Title:
VACUUM PUMP
Document Type and Number:
Japanese Patent JPH01187396
Kind Code:
A
Abstract:
PURPOSE:To obtain a perfectly clean vacuum, by supplying compressed gas respectively to pneumatic bearings which support a driving shaft at two positions in the radial direction and at one position in the thrust direction, and to a gas turbine coupled with the driving shaft, from a common supply source. CONSTITUTION:In the pump casing 30 of a vacuum pump, an axial flow turbo- molecular pump stage 40, a centrifugal compressor stage 47, and a circumferential flow compressor stage 50 are provided respectively. Moreover a driving shaft 35 is provided in the first support 31 and also a gas turbine 36 is provided between the first and second supports 31, 32. In this construction the driving shaft 35 is supported respectively with pneumatic bearings 37, 38 at two positions in the radial direction and a pneumatic bearing 39 at one position in the thrust direction. Moreover the driving shaft 35 is coupled with the gas turbine 36. A common compressed air supply source 53 supplies the compressed air respectively to each of pneumatic bearings 37-39 and the gas turbine 36.
Inventors:
NAKAMORI KAZUAKI
AWATA YOSHIHISA
AWATA YOSHIHISA
Application Number:
JP1070688A
Publication Date:
July 26, 1989
Filing Date:
January 22, 1988
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F04D19/04; F04D25/04; (IPC1-7): F04D19/04; F04D25/04
Domestic Patent References:
| JPS5138113A | 1976-03-30 | |||
| JPS60116895A | 1985-06-24 | |||
| JPS6223597A | 1987-01-31 |
Attorney, Agent or Firm:
Katsuo Ogawa (1 person outside)