Drive transmission mechanism and carrier device using the same

Abstract

To provide a drive transmission mechanism capable of enhancing magnetic coupling strength and transmitting a displacement amount on an atmosphere side (driving side) to a vacuum side (load side) accurately, and a carrier device using the drive transmission mechanism.SOLUTION: A drive transmission mechanism 1 includes: a fixation pipe 10 of a non-magnetic material inside of which is evacuated; a fixation shaft 20 disposed in the fixation pipe; a movable pipe 30 inserted through the fixation shaft in the fixation pipe and moved in an axial direction and a circumferential direction of the fixation shaft; a driven pipe 40 disposed in the atmosphere outside the fixation pipe and driven in the axial direction and the circumferential direction; and a first permanent magnet group 50 that is located on an outer peripheral surface of the movable pipe and in which permanent magnets 51A, 51B are aligned in the axial direction and the circumferential direction and a second permanent magnet group 60 that is located on an inner peripheral surface of the driven pipe and in which permanent magnets 61A, 61B are aligned in the axial direction and the circumferential direction, the first permanent magnet group and the second permanent group magnetically coupled. In the first permanent magnet group 50 and the second permanent magnet group 60, a magnet pole on the side facing the fixation pipe differs between two permanent magnets adjacent to each other in each of the axial direction and the circumferential direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a drive transmission mechanism having magnetic coupling and a conveying device using the same.

Background Art

[0002] For example, in semiconductor manufacturing equipment, robots that operate under vacuum are used. Among robot operations, the vacuum seal used for the turning operation is generally by a direct drive using a magnetic fluid seal.

[0003] However, the magnetic fluid seal has the following demerits. Atmospheric intrusion (pressure spike) occurs due to distortion in the magnetic fluid during driving. Since it is a dispersion of magnetic substances in hydrocarbon oil, it is vulnerable to organic solvents such as alcohol. Since it has a high vapor pressure and the hydrocarbon oil evaporates under high vacuum, it cannot be used. In an active gas atmosphere, corrosion occurs and the seal cannot be maintained.

[0004] If magnetic coupling is used for power transmission between vacuum and atmosphere instead of the direct drive using a magnetic fluid seal, all of these problems can be solved (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the power transmission by magnetic coupling shown in Patent Document 1, it is difficult to accurately transmit the displacement amount from the atmosphere side (drive side) to the vacuum side (load side) like the direct drive performed by the magnetic fluid seal. This is presumably due to the delay in the magnetic coupling of the magnets, similar to the backlash of gears. In addition, in the power transmission by magnetic coupling shown in Patent Document 1, only rotational transmission was possible.

[0007] Therefore, an object of the present invention is to provide a drive transmission mechanism capable of enhancing the magnetic coupling strength and accurately transmitting the displacement amount from the atmosphere side (drive side) to the vacuum side (load side), and a transfer device using the same. Another object of the present invention is to provide a drive transmission mechanism capable of performing not only rotational drive but also linear drive using magnetic coupling, and a transfer device using the same.

Means for Solving the Problems

[0008] (1) One aspect of the present invention is a non-magnetic fixed tube whose interior is evacuated, a fixed shaft disposed within the fixed tube, a movable tube inserted through the fixed shaft within the fixed tube and movable in the axial and circumferential directions, a driven tube disposed in the atmosphere outside the fixed tube and driven in the axial and circumferential directions, a first permanent magnet group in which individual permanent magnets are arranged along the axial and circumferential directions on the outer peripheral surface of the movable tube, a second permanent magnet group in which individual permanent magnets are arranged along the axial and circumferential directions on the inner peripheral surface of the driven tube, and having each of the individual permanent magnets of the first permanent magnet group and the individual permanent magnets of the second permanent magnet group disposed opposite to the first permanent magnet group via the fixed tube are magnetically coupled to each other, In each of the first permanent magnet group and the second permanent magnet group, the magnetic poles on the side facing the fixed tube are different between every two adjacent permanent magnets in the axial and circumferential directions, relating to a drive transmission mechanism.

