JP6008135B2 - Rotating shaft device - Google Patents

Description

  The present invention relates to a rotary shaft device including a rotary shaft coupled to a table that supports a workpiece.

In general, a rotating shaft device is employed in a chemical coating apparatus for applying a chemical solution by a spin coating method, such as a semiconductor coater / developer, and the workpiece is rotated at a high speed (2000-6000 rpm) by the rotating shaft device. Thus, the chemical solution is uniformly applied to the surface of the workpiece. At this time, when the workpiece rotates, it is necessary to maintain the temperature of the workpiece with high accuracy.
However, in the conventional rotating shaft device, the portion of the bearing that rotatably supports the rotating shaft for rotating the workpiece generates heat, and the heat is transmitted to the workpiece to maintain the temperature of the workpiece substantially constant with high accuracy. There was a possibility that it could not be done.

  Therefore, as a conventional technique for suppressing heat transfer to a workpiece, Patent Document 1 discloses a wafer holding vacuum chuck constituting a wafer polishing apparatus, in which a vacuum suction path and a fluid flow path are arranged inside a ceramic structure. In addition, a wafer holding vacuum chuck is disclosed in which the fluid channel is a channel for circulating a fluid such as cooling water for removing heat generated during polishing.

JP 2002-373873 A

  However, in the invention of Patent Document 1, since the diameter of the wafer table is large, when the table is rotated, a large inertia is generated and the load on the motor is remarkably increased. It is necessary to increase the thickness of the table, and considering the incorporation of seal members, etc., a large number of fastening members such as bolts are also required, increasing the overall weight of the table, further increasing inertia and increasing the load on the motor. Can not be adopted because of the increase.

  This invention is made | formed in view of this point, and it aims at providing the rotating shaft apparatus which can maintain the temperature of the workpiece | work on the rotating table substantially constant.

In order to solve the above problems, a rotary shaft device of the present invention is a rotary shaft device having a rotary shaft connected to a table that supports a workpiece, and rotatably supports the rotary shaft via a bearing. a housing, provided in the rotation in the shaft, an inner passage through which cooling medium flows, is provided at the position of the bearing at the peripheral wall of the housing, comprising an outer flow path through which cooling medium flows, wherein the rotation The shaft comprises a large-diameter rotating shaft connected to the table, and an end connected to the end of the large-diameter rotating shaft, and a small-diameter rotating shaft having a smaller diameter than the large-diameter rotating shaft. A small-diameter rotary shaft portion is provided with an inlet and an outlet for a cooling medium communicating with the inner flow path, and a plurality of seal members are provided on the outer periphery of the small-diameter rotary shaft portion to seal the inlet and the outlet. It is characterized by.
As a result, heat generation from the bearing can be suppressed by the cooling medium flowing through the inner flow path and the cooling medium flowing through the outer flow path, so that heat transfer from the bearing to the work can be suppressed, and the temperature of the work can be kept substantially constant. Can be maintained.

  Various aspects of the rotating shaft device of the present invention and their actions will be described in detail in the section of the aspect of the invention below.

(Aspect of the Invention)
In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. In addition, each aspect is divided into a term like a claim, it attaches | subjects a number to each term, and is described in the format which quotes another term as needed. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description, embodiments, etc. accompanying each section, and as long as the interpretation is followed, there may be embodiments in which other constituent elements are added to the aspects of each section. In addition, an aspect in which the constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

