JP2002064129A - Transfer device using traction driving reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transfer device, which is compact, is low in vibrations, is low in noise and is specially suitable for treating a semiconductor wafer, an LCD(Liquid Crystal Display) glass base or the like. SOLUTION: A transfer device is constituted in a structure that the transfer device comprises externally connecting axes 20A and 20B, which are attached with arms 61A and 61B and are coupled with coaxially arranged output axes 21A and 21B, a plurality of intermediate axes 30A and 30B contactedly arranged on the outer peripheries of the axes 20A and 20B and internally connecting circular cylinders 40A and 40B internally connecting with the outer peripheries of the axes 30A and 30B and a carrier 10 for rotatably supporting the axes 30A and 30B is fixed and driving motors 70A and 70B are connected with each group of the axes 30A and 30B via the preceeding stage of the reducers 50A and 50B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a drive device, comprising: a circumscribed shaft; a plurality of intermediate shafts arranged in contact with the outer periphery of the circumscribed shaft;
The present invention relates to a transfer device using a traction drive reduction gear comprising an inscribed cylinder inscribed on the outer periphery of an intermediate shaft.

[0002]

2. Description of the Related Art In a field such as a semiconductor wafer or an LCD (liquid product display) glass substrate, which requires sophisticated processing that dislikes particles, a conveyed object cannot be transported by chucking (eg, grasping the conveyed object). ). For this reason, as a handling system in such a transportation field, at present, the transport is performed by a transport device of a type in which a transported object is merely placed on a hand (end effector) (support only).

[0003]

However, in such a transfer apparatus, an organic substance (rubber or the like) is also supported.
Although there is an inorganic (ceramic or the like) support and an organic support has a relatively large frictional force, there is a problem that it cannot be used in a high-temperature portion. Furthermore, there is a method called vacuum suction, which can be used in the atmosphere, but it can be used in semiconductor wafers and LCDs (liquid product display).
It cannot be used in a vacuum that is often used when processing glass substrates. Further, the vacuum suction has a complicated structure and is expensive.

For this reason, in many cases, the transferred object (eg, wafer) is held only by the frictional force with the hand support. However, such a conveyed product is suddenly moved,
If it is moved while vibrating, the conveyed object slips and shifts, causing problems such as generation of particles, poor positioning, and damage to the conveyed object. For this reason,
Transport devices used in such a sophisticated transport field include:
A drive device capable of carrying (smooth carrying) with as little vibration (acceleration) as possible is required.

[0005]

In a transfer apparatus such as a semiconductor wafer or an LCD (liquid product display) glass base, which dislikes particles and requires elaborate processing, a direct drive (DD) is conventionally used. A driving device of a system has been used (Japanese Patent Laid-Open No. 3-281183). However, since the drive system of the DD system has a small output density (torque / volume, torque / motor capacity), there is a problem that the drive system is large and the power supply capacity is also large.

On the other hand, there is also a transfer device using a speed reducer having a gear mechanism in order to reduce the size of the drive device.
By using a speed reducer having a gear mechanism, it is possible to make the drive device compact. But,
Since the gears are provided, there is a problem that a backlash exists and vibration and noise are caused. Further, in order to reduce vibration and noise, a transfer device using a speed reducer having a gear mechanism requires complicated control and is expensive.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a compact, low-vibration, low-noise semiconductor wafer or LCD (liquid product display) using a traction drive reduction gear as a driving device, which can solve the problems associated with the above-mentioned prior art. It is an object of the present invention to provide a transfer device for processing a glass substrate or the like.

[0008]

According to the present invention, a drive motor, a drive arm driven by the drive motor, and a carrier table connected to the tip of the drive arm are provided. In the transport device provided, the output from the drive motor, a circumscribed shaft, a plurality of intermediate shafts disposed on the outer periphery of the circumscribed shaft, and a traction drive reducer including an inscribed cylinder inscribed on the outer periphery of the intermediate shaft. A transfer device is provided, wherein the transfer device is transmitted to the drive arm through the transfer arm.

According to the transfer device of the present invention, the drive device can be made compact, and the drive can be made smooth and vibration and noise can be reduced by using a traction drive system without teeth in the speed reducer. Conveyance can be performed without any shift of the conveyed object. Since the traction drive speed reducer is used, there is no backlash (backlash), there is no impact due to play at the start of driving, and no displacement of the transported object occurs.

[0010] In the present invention, as set forth in claim 2, the transfer device has two output shafts arranged coaxially, and each output shaft has a circumscribed shaft and an outer periphery of the circumscribed shaft. It is connected to a corresponding drive motor via a traction drive reducer comprising a plurality of arranged intermediate shafts and an inscribed cylinder inscribed on the outer periphery of the intermediate shaft, and two coaxial shafts are provided from the two output shafts. An apparatus capable of taking output can be provided.