[0009] In one aspect of the present invention, in each of the first permanent magnet group and the second permanent magnet group, the magnetic poles on the side facing the fixed tube are different between every two adjacent permanent magnets in the axial direction and the circumferential direction of the fixed axis. That is, in each of the first permanent magnet group and the second permanent magnet group, the polarities of the individual permanent magnets are different like a checkered pattern or a mesh pattern in the developed state. In this way, the magnetic circuit established between the first permanent magnet group and the second permanent magnet group is not only established in the magnetic path passing only between the individual permanent magnets of the first permanent magnet group and the individual permanent magnets of the second permanent magnet group facing them via the fixed tube, but also in the magnetic path passing through the individual permanent magnets adjacent in the axial direction and the circumferential direction. Therefore, the strength of the magnetic coupling between the first and second permanent magnet groups is increased both in the axial direction and in the circumferential direction. In this way, without causing a delay in the magnetic coupling of the magnets similar to the backlash of the gear, the displacement amount from the second permanent magnet group (drive side) on the atmosphere side can be accurately transmitted to the first permanent magnet group (load side) on the vacuum side. Further, according to one aspect of the present invention, not only rotational drive but also linear drive can be performed using the magnetic coupling between the first and second permanent magnet groups enhanced both in the axial direction and in the circumferential direction.

[0010] (2) In one aspect (1) of the present invention, the first drive transmission mechanism and the second drive transmission mechanism can be included. At that time, the fixed tube and the fixed axis are shared by the first drive transmission mechanism and the second drive transmission mechanism, and each of the first drive transmission mechanism and the second drive transmission mechanism can include the movable tube, the driven tube, the first permanent magnet group, and the second permanent magnet group. In this way, with the first drive transmission mechanism and the second drive transmission mechanism, two movable tubes can be rotated in the same direction, or rotated in opposite directions to each other, or linearly moved in the same direction.

[0011] (3) In one aspect (2) of the present invention, it can further include a slider movably supported in the axial direction on the outer peripheral surface of the fixed pipe, a rotary bearing provided on the slider, and first and second rotators rotatably provided in forward and reverse directions with respect to the fixed pipe via the rotary bearing. In this case, the driven pipe of the first drive transmission mechanism is connected to the first rotator, and the driven pipe of the second drive transmission mechanism is connected to the second rotator. Thus, if the slider is linearly moved along the fixed pipe, the first and second driven pipes can be linearly moved via the rotary bearing and the first and second rotators, and the two movable pipes can be linearly moved. By rotationally driving the first rotator and the second rotator in the same direction or in opposite directions to each other, the two movable pipes can be rotated in the same direction or in opposite directions to each other.

[0012] (4) In one aspect (3) of the present invention, it can further include a rotation drive mechanism for rotationally driving the driven pipe around the fixed axis. In this case, the rotation drive mechanism includes a first driven gear fixed to the first rotator, a second driven gear fixed to the second rotator, a rotating shaft that rotates itself or revolves around the fixed axis, a first drive gear fixed to the rotating shaft and meshing with the first driven gear, a second drive gear fixed to the rotating shaft, and a third driven gear meshing with the second drive gear and the second driven gear. When the rotating shaft revolves around the fixed axis, the first and second drive gears and the first to third driven gears also revolve around the fixed axis, and the first and second rotators are rotated in the same direction. When the rotating shaft rotates itself, the first rotator is rotated in the first rotation direction via the first drive gear and the first driven gear, while the second rotator is rotated in a second rotation direction opposite to the first rotation direction via the second drive gear and the second and third driven gears. That is, by selecting the rotation or revolution of the rotating shaft, it is possible to select whether the rotation directions of the first and second rotators (the two driven pipes) are the same direction or opposite directions to each other.

