to the radial direction of the movable base 14 is straight and the cross section perpendicular to the radial direction is an arc.

  The spherical ring 15 has a spherical outer diameter, and is arranged in the cylindrical groove 16 of the connecting portion 14b so as to be slidable in the radial direction. Therefore, the outer diameter of the spherical ring 15 is made to substantially coincide with the inner diameter of the cylindrical groove 16 so that the cylindrical groove 16 can slide in the radial direction. The spherical ring 15 is perpendicular to the surface of the stationary table 11 so that the projection position of the spherical ring 15 on the stationary table 11 maintains the same PCR position at the circumferentially equidistant position of the movable table 14. The structure is supported by the shaft 12 so as to be movable. A rotation stopper 18 is provided between the spherical ring 15 and the movable base 14 so that the spherical ring 15 does not rotate about the axis.

  The above-described shaft 12 is a ball screw shaft (hereinafter, referred to as a ball screw shaft 12) having a screw engraved on its outer peripheral surface, and the spherical ring 15 has a nut member 19 that is screwed into the inner diameter of the ball screw shaft 12. Are coaxially furnished. The ball screw shaft 12 is rotatable by being supported on the stationary base 11 and the reinforcing ring 13 via rolling bearings 17a and 17b. An output shaft of the motor 20 as a drive source is coaxially attached to the lower end portion of the ball screw shaft 12 via a coupling 20a.

  In this link actuating device, the movable table 14 can be moved with respect to the stationary table 11 with two degrees of freedom (X-axis direction and Y-axis direction) in the tilt direction and one degree of freedom (Z-axis direction) in the vertical direction. The movable table 14 is movable with respect to the stationary table 11 through a spherical ring 15 in which a nut member 19 is screwed to each ball screw shaft 12 by driving and controlling a motor 20 provided on each ball screw shaft 12. The movable table 14 is tilted in the XY axis direction with respect to the stationary table 11 and moved in the Z axis direction (vertical direction) to obtain a predetermined posture.

  [Third embodiment]

  The link actuating device in the third embodiment shown in FIGS. 7 to 9 has the same PCR in which the rod portions 25b of the three spherical rods 25 as the spherical members are arranged at the circumferentially equidistant positions on the stationary base 21 as the stationary member. Three spherical holding blocks 22 are fixedly provided at the same PCR position at the circumferentially equidistant position on the lower surface of a disk-shaped movable table 24 as a movable member, and suspended from the stationary table 21. The spherical surface portion 25 a is connected to a spherical surface receiving holder 23 as a receiving portion of the spherical surface holding block 22 of the movable base 24.

  The spherical portion 25 a is perpendicular to the stationary table 21 so that the projection position of the spherical portion 25 a of the spherical rod 25 on the stationary table 21 holds the same PCR position at the circumferentially equidistant position of the movable table 24. The structure is supported so as to be slidable. The rod portion 25b of the spherical rod 25 is supported by the stationary base 21 via a linear motion bearing 27 so as to be slidable in the vertical direction, and the three rod portions 25b are arranged in parallel. A linear motion actuator 30 as a drive source is connected to the lower end of each rod portion 25 b and is disposed in the internal space of the stationary table 21. On the other hand, the spherical portion 25a of the spherical rod 25 is received by the spherical receiving holder 23, and the spherical receiving holder 23 is held by the spherical holding block 22 via the rolling elements 28 so as to be slidable in the radial direction. These three spherical holding blocks 22 are fixed to the movable base 24 at a position where the sliding direction of the spherical receiving holder 23 coincides with the radial direction at the circumferentially equidistant position.

  In this link actuating device, the movable table 24 can be moved with respect to the stationary table 21 with two degrees of freedom (X-axis direction and Y-axis direction) in the tilt direction and one degree of freedom (Z-axis direction) in the vertical direction. The movable base 24 is movable relative to the stationary base 21 by slidingly controlling each spherical rod 25 in the vertical direction with respect to the stationary base 21 by drivingly controlling a linear actuator 30 provided on the rod portion 25b of the spherical rod 25. Thus, the relative rotation between the spherical portion 25a of the spherical rod 25 and the spherical receiving holder 23 and the sliding of the spherical receiving holder 23 in the radial direction cause the movable table 24 to be tilted in the XY axis direction with respect to the stationary table 21, and Z A predetermined posture is obtained by moving in the axial direction (vertical direction).