In this case, the two output shafts arranged coaxially of the transfer device and the output member of the traction drive reducer may be integrally connected, or may be connected via a conductive member such as an endless belt. You may.

Further, the traction drive reducer fixes a carrier rotatably supporting a plurality of intermediate shafts, inputs rotation from at least one of the pair of intermediate shafts, and receives a corresponding circumscribed shaft. The rotation may be input from a circumscribed shaft, the inscribed cylinder in which a plurality of intermediate shafts are inscribed is fixed, and the rotation output is obtained from a carrier that rotatably supports the plurality of intermediate shafts. You may do so.

Further, according to a third aspect of the present invention, in the transfer apparatus, a front-stage speed reducer is connected to a front stage of the traction drive speed reducer, and the front-stage speed reducer includes a circumscribed shaft and a circumscribed shaft. A plurality of intermediate shafts arranged in contact with the outer periphery of the, the traction drive reducer consisting of an inscribed cylinder inscribed in the outer periphery of the intermediate shaft by a transport device characterized by a further reduction gear ratio, It is more preferable because there is no backlash (backlash), and there is no impact due to backlash at the start of driving, so that the transported object does not shift.

Further, in the present invention, a transfer device may be provided, wherein a position detector is provided on the output side of the traction drive reduction gear. In the traction drive system, it is conceivable that a slight slip occurs inside the traction drive due to its structure. For this reason, by adopting a configuration in which the above-described position detector is provided on the output side, even if the traction drive speed reducer slips, the output position can be detected by the position detector,
Recovery, correction, and the like can be performed as appropriate.

Further, in the present invention, the interference is set by setting the sum of the outer diameter of the circumscribed shaft and the outer diameter of the intermediate shaft to twice the inner diameter of the inscribed cylinder, and a torque adjustment function is provided by the interference. It is preferable that the transfer device is characterized in that the transfer is performed. In the present invention, a traction drive reduction gear is used, and even if an arm or the like of the transfer device collides, it can be avoided by causing slippage, so that the transfer device may be damaged like a gear reducer. There is no.
Further, by providing the position detector as described above, it can be easily restored. In addition, as described above, by setting the sum to be twice the sum of the outer diameter of the circumscribed shaft and the outer diameter of the intermediate shaft larger than the inner diameter of the inscribed cylinder, the torque can be set by the interference. Can be adjusted, so that the collision load can be easily set.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. 1A and 1B show a first embodiment of a transfer device 60 using a traction drive reduction gear according to the present invention, wherein FIG. 1A is a schematic cross-sectional view schematically showing the structure of the embodiment, and FIG. It is sectional drawing which follows the AA line. The circumscribed shaft,
The intermediate shaft and the inscribed cylinder are actually in contact with each other, but in FIG. 1A, a small gap is formed between them for clarity of illustration. FIG.
In (b), illustration of the carrier is omitted.

In the present embodiment, as shown in FIG. 1A, the carrier 10 of the present invention is formed in a box shape by a pair of upper and lower plates 11, 12 and a column 13 connecting between the plates. The output circumscribed shaft 20 has an output shaft 21 at its center.
The output shaft 21 of the output circumscribed shaft 20 is rotatably supported by a bearing 23 located at the center of the upper plate 11 of the carrier 10. The arm 61 of the transfer device 60 is attached to the upper end of the output shaft 21.

Around the circumscribed shaft 20, a plurality of (three in the illustrated embodiment) intermediate shafts 30 are arranged equidistantly as shown in FIG. In contact. The circumscribed shaft 20 has a diameter larger than the outer diameter of the intermediate shaft 30, and decelerates the input introduced to the intermediate shaft 30 and outputs the input from the circumscribed shaft 20 as described later.

The inscribed cylinder 4 is provided outside the plurality of intermediate shafts 30.
The inner circumference of 0 is inscribed. Each intermediate shaft 30 has a carrier 10
Both ends are rotatably supported by bearings 31 provided on the upper and lower plates 11 and 12 constituting the above. Thus, the traction drive speed reducer is configured.

A drive motor 70 is connected to at least one of the plurality of intermediate shafts 30 and a driving force is introduced to the intermediate shaft 30. On the other hand, in this embodiment, the output is taken out from the circumscribed shaft 20 while the carrier 10 is fixed. As a modification of this embodiment, it is also possible to fix the inscribed cylinder 40 to introduce an input from the circumscribed shaft 20 and extract an output from the carrier 10.

Further, in order to further increase the reduction ratio of the transfer device 60, the intermediate shaft 30 is provided in front of the input shaft of the traction drive reduction gear, that is, in the embodiment shown in FIG.
Further, between the circumscribing shaft 20 and the drive motor in the above-described modified embodiment, a further preceding reduction gear 50 may be provided. This pre-stage reduction gear 50 may also be a traction drive reduction gear.

