JPH03281183A - Articulated conveying device - Google Patents

Abstract

PURPOSE:To reduce necessary torque, i.e. capacity, of two electric motors by disposing two drive shafts on the same axis and driving the drive shafts with the aid of the respective independent electric motors. CONSTITUTION:Two drive shafts 48 and 51 are disposed on the same axis and capable of being driven by independent electric motors 46 and 49, respectively. Namely, when a conveying table 44 is linearly moved, the two drive shafts 48 and 51 are rotationally driven in reverse direction by the same angle arc at the same speed with the aid of the electric motors 46 and 49. When the conveying table 44 is revolved, the two drive shafts 48 and 51 are rotationally driven in the same direction in the same angle arc at the same speed with the aid of the electric motors 46 and 49.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to, for example, in order to form a thin film on a semiconductor wafer, the semiconductor wafer is transported into a vacuum processing apparatus, and then the processed semiconductor wafer is placed in a predetermined position. This invention relates to a multi-joint transport device used for transporting pipes.

C. Prior art and its problems] FIG. 12 shows a multi-joint arm device or a multi-joint arm device described in JP-A-60-183736. 10)
includes a first multi-joint arm (11) and a second multi-joint arm (14). The first Tosekin mushroom arm (11
) consists of two parts, namely the driving part (I2) and the driven part (
13), which are connected by a bin connection part (17). Similarly, the second articulated arm (14)
is composed of two parts, a driving part (15) and a driven part (16).
), which are connected by a bin connection (18). In this embodiment, the drive unit (121
(151 is shorter than the driven parts (13) and (16).

The drive parts (12) and (15) in R9i have circular gears (20) and (21), respectively. Gear (201(
21) can be integrally formed as part of the drive part (12) (15), or can be formed separately and fixed to the drive part by suitable attachment means. The gear (20) is a binion (driving small gear) (22
) are combined to work together. Gear (20) is driven by a pinion (22), which in turn drives gear (21). Driven part (13) (161
Each case has a semicircular rotational restraint gear (231 (24)).A moving platform (25) or other suitable holder for carrying an object is connected to the rotational restraint gear (23) by a bearing (261 (27)). (24). Instead of a rotationally restraining gear, a friction surface or cable and pulley combination can also be used; in this case, the driven part (13
) (It is said that rotation of the end of 161 can be prevented.

When the binion (22) rotates clockwise, the gear (20
) and the drive unit (12) rotate counterclockwise, and the gear [2
1) and the drive part (15) can be understood to rotate clockwise. As a result, the articulated arm (11) (14)
The movable table (25) moves in a harmonic motion towards the gears (20) and (21). It prevents rotation, so the object being carried undergoes linear motion.

The above gears (20) (21) and the binion (22) are provided on a U-shaped support base (30), and the binion (22) is connected to the first electric motor provided on the support base (30). It is designed to be driven by Furthermore, a support stand (3
The support base (30) is configured to be rotationally driven around its central axis by a second electric motor provided on the base (36) below the support base (30).

On the other hand, Japanese Patent Application Laid-Open No. 160949/1983 also discloses a conveying device similar to the above-mentioned one.

[Problems to be Solved by the Invention] These conveying devices have the following drawbacks.

(1) The mechanisms for directional rotation or rotational movement and extension and contraction of the arm, that is, the rotational movement and linear movement of the transport platform, are mutually independent; therefore, for changing the direction,
That is, the second electric motor for rotating the conveyance table is required to rotate the arm and the entire extension/contraction mechanism. Therefore, the second electric motor used for this requires a large torque. Alternatively, due to insufficient torque, it is necessary to reduce the speed through a reduction gear to perform the turning motion. In this case, it is necessary to provide a large number of gears for the reduction mechanism.

Furthermore, since the entire body must be rotated, it has the disadvantage that multiple rotations cannot be performed.

(2) Since gears or timing belts are used in the drive part of the arm's telescoping mechanism and the drive part for the swing movement, there are problems such as backlash, which makes it difficult to make high-precision positioning adjustments with good reproducibility. Difficult to do.

(3) There are many mechanical parts, and the configuration is complicated.

(4) When used as a vacuum conveyance mechanism, two gears (201 (211) and a shaft seal for rotating the support base (30), that is, a three-shaft vacuum seal are rotated. The introduction mechanism must be used and vacuum seals are expensive, making the overall device even more expensive.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a multi-joint transport device with a simple structure that can eliminate each of the above-mentioned drawbacks.

