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:
Oct. 15, 1991
Filed:
Feb. 23, 1990
Applicant:
Inventors:
Assignee:
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Primary Examiner:
Int. Cl.
CPC ...
F04C / ;
U.S. Cl.
CPC ...
4182011 ;
Abstract
A displacement compressor has a housing defining a chamber and having an inlet and an outlet for the chamber. A pair of meshing helical rotors are rotatably supported about parallel axes in the chamber, so that a compressible fluid may be pumped from the inlet to the outlet. A recess in the wall of the housing is positioned in the chamber and around the outlet and has a substantially trapezoidal shape, in plan. The non-parallel edges of the substantially trapezoidal shape are angled with respect to the axial direction of the rotors, preferably by an angle which is substantially equal to the twist angle of the rotors. Noise producing pressure pulsations at the outlet are thereby reduced.