Next, with reference to FIG. 2, a description will be given of a second embodiment of the transfer device 60 using a traction drive reduction gear according to the present invention, in which a plurality of outputs are taken out coaxially. FIG. 2 shows a second embodiment according to the present invention, wherein (a)
2A is a schematic cross-sectional view, FIG. 2B shows a cross section at a position A in FIG. 2A, and FIG. 2C shows a cross section at a position B in FIG. 2A.

The carrier 10 composed of a pair of upper and lower plates 11 and 12 is connected by a column 13 to form a strong box-like state. An output circumscribed shaft 20A having a hollow output shaft 21A at the center of the carrier 10 and an output circumscribed shaft 20
An output circumscribed shaft 20B having an output shaft 21B penetrating through the hollow output portion of A is coaxially arranged. Hollow output shaft 2
1A and the upper end of the output shaft 21B, the arm portion (the first arm 61A and the second arm 6
1B) is attached.

Around each output circumscribed shaft 20A, 20B,
As shown in FIGS. 2B and 2C, a plurality of intermediate shafts 30A and 30B are arranged, respectively,
A and 20B are in contact with the outer periphery. The intermediate shaft 30
As shown in FIG. 2 (a), both ends of A and 30B are rotatably supported by the carrier 10 by bearings 31A and 31B.

Further, inscribed cylinders 40A, 40B are provided outside the respective intermediate shafts 30, and the inscribed cylinders 40A, 40B are provided.
The inner peripheral surface of B is in contact with the outside of the intermediate shafts 30A, 30B. The circumscribed shafts 20A, 20B forming each set,
A plurality of intermediate shafts 30A, 30B and inscribed cylinders 40A, 4
In this embodiment, the output shafts 21A and 21B of the speed reducer composed of two sets are coaxially arranged. Thus, the traction drive speed reducer is configured.

Each set of intermediate shafts 30
For example, drive motors 70A and 70B are connected to at least one of the shafts A and 30B to introduce a rotation input. The carrier 10 is fixedly supported.

As a result, the power input from the intermediate shafts 30A and 30B is reduced, and the output shafts 21A and
1B. In order to further increase the speed reduction ratio of this speed reducer, another speed reducer is provided before the input shaft of each speed reducer, that is, between the intermediate shafts 30A, 30B and the drive motors 70A, 70B. 50A,
50B may be provided. According to the present invention, even in the case of such a large reduction ratio, a planar arrangement can be achieved.

FIG. 3 shows a third embodiment of the transfer device 60 using the traction drive speed reducer according to the present invention. In the embodiment shown in FIG. 2, a pair of upper and lower plates 11,
The intermediate shafts 30A, 30A are
B and the circumscribed shafts 20A and 20B are respectively supported. However, if there is a concern that the interval between the upper and lower carriers 10 becomes longer, it is preferable to use the embodiment shown in FIG. In this embodiment, one plate 14 is further provided between the set of the circumscribed shafts 20A and 20B, the intermediate shafts 30A and 30B, and the inscribed cylinders 40A and 40B.
, The carrier 10 is composed of three plates.

By doing so, the intermediate shaft 30
The distance between the bearings 31A, 31A and between the bearings 31B, 31B of the shafts supporting the shafts A, 30B can be reduced, and the deformation of the respective intermediate shafts 30A, 30B can be reduced. In addition, with respect to the circumscribed shafts 20A and 20B, in particular, the inner circumscribed shaft 20B can be supported at both ends by bearings 23B provided on the plates 11 and 14, whereby the deformation can be further reduced.

Next, a more specific embodiment of the transfer device 60 using the traction drive drive device according to the present invention will be described with reference to FIG. FIG. 4 shows a modification of the embodiment described with reference to FIG. 1, that is, a transfer device 60 using a traction drive reduction gear of a type in which an inscribed cylinder is fixed and an input is made from a circumscribed shaft and an output is taken out of a carrier. (A) is a longitudinal sectional view showing a more specific embodiment,
FIG. 4B is a sectional view taken along line AA of FIG.

The arm (not shown) of the transfer device 60 is a semiconductor wafer or LCD (liquid product display) such as a clean room.
It is provided inside a processing chamber for processing a glass substrate and the like, the inside of the processing chamber is depressurized (a so-called vacuum state), and a driving device for driving an arm is provided outside the processing chamber. The boundary is a plate-like portion 62a at the head of the mount 62 for mounting the transfer device. The transport device mounting mount 62 includes a plate-like portion 62a of the head and a cylindrical portion 6 that is integrally attached to the plate-like portion 62a and protrudes downward.
2b.

