Transmission device

Abstract

To enable displacement other than rotation in addition to the rotation to be transmitted to an object.SOLUTION: A transmission device includes: a shaft body extending in a predetermined direction; a housing that is a cylindrical member surrounding and accommodating the shaft body and in which one end side of the shaft body is closed and the other end side is opened; a holding mechanism that holds the shaft body so as to be displaceable with respect to the housing in a predetermined first region along a shaft line; a rotary motor disposed in a predetermined second region along the shaft line in the shaft body; and a linear motor disposed in a predetermined third region along the shaft line in the shaft body.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a transmission device for displacing an object. [Background technology]

[0002] Conventionally, processing has been performed while rotating a rotating object in a decompressed closed space, such as in the process of manufacturing semiconductors. Here, the power for rotating the rotating object is generally transmitted from the outside through a partition wall that divides the closed space, and for example, the use of a magnetic coupling that can transmit the rotation of a drive shaft to a driven shaft by magnetism in a non-contact manner has been proposed (see Patent Document 1).

[0003] In this case, the drive shaft of the magnetic coupling is placed on the outside of the partition wall and the driven shaft is placed on the inside of the partition wall, and by rotating the drive shaft with a motor from the outside of the partition wall, this rotation can be transmitted via the driven shaft to the rotating object inside. Because the rotation can be transmitted without contact, the closed space does not communicate with the outside, and the reduced pressure state can be maintained. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6475062 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in this configuration, the drive shaft of the magnetic coupling is placed outside the partition wall, and the motor is connected to rotate this drive shaft, so only rotation can be transmitted. If it were possible to transmit displacements other than rotation, the degree of freedom in processing objects in a closed space would increase, but this has not been done.

[0006] The present invention has been made to solve such problems, and its object is to provide a technique that makes it possible to transmit displacements other than rotation to an object. [Means for solving the problem]

[0007] In order to solve the above problem, a transmission device of a first aspect includes a shaft extending in a predetermined direction, a housing which is a cylindrical member surrounding and accommodating the shaft, the housing having one end side of the shaft closed and the other end side open, a holding mechanism which holds the shaft displaceably relative to the housing in a predetermined first region along its axis, a rotary motor arranged on the shaft in a predetermined second region along its axis, and a linear motor arranged on the shaft in a predetermined third region along its axis, the holding mechanism includes a holding portion which is provided inside the housing so as to surround the shaft around its axis in the first region, and holds the shaft displaceably along its axis, and a bearing portion which is interposed between an inner peripheral surface of the housing and the holding portion in the first region, and holds the holding portion and the shaft rotatably about the axis relative to the housing, and the rotary motor includes a linear motor arranged in the second region, the linear motor being arranged in the first region, the linear motor being ... first region, the linear motor being arranged in the first region, the linear motor being arranged in the first region, the linear motor being arranged in the first region, The linear motor comprises a linear stator arranged inside the housing to extend along the axis of the shaft in the third region and drives the shaft in response to axial displacement, and a linear mover fixed to the housing in the third region, surrounding the shaft around its axis from outside the housing and driving the shaft in response to axial displacement, and a linear mover fixed to the housing in the third region, surrounding the shaft around its axis from outside the housing and driving the shaft in response to axial displacement, and a linear mover fixed to the housing in the third region, surrounding the shaft around its axis from outside the housing and driving the shaft in response to axial displacement, and with an object to be displaced attached to the other end of the shaft, the shaft is displaced by passing current through the rotary motor and the linear motor, and the displacement is transmitted to the object to be displaced.

[0008] In the transmission device of this aspect, when the rotary motor is energized, the shaft body rotates about its axis, and this rotation can be transmitted to a displacement object attached to the other end of the shaft body. In addition, when the linear motor is energized, the shaft body is displaced in the axial direction, and this displacement can be transmitted to a displacement object attached to the other end of the shaft body. In this way, with this aspect, in addition to rotation, other displacements can be transmitted to a displacement object via the shaft body.

[0009] This aspect may be modified as in a second aspect described below. In the transmission device of the second aspect, the first region and the second region are regions that overlap in the axial direction, the holding mechanism is provided so that the holding part follows the rotation about the axis by the shaft, and the rotary motor is provided so that the rotary mover surrounds the holding part about the axis inside the housing and causes the holding part to follow the rotation about the axis, while the rotary stator surrounds the holding part about the axis from outside the housing.

[0010] In the transmission device of this aspect, by overlapping the first region of the shaft body in which the retaining mechanism is provided and the second region in which the rotary motor is provided, the axial length can be shortened, thereby making the transmission device more compact.