[Means for Solving the Problems] The above object is to provide a pair of driving arms, a pair of driven arms each having one end pivotally connected to one end of the driving arm, and a pair of driven arms having one end pivotally connected to the other end of the driven arm. In a multi-joint transport device consisting of a pivotally mounted transport platform and drive shafts fixed to the other end of the drive arm, both drive shafts are arranged coaxially and each is driven by an independent electric motor. When the conveyance table is moved in a straight line, the moving shafts of both parts are rotated by the same angle and at the same speed in opposite directions, and when the conveyance table is made to rotate, the moving shafts of both parts are rotated by the same angle. This is achieved by a multi-joint conveyance device characterized in that the rotations are driven at the same speed and in the same direction.

[For production]

When the conveyor table is moved in a straight line, both moving shafts fixed to one end of a pair of drive arms are rotated by the same angle and at the same speed in opposite directions. Since the moving axes are rotated by the same angle, at the same speed, and in the same direction, two electric motors are required to perform the turning movement and the linear movement, as in the past. Since it is necessary for one electric motor to drive the entire driving arm and a pair of driven arms, a large torque is required, or a reduction mechanism is required, and the configuration is complicated due to the large number of gears.
However, according to the present invention, the electric motor for performing linear movement and turning movement is common and only drives one drive arm and one driven arm, so the torque can be increased even more than before. It can be made smaller and does not require a reduction gear.

Further, since it is possible to completely eliminate the need for gears, there is no backlash problem and highly accurate positioning with good reproducibility can be performed. Further, since only two shafts are required for the vacuum seal, the cost of the device can be significantly reduced.

Also, since only the drive shaft rotates, multiple rotations can be achieved.

[Example] Hereinafter, an articulated transport device according to an example of the present invention will be described with reference to the drawings.

1 to 5 show a multi-joint conveyance device according to a first embodiment of the present invention. In the figures, the present conveyance device is indicated as a whole by (40), and as clearly shown in FIG. As in the conventional case, the arm mechanism consists of a pair of drive arms (41a).
(41b) and axis f42a at this one end (42b
) A pair of driven arms (43a) pivotally connected by (
43b) and a driven arm (43a) (4
The other end of 3b) is connected to the carrier (44) via bearing mechanisms (45a) and (45b) as in the conventional case. As clearly shown in FIGS. 2 and 3, according to the present invention, the other ends of the drive arms (41a) (41b) are fixed at the tips of shafts that are coaxially arranged and driven independently. There is. That is, according to this embodiment, one axis (5
1) is a hollow shaft, and a solid shaft (48) passes through the center thereof, and the lower end thereof is connected to the rotation shaft (46a) of the first electric motor (46) via a coupling (47). are combined.

The other end of the drive arm (41a) is fixed to the tip (48a) of the solid shaft (48). Further, the other drive arm (4) is attached to the tip (51a) of the hollow shaft (51).
1b) the other end is fixed. The hollow shaft (51) is the rotating shaft of the second electric motor (49), and as mentioned above, this rotating shaft is hollow, and the bearing mechanism for rotatably supporting this shaft is connected to the stator portion (50). ). Furthermore, although the first electric motor (46) and the second electric motor (49) are driven independently, a control circuit is provided to set the driving start of these to - and to control the rotational phase, rotational direction, and rotational speed. It is assumed that the terminal is connected to the terminal via a conductive wire (not shown). Electric motor (46) (49)
If the motor is a pulse motor, the number of pulses, pulse interval, etc. are set by the control circuit.

The shaft (48) protrudes slightly upward from the hollow shaft (51), and the above-mentioned one drive arm (48a) is attached to this tip (48a).
41a) is fixed at one end, and a shaft (42a) is fixed at the other end, which is pivotally connected to the negative driven arm (43a). That is, one driven arm (43a) is rotatable at one end about the shaft (42a) with respect to the one driving arm (41a). Similarly, a shaft (42b) is fixed to one end of the other drive arm (41b), but this length is longer than the other shaft (42a) described above, and the tip thereof is at the same level. ing.

That is, one end of one driven arm (43bl) is rotatably coupled to the tip of the shaft (42b).

That is, these driven arms (43a) are pivotally connected.
(43b) are connected so that they are in the same horizontal plane. Therefore, the bearing mechanism (45a) f4 is attached to its tip.
5b) is supported horizontally by one end of the driven arm (43a) (43b).