The cylindrical portion 62 of the mount 62 for mounting the transfer device.
A bearing 23 is provided in b, and the output shaft 21 is rotatably supported by the bearing 23. At the upper end of the output shaft 21, an arm (not shown) of the transfer device 60 that handles a semiconductor wafer, an LCD (liquid product display) glass substrate, and the like is attached.

The carrier 10 of the traction drive reduction gear according to the present invention is formed in a box shape by a pair of upper and lower plates 11 and 12 and a column portion 13 connecting between the plates.
The carrier 10 (the upper plate 11, the lower plate 12, and the pillar 13) is integrally attached to the lower end of the output shaft 21 by a bolt 65.

As shown in FIG. 4A, bearings 31 are provided on the upper and lower plates 11 and 12 constituting the carrier 10, and both ends of the intermediate shaft 30 are rotatably supported by the bearings 31. Furthermore, a rotatable circumscribed shaft 20 extends through a hole located in the center of the lower plate 12, and a plurality (three in the illustrated embodiment) of intermediate shafts 30 are provided as shown in FIG. , Are arranged equally around the circumscribed shaft 20 and are in contact with the outer periphery of the circumscribed shaft 20. The intermediate shaft 30 has a diameter larger than the outer diameter of the circumscribed shaft 20. The inscribed cylinder 40 is fixedly installed inside the cylindrical portion 62b of the mount 62 for mounting the transfer device, and the inner periphery of the inscribed cylinder 40 is inscribed outside the plurality of intermediate shafts 30 described above.

As described above, the inscribed cylinder 40 is fixed, and a traction drive reducer configured to input from the circumscribed shaft 20 and output from the carrier 10 is configured. The rotation of the drive motor 70 is reduced, and the drive motor 70 is integrated with the carrier 10. The output shaft 21 that is attached is driven, and an arm (not shown) of the transfer device 60 attached to the upper end of the output shaft 21 is operated.

The gap between the inside of the output shaft 21 above the bearing 23 and the inside of the cylindrical portion 62b of the mount 62 for mounting the transfer device and the plate-like portion 62a of the mount 62 for mount the transfer device.
A shaft seal 63 made of a non-contact type seal or a contact type seal such as a magnetic fluid seal is provided in a gap between the opening formed at the center of the shaft and the inside of the output shaft 21 to maintain the vacuum inside the processing chamber. I have. Reference numeral 64 denotes an oil seal for preventing oil from leaking from the traction drive reduction gear.

The output shaft 21 has a shoulder 21a below the upper shaft seal 63 (ie, outside the vacuum processing chamber) and above the bearing 23. The shoulder 21a has a donut plate shape. The sign plate 67 of the outer shaft position detector is a bolt 6
8 is fixed. In addition, a detection unit 69 is provided inside the cylindrical portion 62b of the mount 62 for mounting the transfer device, and detects the rotation position of the output shaft 21 by detecting the code on the code plate 67 described above.

Further, in order to further increase the reduction ratio of the transfer device 60, the circumscribed shaft 20 and the drive motor 70 are provided in front of the input shaft of the traction drive reducer described above.
, A further pre-stage reduction gear 50 is provided. The front-stage speed reducer 50 of this embodiment has the same structure as the above-described traction drive speed reducer, fixes the inscribed cylinder 53, inputs the rotation of the drive motor 70 from the circumscribed shaft 51, and extracts the output from the carrier 54. A traction drive speed reducer of the type, in which a carrier 54 supports a number of intermediate shafts 55 circumscribing the circumscribed shaft 51, and the circumscribed shaft 51 is connected to an output shaft of a drive motor 70, and the carrier 54 is described above. The traction drive reduction gear circumscribed shaft 20 is integrally connected.

The transport device 60 of the present embodiment having the above configuration
In, the power input from the driving motor 70 is
The speed is reduced by the pre-stage reduction gear 50, and the output is
0 is input to the circumscribed shaft 20 for driving the output shaft 21. The input rotation is reduced by the first-stage traction drive reducer to rotate the output shaft 21 and drive the arm 61 attached to the output shaft 21.

According to the transfer device of the present embodiment, the following effects can be obtained. In the present embodiment, a traction method (rolling transmission) or a friction method (friction transmission by non-metal) having no teeth is used for the speed reduction mechanism of the driving device, and a slip (displacement) occurs on a transfer object such as a wafer. In addition, the traction system has no backlash (backlash) as seen in a gear mechanism, so there is no shock due to backlash at the start of driving, and no slippage (shift) occurs in the transported object. Therefore, the above compactness, extremely low vibration, and low noise can be achieved.

In the traction system, the reduction gear has no teeth, so that it is conventionally unsuitable for high-precision positioning. In the above embodiment, however, an encoder (code plate 6) is attached to the output shaft 21.
7 and the detector 69) of the detector solve the problem of being unsuitable for high-precision positioning.