[0011] Furthermore, each of the above aspects may be as described below in a third aspect. The transmission device of the third aspect includes a magnetic fluid seal that seals an internal space surrounded by the housing at a sealing position on the other end side of the shaft from each of the first to third regions by interposing a magnetic fluid between the shaft and the housing over the entire circumference around the axis.

[0012] In this aspect of the transmission device, the internal space surrounded by the housing is sealed at the sealing position, so that even if impurities (gas, cutting chips, etc.) are generated around parts that operate through physical contact, they can be prevented from reaching the object to be displaced. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a front view of a transmission device and a vacuum chamber according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view (view taken along the line AA in FIG. 1 ) of a transmission device and a vacuum chamber according to an embodiment of the present disclosure, taken along a plane intersecting an axial direction and a direction perpendicular to the axial direction; [Diagram 3] FIG. 1 is a cross-sectional view of a main part (upper end side) of a transmission device according to an embodiment of the present disclosure, taken along a plane formed by the axial direction and a direction intersecting the axial direction; [Figure 4] FIG. 1 is a cross-sectional view of a main part (lower end side) of a transmission device according to an embodiment of the present disclosure, taken along a plane formed by an axial direction and a direction intersecting the axial direction; [Diagram 5] FIG. 1 is a cross-sectional view of a magnetic fluid seal and its periphery in a transmission device according to an embodiment of the present disclosure, taken along a plane defined by an axial direction and a direction intersecting the axial direction; [Figure 6] FIG. 13 is a cross-sectional view of a main portion of a transmission device according to another embodiment of the present disclosure. [Figure 7] FIG. 1 is a cross-sectional view of a main portion illustrating a state in which a shaft is displaced in a transmission device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The transmission device 1 is attached to an apparatus that processes a rotating object while rotating it in a depressurized closed space, so as to rotate the rotating object. In this embodiment, as shown in Fig. 1 and Fig. 2, a configuration is exemplified in which the transmission device 1 is attached to a vacuum chamber 300 of a semiconductor manufacturing apparatus that processes a displacement object 200, that is, a turntable, while rotating the turntable, in a depressurized closed space, so as to rotate the turntable.

[0015] (1) Overall structure As shown in Figures 1 and 2, the transmission device 1 comprises a shaft body 10 extending in a predetermined direction (up and down in the figure), a cylindrical housing 20 that surrounds and accommodates the shaft body 10 around its axis 100, a holding mechanism 30 that holds the shaft body 10 displaceably relative to the housing 20 in a first region 11 described below, a rotary motor 40 arranged in a second region 13 of the shaft body 10 described below, a linear motor 50 arranged in a third region 15 of the shaft body 10 described below, and a magnetic fluid seal 60 that seals the internal space surrounded by the housing 20.

[0016] The housing 20 is a cylindrical member extending along the axis 100, with one end of the shaft 10 (the lower end in Figures 1 and 2) being closed and the other end (the upper end in the same figures) being open.

[0017] 3, the retaining mechanism 30 retains the shaft body 10 in a first region 11 along the axis 100 so as to be displaceable relative to the housing 20, and includes a retaining portion 31 and a bearing portion 33. In this embodiment, a region over a certain length on the other end side of the shaft body 10 is defined as the first region 11.

[0018] Of these, the retaining portion 31 is provided in the first region 11 inside the housing 20 so as to surround the shaft body 10 around its axis 100, retains the shaft body 10 so as to be displaceable along the axis 100, and is driven by the rotation of the shaft body 10 about the axis. In this embodiment, the first region 11 of the shaft body 10 is configured as a spline shaft, and the retaining portion 31 is configured as a spline nut corresponding to this spline shaft, thereby realizing a spline bearing.

[0019] Furthermore, the bearing portion 33 is interposed between the inner peripheral surface of the housing 20 and the holding portion 31 in the first region 11, and holds the holding portion 31 and the shaft 10 so as to be rotatable around the axis 100 relative to the housing 20. In this embodiment, the bearing portion 33 is a ball bearing provided so as to be interposed between the inner peripheral surface of the housing 20 and the outer peripheral surface of the holding portion 31.

[0020] The rotary motor 40 includes a rotary mover 41 and a rotary stator 43. Of these, the rotary mover 41 is provided in a second region 13 along the axis 100 inside the housing 20 so as to surround the shaft body 10 around the axis 100, and is a rotor that causes the shaft body 10 to rotate around the axis 100.