The first embodiment of the present invention is constructed as described above, and its operation will be explained next.

First, the rotating movement of the conveyor table (44) will be explained.

In this case, the first electric motor (46) and the second electric motor (49) operate at the same speed in the same direction and at the same angle.
It is rotated in the direction of the arrow shown in the figure.

Now, if we are to make a 90 degree turn, we will start driving at the same time by supplying the corresponding number of pulses to each electric motor (461 (49)), rotate 90 degrees, and both electric motors (461T49) They stop at the same time.As a result, the carrier (44) assumes a position rotated by 90 degrees around the shaft (48) or the hollow shaft (51), as shown in FIG. 4B.

That is, the conveyance table (44) stops at a position rotated by 90 degrees around the shafts (48) (51). Thereby, for example, a semiconductor wafer placed on the carrier table (44) can be fed by moving straight toward the thin film forming section of the vacuum processing apparatus.

Next, the rectilinear movement of the conveyor table (44) will be explained. In this case, the first electric motor (46) and the second electric motor (46)
9) is given a driving pulse so that it rotates in the opposite direction at the same speed and by the same angle. The number of pulses is
This corresponds to the straight-line movement distance of 4). FIG. 5A shows the initial position, and in this state the first and second electric motors (461 (4
9), it takes a position as shown in FIG. 5B for a certain number of driving pulses.

That is, the drive arm (41al (41b)
In the figure, they rotate in opposite directions. That is, one drive arm (41a) rotates counterclockwise around the shaft (48), and the other drive arm (41b) rotates clockwise around the hollow shaft (51) as shown in FIG. 5B. take a position. That is, the carrier (44) moves forward from the position shown in FIG. 5A to the position shown in FIG. 5B. After this, the first and second electric motors (46) and (49) are further driven to a predetermined pulse amount, causing the drive arm (41a) to move counterclockwise and the other drive arm (41b) to move clockwise at the same speed. It rotates and eventually assumes the position shown in Figure 5C. As a result, the carrier (44) can move further forward than in FIG. 5B and take a predetermined position. In this way, for example, a semiconductor wafer can be accurately positioned and fed to a predetermined position by further moving the carrier (44) straight from the position shown in FIG. 4B.

FIG. 6 and FIG. 7 show a multi-joint conveyance device according to a second embodiment of the present invention, and correspond to FIG. 2 showing the first embodiment. are given the same reference numerals, and detailed explanation thereof will be omitted. That is, the drive arm (41a) which is each component in the arm mechanism
) (41b), driven arm (43a) (43b)
are exactly the same components, but their positional relationship is different. That is, in this embodiment, the first and second electric motors (
61) and (62) are disposed facing each other in the vertical direction, and their rotation axes (61a) and (62a) are coaxial, and unlike the first embodiment, both are ordinary electric motors instead of hollow shaft electric motors. Can be used. These electric motors (61)
(62) are arranged above and below, so this rotation axis (
61a) (62a) Since the vertical positional relationship of the drive arms (41a) and (41b) fixed to the tip portions is different, the bottles (63a) and (63b) fixed to one end thereof are different.
Unlike the first embodiment, the projecting direction is opposite to that of the first embodiment, but their lengths are the same, so that the driven arms (43a) and (43b) can be disposed and connected within the same horizontal level.

In this embodiment as well, when the conveyor table (44) is to be rotated, the rotating shafts (61a) and (62a) of the first electric motor (61) and the second electric motor (62) are started to be driven at the same time in the same direction. It is rotated by the same angle at the same speed. This makes it possible to perform a turning movement as shown in FIGS. 4A and 4B.

In addition, when moving the conveyance platform (44) in a straight line, similarly, the rotation shafts (61a) (62a) of the first electric motor (6I) and the second electric motor (62) are moved in opposite directions at the same angle and at the same speed. Rotationally driven. As a result, similarly to the first embodiment, the positions shown in FIGS. 5A, 5B, and 5C can be sequentially taken, and the conveyance table (44) can be advanced a predetermined distance.

FIG. 8 shows a multi-joint conveyance device according to a third embodiment of the present invention. The device as a whole is designated by (80), and parts corresponding to those in the first embodiment are given the same reference numerals. A detailed explanation thereof will be omitted.

