Vacuum pump and heat insulating spacer used in vacuum pump

Patent metadata

Field	Value
Publication number	US-2016348695-A1
Application number	US-201515116716-A
Country	US
Kind code	A1
Filing date	Jan 8, 2015
Priority date	Feb 14, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

Provided is a vacuum pump for preventing solidification of gas in a thread groove portion, and a heat insulating spacer used in the vacuum pump. The vacuum pump includes a heat insulating spacer that is interposed between a casing and an outer circumferential stator having a thread groove portion, supports the outer circumferential stator coaxially with a rotor in a rotor radial direction, with keeping a gap between the casing and the outer circumferential stator, and has lower thermal conductivity than the casing and the outer circumferential stator.

First claim

1 . A vacuum pump, comprising:
a casing; a rotor that is supported rotatably in the casing and has a rotor cylinder portion; a stator having a substantially cylindrical shape, disposed coaxially with the rotor between the casing and the rotor cylinder portion; a thread groove portion engraved on either an outer circumferential surface of the rotor cylinder portion or an inner circumferential surface of the stator; and a heat insulating spacer that is interposed between the casing and the stator, supports the stator in a rotor radial direction, with keeping a gap between the casing and the stator, and has lower thermal conductivity than at least either the casing or the stator.

2 . The vacuum pump according to claim 1 , wherein the heat insulating spacer supports the stator also in a rotor axial direction.

3 . The vacuum pump according to claim 1 , wherein the casing has:
a cylinder portion; and a base provided under the cylinder portion, and the heat insulating spacer has: an axial supporting portion having a substantially cylindrical shape, extended along a rotor axial direction and interposed between the base and a supported portion provided circumferentially on an outer circumferential surface of the stator; a first radial supporting portion provided circumferentially on an outer circumferential surface of the axial supporting portion and coming into contact with an inner circumferential surface of the casing; and a second radial supporting portion provided circumferentially on an inner circumferential surface of the axial supporting portion and coming into contact with the outer circumferential surface of the stator.

4 . The vacuum pump according to claim 3 , wherein
the first radial supporting portion is disposed on one end side of the axial supporting portion, and the second radial supporting portion is disposed on the other end side of the axial supporting portion.

5 . The vacuum pump according to claim 3 , wherein the axial supporting portion is formed to have lower rigidity than the first radial supporting portion and bends in the rotor radial direction in response to thermal expansion of the stator.

6 . The vacuum pump according to claim 3 , wherein one end of the axial supporting portion is stretched farther downward from the first radial supporting portion in the rotor axial direction and comes into contact with the base.

7 . A heat insulating spacer, which is used in the vacuum pump described in 1 .

8 . The vacuum pump according to claim 2 , wherein
the casing has: a cylinder portion; and a base provided under the cylinder portion, and the heat insulating spacer has: an axial supporting portion having a substantially cylindrical shape, extended along a rotor axial direction and interposed between the base and a supported portion provided circumferentially on an outer circumferential surface of the stator; a first radial supporting portion provided circumferentially on an outer circumferential surface of the axial supporting portion and coming into contact with an inner circumferential surface of the casing; and a second radial supporting portion provided circumferentially on an inner circumferential surface of the axial supporting portion and coming into contact with the outer circumferential surface of the stator.

9 . The vacuum pump according to claim 8 , wherein
the first radial supporting portion is disposed on one end side of the axial supporting portion, and the second radial supporting portion is disposed on the other end side of the axial supporting portion.

10 . The vacuum pump according to claim 8 , wherein the axial supporting portion is formed to have lower rigidity than the first radial supporting portion and bends in the rotor radial direction in response to thermal expansion of the stator.

11 . The vacuum pump according to claim 4 , wherein the axial supporting portion is formed to have lower rigidity than the first radial supporting portion and bends in the rotor radial direction in response to thermal expansion of the stator.

12 . The vacuum pump according to claim 8 , wherein one end of the axial supporting portion is stretched farther downward from the first radial supporting portion in the rotor axial direction and comes into contact with the base.

13 . The vacuum pump according to claim 4 , wherein one end of the axial supporting portion is stretched farther downward from the first radial supporting portion in the rotor axial direction and comes into contact with the base.

14 . The vacuum pump according to claim 5 , wherein one end of the axial supporting portion is stretched farther downward from the first radial supporting portion in the rotor axial direction and comes into contact with the base.

15 . A heat insulating spacer, which is used in the vacuum pump described in claim 2 .

16 . A heat insulating spacer, which is used in the vacuum pump described in claim 3 .

17 . A heat insulating spacer, which is used in the vacuum pump described in claim 8 .

18 . A heat insulating spacer, which is used in the vacuum pump described in claim 4 .

19 . A heat insulating spacer, which is used in the vacuum pump described in claim 5 .

20 . A heat insulating spacer, which is used in the vacuum pump described in claim 6 .

Assignees

• Edwards Japan Ltd

Inventors

• Sakaguchi Yoshiyuki
• Kurokawa Norihiro

Classifications

• F04D19/044

  Holweck-type pumps · CPC title

• F05D2260/607

  Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles · CPC title

• F05D2230/642

  using maintaining alignment while permitting differential dilatation · CPC title

• F04D19/042 Primary

  Turbomolecular vacuum pumps · CPC title

• F04D29/5853 Primary

  heat insulation or conduction · CPC title