[0021] In addition, rotary stator 43 surrounds shaft body 10 around axis 100 from the outside of housing 20 in second region 13, and is fixed to housing 20 in a positional relationship opposing rotary mover 41 in the inner and outer directions.

[0022] In this embodiment, the first region 11 and the second region 13 are regions that overlap in the direction of the axis 100, and the rotary motor 40 is arranged concentrically with the holding mechanism 30. Specifically, the rotary mover 41 is provided inside the housing 20 so as to surround the holding portion 31 around the axis 100, and the rotary stator 43 surrounds the holding portion 31 around the axis 100 from the outside of the housing 20.

[0023] 4, the linear motor 50 includes a linear stator 51 and a linear mover 53. Of these, the linear stator 51 is provided in a third region 15 along the axis 100 so as to extend along the axis 100 inside the housing 20, and causes the shaft body 10 to follow the displacement in the direction of the axis 100. In this embodiment, a region over a certain length on one end side of the shaft body 10 is defined as the third region 15, and magnetic poles constituting the linear stator 51 are arranged here along the axis 100.

[0024] In addition, the linear mover 53 surrounds the shaft 10 around the axis 100 from the outside of the housing 20 over a certain range in the third region 15, and is fixed to the housing 20 in a positional relationship opposing the linear stator 51 in the inward and outward directions.

[0025] As shown in Figure 5, the magnetic fluid seal 60 seals the internal space surrounded by the housing 20 by interposing a magnetic fluid 61 between the shaft body 10 and the housing 20 at a sealing position 17 located on the other end side of each of the first to third regions of the shaft body 10, around the entire circumference of the axis 100.

[0026] This magnetic fluid seal 60 is made up of an inner magnetic fluid seal 60 that closes the internal space on the shaft 10 side at the seal position 17, and an outer magnetic fluid seal 60 that closes the internal space on the housing 20 side.

[0027] The inner magnetic fluid seal 60 has a pair of magnetic poles 63 that protrude from the housing 20 side toward the shaft 10 at the sealing position 17, and a magnetic fluid 61 is interposed between the tip sides of the magnetic poles 63 and the shaft 10. On the other hand, the outer magnetic fluid seal 60 has a pair of magnetic poles 63 that protrude from the shaft 10 side toward the housing 20 at the sealing position 17, and a magnetic fluid 61 is interposed between the tip sides of the magnetic poles 63 and the shaft 10.

[0028] Of these, the magnetic poles 63 have permanent magnets 65 sandwiched between their respective end sides, and a magnetic circuit (see dashed line in the same figure) is formed between the tip side and the shaft body 10 or the housing 20, thereby magnetically retaining the magnetic fluid 61.

[0029] In the transmission device 1 configured in this manner, as shown in Figures 1 and 2, with a displacement object 200 attached to the other end of the shaft body 10, the shaft body 10 is displaced by passing current through the rotary motor 40 and the linear motor 50, and this displacement is transmitted to the displacement object 200.

[0030] (2) Variations Although the embodiment of the present invention has been described above, it goes without saying that the present invention is in no way limited to the above embodiment, and various other forms can be adopted as long as they fall within the technical scope of the present invention.

[0031] For example, in the above embodiment, the configuration has been exemplified in which the retaining portion 31 realizes a spline bearing together with the first region 11 of the shaft body 10. However, the retaining portion 31 may have a configuration other than a spline bearing as long as it can hold the shaft body 10 displaceably along the axis 100.

[0032] In the above embodiment, the first region 11 and the second region 13 in the shaft body 10 are overlapping regions in the direction of the axis 100. However, the first region 11 and the second region 13 may be regions separated in the direction of the axis 100, and the holding mechanism 30 and the rotary motor 40 may not be arranged concentrically.

[0033] In the above embodiment, the configuration has been exemplified in which the holding mechanism 30 and the rotary motor 40 are arranged in the first region 11 and the second region 13 which are the other end side of the shaft body 10, and the linear motor 50 is arranged in the third region 15 which is one end side. However, these positional relationships are not particularly limited, and for example, as shown in Fig. 6, a configuration may be used in which the holding mechanism 30 and the rotary motor 40 are arranged on one end side of the shaft body 10 as the first region 11 and the second region 13, and the linear motor 50 is arranged on the other end side as the third region 15.

[0034] In the above embodiment, the configuration has been exemplified in which the bearing portion 33 is provided only on the other end side of the shaft body 10 as a component of the displacement mechanism 30. However, the bearing portion 33 may also be provided on one end side of the shaft body 10 (see FIG. 6).

