The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 2013
Filed:
May. 24, 2012
Shiro Tanigawa, Kanagawa, JP;
Shiro Tanigawa, Kanagawa, JP;
Anest Iwata Corporation, , JP;
Abstract
A multistage vacuum pump has a pair of rotors disposed in each of pump chambers connected in stages. As the rotors rotate while intermeshing, a suctioned gas is compressed and discharged, angles of the rotors are adjusted so that a phase angle Δθ of the rotors of adjacent pump chambers relative to a rotation angle C of the rotors during a single cycle of the pump chambers from intake to discharge and the number of stages S of the rotors satisfies Δθ≦C/S. When a rotor angle is φ1, an mth stage rotor angle is φm, and an nth stage rotor angle is φn in order from an upstream side of a gas flow direction, relationships of φ1<φm≦φn and φ1<φn, where n and m are natural numbers and n>m, are satisfied.