[0013] (5) Another aspect of the present invention is the drive transmission mechanism described in one aspect (4) of the present invention, Including two drive arms driven by the driving force transmitted by the drive transmission mechanism, a frog-leg type robot that pivots, extends and retracts, and moves up and down, and relates to a conveying device having the same.

[0014] According to another aspect of the present invention, when the two drive arms are rotated in the same direction, the frog-leg type robot arm pivots, and when rotated in the opposite direction, the frog-leg type robot arm extends and retracts, and when linearly moved in the same direction, the frog-leg type robot arm moves up and down.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

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Figure 4

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Figure 8

Modes for Carrying Out the Invention

[0016] 1. First Embodiment Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIGS. 1(A) and 1(B), the drive transmission mechanism 1 includes a fixed tube 10, a fixed shaft 20, a movable tube 30, a driven tube 40, a first permanent magnet group 50, and a second permanent magnet group 60. The inside of the fixed tube 10 is evacuated. The fixed tube 10 is made of a non-magnetic material, and the movable tube 30 and the driven tube 40 are preferably made of a magnetic material. When the movable tube 30 and the driven tube 40 are made of a magnetic material, they can be used as part of a magnetic circuit. The fixed shaft 20 is disposed within the fixed tube 10. The movable tube 30 is inserted through the fixed shaft 20 within the fixed tube 10 and is moved in the axial direction A and the circumferential direction B of the fixed shaft 20. The driven tube 40 is disposed in the atmosphere outside the fixed tube 10 and is driven in the axial direction A and the circumferential direction B.

[0017] The first permanent magnet group 50 has individual permanent magnets arranged along the axial direction A and the circumferential direction B on the outer peripheral surface of the movable tube 30. The second permanent magnet group 60 has individual permanent magnets arranged along the axial direction A and the circumferential direction B on the inner peripheral surface of the driven tube 40. Then, each individual permanent magnet of the first permanent magnet group 50 and each individual permanent magnet of the second permanent magnet group 60 disposed opposite the first permanent magnet group 50 via the fixed tube 10 are magnetically coupled to each other. That is, in FIGS. 1(A) and 1(B), one magnet 51A of the first permanent magnet group 50 and one magnet 61A of the second permanent magnet group 60 face each other, and the pole on the side of the magnet 51A facing the fixed tube 10 is the S pole, and the pole on the side of the magnet 61A facing the fixed tube 10 is the N pole. In FIGS. 1(A) and 1(B), another one magnet 51B of the first permanent magnet group 50 and another one magnet 61B of the second permanent magnet group 60 face each other, and the pole on the side of the magnet 51B facing the fixed tube 10 is the N pole, and the pole on the side of the magnet 61B facing the fixed tube 10 is the S pole.

[0018] Furthermore, in each of the first permanent magnet group 50 and the second permanent magnet group 60, the magnetic poles on the side facing the fixed tube 10 are different between every two adjacent permanent magnets in the axial direction A and the circumferential direction B. That is, in the first permanent magnet group 50, the magnetic poles on the side facing the fixed tube 10 are different between every two adjacent permanent magnets 51A and 51B in the axial direction A and the circumferential direction B. Similarly, in the second permanent magnet group 60, the magnetic poles on the side facing the fixed tube 10 are different between every two adjacent permanent magnets 61A and 61B in the axial direction A and the circumferential direction B. Note that the number of the individual permanent magnets 51A, 51B, 61A, and 61B arranged along the axial direction A and the circumferential direction B in the first permanent magnet group 50 and the second permanent magnet group 60 can be variously modified and implemented.

[0019] According to this embodiment, in each of the first permanent magnet group 50 and the second permanent magnet group 60, the polarities of the individual permanent magnets 51A, 51B, 61A, and 61B are different like a checkered pattern or a mesh pattern in the developed state. For this reason, the magnetic coupling strength between the first and second permanent magnet groups 50 and 60 is increased, and the displacement amount from the second permanent magnet group 60 (driving side) on the atmosphere side can be accurately transmitted to the first permanent magnet group 50 (load side) on the vacuum side.