Further, in the transfer device of this embodiment, the bearing 23
A shaft seal 63 made of a non-contact type seal, such as a magnetic fluid seal, or a contact type seal is provided above the main body to maintain a vacuum inside the processing chamber, and can be used in a vacuum or in the atmosphere.

Further, in the case of the transfer device 60 having the speed reducer, since the input is mechanically connected to the output, even if a collision is caused by any cause during the transfer, the transfer continues if the motor is within the upper limit torque of the motor. And may damage the conveyed object and the conveying device 60, and in the worst case,
Humans may be pinched and damaged. On the other hand, in the transfer device of the present embodiment, since the speed reducer having the traction system has no teeth, when a torque exceeding a certain level is applied, a slip phenomenon occurs inside the traction drive, so that the impact due to the collision is absorbed. can do. Also,
As described above, even if a position shift occurs due to the slip, since the encoder is provided on the output side, return (origin return or the like) can be easily performed.

Still another embodiment will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing an embodiment in which the transfer device 60 using the traction drive reducer shown in FIG. 3 is more concretely illustrated. FIG. 6A is a cross-sectional view taken along line AA of FIG.
6B is a sectional view taken along the line BB of FIG. 5, FIG. 7A is a sectional view taken along the line CC of FIG. 5, and FIG. 7B is a sectional view taken along the line DD of FIG.

The arm portion of the transfer device 60 (the first arm 61
A and the second arm 61B) are in a clean room or the like.
The first arm 6 is provided inside a processing chamber for processing a semiconductor wafer, an LCD (liquid product display) glass substrate, and the like, and the inside of the processing chamber is reduced in pressure (a so-called vacuum state).
A driving device for driving the 1A and the second arm 61B is provided outside the processing chamber, and a boundary between the driving device and the second arm 61B is a plate-like portion 62a of the head of the mount 62 for mounting the transfer device. The transport device mounting mount 62 is composed of a plate-like portion 62a of the head and a cylindrical portion 62b attached integrally with the plate-like portion 62a and protruding downward.

Hollow output shaft (outer shaft) coaxial with each other
21A and a solid output shaft (inner shaft) 21B are rotatably supported by bearings 23A and 23B on a carrier mounting mount 62 in the same manner as in the embodiment shown in FIG. That is, the hollow output shaft (outer shaft) 21A is rotatably supported by a bearing 23A provided inside the cylindrical portion 62b, and the solid output shaft (inner shaft) 21B is provided inside the hollow output shaft (outer shaft) 21A. It is rotatably supported by a bearing 23B provided.

The hollow output shaft (outer shaft) 2 above the bearing 23B
The gap between the inside of 1A and the outside of the solid output shaft (inner shaft) 21B, the opening formed in the center of the plate-like portion 62a of the mount 62 for mounting the transfer device, and the outside of the hollow output shaft (outer shaft) 21A. A shaft seal 63 made of a non-contact type seal such as a magnetic fluid seal or a contact type seal is provided in the gap to maintain the vacuum inside the processing chamber.

The hollow output shaft (outer shaft) 21A and the solid output shaft (inner shaft) 21B have semiconductor wafers and LCDs, respectively.
(Liquid product display) First arm 61 that handles glass base etc.
A and the second arm 61B are attached by bolts 64A and 64B.

An output shaft (outer shaft) 21A comprising a hollow cylindrical shaft
Of the circumscribed shaft 20 with a bolt 65A at the tip of the lower end.
A has been concluded. As shown in FIG. 6A, the circumscribed shaft 20A has a disk shape, the center of which is hollow, and a solid output shaft (inner shaft) 21B can be penetrated. In the embodiment, the outer peripheral surface of the circumscribed shaft 20A has 3
The intermediate shafts 30A of the book are evenly in contact with each other.

Further, the intermediate shaft 30A is inscribed in the inner surface of the donut-shaped inscribed cylinder 40A. Here, the sum of twice the outer diameter of the circumscribed shaft 20A and the outer diameter of the intermediate shaft 30A is set larger than the inner diameter of the inscribed cylinder 40A, and the interference is set. The torque is adjusted to the traction drive reduction gear by the interference. Has functions. In this embodiment, the carrier 10 is fixed, and one of the intermediate shafts 30A is connected to a drive front reduction gear 50A for driving the hollow output shaft (outer shaft) 21A. Power from the outer shaft drive motor 70A is transmitted via the motor 50A,
An output can be taken out from the circumscribed shaft 20A.

At the lower part of the solid shaft output shaft (inner shaft) 21B, below the circumscribed shaft 20A, a mount 66 for mounting a circumscribed shaft is connected by a spline 21Ba. Bolts 6
The circumscribed shaft 20B is fastened by 5B. Circumscribed shaft 2
0B has a disk shape as shown in FIG.
Its central part is hollow and solid output shaft (inner shaft) 21
The lower end of B is penetrable. This circumscribed shaft 20B
Bolt 65 for fixing the above-mentioned circumscribed shaft 20A.
A bolt through hole 20Ba for passing A is provided.

