Title:
TURBO-MOLECULAR PUMP
Document Type and Number:
Japanese Patent JP3532653
Kind Code:
B2
Abstract:
PURPOSE: To design a blade cascade of a turbo-molecular pump excellent in exhaust performance in an extensive area capable of providing exhaust speed in the same degree as in a free molecule flow region even in an intermediate flow region (0.1 to 1Pa) as well as in the free molecular flow region where suction port side pressure is high vacuum.
CONSTITUTION: A spacing (s) of cascades 5a, 6a is made 20% or less than 20% of an average free path h of gas molecule, a spacing code ratio s0 of the cascades 5a, 6a is found by theoretical computation, and the cascades 5a, 6a are formed so as to provide a high compression ratio (k) in the region that the spacing code ratio s0 is s0=0.5 to 1.5 in a turbo-molecular pump consisting of the multiple stage axial flow cascades 5a, 6a.
Inventors:
Iguchi, Masashi
Ikegami, Tatsuji
Nakamura, Junichi
Ikegami, Tatsuji
Nakamura, Junichi
Application Number:
JP7454595A
Publication Date:
May 31, 2004
Filing Date:
March 07, 1995
Export Citation:
Assignee:
OSAKA SHINKU KIKI SEISAKUSHO:KK
International Classes:
F04D19/04; (IPC1-7): F04D19/04
Attorney, Agent or Firm:
小山 輝晃
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