[0020] The reason for this will be described by comparing the present embodiment shown in FIGS. 2(A) and 2(B) with the prior art of, for example, Patent Document 1 shown in FIGS. 3(A) and 3(B).

[0021] First, in the drive transmission mechanism 1A of the comparative example shown in FIGS. 3(A) and 3(B), unlike FIG. 1, the first permanent magnet group 50A and the second permanent magnet group 60A are different, and the fixed tube 10, the fixed shaft 20, the movable tube 30, and the driven tube 40 are the same as those in FIG. 1. The first permanent magnet group 50A is provided with four bar-shaped permanent magnets 51C extending along the axial direction in the circumferential direction. The second permanent magnet group 60A is provided with four bar-shaped permanent magnets 61C extending along the axial direction in the circumferential direction. The magnetic circuit established between the first permanent magnet group 50A and the second permanent magnet group 60A is, as shown in FIGS. 3(A) and 3(B), established only in the magnetic path M1 passing only between each bar-shaped permanent magnet 51C of the first permanent magnet group 50A and each bar-shaped permanent magnet 61C of the second permanent magnet group 60A facing them via the fixed tube 10.

[0022] On the other hand, in the drive transmission mechanism 1 of the present embodiment shown in FIGS. 1(A) and 1(B), the magnetic circuit established between the first permanent magnet group 50 and the second permanent magnet group 60 is not only established in the magnetic path M1 passing only between each permanent magnet 51A, 51B of the first permanent magnet group 50 and each permanent magnet 61A, 61B of the second permanent magnet group 60 facing them via the fixed tube 10, as shown in FIGS. 2(A) and 2(B), but also established in the magnetic path M2 passing through the adjacent permanent magnets 51A, 51B, 61A, 61B in the axial direction A and the circumferential direction B.

[0023] Therefore, the strength of the magnetic coupling between the first and second permanent magnet groups 50 and 60 is increased both in the axial direction and in the circumferential direction. Thus, without causing a delay in the magnetic coupling of the magnets similar to the backlash of the gears, the displacement amount from the second permanent magnet group (drive side) 60 on the atmosphere side can be accurately transmitted to the first permanent magnet group (load side) 50 on the vacuum side. Further, according to the present embodiment, using the magnetic coupling between the first and second permanent magnet groups 50 and 60 enhanced both in the axial direction and in the circumferential direction, not only rotational drive but also linear drive can be performed.

[0024] 2. Second Embodiment In FIGS. 4 and 5, the drive transmission mechanism 100 includes a first drive transmission mechanism 100A and a second drive transmission mechanism 100B. The fixed pipe 10 and the fixed shaft 20 shown in FIGS. 1(A) and 1(B) are shared by the first drive transmission mechanism 100A and the second drive transmission mechanism 100B. The first drive transmission mechanism 100A includes a movable pipe 30A, a driven pipe 40A, a first permanent magnet group 50A, and a second permanent magnet group 60A. The second drive transmission mechanism 100B also includes a movable pipe 30B, a driven pipe 40B, a first permanent magnet group 50B, and a second permanent magnet group 60B. That is, each of the first drive transmission mechanism 100A and the second drive transmission mechanism 100B has the same structure as the structure shown in FIGS. 1(A) and 1(B), and only the fixed pipe 10 and the fixed shaft 20 are shared. Thus, the first drive transmission mechanism 100A can rotate the movable pipe 30A in the forward and reverse directions or move the movable pipe 30A in the axial direction. Independently of this, the second drive transmission mechanism 100B can rotate the movable pipe 30B in the forward and reverse directions or move the movable pipe 30B in the axial direction.

