Turbo vacuum pump

• US 5,451,147 A
• Filed: 09/30/1991
• Issued: 09/19/1995
• Est. Priority Date: 09/28/1990
• Status: Expired due to Term

• Current Assignee: Hitachi Plant Technologies Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Ueda, Shinjiro, Sakagami, Seiji, Mase, Masahiro, Nagaoka, Takashi
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): KORYTNYK, PETER G
• Application Number:
  US07/767,666
• Time in Patent Office: 1,450 Days
• Field of Search: 417/423.4, 415/90, 384/100, 384/107, 384/109
• US Class Current: 417/423.4
• CPC Class Codes: F04D 17/168 Pumps specially adapted to produce a vacuum
• CPC Class Codes: F04D 19/04 specially adapted to the production of a high vacuum, e.g. molecular pumps
• CPC Class Codes: F04D 23/008 Regenerative pumps for liquids or for liquids and elastic fluids F04D5/002
• CPC Class Codes: F04D 29/0513 hydrostatic; hydrodynamic thrust bearings
• CPC Class Codes: F04D 29/057 hydrostatic; hydrodynamic

Abstract

A compact, easy-to-handle turbo vacuum pump includes a housing having an inlet port and an outlet port; a cylindrical rotor disposed in the housing and having a stepped peripheral surface and a plurality of blades secured to protruding corners of the steps; and a pumping mechanism portion in which a pumping stage is formed by a stator which faces the blades of the rotor across a narrow gap, and in which peripheral pump flow paths are provided in step-like recessions inside the stator. The turbo vacuum pump further includes a rotating shaft which is connected to the rotor and is rotatably supported by a radial gas bearing and a thrust gas bearing; and a motor portion for operating the rotor. Gas sucked in through the inlet port can be discharged into the atmosphere through the outlet port.

Claims

1. A turbo vacuum pump comprising:

a housing having an inlet port and an outlet port;

a cylindrical rotor disposed in the housing and having a stepped peripheral surface and a plurality of blades secured to protruding corners of the stepped peripheral surface;

a pumping mechanism portion in which a pumping stage is formed by a stator facing the blades of said rotor across a narrow gap, and in which peripheral pump flow paths are provided in step-like recessions inside the stator;

a rotary shaft connected to said rotor and rotatably supported by a radial gas bearing capable of supporting loads of said shaft in a radial direction of said shaft and a grease-lubricating ball bearing capable of supporting loads of said shaft in a radial direction of said shaft and in a thrust direction of said shaft and

a motor portion for operating said rotor, said motor portion being located along an axial length of said rotary shaft between said radial gas bearing and said grease-lubricating ball bearing with said radial gas bearing being located between said pumping mechanism portion of said pump and said motor portion;

wherein gas drawn in through the inlet port can be discharged into the atmosphere through the outlet port.

2. A turbo vacuum pump according to claim 1, wherein the radial gas bearing is a hydrodynamic type gas bearing.

3. A turbo vacuum pump according to claim 1, wherein a means for cooling air is provided in the motor portion.

4. A turbo vacuum pump according to claim 1, wherein a spiral grooved pump stage is disposed on the side of an inhaling opening of a peripheral pump stage.

5. A turbo vacuum pump comprising:

a housing having an inlet port and an outlet port;

a cylindrical rotor disposed in the housing and having a stepped peripheral surface and a plurality of blades secured to protruding corners of the stepped peripheral surface;

a pumping mechanism portion in which a pumping stage is formed by a stator facing the blades of said rotor across a narrow gap, and in which peripheral pump flow paths are provided in step-like recessions inside the stator;

a rotary shaft connected to said rotor and rotatably supported by a hydrodynamic type radial gas bearing capable of supporting loads of said shaft in a radial direction of said shaft and a grease-lubricating ball bearing; and

a motor portion for operating said rotor, said motor portion being located along an axial length of said rotary shaft between said hydrodynamic type radial gas bearing and said grease-lubricating ball bearing with said radial gas bearing being located between said pumping mechanism portion of said pump and said motor portion;

wherein gas drawn in through the inlet port can be discharged into the atmosphere through the outlet port.

6. A turbo vacuum pump according to claim 5, wherein a means for cooling air is provided in the motor portion.

7. A turbo vacuum pump according to claim 5, wherein a spiral grooved pump stage is disposed on the side of an inhaling opening of a peripheral pump stage.