As shown in FIG. 6B, in this embodiment, three intermediate shafts 30B are equally circumscribed around the circumscribed shaft 20B, and the circumscribed shaft 20B has a donut shape. Inscribed in the inscribed cylinder 40B. Here, the sum of twice the outer diameter of the circumscribed shaft 20B and the outer diameter of the intermediate shaft 30B is set larger than the inner diameter of the inscribed cylinder 40B, and the interference is set. The torque is adjusted to the traction drive reduction gear by the interference. Has functions. In this embodiment, the carrier 10 is fixed, and one of the intermediate shafts 30B is connected to a solid output shaft (inner shaft) 21B driving front-stage speed reducer 50B. The power from the inner shaft drive motor 70B is transmitted via 50B,
The output can be taken out from the circumscribed shaft 20B.

Note that in FIGS. 6A and 6B,
Reference numeral 13 denotes a carrier column for firmly connecting the upper and lower plates 11, 12, and 14 integrally. FIG. 6 (b)
In the above, the gap between the circumscribed shaft 20B and the inscribed cylinder 40B is formed by the intermediate shaft 3 that drives the hollow cylindrical output shaft (external shaft) 21A.
The lower end of 0A penetrates in a non-contact state.

A shoulder 21Aa is formed on the hollow output shaft (outer shaft) 21A below the shaft seal 63 (that is, outside the vacuum processing chamber) and above the bearing 23A, and a donut is formed on the shoulder 21Aa. A plate 67A of the plate-shaped outer shaft position detector is fastened by bolts 68A. Further, a detection unit 69A of an outer shaft position detector is provided on the carrier 10 side of the transfer device 60, and detects the code on the code plate 67A to detect the rotational position of the output shaft 21A. ing.

On the other hand, at the lower end portion 21Bb of the solid output shaft (inner shaft) 21B (that is, outside the vacuum processing chamber), a disc-shaped sign plate 67B of the inner shaft position detector is provided with a bolt 6
8B, a detection section 69B of an inner shaft position detector is provided on the carrier 10 side of the transport device 60 opposite to the code plate 67B, as shown in FIG. 5B. Thus, the rotational position of the output shaft 21B is detected.

In this embodiment, the outer shaft front-stage speed reducer 50A and the inner shaft front-stage speed reducer 50B are traction drive type speed reducers, respectively. Outer shaft drive motor 70A and inner shaft drive motor 70B for driving hollow output shaft (outer shaft) 21A and solid output shaft (inner shaft) 21B
Are connected to each other. A plurality of intermediate shafts 52 equally circumscribe the outer periphery of the circumscribed shaft 51, and
The outside of 2 is inscribed in the inscribed cylinder 53. The inscribed cylinder 53 of this speed reducer is fixed, and the output is taken out from the carrier 54.
Outputs from these carriers 54 are input to the above-described first stage intermediate shafts 30A and 30B, respectively. In this reduction gear, too, the sum of twice the outer diameter of the circumscribed shaft 51 and the outer diameter of the intermediate shaft 52 is set larger than the inner diameter of the inscribed cylinder 53 to set the interference, and the torque is adjusted by the interference. Has functions.

The transport device 60 of the present embodiment having the above-described configuration.
In, the power input from the outer shaft driving motor 70A is reduced by the front-stage speed reducer 50A, and the output is input to the outer shaft driving intermediate shaft 30A of the transfer device 60.
Then, the inputted rotation is reduced by the first-stage traction drive reducer and the hollow output shaft (outer shaft) 21A
To drive the first arm 61A attached to the hollow output shaft (on the outer shaft) 21A. Similarly, the rotational force of the inner shaft drive motor 70B is input to the inner shaft pre-stage reducer 50B, where a predetermined deceleration is performed, and then to the intermediate shaft 30B of the subsequent inner shaft drive reducer. The second arm 61B is driven via a solid output shaft (inner shaft) 21B.

According to the transfer apparatus of the present embodiment, the following effects can be obtained. In this embodiment, the two output shafts are arranged coaxially, and the transport device is compact. In addition, the traction method (rolling transmission) or the friction method (friction transmission by non-metal) that does not have teeth is used for the speed reduction mechanism of the drive device, so that the transfer object such as a wafer does not slip (displace). In addition, the traction system does not have backlash (play) as seen in a gear mechanism, so that there is no shock due to play at the start of driving, and no slip (shift) occurs in the conveyed object. Therefore, the above compactness, extremely low vibration, and low noise can be achieved.