[0035] Also, in the above embodiment, the rotary mover 41 is provided so as to surround the holding portion 31 around the axis 100, and configured to follow the rotation of the holding portion 31. However, it is sufficient that the rotary mover 41 can cause the shaft body 10 to follow its rotation around the axis 100, and the rotary mover 41 may be provided so as to surround the shaft body 10 itself around the axis 100 in an area where the holding portion 31 is not provided, and configured to follow the shaft body 10.

[0036] (3) Action and effect In the transmission device 1 of the above embodiment, when the rotary motor 40 is energized, the shaft body 10 rotates about the axis 100, and this rotation can be transmitted to the displacement object 200 attached to the other end side of the shaft body 10. In addition, when the linear motor 50 is energized, the shaft body 10 is displaced along the axis 100, and this displacement can be transmitted to the displacement object 200 attached to the other end side of the shaft body 10 (see the arrow in FIG. 6). In this way, in this embodiment, in addition to rotation, other displacements can be transmitted to the displacement object 200 via the shaft body 10.

[0037] In addition, in the transmission device 1 of the above embodiment, by overlapping the first region 11 in which the holding mechanism 30 is provided and the second region 13 in which the rotary motor 40 is provided in the shaft body 10, the length in the direction of the axis 100 can be shortened, thereby making the transmission device 1 more compact.

[0038] Furthermore, in the transmission device 1 of the above embodiment, the internal space surrounded by the housing 20 is blocked at the sealing position 17, so that even if impurities (gas, cutting chips, etc.) are generated around parts that operate involving physical contact, these can be prevented from reaching the displacement object 200. [Explanation of symbols]

[0039] 1...transmission device, 10...shaft body, 17...sealing position, 20...housing, 30...holding mechanism, 31...holding portion, 33...bearing portion, 40...rotary motor, 41...rotary mover, 43...rotary stator, 50...linear motor, 51...linear stator, 53...linear mover, 60...magnetic fluid seal, 61...magnetic fluid, 63...magnetic pole, 65...permanent magnet, 100...axis, 200...object to be displaced, 300...vacuum chamber.

Claims

1. A shaft extending in a predetermined direction; a housing which is a cylindrical member that surrounds and houses the shaft body, the housing having one end side of the shaft body closed and the other end side open; a holding mechanism that holds the shaft body displaceably relative to the housing in a predetermined first region along the axis of the shaft body; a rotary motor disposed in a second region along the axis of the shaft; a linear motor disposed in a predetermined third region along the axis of the shaft; The holding mechanism includes: a holding portion provided in the first region so as to surround the shaft body around its axis inside the housing and holding the shaft body so as to be displaceable along the axis; a bearing portion interposed between an inner peripheral surface of the housing and the holding portion in the first region and configured to hold the holding portion and the shaft body so as to be rotatable about an axis relative to the housing, The rotary motor includes: a rotary mover provided in the second region so as to surround the shaft body about its axis inside the housing and causing the shaft body to rotate in response to rotation about the axis; a rotary stator that surrounds the shaft from outside the housing in the second region, and is fixed to the housing in a positional relationship facing the rotary mover in the inward and outward direction; The linear motor is a linear stator provided in the third region so as to extend along an axis of the shaft inside the housing and cause the shaft to follow a displacement in the axial direction; a linear mover that surrounds the shaft from outside the housing around its axis in the third region and is fixed to the housing in a positional relationship facing the linear stator in the inner and outer directions, a rotary motor and a linear motor are energized to displace the shaft body while a displacement object is attached to the other end of the shaft body, and the displacement is transmitted to the displacement object; Transmission device.

2. The first region and the second region are regions that overlap in an axial direction, The holding mechanism includes: The holding portion is provided so as to be rotated by the shaft body about an axis line, The rotary motor includes: The rotary movable member is provided inside the housing so as to surround the holding portion about an axis line, and causes the holding portion to rotate about the axis line; The rotary stator surrounds the holding portion from the outside of the housing around an axis. The transmission device according to claim 1 .

3. a magnetic fluid seal that seals an internal space surrounded by the housing at a sealing position on the other end side of the shaft body relative to each of the first to third regions by interposing a magnetic fluid between the shaft body and the housing over the entire circumference around the axis. A transmission device according to claim 1 or 2.

4. The first region of the shaft body is configured as a spline shaft, The holding portion is configured as a spline nut corresponding to the spline shaft of the first region. A transmission device according to claim 1 or 2.

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