[0025] In FIG. 4, it can further include a slider 110 movably supported in the axial direction A on the outer peripheral surface of the fixed pipe 10, a rotary bearing 120 provided on the slider, and first and second rotating bodies 130A, 130B rotatably provided in the circumferential direction B in the forward and reverse directions with respect to the fixed pipe 10 via the rotary bearing 120. In this case, the driven pipe 40A of the first drive transmission mechanism 100A is connected to the first rotating body 130A, and the driven pipe 40B of the second drive transmission mechanism 110B is connected to the second rotating body 130B. When the slider 110 is linearly moved along the fixed pipe 10, the first and second driven pipes 40A, 40B can be linearly moved via the rotary bearing 120 and the first and second rotating bodies 130A, 130B, and the two movable pipes 30A, 30B can be linearly moved. When the first rotating body 120A is rotated, the driven pipe 40A of the first drive transmission mechanism 100A rotates integrally, and the movable pipe 30A can be rotated in the same direction or the reverse direction. Thus, the two movable pipes 30A, 30B can be rotated in the same direction or in opposite directions to each other, or linearly moved in the same direction.

[0026] In FIG. 4, a rotary drive mechanism 200 for rotationally driving the driven pipes 40A and 40B around the fixed shaft 20 can be further provided. The rotary drive mechanism 200 includes a first driven gear 210A provided on the first rotating body 130A, a second driven gear 210B provided on the second rotating body 130B, a rotating shaft 220 that rotates or revolves around the fixed shaft 20, a first drive gear 230A fixed to the rotating shaft 220 and meshing with the first driven gear 210A, and a second drive gear 230B fixed to the rotating shaft 220. Here, the rotation (rotation or revolution) of the rotating shaft 220 of the rotary drive mechanism 200 is transmitted to the first rotating body 130A via the first drive gear 230A and the first driven gear. On the other hand, as shown in FIG. 4, the second drive gear 230B and the second driven gear 210B are not directly meshed, and include a third driven gear composed of an odd number of gears interposed between the second drive gear 230B and the second driven gear 210B, which is omitted in FIG. 4. If the rotating shaft 220 is revolved around the fixed shaft 20, the first and second drive gears 230A and 230B and the first to third driven gears 210A, 210B, and 210C also revolve around the fixed shaft 20, and the first and second rotating bodies 130A and 130B rotate in the same direction. When the rotating shaft 220 rotates, the first rotating body 130A rotates in the first rotation direction via the first drive gear 230A and the first driven gear 210A, while the second rotating body 130B rotates in the second rotation direction opposite to the first rotation direction via the second drive gear 230B and the second and third driven gears 210B and 210C. That is, if the rotation or revolution of the rotating shaft 220 can be selected, it is possible to select whether the rotation directions of the first and second rotating bodies 130A and 130B (the driven pipes 40A and 40B) are the same direction or opposite to each other.

[0027] 3. Third Embodiment Figures 6 to 8 show a frog leg type robot 300 driven by the drive transmission mechanism 100 shown in FIGS. 4 and 5. This robot arm includes a swing axis 310 concentric with the fixed axis 20 in FIG. 4, two drive arms 320A and 320B that are swing-driven around the swing axis 310 or moved up and down along the axial direction of the swing axis 310, two driven arms 330A and 330B, and a holding part supported by the two driven arms 330A and 330B, for example, a wafer holding part 340. The two drive arms 320A and 320B are respectively pin-connected to the two driven arms 330A and 330B. The two driven arms 330A and 330B are pin-connected to the wafer holding part 340. The two drive arms 320A and 320B are driven by the driving force transmitted by the drive transmission mechanism 100. The drive arm 320A is connected to the first movable tube 30A, and the drive arm 320B is connected to the second movable tube 30B.