In the traction system, since the reduction gear has no teeth, it is conventionally unsuitable for high-precision positioning. However, in the above embodiment, the output side (that is, the hollow output shaft (outer shaft) 21A and the solid output By providing the encoder (code plates 67A, 67B and the detectors 69A, 69B of the position detector) on the shaft (inner shaft) 21B, the problem of being unsuitable for high-precision positioning is solved.

Further, in the transfer device of this embodiment, the bearing 23
A gap formed between the inside of the hollow output shaft (outer shaft) 21A above B and the outside of the solid output shaft (inner shaft) 21B and an opening formed at the center of the plate-shaped portion 62a of the mount 62 for mounting the transfer device. A shaft seal 63 made of a magnetic fluid seal or a contact type seal is provided in a gap between the hollow output shaft (outer shaft) 21A and the outside to maintain a vacuum inside the processing chamber.
It can be used in vacuum and air.

Further, in the case of the transfer device 60 having a speed reducer, since the input is connected mechanically to the output, even if a collision is caused by any cause during the transfer, the transfer continues if it is within the upper limit torque of the motor. And may damage the conveyed object and the conveying device 60, and in the worst case,
Humans may be pinched and damaged. On the other hand, in the transfer device of the present embodiment, since the speed reducer having the traction system has no teeth, when a torque exceeding a certain level is applied, a slip phenomenon occurs inside the traction drive, so that the impact due to the collision is absorbed. can do. In addition, in the transfer device of the present embodiment, the load torque of the traction drive (torque at which slippage occurs) can be freely adjusted by adjusting the tightening margin of the outer pressure ring (inscribed cylinder).
Can be set. Further, even if a positional shift occurs due to slippage, as described above, since the encoder is provided on the output side, return (origin return, etc.) can be easily performed.

FIGS. 8A and 8B show another specific embodiment of the transfer apparatus, wherein FIG. 8A is a longitudinal sectional view, and FIG.
It is AA sectional drawing of.

In the embodiment shown in FIGS. 5 to 7, the hollow output shaft (outer shaft) 21A and the solid output shaft (inner shaft) 21B of the transfer device 60 have a coaxial double structure. These hollow output shaft (outer shaft) 21A and solid output shaft (inner shaft) 21B are connected to bolts 65A, 65 on circumscribed shafts 20A, 20B of a traction drive reduction gear as a driving device.
B.

On the other hand, in the embodiment shown in FIG. 8, the hollow output shaft (outer shaft) 21A and the solid output shaft (inner shaft) 21B of the transfer device 60 have a coaxial double structure. These hollow output shafts (outer shafts) 21A and solid output shafts (inner shafts) 21B are connected to output shafts (in the embodiment, carriers 10A and 10B) of the traction drive reducer by an endless belt, and the hollow output shafts are connected. (Outer shaft) 21A
For both the solid output shaft (inner shaft) 21B and the solid output shaft (inner shaft) 21B, the traction drive speed reducer for driving the transfer device 60 and the preceding stage speed reducer can have the same structure.

An endless belt pulley 90 is attached to the lower ends of the hollow output shaft (outer shaft) 21A and the solid output shaft (inner shaft) 21B.
A and 90B are integrally attached by bolting or spline connection.

On the other hand, a set of traction drive reducers 93A and 93B for driving the transfer device 60 (hereinafter referred to as rear reducers), the front reducers 50A and 50B and the drive motors 70A and 70B are connected to a hollow output shaft (outer shaft). 8) Two sets are prepared for 21A and the solid output shaft (inner shaft) 21B, and they are installed on the left and right of the hollow output shaft (outer shaft) 21A and the solid output shaft (inner shaft) 21B in FIG.

The rear reduction gears 93A and 93B are shown in FIG.
Has a structure similar to that shown in FIG.
A traction drive speed reducer 40B is fixed, and the traction drive speed reducer receives input from the circumscribed shafts 20A, 20B and outputs from the carriers 10A, 10B.
The rotation of OB is reduced, and the output shaft 21 integrally attached to the carrier 10 is driven. Each rear reduction gear 93A,
Output shaft 9 connected to carriers 10A and 10B of 93B
Endless belt pulleys 91A and 91B are integrally attached to 5A and 95B.

An endless belt 92B is provided between an endless belt pulley 90A formed on the lower end of the hollow output shaft (outer shaft) 21A and an endless belt pulley 91B formed on an output shaft 95B connected to the carrier 10B. An endless belt is provided between an endless belt pulley 90B formed on the lower end of the solid output shaft (inner shaft) 21B and an endless belt pulley 92A formed on the output shaft connected to the carrier 10A. 92A.

The pre-stage reduction gears 50A, 50A, 5A
OB has the same structure as that of the above-described traction drive reduction gear, and fixes the inscribed cylinder 53;
A, the rotation of 70B is input from the circumscribed shaft 51, and the carrier 5
4 is a traction drive reduction gear of a type that takes output from the carrier 4, a carrier 54 supports a number of intermediate shafts 55 circumscribing the circumscribed shaft 51, and the circumscribed shaft 51 is
0A and 70B are connected to the output shaft.