(1) A rotary shaft device including a rotary shaft coupled to a table that supports a workpiece, a housing that rotatably supports the rotary shaft via a bearing, and a cooling medium provided in the rotary shaft. A large-diameter rotary shaft connected to the table, and an inner flow path through which the cooling medium flows. And a small-diameter rotary shaft portion that is smaller in diameter than the large-diameter rotary shaft portion and is connected to the inner flow path. An inlet and outlet for the cooling medium are provided, and a plurality of seal members for sealing the inlet and outlet are provided on the outer periphery of the small-diameter rotary shaft portion (Invention of Claim 1) Equivalent).
In the rotating shaft device of item (1), the heat generated from the bearing when the rotating shaft rotates is generated by the cooling medium flowing in the inner flow path provided in the rotating shaft and the outer flow provided at the bearing position in the housing. Therefore, the heat transfer from the bearing to the workpiece can be suppressed, and the temperature of the workpiece can be maintained substantially constant.
In addition, since the inlet and outlet are provided in the small-diameter rotary shaft, and the seal member that seals the inlet and outlet is arranged on the outer peripheral surface of the small-diameter rotary shaft, it acts on the seal member when the rotary shaft rotates at high speed. The load to be performed can be suppressed as much as possible, and the durability of the seal member can be improved.

( 2 ) In the item (1) , the inner flow path includes a radial flow path extending in a radial direction and an axial flow path communicating with the radial flow path and extending in the axial direction. The rotating shaft device according to claim 1 (corresponding to the invention of claim 2 ).
In the rotating shaft device according to the item ( 2 ), since the axial flow path can be disposed close to the bearing by forming the radial flow path, the cooling efficiency of the bearing is improved.

( 3 ) The rotating shaft device according to ( 2 ), wherein the axial flow path is provided at a plurality of locations along the axial direction.
In the rotating shaft device according to the item ( 3 ), the cooling medium can reciprocate in the axial direction a plurality of times in the rotating shaft by the plurality of axial flow paths, so that the cooling efficiency of the bearing is further improved.

( 4 ) The rotating shaft device according to any one of (1) to ( 3 ), wherein the bearings are respectively provided at both ends of the large-diameter rotating shaft portion.
In the rotating shaft device according to the item ( 4 ), even when a plurality of bearings are provided, the cooling efficiency for each bearing is not lowered by the cooling medium flowing in the inner flow path and the cooling medium flowing in the outer flow path.

( 5 ) The rotating shaft according to ( 4 ), wherein the cooling medium from the cooling medium inlet provided in the housing first flows into the outer flow path corresponding to the bearing near the table. apparatus.
In the rotating shaft device according to the item ( 5 ), it is possible to preferentially cool the heat generated from the bearing closer to the workpiece, and heat transfer from the bearing to the workpiece can be further suppressed.

( 6 ) The rotation according to any one of (1) to ( 5 ), wherein the outer flow path includes a circumferential groove extending in a circumferential direction on an outer periphery of the large-diameter rotating shaft. Axle device.
In the rotating shaft device according to item ( 6 ), the outer flow path can be easily formed.

( 7 ) The rotating shaft device according to ( 6 ), wherein a plurality of the circumferential groove portions are provided, and the number of the circumferential groove portions is larger than the number of the bearings.
In the rotating shaft device according to item ( 7 ), the cooling efficiency for each bearing is further improved.

( 8 ) The rotating shaft device according to any one of (1) to ( 7 ), wherein the axial flow path is disposed radially outside a vacuum suction passage provided in the rotating shaft.
In the rotating shaft device according to the item ( 8 ), since the axial flow path is disposed close to the bearing, the cooling efficiency to the bearing is further improved.

  ADVANTAGE OF THE INVENTION According to this invention, the rotating shaft apparatus which can maintain the temperature of the workpiece | work on the rotating table substantially constant can be provided.