[0028] According to the third embodiment, when the two drive arms 320A and 320B are rotated in opposite directions to each other by the drive transmission mechanism 100, as shown in FIGS. 7 and 8, the frog leg type robot arm composed of the two drive arms 320A and 320B and the two driven arms 330A and 330B expands and contracts. When the two drive arms 320A and 320B are rotated in the same direction by the drive transmission mechanism 100, the frog leg type robot arm pivots so as to change its direction. When the two drive arms 320A and 320B are linearly moved and moved up and down by the drive transmission mechanism 100, the frog leg type robot arm moves up and down. In this way, the frog leg type robot 300 can convey and transfer an object to be conveyed, for example, a semiconductor wafer.

Explanation of Reference Numerals

[0029] 1. 100... drive transmission mechanism, 10... fixed tube, 20... fixed shaft, 30... movable tube, 30A, 3B... first and second movable tubes, 40... driven tube, 40A, 40B... first and second driven tubes, 50... first permanent magnet group, 51A, 51B... individual permanent magnets, 60... second permanent magnet group, 61A, 61B... individual permanent magnets, 100A... first drive transmission mechanism, 100B... second drive transmission mechanism, 110... slider, 120... rotary bearing, 130A... first rotating body, 130B... second rotating body, 200... rotary drive mechanism, 210A... first driven gear, 210B... second driven gear, 220... rotating shaft, 230A... first drive gear, 230B... second drive gear, 300... frog leg type robot, 320A, 320B... two drive arms, 330A, 330B... two driven arms

Claims

1. A non-magnetic fixed tube whose interior is evacuated, A fixed shaft disposed within the fixed tube, A movable tube inserted through the fixed shaft within the fixed tube and movable in the axial and circumferential directions of the fixed shaft, A driven tube disposed in the atmosphere outside the fixed tube and driven in the axial and circumferential directions, A first permanent magnet group in which individual permanent magnets are arranged along the axial and circumferential directions on the outer peripheral surface of the movable tube, A second permanent magnet group in which individual permanent magnets are arranged along the axial and circumferential directions on the inner peripheral surface of the driven tube, having, each of the individual permanent magnets of the first permanent magnet group and each of the individual permanent magnets of the second permanent magnet group disposed opposite the first permanent magnet group via the fixed tube are magnetically coupled to each other, In each of the first permanent magnet group and the second permanent magnet group, a magnetic pole on the side facing the fixed tube is different between every two adjacent permanent magnets in the axial and circumferential directions, a drive transmission mechanism.

2. In claim 1, including a first drive transmission mechanism and a second drive transmission mechanism, In the first drive transmission mechanism and the second drive transmission mechanism, the fixed tube and the fixed shaft are shared, Each of the first drive transmission mechanism and the second drive transmission mechanism includes the movable tube, the driven tube, the first permanent magnet group, and the second permanent magnet group, a drive transmission mechanism.

3. In claim 2, A slider movably supported in the axial direction on the outer peripheral surface of the fixed tube, A rotary bearing provided on the slider, First and second rotators rotatably provided in forward and reverse directions with respect to the fixed tube via the rotary bearing, further having, The driven tube of the first drive transmission mechanism is connected to the first rotator, and the driven tube of the second drive transmission mechanism is connected to the second rotator, a drive transmission mechanism.

4. In claim 3, further having a rotary drive mechanism for rotationally driving the driven tube around the fixed shaft, The rotary drive mechanism includes, A first driven gear fixed to the first rotator, A second driven gear fixed to the second rotator, A rotary shaft that rotates on its own or revolves around the fixed shaft, A first drive gear fixed to the rotary shaft and meshing with the first driven gear, A second drive gear fixed to the rotary shaft, A third driven gear composed of an odd number of gears interposed between the second drive gear and the second driven gear, including, a drive transmission mechanism.

5. The drive transmission mechanism according to claim 4, A frog-leg type robot including two drive arms driven by a driving force transmitted by the drive transmission mechanism, and capable of turning, extending / contracting, and ascending / descending, and a conveying device having the same.

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