In this embodiment, the first electric motor (71) has the same configuration as in the first embodiment, but the hollow shaft (73) that it passes through is not the rotating shaft of the second electric motor, but is an independent member. An annular gear (74) is fixed to the lower end. This is engaged with a third gear (76) fixed to the rotating shaft of the second electric motor (72) via a connecting gear (75). These gears (74) (75) (76)
have the same diameter and the same number of teeth. Therefore, the rotation direction of the rotation shaft of the second electric motor (72) is the same as the rotation direction of the gear (74), that is, the hollow shaft [73], and the rotation speed can be the same. Therefore, the same control as in the first embodiment and the second embodiment can be performed. This embodiment also has the same effect as the above-mentioned embodiment, but the assembly is simple and the gears (74) (75
) (76), but since the number of gears can be reduced compared to the conventional method, the problem of backlash can be made smaller.

In the above embodiments, no description was given of the relationship between each part and the vacuum, but now a case will be described in which the transfer table (44) is operated in a vacuum. In this case, it is necessary to vacuum-seal between the motor side and the transfer table side, and Fig. 9 shows an example of this, and parts corresponding to the above embodiment are given the same reference numerals and details thereof. Although detailed explanation will be omitted, a flange member (81) having mounting holes in one direction is fixed to a part of the partition wall (82) of the vacuum chamber, and the outer circumferential surface of the hollow shaft (51) inserted through this flange member (81) is fixed to a part (82) of the partition wall of the vacuum chamber. and the inner peripheral wall surface of this mounting flange (81) are axially sealed via a vacuum seal S2, and
A second vacuum seal S1 provides a shaft seal between the outer peripheral surface of the shaft (48) and the inner peripheral wall surface of the hollow shaft (51). The above-mentioned arm mechanism and transfer platform are disposed at the tip of the shaft (48) (511), but these are located in the vacuum chamber, and the lower side in FIG. 9, that is, the first , the second electric motor side is assumed to be on the atmosphere side.

Conventionally, in order to perform the above sealing action, the 11th
Shaft seals must be made as shown in the figure. That is, to explain with reference to FIG. 12, the drive shaft (20) (21) in the conventional device is fixed at the center of the
20a) (21a) The upper end portions are shown in FIG. 11, and these are inserted through insertion holes formed in the rotating shaft (83), and the inner circumferential wall surface of these insertion holes and the shaft (20a)
Vacuum seals S3 and S4 are interposed between the outer peripheral wall surface of (21a) and the outer peripheral wall surface of (21a). To explain with reference to FIG. 12, the rotation shaft (83) is arranged below the support base (30) and rotates the entire arm mechanism provided on the base (36) below the support base. The above-mentioned drive shafts (20a) (21a) are connected to the drive shaft of the electric motor for
A hole is formed for insertion. Then, a vacuum seal S3 is applied between this outer peripheral wall surface, the inner wall surface of the hole of the mounting flange (85) attached to the partition wall (86) of the vacuum chamber, and the outer peripheral surface of the rotating shaft (83). In other words, three vacuum seals are required in the prior art, but according to the present invention, only two vacuum seals are required as shown in FIG. Therefore, the number of expensive vacuum seals can be reduced, and the cost of the device can be significantly reduced.

FIG. 10 shows a multi-joint conveyance device according to a fourth embodiment of the present invention. In the figure, parts corresponding to those in the above embodiment are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

In this embodiment, the solid shaft (91) is the rotating hollow shaft (
92), and one end of one of the drive arms is fixed to its tip as in the above embodiment, and a gear (100) is fixed to its lower end. Axis (91
) is rotatably supported by a pair of bearings (93) (95) installed between it and the rotating hollow shaft (92).
), and this outer race is fixed to the inner circumferential wall of the rotating hollow shaft (92). The gear (10) is also attached to the lower end of the rotating hollow shaft (92).
A gear (97) having the same shape and the same number of teeth as 0) is fixed, and the rotating hollow shaft (92) is fitted with a pair of bearings (94).
) is fixed to the inner race of F96), and this outer race is fixed to the hollow pipe (103) as a fixed part.
is fixed to the inner wall of the The gear (97) meshes with a gear (98) fixed to the tip of the rotating shaft of the first electric motor (99), and the gear (100) meshes with the second electric motor (10).
It meshes with the gear (102) fixed to the tip of the rotating shaft of 1). The gears (981 (102)) have the same diameter and the same number of teeth. Therefore, when the first electric motor (99) and the second electric motor (lOl) are rotated 9 times in the same direction, the gears (981 (102)) are the same. 97) (100
), but since they have the same number of teeth, the rotating hollow shaft (92) and the solid shaft (91) rotate in the same direction. That is, in this case, the arm is rotated.

Similarly to the above embodiment, when the first electric motor (99) and the second electric motor (1011) are rotated in opposite directions, the gears (1oo) (1021 and (971 (98)) are engaged in opposite directions. The rotating hollow shaft (92) and the solid shaft (91) rotate.Thereby, the transport platform (44) can perform linear movement as described above.Other functions and effects are described above. This is the same as in the embodiment. Note that in the first to third embodiments, the bearings for the solid shaft and the hollow shaft were not explained, but each pair of bearings (93) ( 95) and (94)
(96) may be used as a shaft support.

Furthermore, if so-called vacuum motors that can be used in a vacuum are used as the first and second electric motors, vacuum seals as shown in Figs. It can be set to zero operation. As a vacuum motor, for example, A
There is a G (axial gap) motor in which the stake is sealed and a rotor is placed with a gap in the axial direction.

Although each embodiment of the present invention has been described above, the present invention is of course not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, as the first and second electric motors,
In the so-called radial gap motor, the stator is annular, and a rotor is disposed inside the stator through a gap in the radial direction, and the above-mentioned shaft and hollow shaft are connected to this, but instead of this, An axial gap motor (so-called AG motor) may also be used. That is, a rotating body is arranged with a gap in the axial direction from the stator, and as is well known, a plurality of coils are arranged on the stator at equal angular intervals, and the coils are sequentially energized by switching between alternating current and N pole. An axial gear motor that rotates a rotating body by alternately generating south poles may also be used. In this case, if the carrier is used in a vacuum chamber, only the rotating part can be disposed in the vacuum chamber, and the stator side can be disposed on the atmosphere side. In this case, it becomes possible to further reduce the number of vacuum seals.

Furthermore, in the above embodiments, the case where the carrier is used in a vacuum chamber has been described, but of course the present invention is also applicable to the case where the entire carrier is used in the atmosphere. In this case, of course, vacuum sealing is not necessary, but the number of parts is reduced compared to conventional technology, and there is no need to use gears, so there is no problem of backlash (accurate positioning of the transfer platform) be able to.

Further, in the above embodiments, the conveyance table is moved in a straight line and rotated in a horizontal plane, but instead of this, the conveyance table may be moved in a straight line and turned in a vertical plane. In this case, the shape of the carrier may be appropriately configured to prevent the semiconductor wafer or object placed thereon from falling. Alternatively, it may be provided with an engaging portion for engaging the object to be placed. In this case, the driving arm and the driven arm are disposed in a vertical plane unlike in the above embodiment, but the shaft of the electric motor was also disposed to extend in the vertical direction in the above embodiment, but it is now arranged in the horizontal direction. It will be installed. However, according to the present invention, it is necessary that these be arranged coaxially.

In addition, in the above modification, the carriage is moved in a straight line and rotated in a vertical plane, but it is also possible to move the carriage in a straight line between a vertical plane and a horizontal plane, that is, in an oblique direction, and The transfer table may be rotated within this diagonal plane, but in this case, the transfer table is provided with a mechanism that always faces the horizontal direction, and the vacuum processing apparatus such as the semiconductor wafer is placed horizontally. Objects to be processed within the container may be transported.

Further, in the above embodiment, the lengths of the driving arm and the driven arm are changed to make the latter longer as in the conventional conveying device shown in FIG. 11, but it is possible to reverse this or
Furthermore, a difference in length may be made.

3 In addition, in the above embodiment, the pivot mechanism was explained by simply using a pin and a hole for fitting the pin to pivotally connect the driving arm and the driven arm, but instead of this, a known bearing mechanism may be used. It may also be used for pivoting and support. The same applies to the pivotal connection between the carrier table and one end of the double-wave drive arm.

In addition, in the first embodiment described above, the rotary shaft of the first electric motor (46) is inserted into the hollow shaft (51).
1) To make it longer, a coupling (47) was provided between the rotating shaft (46a) of the electric motor (46) and the shaft portion (48) to be inserted, but this may be omitted depending on the load on the arm. The drive arm may be directly fixed to the tip of the long shaft of the electric motor.