  The linear motion bearing 27 is interposed between the stationary base 21 and the rod portion 25 b of the spherical rod 25, and the rolling element 28 is interposed between the spherical receiving holder 23 and the spherical holding block 22. The spherical rod 25 and the spherical receiving holder 23 can be moved smoothly. In addition, since the spherical portion 25a of the spherical rod 25 and the spherical receiving holder 23 are configured to be received by a ball-to-sphere, the supporting rigidity of both can be improved.

  [Fourth embodiment]

  The link actuating device in the fourth embodiment shown in FIGS. 10 to 14 has three spherical rods 35 and 35 ′ as spherical members suspended from a stationary base 31 as a stationary member at circumferentially equidistant positions. The movable base 34 as a movable member is disposed on the spherical rods 35 and 35 '. Cylindrical grooves 36 and 36 'serving as receiving portions are formed on the lower surface of the movable table 34 along the radial direction at equal circumferential positions. The three spherical rods 35 and 35 'are composed of spherical portions 35a and 35a' located immediately below the movable base 34 and rod portions 35b and 35b 'extending vertically from the spherical portions 35a and 35a'. The portions 35a and 35a ′ are slidably disposed in the cylindrical grooves 36 and 36 ′ of the movable table 34, and the rod portions 35b and 35b ′ are respectively disposed in parallel. Of these three spherical rods 35, 35 ′, one spherical rod 35 ′ is fixed to the stationary base 31, and the remaining two spherical rods 35 have their rod portions 35 b that have linear motion bearings 37. It is provided on the stationary table 31 so as to be slidable in the vertical direction. The spherical portion 35a slides in the vertical direction with respect to the stationary table 31 so that the projection position of the spherical portion 35a of the spherical rod 35 on the stationary table 31 holds the PCR position at the circumferentially equidistant position of the movable table 34, respectively. The structure is supported as possible.

  A rack portion 32 is formed at a substantially central portion in the axial direction of the rod portion 35b of the two spherical rods 35 slidably provided on the stationary base 31, and serves as a drive source disposed in the internal space of the stationary base 31. A gear 33 provided coaxially with the output of the motor 40 is engaged with the rack portion 32 described above.

  In this link actuating device, one spherical rod 35 ′ is fixed to the stationary table 31, and the remaining two spherical rods 35 are slidably attached to the stationary table 31. The table 34 can be moved in the tilt direction with two degrees of freedom (X-axis direction and Y-axis direction). The movable table 34 is movable with respect to the stationary table 31 by driving and controlling a motor 40 connected to the rod portions 35 b of the two spherical rods 35 via the rack portion 32 and the gear 33. The movable table 34 is tilted in the XY axis direction with respect to the stationary table 31 via the part 35a, and a predetermined posture is obtained.

  The radial positions of the shaft centers of the three spherical rods 35, 35 ′, that is, the PCR positions may not be the same. In the illustrated example, the outer diameter of the spherical portion 35a ′ of one fixed spherical rod 35 ′. Is smaller than the outer diameter of the spherical portion 35a of the other two spherical rods 35, and the PCR is also reduced. Accordingly, the cylindrical grooves 36 and 36 ′ of the movable table 34 also have the inner diameter of the cylindrical groove 36 ′ in which the spherical portion 35 a ′ of the spherical rod 35 ′ is accommodated in the spherical portions 35 a of the other two spherical rods 35. It is smaller than the groove inner diameter of the cylindrical groove 36 formed. In this way, the entire apparatus is made compact. Conversely, by increasing the outer diameter of the spherical portion 35a of the two spherical rods 35, the contact portion with the movable table 34 is increased to improve the holding force, and the PCR is increased by increasing the PCR. Since the slide amount of the spherical rod 35 with respect to the movable angle amount can be increased, the angle accuracy can be improved.

It is a top view which shows 1st embodiment of the link actuator which concerns on this invention. It is a front view which shows the link action | operation apparatus of FIG. It is sectional drawing which follows the AA line of FIG. It is a principal part expanded sectional view which shows the modification of the link action | operation apparatus of FIG. It is a top view including the one part omission part which shows 2nd embodiment of this invention. It is a front view containing the partial cross section which shows the link action | operation apparatus of FIG. It is a top view which shows 3rd embodiment of this invention. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which follows the CC line of FIG. It is a top view which shows 4th embodiment of this invention. It is sectional drawing which follows the DD line | wire of FIG. It is sectional drawing which follows the EE line | wire of FIG. It is sectional drawing which follows the FF line of FIG. It is a schematic perspective view which shows the operation state of the link actuator of 4th embodiment.