FIG. 1 is a cross-sectional view of a rotary shaft device according to an embodiment of the present invention. FIG. 2 is a diagram showing a plurality of flow paths through which the cooling medium flows in the rotation shaft of FIG. FIG. 3 is a perspective view of the upper housing of FIG. FIG. 4 is a view showing a plurality of flow paths through which the cooling medium flows in the peripheral wall portion of the upper housing in FIG. 3.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to FIGS.
The rotary shaft device 1 according to the embodiment of the present invention, for example, spins a workpiece W (for example, a wafer) on the table 2 at a high speed to apply a chemical solution uniformly on the surface of the workpiece W, so-called spin. It is employed in a chemical solution application facility that applies a chemical solution by a coating method.
As shown in FIG. 1, the rotary shaft device 1 according to the embodiment of the present invention includes a table 2 to which a workpiece W is fixed, a rotary shaft 3 having an upper end connected to the table 2, and the rotary shaft. A motor 4 to which a lower end of the rotary shaft 3 is connected, an upper housing 12 that supports a large-diameter rotary shaft portion 5 of the rotary shaft 3 via an upper bearing 10 and a lower bearing 11, and a small-diameter rotary shaft portion 6 of the rotary shaft 3. And a lower housing 13 to be supported.

  As shown in FIG. 1, the rotary shaft 3 includes a large-diameter rotary shaft portion 5 whose upper end is coupled to the table 2 and an axially extending integrally from the lower end of the large-diameter rotary shaft portion 5. It comprises a small-diameter rotating shaft portion 6 having a smaller diameter than the portion 5. The upper end surface of the large-diameter rotating shaft portion 5 is fixed so as to come into contact with the substantially radial center of the lower surface of the table 2. On the other hand, the lower end of the small-diameter rotating shaft portion 6 is connected to the output shaft 4 a from the motor 4. The large-diameter rotating shaft 5 is rotatably supported by the upper housing 12 via a plurality of upper bearings 10 and a plurality of lower bearings 11. In the present embodiment, the upper bearing 10 is disposed at two locations close to each other between the upper outer peripheral surface of the large-diameter rotating shaft portion 5 and the upper housing 12. The lower bearing 11 is disposed at two locations close to each other between the lower outer peripheral surface of the large-diameter rotating shaft portion 5 and the upper housing 12. The small-diameter rotating shaft portion 6 of the rotating shaft 3 is supported in the lower housing 13. The motor 4 is supported by a substantially rectangular plate-like member 15 whose main body has an opening 15a. The plate-like member 15 is connected and supported by a frame 16 and a plurality of support shafts 17.

Here, the rotary shaft side vacuum suction passages 18 and the inner flow passages 20 provided in the rotary shaft 3 described below are not shown in FIG. 1, and are shown in detail in FIG.
As shown in FIG. 2, the rotary shaft 3 is provided with a plurality of rotary shaft-side vacuum suction passages 18 (three in the present embodiment) along the axial direction from the substantially radial center of the upper surface thereof. As shown in FIG. 1, the table 2 is provided with a plurality of table side vacuum suction passages 19 penetrating in the axial direction substantially at the center in the radial direction. These rotary shaft side vacuum suction passages 18 provided in the rotary shaft 3 and the table side vacuum suction passage 19 provided in the table 2 are in airtight communication. Each rotary shaft-side vacuum suction passage 18 of the rotary shaft 3 communicates with a suction port 98 that is drilled in the radial direction from the outer peripheral surface of the small-diameter rotary shaft portion 6.

As shown in FIG. 2, an inner flow path 20 through which the cooling medium flows is formed in the rotating shaft 3. The inner flow path 20 includes an inner main flow path 21 formed in the large-diameter rotation shaft portion 5 and an inner inflow / outflow path 22 formed in the small-diameter rotation shaft portion 6 and communicating with the inner main flow path 21. .
The inner main flow path 21 communicates with the first to fifth lower radial flow paths 51 to 55 extending in the radial direction and the first to fifth lower radial flow paths 51 to 55 and extends in the axial direction. First to eighth axial flow paths 31 to 38, first to fourth upper radial flow paths 41 to 44 that communicate with the first to eighth axial flow paths 31 to 38 and extend in the radial direction; Consists of. The first to eighth axial flow paths 31 to 38 are disposed outside the rotary shaft side vacuum suction passages 18. The first to eighth axial flow paths 31 to 38 are formed by being drilled from the upper surface of the large-diameter rotating shaft portion 5. Each opening of the 1st-8th axial direction flow paths 31-38 formed in the upper surface of the large diameter rotating shaft part 5 is sealed by sealing means (not shown), such as a seal plug, for example. Further, the first to fourth upper radial flow paths 41 to 44 and the first to fifth lower radial flow paths 51 to 55 are formed by being drilled from the outer peripheral surface of the large-diameter rotating shaft portion 5. Each opening of the first to fourth upper radial flow paths 41 to 44 and the first to fifth lower radial flow paths 51 to 55 formed on the outer peripheral surface of the large-diameter rotating shaft portion 5 is, for example, a seal plug or the like It is sealed by a sealing means (not shown).

  The inner outflow / inflow passage 22 includes an inflow passage 61 that communicates with the inner main passage 21 and extends in the axial direction, and an outflow passage 62 that communicates with the inner main passage 21 and extends in the axial direction. The inflow channel 61 and the outflow channel 62 are formed by being drilled from the lower surface of the small-diameter rotating shaft portion 6. Each opening of the inflow channel 61 and the outflow channel 62 formed on the lower surface of the small-diameter rotating shaft portion 6 is sealed by a sealing means (not shown) such as a seal plug. The small-diameter rotating shaft portion 6 is formed with an inlet 25 and an outlet 26 for the cooling medium. The inflow port 25 and the outflow port 26 are formed by being drilled from the outer peripheral surface of the small-diameter rotating shaft portion 6. The inflow port 25 communicates with the inflow channel 61 of the inner outflow / inflow channel 22 and is connected to the inflow port member 63 via an inflow hole 94 of the lower housing 13 described later. On the other hand, the outflow port 26 communicates with the outflow channel 62 of the inner outflow / inflow channel 22 and is connected to the outflow port member 64 through an outflow hole 95 of the lower housing 13 described later. Note that a suction port 98 extending in the radial direction is formed in the small-diameter rotating shaft portion 6.

The connection form of the inner main flow path 21 in the large-diameter rotating shaft portion 5 and the inner inflow / outflow path 22 in the small-diameter rotating shaft portion 6 will be described in detail with reference to FIG.
The inflow passage 61 in the small-diameter rotating shaft portion 6 is connected to a midway portion of the first lower radial passage 51 in the large-diameter rotating shaft portion 5. One end of the first lower radial flow path 51 is connected to the lower end of the first axial flow path 31. The upper end of the first axial flow path 31 is connected to one end of the first upper radial flow path 41. The upper end of the second axial flow path 32 is connected to a middle portion of the first upper radial flow path 41. The lower end of the second axial flow path 32 is connected to a middle portion of the second lower radial flow path 52. The lower end of the third axial flow path 33 is connected to one end of the second lower radial flow path 52. The upper end of the third axial flow path 33 is connected to one end of the second upper radial flow path 42. The upper end of the fourth axial flow path 34 is connected to a middle portion of the second upper radial flow path 42. The lower end of the fourth axial flow path 34 is connected to a midway portion of the third lower radial flow path 53. The lower end of the fifth axial flow path 35 is connected to one end of the third lower radial flow path 53. The upper end of the fifth axial flow path 35 is connected to one end of the third upper radial flow path 43. The upper end of the sixth axial flow path 36 is connected to a middle portion of the third upper radial flow path 43. The lower end of the sixth axial flow path 36 is connected to an intermediate portion of the fourth lower radial flow path 54. The lower end of the seventh axial flow path 37 is connected to one end of the fourth lower radial flow path 54. The upper end of the seventh axial flow path 37 is connected to one end of the fourth upper radial flow path 44. The upper end of the eighth axial flow path 38 is connected to a middle portion of the fourth upper radial flow path 44. The lower end of the eighth axial flow path 38 is connected to one end of the fifth lower radial flow path 55. The upper end of the outflow passage 62 in the small-diameter rotating shaft portion 6 is connected to the middle portion of the fifth lower radial passage 55.

  By forming the first to fourth upper radial flow paths 41 to 44 and the first to fifth lower radial flow paths 51 to 55 in the large diameter rotary shaft part 5, The first to eighth axial flow paths 31 to 38 are arranged so as to be as close as possible to the upper bearings 10 and the lower bearings 11 in the radial direction.

  And if a cooling medium is supplied to the inflow port 25 of the small diameter rotating shaft part 6, an inflow port 25 of the small diameter rotating shaft part 6-> inflow channel 61 (inner outflow inflow path 22)-> 1st lower side Radial flow channel 51 (inner main flow channel 21) → first axial flow channel 31 (inner main flow channel 21) → first upper radial flow channel 41 (inner main flow channel 21) → second axial flow channel 32 (inner side) Main flow path 21) → second lower radial flow path 52 (inner main flow path 21) → third axial flow path 33 (inner main flow path 21) → second upper radial flow path 42 (inner main flow path 21) → Fourth axial flow path 34 (inner main flow path 21) → third lower radial flow path 53 (inner main flow path 21) → Fifth axial flow path 35 (inner main flow path 21) → third upper radial flow Path 43 (inner main flow path 21) → sixth axial flow path 36 (inner main flow path 21) → fourth lower radial flow path 54 (inner main flow path 21) → seventh axial direction Path 37 (inner main flow path 21) → fourth upper radial flow path 44 (inner main flow path 21) → eighth axial flow path 38 (inner main flow path 21) → fifth lower radial flow path 55 (inner main flow) Channel 21) → outflow channel 62 (inside outflow / inflow channel 22) → outflow through the outlet 26 of the small-diameter rotating shaft 6.

  As shown in FIGS. 1 and 3, the upper housing 12 is formed in a cylindrical shape. Upper bearing housing grooves 66, 66 (two locations in the present embodiment) are formed on the upper inner peripheral surface of the upper housing 12. Lower bearing housing grooves 67, 66 are formed on the lower inner peripheral surface of the upper housing 12. 67 (two places in this embodiment) are formed. Further, on the outer peripheral surface of the upper housing 12, outer flow paths 70 are formed at the positions of the upper bearing 10 and the lower bearing 11, respectively. The outer flow path 70 is provided on the outer peripheral surface of the upper housing 12, and a plurality of upper circumferential groove portions 71 extending in the circumferential direction around the positions where the upper bearings 10 are disposed, and the lower bearings 11 are disposed. It comprises a plurality of lower circumferential groove portions 72 extending in the circumferential direction around the position. In the present embodiment, three upper circumferential groove portions 71 are provided for the two upper bearings 10, and three lower circumferential groove portions 72 are provided for the two lower bearings 11. . That is, the quantity of the upper circumferential groove 71 is larger than the quantity of the upper bearing 10, while the quantity of the lower circumferential groove 72 is larger than the quantity of the lower bearing 11. The plurality of upper circumferential groove portions 71 communicate with each other. On the other hand, the plurality of lower circumferential grooves 72 are also in communication with each other. An upper cover 73 is provided on the upper outer peripheral surface of the upper housing 12 so as to cover each upper circumferential groove 71. A seal member 75 a is disposed between the outer peripheral surface of the upper housing 12 and the inner peripheral surface of the upper cover 73 above the uppermost upper circumferential groove 71 among the upper circumferential grooves 71. Further, a seal member 75 b is also arranged between the outer peripheral surface of the upper housing 12 and the inner peripheral surface of the upper cover 73 below the lowermost upper peripheral groove 71 among the upper peripheral grooves 71. On the other hand, a lower cover 74 is provided on the lower outer peripheral surface of the upper housing 12 so as to cover each lower circumferential groove 72. A seal member 75 c is disposed between the outer peripheral surface of the upper housing 12 and the inner peripheral surface of the lower cover 74 above the uppermost lower peripheral groove portion 72 among the lower peripheral groove portions 72. Further, a seal member 75 d is disposed between the outer peripheral surface of the upper housing 12 and the inner peripheral surface of the lower cover 74 below the lowermost lower circumferential groove portion 72 among the lower circumferential groove portions 72. . By these seal members 75a, 75b, 75c, and 75d, the outer flow path 70 provided in the upper housing 12 is hermetically and airtightly sealed.

  Further, a projecting portion 76 that projects outward is formed on the outer peripheral surface of the upper housing 12 in the substantially axial center. The protruding portion 76 is supported by the frame body 16. Referring also to FIG. 4, cooling medium inflow port 78 and outflow port 79 are formed in the outer peripheral surface of projecting portion 76, respectively. An inflow port member 80 is connected to the inflow port 78. An outflow port member 81 is connected to the outflow port 79. An axial inflow path 85, an axial communication path 86, and an axial outflow path 87 that extend in the axial direction are provided in the peripheral wall portion of the upper housing 12. The axial inflow path 85, the axial communication path 86, and the axial outflow path 87 are formed by being drilled from the lower surface of the upper housing 12. The openings 85a, 86a, 87a of the axial inflow passage 85, the axial communication passage 86, and the axial outflow passage 87 formed on the lower surface of the upper housing 12 are sealed by sealing means (not shown) such as a seal plug, for example. The The inflow port 78 provided in the projecting portion 76 and each upper circumferential groove portion 71 communicate with each other through the axial inflow passage 85. Each upper circumferential groove 71 and each lower circumferential groove 72 communicate with each other through an axial communication path 86. Each lower circumferential groove 72 and an outlet 79 provided in the projecting portion 76 communicate with each other through an axial outflow passage 87.

  When the cooling medium is supplied to the inflow port member 80 provided in the upper housing 12, the cooling medium flows into the inlet 78 → the axial inflow path 85 → the upper circumferential groove 71 → the axial communication path 86 → the lower side. The gas flows out from the outflow port member 81 provided in the upper housing 12 through the side circumferential groove 72 → the axial outflow passage 87 → the outflow port 79.

  As shown in FIGS. 1 and 2, the small-diameter rotating shaft portion 6 of the rotating shaft 3 is supported in the cylindrical lower housing 13 via a plurality of seal members 90a, 90b, 90c, and 90d. An annular support member 91 is connected to the upper portion of the lower housing 13. The annular support member 91 is connected to the projecting portion 76 of the upper housing 12 by a plurality of support shafts 92. The outlet 26 of the small-diameter rotating shaft portion 6 communicates with the outlet port member 64 through an outlet hole 95 provided in the lower housing 13 and extending in the radial direction. Seal members 90 a and 90 b are respectively disposed between the outer peripheral surface of the small-diameter rotary shaft portion 6 and the inner peripheral surface of the lower housing 13 on the upper side and the lower side of the outlet 26 of the small-diameter rotary shaft portion 6. As a result, liquid-tight and air-tight sealing is performed from the outlet 26 of the small-diameter rotating shaft portion 6 to the outflow hole 95 of the lower housing 13. The inlet 25 of the small-diameter rotating shaft portion 6 communicates with the inflow port member 63 via a radially inflow hole 94 provided in the lower housing 13. Seal members 90 b and 90 c are respectively disposed between the outer peripheral surface of the small-diameter rotary shaft portion 6 and the inner peripheral surface of the lower housing 13 on the upper side and the lower side of the inlet 25 of the small-diameter rotary shaft portion 6. As a result, the inlet 25 of the small-diameter rotating shaft 6 and the inlet 94 of the lower housing 13 are sealed in a liquid-tight and air-tight manner. The suction port 98 of the small-diameter rotating shaft portion 6 communicates with the suction port member 100 through a suction hole 99 provided in the lower housing 13 and extending in the radial direction. Seal members 90 c and 90 d are respectively disposed between the outer peripheral surface of the small-diameter rotary shaft portion 6 and the inner peripheral surface of the lower housing 13 on the upper side and the lower side of the suction port 98 of the small-diameter rotary shaft portion 6. As a result, the suction port 98 of the small-diameter rotating shaft portion 6 and the suction hole 99 of the lower housing 13 are sealed in a liquid-tight and air-tight manner.

  In the rotary shaft device 1 according to the embodiment of the present invention, vacuum suction is performed from the suction port member 100 provided in the small-diameter rotary shaft portion 6 through the rotary shaft side vacuum suction passage 18 and the table side vacuum suction passage 19. Thus, the workpiece W on the table 2 is sucked and fixed. Subsequently, the rotation shaft 3 is rotated by driving the motor 4, and the workpiece W on the table 2 is rotated. At the same time, the cooling medium is supplied to the inflow port member 63 provided in the lower housing 13. Then, the cooling medium passes through the inflow passage 61 in the small-diameter rotating shaft portion 6 from the inlet 25 and the first to fifth lower radial flow passages 51 to 55 and first to eighth in the large-diameter rotating shaft portion 5. Via the outflow port member 64 provided in the lower housing 13 from the outflow port 26 through the axial direction flow paths 31 to 38, the first to fourth upper radial flow paths 41 to 44, and the outflow path 62 in the small-diameter rotating shaft portion 6. It begins to leak. The cooling medium is also supplied to the inflow port member 80 provided in the upper housing 12. Then, the cooling medium flows from the inlet 78 of the upper housing 12 to each upper circumferential groove 71 via the axial inflow path 85, and from each upper circumferential groove 71 to the axial communication path 86. It reaches each lower circumferential groove 72 and finally flows out from the outlet 79 through the outlet port member 81 provided in the upper housing 12 via the axial outlet path 87.

  As a result, each upper bearing 10 that rotatably supports the rotating shaft 3 is provided with a cooling medium that flows in the first to eighth axial flow paths 31 to 38 in the large-diameter rotating shaft portion 5 and the upper housing 12. The heat generation is suppressed by the cooling medium flowing in each upper circumferential groove 71, and heat transfer from each upper bearing 10 to the workpiece W can be suppressed. Each lower bearing 11 that rotatably supports the rotating shaft 3 includes a cooling medium that flows in the first to eighth axial flow paths 31 to 38 in the large-diameter rotating shaft portion 5, and the upper housing 12. Heat generation is suppressed by the cooling medium flowing in each lower circumferential groove 72, and heat transfer from each lower bearing 11 to the workpiece W can be suppressed.

  As described above, in the rotating shaft device 1 according to the embodiment of the present invention, the first to eighth shafts serve as the inner flow path 20 through which the cooling medium flows in the large-diameter rotating shaft portion 5 of the rotating shaft 3. Directional flow paths 31 to 38, first to fifth lower radial flow paths 51 to 55, and first to fourth upper radial flow paths 41 to 44, and each upper bearing 10 of the upper housing 12 is provided. Each upper circumferential groove 71 as an outer flow path 70 through which a cooling medium flows is provided at a corresponding position, and each lower circumferential groove 72 as an outer flow path 70 is provided at a position corresponding to each lower bearing 11. Yes. Thereby, when the rotary shaft 3 rotates, heat generation from each upper bearing 10 and each lower bearing 11 can be suppressed by the cooling medium, and heat transfer from each upper bearing 10 and each lower bearing 11 to the workpiece W can be achieved. Can be avoided. As a result, the temperature of the workpiece W on the rotating table 2 can be maintained substantially constant.

  Further, in the rotary shaft device 1 according to the embodiment of the present invention, the rotary shaft 3 includes the large-diameter rotary shaft portion 5 and the small-diameter rotary shaft portion 6. An inflow port 25 and an outflow port 26 that communicate with the inner outflow / inflow channel 22 (inflow channel 61 and outflow channel 62) are provided, and the inflow port 25 is provided between the outer peripheral surface of the small-diameter rotating shaft 6 and the lower housing 13. And a plurality of seal members 90a, 90b, 90c for sealing the outlet 26, the load acting on the seal members 90a, 90b, 90c can be suppressed as much as possible when the rotary shaft 3 rotates at a high speed. The durability of the members 90a, 90b, 90c can be improved. That is, since the seal members 90a, 90b, and 90c are arranged on the small-diameter rotating shaft portion 6, when the rotating shaft 3 rotates at a high speed, the smaller-diameter rotating shaft portion 6 and the configuration arranged on the large-diameter rotating shaft portion 5 are used. The peripheral speed of the contact surface between the seal members 90a, 90b, and 90c can be reduced, and as a result, the load acting on the seal members 90a, 90b, and 90c can be reduced. The durability of 90b and 90c can be improved. A suction port 98 for sucking and fixing the workpiece W is also provided in the small-diameter rotary shaft portion 6, and the suction port 98 and the suction hole 99 of the lower housing 13 are provided between the outer peripheral surface of the small-diameter rotary shaft portion 6 and the lower housing 13. Since the seal members 90c and 90d are connected in a liquid-tight and air-tight manner, the load acting on the seal members 90c and 90d can be reduced when the rotary shaft 3 rotates at a high speed.

  Further, in the rotary shaft device 1 according to the embodiment of the present invention, the first to fourth upper radial flow paths 41 to 44 and the first to fifth lower radial flow paths 51 are provided in the large-diameter rotary shaft portion 5. ˜55 can be arranged so that the first to eighth axial flow paths 31 to 38 can be arranged as close as possible to the upper bearings 10 and the lower bearings 11 in the radial direction. 10 and the cooling efficiency of each lower bearing 11 can be further improved.

  Furthermore, in the rotating shaft device 1 according to the embodiment of the present invention, the cooling medium from the inflow port 78 provided in the upper housing 12 first passes through the axial inflow path 85 to each upper bearing 10 corresponding to each upper bearing 10. Since it flows into the circumferential groove 71, it becomes possible to preferentially cool each upper bearing 10 closer to the workpiece W, and heat transfer to the workpiece W can be further suppressed.

  1 rotary shaft device, 2 table, 3 rotary shaft, 5 large-diameter rotary shaft, 6 small-diameter rotary shaft, 10 upper bearing, 11 lower bearing, 12 upper housing, 13 lower housing, 20 inner flow path, 21 inner mainstream Path, 22 inner outflow / inlet path, 25 inlet (small diameter rotating shaft), 26 outlet (small diameter rotating shaft), 31-38 first to eighth axial flow paths, 41-44 first to fourth upper Radial flow path, 51-55 first to fifth lower radial flow path, 61 inflow flow path, 62 outflow flow path, 70 outer flow path, 71 upper circumferential groove, 72 lower circumferential groove, 78 flow Inlet (upper housing), 79 Outlet (upper housing), 85 Axial inflow path, 86 Axial communication path, 87 Axial outflow path, 90a, 90b, 90c, 90d Seal member, W Workpiece

Claims (2)

A rotary shaft device having a rotary shaft connected to a table that supports a workpiece,
A housing that rotatably supports the rotating shaft via a bearing;
An inner flow path provided in the rotating shaft and in which a cooling medium flows;
An outer flow path provided at a position of the bearing at a peripheral wall portion of the housing and through which a cooling medium flows ,
The rotating shaft includes a large-diameter rotating shaft portion coupled to the table, and a small-diameter rotating shaft portion integrally connected to an end portion of the large-diameter rotating shaft portion and having a smaller diameter than the large-diameter rotating shaft portion. ,
The small-diameter rotating shaft portion is provided with an inlet and an outlet for a cooling medium communicating with the inner flow path, and a plurality of seal members are provided on the outer periphery of the small-diameter rotating shaft portion to seal the inlet and the outlet. A rotating shaft device characterized by that. 2. The rotating shaft according to claim 1 , wherein the inner flow path includes a radial flow path extending in a radial direction and an axial flow path communicating with the radial flow path and extending in the axial direction. apparatus.