Further, in the above embodiments, the tip of the solid shaft (48) through which the hollow shaft (51) is inserted is made to protrude outside from the hollow shaft (51), but even if it does not protrude, An arc-shaped notch is formed in the part, and the arm attachment part attached to the tip of the shaft through which the hollow shaft is inserted halfway is inserted into the notch, and one end of the drive arm is fixed to this tip. The drive arm may be rotated within the range of an arcuate slit formed in the section.

In this case, the rotating shaft (46a) of the first electric motor (46)
Since (48) can be made even shorter, there is no need to use the coupling (47) as in the embodiment.

[Effects of the Invention] As described above, according to the multi-joint conveyance device of the present invention, two
The required torque of two electric motors is smaller than before, that is,
The capacity can be made smaller, and the cost required for this can be reduced.Also, when using the carrier in a vacuum chamber, shaft seals are required, but the number of shaft seals can be reduced compared to conventional methods. Since this can be done, the cost required for this can also be reduced. In addition, since there is no need for a large number of gears or the need for gears to be fully heated, there is no backlash problem caused by these gears, and the carrier can be easily positioned at a predetermined position with high precision. be able to.

Furthermore, since only the drive shaft rotates, multiple rotations are possible.

[Brief explanation of drawings]

FIG. 1 is a plan view of the multi-joint conveyance device according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view along the line ■-■ in FIG. 1, and FIG. 3 is a plane along the line III--III in FIG. 1. figure,
4A and 4B are schematic plan views for explaining the operation of the first embodiment; FIGS. 5A, 5B, and 5C are schematic plan views for explaining the operation of the first embodiment; 6 is a sectional view similar to FIG. 2 of a multi-joint conveyance device according to a second embodiment of the present invention, FIG. 7 is a sectional view similar to FIG. 3 of the same embodiment,
FIG. 8 is a cross-sectional view similar to FIG. 2 of the multi-joint transfer device according to the third embodiment of the present invention, and FIG. 9 is a cross-sectional view of the multi-joint transfer device according to the third embodiment of the present invention, and FIG. FIG. 10 is a sectional view similar to FIG. 2 of the multi-joint device according to the fourth embodiment of the present invention, and FIG. 11 is FIG. 9 of the shaft seal portion used in the conventional device. A sectional view similar to the above and FIG. 12 are a plan view of a conventional multi-joint conveyance device. In addition, in the figure, 40) 41a) (41b) ---- 43aH43b) 46) f6i) (99) 46a (61a) f62a ) ・ 48) (91)... 49) (62) (1011... 51) (92)... Electric motor rotation axis of joint transfer device moving arm drive arm 1 Actual shaft 2 electric motor empty shaft agent Yasuo Iisaka 7 JP-A-3-281183 (10)

Claims (5)

[Claims] (1) A pair of drive arms, a pair of driven arms each having one end pivotally attached to one end of the drive arm, a conveyance table pivotally attached to the other end of the drive arm, and In a multi-joint transport device consisting of drive shafts fixed to the other end, the drive shafts are arranged coaxially and each is driven by an independent electric motor, and when the transport platform is moved in a straight line, Both drive shafts are driven to rotate by the same angle in opposite directions at the same speed, and when the conveyance platform is rotated, both drive shafts are driven to rotate by the same angle in the same direction at the same speed. An articulated transport device featuring: (2) The multi-joint conveyance device according to claim 1, wherein one of the drive shafts is hollow, and the other drive shaft passes through the hollow. (3) The inner periphery of the mounting opening provided between the inner circumferential wall surface of the one hollow drive shaft and the outer circumferential wall surface of the other drive shaft, and between the outer circumferential wall surface of the one hollow drive shaft and the vacuum chamber wall. The vacuum cleaner according to claim 2, wherein both of the electric motors are disposed on the atmosphere side with a shaft seal between them and a wall surface, and the drive arm, the driven arm, and the conveyance table are disposed inside the vacuum chamber. Joint transport device. (4) The two drive shafts are vertically spaced apart from each other, and each
The multi-joint conveyance device according to claim 1, wherein the multi-joint conveyance device is driven by the electric motors arranged above and below. (5) Both the electric motors are disposed on the atmosphere side by sealing between the outer circumferential wall surfaces of the two drive shafts and the inner circumferential wall surfaces of the pair of mounting openings provided in the vacuum chamber wall, and the drive arm; The multi-joint transfer device according to claim 4, wherein the driven arm and the transfer table are arranged inside the vacuum chamber.