Explanation of symbols

1 Stationary member (stationary stand)
2 axis 4 movable member (movable stand)
5 Spherical member (spherical ring)
6 Receiving part (cylindrical groove)
7 Static mechanism (stopper screw)
11 Stationary member (stationary stand)
12 shafts (ball screw shaft)
14 Movable member (movable stand)
15 Spherical member (spherical ring)
16 Receiving part (cylindrical groove)
20 Drive source (motor)
21 Stationary member (stationary stand)
22 Spherical surface holding block 23 Spherical surface holder 24 Movable member (movable base)
25 Spherical member (spherical rod)
25a Spherical section 25b Rod section 30 Drive source (linear actuator)
31 Stationary member (stationary stand)
32 Rack part 33 Gear 34 Movable member (movable stand)
35,35 'Spherical member (spherical rod)
35a, 35a 'spherical surface portion 35b, 35b' rod portion 36, 36 'receiving portion (cylindrical groove)

Claims (5)

In the movable member with respect to the stationary member, three receiving portions are provided at circumferentially equidistant positions in the radial direction from the center of the axis within a plane perpendicular to the axis, and a spherical member is provided in each receiving portion of the movable member in the radial direction. Each spherical member is slidably arranged in the axial direction so that the respective PCR positions are held at the circumferentially equidistant positions. A link actuating device, characterized in that a mechanism is provided between the spherical member and the stationary member or between the spherical member and the movable member, and a mechanism for causing the movable member to remain stationary with respect to the stationary member . The receiving portion is a cylindrical groove provided in the movable member at a circumferentially equidistant position in a radial direction from the axis center within a plane perpendicular to the axis thereof, and the spherical member has a spherical outer peripheral surface. A spherical ring having a cylindrical hole on its inner diameter, and a movable member via a spherical ring on three shafts fixed to each PCR position at the circumferentially equidistant position of the stationary member and arranged parallel to each other The link actuating device according to claim 1 , wherein a mechanism for suspending the movable member in a predetermined posture with respect to the stationary member is a stopper screw provided on the movable member . The receiving portion is a cylindrical groove provided in the movable member at a circumferentially equidistant position in a radial direction from the axis center within a plane perpendicular to the axis thereof, and the spherical member has a spherical outer peripheral surface. A spherical ring having a cylindrical hole on its inner diameter, and a movable member via a spherical ring on three shafts fixed to each PCR position at the circumferentially equidistant position of the stationary member and arranged parallel to each other Are mounted so as to be movable in the axial direction, the shaft is used as a ball screw shaft, a nut member screwed into the ball screw shaft is provided in the spherical ring, and the movable member is in a predetermined posture with respect to the stationary member. The link actuating device according to claim 1 , wherein the mechanism to be stopped by the motor is a motor connected to a shaft end of a ball screw shaft. The receiving portion is a spherical holding block provided on the movable member at a circumferentially equidistant position in the radial direction from the axis center within a plane perpendicular to the axis thereof. The spherical member includes the spherical portion and the spherical surface thereof. A spherical receiving holder that receives the spherical portion of the spherical rod in each spherical holding block of the movable member so as to be slidable in the radial direction, and to the stationary member at the center of the spherical portion of the spherical rod. The spherical rods are slidably mounted in the stationary member so that the projected positions of the circularly spaced projection positions hold the respective PCR positions, and the movable member is attached to the stationary member. The link actuating device according to claim 1 , wherein the mechanism that is stationary in a predetermined posture is a linear motion actuator that is coupled to an end of the rod portion. The receiving portion is a cylindrical groove provided in the movable member at a circumferentially equidistant position in the radial direction from the axis center within a plane perpendicular to the axis thereof, and the spherical member includes the spherical portion and the spherical portion thereof. A spherical rod having a rod portion extending from, a mechanism for slidably mounting the rod portion of the spherical rod on the stationary member in the axial direction, and causing the movable member to be stationary in a predetermined posture with respect to the stationary member , The link actuating device according to claim 1 , wherein the motor is coupled to a rack portion provided on a rod portion of the spherical rod with a gear.

Images