The other structures, functions and effects are the same as those of the embodiment shown in FIG. 4 or FIGS.

In FIG. 8, the position detector (code plate 67)
A, 67B and detectors 69A, 69B) (FIG. 8)
The detection unit 69B is not shown in the figure) and the hollow output shaft (outer shaft) 2
1A and the solid output shaft (inner shaft) 21B, but in this embodiment, the belt pulleys 90A, 90B, 91A, 91B
To the endless belts 92A, 92A.
Since the backlash between B and the belt pulleys 90A, 90B, 91A, 91B can be eliminated, a rotational position detector may be provided on each output shaft of the traction drive reduction gears 93A, 93B.

[0072]

The transfer apparatus using the traction drive speed reducer as the drive unit according to the present invention is compact and has low vibration and low noise, and is particularly used for processing semiconductor wafers and LCD (liquid product display) glass substrates. Suitable as a device.

[Brief description of the drawings]

FIGS. 1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a cross-sectional view schematically showing the structure of the embodiment, and FIG.
It is sectional drawing which follows a line.

2A and 2B show a second embodiment according to the present invention, in which FIG. 2A is a schematic cross-sectional view, FIG. 2B shows a cross section at a position A in FIG. 2A, and FIG. () Shows a cross section at the position B.

FIG. 3 is a schematic sectional view similar to FIG. 2 (a), showing a third embodiment according to the present invention.

FIG. 4 shows an embodiment in which the transport device is made more specific,
(A) is a longitudinal sectional view, and (b) is an AA sectional view of (a).

FIG. 5A is a cross-sectional view of another embodiment in which the transfer device according to the present invention is more specifically illustrated, and FIG. 5B is a solid output shaft (inner shaft) of the embodiment illustrated in FIG. FIG. 5 is a partial view showing a detection unit of an inner shaft position detector attached to a lower end of the sensor.

6A and 6B are cross-sectional views of the embodiment shown in FIG. 5, wherein FIG. 6A is a cross-sectional view taken along line AA of FIG. 5, and FIG. 6B is a cross-sectional view taken along line BB of FIG.

FIGS. 7A and 7B are cross-sectional views of the embodiment shown in FIG. 5; FIG. 7A is a cross-sectional view taken along the line CC in FIG. 5;

FIGS. 8A and 8B show still another embodiment in which the transfer device is specifically illustrated. FIG. 8A is a longitudinal sectional view, and FIG.
It is sectional drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Carrier 11, 12, 14 Plate 13 Column part 20, 20A, 20B Output circumscribed shaft 21, 21A, 21B Output shaft 23 Bearing 30, 30A, 30B Intermediate shaft 40, 40A, 40B Inscribed cylinder 31, 31A, 31B Bearing 50 , 50A, 50B Reduction gear 70, 70A, 70B Drive motor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F060 AA01 EB12 GA05 GA13 GB29 GC01 GC03 GD07 GD14 3J051 AA01 BA03 BB07 BC01 BD02 BE03 FA07 5F031 CA02 CA05 JA32 LA07 PA26

Claims (5)

[Claims] 1. A transfer device comprising a drive motor, a drive arm driven by the drive motor, and a transfer table connected to a tip of the drive arm, wherein an output from the drive motor is a circumscribed shaft. A transfer device that is transmitted to the drive arm via a traction drive reducer including a plurality of intermediate shafts arranged on the outer periphery of the circumscribed shaft and an inscribed cylinder inscribed on the outer periphery of the intermediate shaft. . 2. The transfer device has two output shafts arranged coaxially, each of the output shafts having a circumscribed shaft, a plurality of intermediate shafts arranged on the outer periphery of the circumscribed shaft, and an intermediate shaft. It is connected to a corresponding drive motor via a traction drive reducer consisting of an inscribed cylinder inscribed on the outer periphery, so that two coaxial outputs can be taken out from the two output shafts. The transport device according to claim 1. 3. A front-stage speed reducer is connected to a front stage of the traction drive speed reducer. The front-stage speed reducer includes a circumscribed shaft, a plurality of intermediate shafts arranged in contact with the outer periphery of the circumscribed shaft, and The transfer device according to claim 1, further comprising a traction drive reduction device including an inscribed cylinder inscribed in an outer periphery. 4. A position detector is provided on an output side of the traction drive speed reducer.
The transfer device according to any one of the above. 5. The interference is set by making the sum of the outer diameter of the circumscribed shaft and the outer diameter of the intermediate shaft twice larger than the inner diameter of the inscribed cylinder, and a torque adjustment function is provided by the interference. The transport device according to claim 4, wherein: