Vacuum Pump

Abstract

The subject of the present invention is to prevent the user from contacting the high-temperature part of the vacuum pump. The vacuum pump (1) of the present invention includes: a rotor cylinder (25); a motor (28) that rotates the rotor cylinder (25); a stator cylinder (26) that together with the rotor cylinder (25) constitutes a threaded groove pump; a base (4) that accommodates the rotor cylinder (25) and the stator cylinder (26); a heater (51) that heats the housing (3) or the stator cylinder (25); a cooling device (8) installed on the base (4); and a cover member (7) that is arranged on the outer peripheral side of the stator cylinder (26) and the outer peripheral side of the base (4), covers the base (4) through an air insulation layer (S3), and contacts the cooling device (9).

Description

Technical Field

[0001] The present disclosure relates to a vacuum pump. Background Art

[0002] In semiconductor manufacturing devices that perform chemical vapor deposition (CVD) film formation or etching, vacuum pumps such as turbomolecular pumps are used. In such vacuum pumps, products adhere to the inside of the vacuum pump, causing problems such as hindering the rotation of the rotor or requiring short-term maintenance. In order to cope with such problems, the temperature of the part of the pump that contacts the gas is increased to a high temperature to prevent the adhesion of reaction products (for example, as described in Patent Documents 1 and 2).

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2015-229936

[0006] [Patent Document 2] Japanese Patent Application Publication No. 2018-162725 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] In a vacuum pump, the temperature of the stator cylindrical portion of a thread groove pump becomes particularly high, and the outer periphery of the housing accommodating the portion also becomes high in temperature. There is a need to avoid the risk of a user touching the high temperature portion.

[0009] [Technical means to solve the problem]

[0010] A vacuum pump according to a first aspect of the present disclosure includes:

[0011] Rotor cylinder;

[0012] A motor for rotating the rotor cylinder;

[0013] A stator cylindrical portion, which together with the rotor cylindrical portion constitutes a thread groove pump;

[0014] A base, accommodating the rotor cylindrical portion and the stator cylindrical portion;

[0015] A heater for heating the base or the stator cylinder;

[0016] A cooling device, mounted on the base;

[0017] The cover member is arranged on the outer peripheral side of the stator cylindrical portion and the outer peripheral side of the base, covers the base via an air heat insulating layer, and contacts the cooling device.

[0018] [Effects of the Invention]

[0019] The vacuum pump disclosed herein includes a cover member disposed on the outer circumference of the stator cylinder and the outer circumference of the base and covering the base via an air insulation layer, thereby being able to avoid the risk of a user touching a high temperature portion with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional view of the vacuum pump 1 according to the first embodiment.

[0021] [Explanation of Symbols]

[0022] 1: Vacuum pump;

[0023] 2: rotor;

[0024] 3: Shell;

[0025] 4: Shell;

[0026] 5: base;

[0027] 11: axis;

[0028] 21: rotor blade unit;

[0029] 22: rotor blades;

[0030] 23: stator blade unit;

[0031] 24: stator blades;

[0032] 25: rotor cylinder;

[0033] 26: stator cylinder;

[0034] 28: Motor;

[0035] 7: Cover member;

[0036] 8: Cooling device;

[0037] 9: Power supply device;

[0038] S3: Air insulation layer. DETAILED DESCRIPTION

[0039] <First embodiment>

[0040] (1) Structure of vacuum pump 1

[0041] The vacuum pump 1 of the first embodiment includes a turbomolecular pump and a thread groove pump. The vacuum pump 1 is connected to an exhaust target device including an exhaust target space. After the gas from the exhaust target space is exhausted by the turbomolecular pump, it is exhausted by the thread groove pump to the outside of the vacuum pump 1 .

[0042] like Figure 1 As shown, the vacuum pump 1 includes a housing 3, a rotor 2, a motor 28, a plurality of stator blade units 23, a stator cylinder 26, heaters 51 to 53, a cooling device 8, a power supply device 9, and a cover member 7. The housing 3 accommodates the rotor 2, the motor 28, the multi-stage stator blade units 23, and the stator cylinder 26. The cooling device 8 is arranged in such a manner that one surface 8a contacts the housing 3. The other surface 8b of the cooling device 8 is arranged in such a manner that it contacts the power supply device 9. The cover member 7 is arranged on the outer periphery of the housing 3 in such a manner that the housing 3 is covered with an air insulation layer S3.

[0043] The housing 3 includes a shell 4 and a base 5 .

[0044] The housing 4 accommodates a multi-stage rotor blade unit 21 and a multi-stage stator blade unit 23. The housing 4 includes a first end 12 and a second end 13. A first internal space S1 is formed inside the housing 4. An air intake port 14a is formed at the first end 12. The first end 12 is mounted on an exhaust target device. The first internal space S1 is connected to the air intake port 14a. The second end 13 is located opposite to the first end 12 in the axial direction A1 of the rotor 2. The second end 13 is connected to the base 5.

[0045] The base 5 accommodates the rotor cylindrical portion 25 and the stator cylindrical portion 26. The base 5 includes a base first end portion 15, a base second end portion 16, and an exhaust pipe 17. The base 5 forms a second internal space S2. The base first end portion 15 is connected to the second end portion 13 of the housing 4. The base second end portion 16 is configured to contact one side 8a of the cooling device 8. The second internal space S2 is connected to the first internal space S1 of the housing 4. The exhaust pipe 17 forms an exhaust port 17a. The exhaust port 17a is connected to the second internal space S2.

[0046] The gas (gas molecules) flowing into the vacuum pump 1 from the exhaust target space enters the first internal space S1 from the suction port 14a. The gas passes through the turbomolecular pump and the thread groove pump from the first internal space S1 to the second internal space S2. The gas is exhausted from the second internal space S2 to the outside of the vacuum pump 1 through the exhaust port 17a.

[0047] The rotor 2 includes a shaft 11 , a plurality of rotor blade units 21 , and a rotor cylindrical portion 25 .

[0048] The shaft 11 extends along the axial direction A1 of the rotor 2. In the following description, in the axial direction A1, the direction from the housing 4 toward the base 5 is defined as a downward direction, and the opposite direction is defined as an upward direction.

[0049] The vacuum pump 1 further includes a plurality of bearings 27A to 27D. The plurality of bearings 27A to 27D are mounted on the base 5. The plurality of bearings 27A to 27D rotatably support the rotor 2. The plurality of bearings 27A to 27D include, for example, magnetic bearings. However, the plurality of bearings 27A to 27D may include other types of bearings such as ball bearings.

[0050] The motor 28 drives the rotor 2 to rotate. The motor 28 includes a motor rotor 31 and a motor stator 32. The motor rotor 31 is mounted on the shaft 11. The motor stator 32 is mounted on the base 5. The motor stator 32 and the motor rotor 31 are arranged to face each other.

[0051] The plurality of rotor blade units 21 are connected to the shaft 11, respectively. The plurality of rotor blade units 21 are arranged at intervals from each other along the axial direction A1. Each rotor blade unit 21 includes a plurality of rotor blades 22. Although not shown in the figure, the plurality of rotor blades 22 extend radially with the shaft 11 as the center. In addition, in the figure, only one of the plurality of rotor blade units 21 and one of the plurality of rotor blades 22 are marked with a symbol, and the symbols of the other rotor blade units 21 and the other rotor blades 22 are omitted.

[0052] The multi-stage stator blade unit 23 is connected to the inner surface of the housing 4. The multi-stage stator blade units 23 are arranged at intervals from each other in the axial direction A1. The multi-stage stator blade units 23 are respectively arranged between the multi-stage rotor blade units 21. Each stator blade unit 23 includes a plurality of stator blades 24. Although not shown in the figure, the multi-stage stator blades 24 extend radially with the shaft 11 as the center.

[0053] The multi-stage rotor blade units 21 and the multi-stage stator blade units 23 constitute a turbomolecular pump. In the drawings, only one of the plurality of stator blade units 23 and one of the plurality of stator blades 24 is denoted by a reference numeral, and the reference numerals of the other stator blade units 23 and other stator blades 24 are omitted.

[0054] The rotor cylindrical portion 25 is disposed below the rotor blade unit 21. The rotor cylindrical portion 25 extends along the axial direction A1.

[0055] The stator cylinder 26 is arranged outside the rotor cylinder 25 in the radial direction. The stator cylinder 26 is connected to the base 5. The stator cylinder 26 is arranged facing the rotor cylinder 25 in the radial direction of the rotor cylinder 25. A spiral groove is provided on the inner circumferential surface of the stator cylinder 26. The rotor cylinder 25 and the stator cylinder 26 constitute a thread groove pump.

[0056] The power supply device 9 controls the motor 28, the magnetic bearing 27A, the magnetic bearing 27D, and / or the heaters 51 to 53. The power supply device 9 appropriately converts the electricity supplied from the external power supply and supplies it to the motor 28, the magnetic bearing 27A, the magnetic bearing 27D, and / or the heaters 51 to 53. The power supply device 9 includes a power supply housing, a processor housed in the power supply housing, an alternating current (AC)-direct current (DC) converter, a DC-DC converter, an inverter, a DC power supply, and / or an excitation amplifier. Since the power supply device 9 generates heat, it is cooled by the cooling device 8. The power supply housing of the power supply device 9 is arranged in contact with the lower surface 8b of the cooling device 8.

[0057] The cooling device 8 includes a metal material. An example of a metal material is aluminum. The cooling device 8 includes a cooling medium passage for circulating a liquid coolant. The liquid coolant is, for example, water. The cooling device 8 can be formed into a metal tube by casting. The metal tube is, for example, a copper tube. The cooling device 8 is mounted on the second end portion 16 of the base 5. The cooling device 8 includes an upper surface 8a and a lower surface 8b. The lower surface 8b is configured to contact the power supply device 9. The cooling device 8 cools the power supply device 9. The upper surface 8a is configured to contact the base 5 and the cover member 7. The cooling device 8 cools the base 5 and the cover member 7. The outer diameter of the upper surface 8a of the cooling device 8 is larger than the outer diameter of the lower end surface of the base. A mounting portion for mounting the cover member 7 is provided on the upper surface 8a of the cooling device 8.

[0058] The first heater 51 is provided on the outer periphery of the susceptor 5 . The first heater 51 heats the outer periphery of the susceptor 5 and the stator cylindrical portion 26 .

[0059] The second heater 52 is disposed on the outer periphery of the casing 4 at the outer periphery of the multi-stage stator blade unit 23. The second heater 52 heats the multi-stage stator blade unit 23.

[0060] The third heater 53 is disposed on the outer periphery of the exhaust pipe 17. The third heater 53 heats the exhaust pipe 17. The heating temperature of the third heater is higher than the heating temperature of the first heater and the heating temperature of the second heater.

[0061] In the gas path of the vacuum pump 1, the multi-stage stator blade unit 23, the stator cylinder 26, the portion of the base 5 facing the second internal space S2, the exhaust pipe 17, etc. are heated by a heater to prevent gas adhesion. In particular, other parts are heated to a higher temperature than the multi-stage stator blade unit 23. In addition, in order to control the temperature, a cooling mechanism is also arranged near the outer periphery of the multi-stage stator blade unit 23, in other words, near the outer periphery of the housing 4 according to the second heater 52. The outside of the base 5 becomes high temperature. The temperature of the outside of the base 5 reaches about 100°C. If the user touches this place with his hand, there is a risk of burns. Therefore, in this embodiment, in order to avoid the risk of the user touching the high-temperature outer periphery of the base 5, a cover member 7 is arranged.

[0062] The cover member 7 is arranged on the outer peripheral side of the housing 3, specifically, the base 5, and the outer peripheral side of the stator cylindrical portion 26. That is, the cover member 7 is arranged in a manner to surround the base 5 and the stator cylindrical portion 26. Therefore, the cover member 7 can prevent the user (operator) from touching the base 5 that has become hot. The cover member 7 is arranged across the air insulation layer S3 and is not in direct contact with the housing 3, specifically, the base 5. Therefore, it is possible to effectively prevent the heat of the stator cylindrical portion 26 and the base 6 from being directly or through heat radiation transmitted to the cover member 7 and the cover member 7 from becoming hot. The position where the cover member 7 is arranged is below the first end portion 15 of the base. The cover member 7 is arranged in contact with the upper surface 8a of the cooling device 8. The cover member 7 is fixed to the cooling device 8. Therefore, cooling the cover member 7 by the cooling device 8 can also better prevent the cover member 7 from becoming hot. In this embodiment, the outer diameters of the cooling device 8 and the power supply device 9 are formed larger than the outer diameter of the base 5, and a mounting portion for mounting the cover member 7 is formed on the upper surface 8a of the cooling device 8. That is, the cooling device 8 protrudes radially outward relative to the base 5, and the protruding area constitutes the mounting portion. The cover member 7 is mounted on the mounting portion.

[0063] The cover member 7 is formed in a tubular shape on the outer periphery of the tubular (e.g., cylindrical) base 5, and is formed in a polygonal shape (not particularly limited, for example, a regular octagon, etc.) when viewed from above. However, the cover member cannot be formed at the position where the exhaust pipe 17 is arranged, so it does not become a complete tubular shape. The cover member 7 can be formed by bending a single plate, or by combining a plurality of rectangular plate-like members. For example, the cover member 7 can be formed by combining 2 to 4 plate-like members formed by bending a flat plate at a specific angle. Therefore, it is easy to manufacture and has low cost. The thickness of the plate constituting the cover member is greater than 1 mm and less than 10 mm. The material of the cover member is metal or plastic. In terms of ease of processing, metal is preferred.

[0064] The thickness of the air insulation layer is preferably 1 mm or more, more preferably 3 mm or more, and further preferably 10 mm or more at the portion where the outer periphery of the base 5 is closest to the cover member 7. In addition, the thickness of the air insulation layer is preferably 100 mm or less, more preferably 50 mm or less at the portion where the outer periphery of the base 5 is closest to the cover member 7. If the thickness of the air insulation layer is too thin, the insulation performance is insufficient, and if it is too thick, the vacuum pump 1 becomes larger.

[0065] The vacuum pump 1 of the above embodiment is a composite pump in which a turbomolecular pump and a thread groove pump are integrated. However, the turbomolecular pump may be omitted. That is, the vacuum pump 1 may include only the thread groove pump.

[0066] <Second embodiment>

[0067] (2) Structure of Vacuum Pump of Second Embodiment

[0068] The vacuum pump 1 of the second embodiment does not include the second heater 52 of the first embodiment, but instead includes a fourth heater for heating the stator cylindrical portion 26. The other structures of the vacuum pump 1 are the same as those of the first embodiment.

[0069] In the vacuum pump 1 of the second embodiment, the outer periphery of the susceptor 5 also becomes hot. Therefore, similarly to the vacuum pump 1 of the first embodiment, the cover member 7 can prevent the user from being in danger of contacting the high temperature portion.

[0070] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments, and various modifications can be made without departing from the gist of the present disclosure. In particular, the embodiments described in this specification can be arbitrarily combined as needed.

[0071] (3) Implementation Method

[0072] Those skilled in the art will appreciate that the above-mentioned multiple exemplary embodiments are specific examples of the following embodiments.

[0073] (Item 1) A vacuum pump according to one embodiment includes:

[0074] Rotor cylinder;

[0075] A motor for rotating the rotor cylinder;

[0076] A stator cylindrical portion, which together with the rotor cylindrical portion constitutes a thread groove pump;

[0077] A base, accommodating the rotor cylindrical portion and the stator cylindrical portion;

[0078] A heater for heating the base or the stator cylinder;

[0079] a cooling device mounted on the base; and

[0080] The cover member is arranged on the outer peripheral side of the stator cylindrical portion and the outer peripheral side of the base, covers the base via an air heat insulating layer, and contacts the cooling device.

[0081] The vacuum pump described in the first item uses a cover member to cover the outer peripheral side of the base on the outer peripheral side of the stator cylinder, thereby preventing the user from touching the base, which is a high-temperature part. The cover member covers the base through an air insulation layer and is not directly connected to the base, thereby effectively preventing the cover member from becoming hot. Since the structure is that the cover member is not connected to the base, there is no need to provide an insulation component to prevent the heat of the base from being transferred to the cover member, thereby reducing costs and the number of components. Furthermore, the cover member is installed on a cooling device and is cooled by the cooling device, thereby effectively preventing the cover member from becoming hot. As a result, the danger of users touching the high-temperature part can be effectively avoided.

[0082] (Item 2) The vacuum pump according to Item 1, further comprising:

[0083] a power supply device for supplying power to the motor,

[0084] The power supply device is arranged in contact with the cooling device,

[0085] The base and the cover member are arranged so as to be in contact with a surface of the cooling device opposite to a surface in contact with the power supply device.

[0086] The vacuum pump described in the second item includes a power supply device, and a cooling device is used to cool both the power supply device and the cover member, so the risk of a user contacting a high-temperature part can be reduced with a simple structure.

[0087] (Item 3) In the vacuum pump described in Item 1,

[0088] The cooling device is mounted on the lower end surface of the base.

[0089] The outer diameter of the cooling device is larger than the outer diameter of the lower end surface of the base, and a mounting portion for mounting the cover member is provided on the upper surface of the cooling device.

[0090] The lower end of the cover member is mounted on the mounting portion.

[0091] According to the vacuum pump described in the third aspect, the cover member can be stably attached to the upper surface of the cooling device, and the cover member can be cooled more satisfactorily.

[0092] (Item 4) The vacuum pump according to Item 1, further comprising:

[0093] A plurality of rotor blades are rotated together with the rotor cylinder by the motor;

[0094] A plurality of stator blades, together with the plurality of rotor blades, form a turbomolecular pump; and

[0095] The casing accommodates the multiple sections of rotor blades and the multiple sections of stator blades.

[0096] According to the vacuum pump described in the fourth item, the housing of the vacuum pump is formed by an upstream shell and a downstream base. In addition, the cover member is arranged in a manner to cover at least the outer periphery of the base. The cooling device is connected to the base, and the cover member is connected to the cooling device.

[0097] (Item 5) In the vacuum pump described in any one of Items 1 to 3,

[0098] The cover member is formed into a cylindrical shape by one or more plate-shaped members formed by bending a flat plate.

[0099] According to the vacuum pump described in the fifth item, the cover member is formed by bending a flat plate, so the cover member can be easily manufactured at a low cost.

[0100] (Item 6) In the vacuum pump described in any one of Items 1 to 3,

[0101] The outer periphery of the base is cylindrical, and the cover member is cylindrical.

[0102] The air heat insulating layer has a thickness of 1 mm or more and 100 mm or less at a portion of the outer periphery of the base that is most adjacent to the cover member.

[0103] In the vacuum pump described in item 6, the thickness of the air insulation layer is 1 mm or more, so the outer periphery of the base and the cover member are thermally insulated. The thickness of the air insulation layer is 100 mm or less, so the vacuum pump can be prevented from becoming too large.

Claims

1. A vacuum pump, wherein: include: Rotor cylinder; A motor for rotating the rotor cylinder; A stator cylindrical portion, which together with the rotor cylindrical portion constitutes a thread groove pump; A base, accommodating the rotor cylindrical portion and the stator cylindrical portion; A heater for heating the base or the stator cylinder to prevent gas adhesion; A cooling device, mounted on the base; as well as a cover member disposed on the outer peripheral side of the stator cylindrical portion and the outer peripheral side of the base, covering the base via an air insulation layer so that the cover member does not directly contact the base, and contacting the cooling device so that the cover member is cooled by the cooling device, The cover member is arranged to surround an outer peripheral side surface of the base to prevent a user from contacting the base.

2. The vacuum pump according to claim 1, wherein: Also includes: a power supply device for supplying power to the motor, The power supply device is arranged in contact with the cooling device, The base and the cover member are arranged so as to be in contact with a surface of the cooling device opposite to a surface in contact with the power supply device.

3. The vacuum pump according to claim 1, wherein The cooling device is mounted on the lower end surface of the base. The outer diameter of the cooling device is larger than the outer diameter of the lower end surface of the base, and a mounting portion for mounting the cover member is provided on the upper surface of the cooling device. The lower end of the cover member is mounted on the mounting portion.

4. The vacuum pump according to claim 1, wherein: Also includes: A plurality of rotor blades are rotated together with the rotor cylinder by the motor; A plurality of stator blades, together with the plurality of rotor blades, form a turbomolecular pump; and The casing accommodates the multiple sections of rotor blades and the multiple sections of stator blades.

5. The vacuum pump according to any one of claims 1 to 3, wherein The cover member is formed into a cylindrical shape by one or more plate-shaped members formed by bending a flat plate.

6. The vacuum pump according to any one of claims 1 to 3, wherein The outer periphery of the base is cylindrical, and the cover member is cylindrical. The air heat insulating layer has a thickness of 1 mm or more and 100 mm or less at a portion of the outer periphery of the base that is most adjacent to the cover member.

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