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:
Dec. 11, 1984
Filed:
Jul. 25, 1983
Hidetomo Mori, Ibaraki, JP;
Akira Suzuki, Atsugi, JP;
Riichi Uchida, Ibaraki, JP;
Shigeru Sasaki, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An oil-free rotary displacement compressor including a casing having a main casing defining a compression space, a pair of rotors housed in the compression space and each having a screw thread portion and shaft portions, radial bearings and thrust bearings for journalling the rotors, shaft sealing means for sealing the shaft portions to avoid gas leaks from the compression space to outside and entry of oil into the compression space from the bearings. Floating type screw seal rings, each formed on the inner surface with a spiral screw thread and a root of thread, are each fitted over one of the suction-side shaft portions and supported by the casing in such a manner as to be movable in both the radial and the axial directions with respect to the casing. Stationary type screw seal rings, each formed with a spiral screw thread and a root of thread are each fitted over one of the discharge-side shaft portions and supported by the casing in such a manner as to be movable only in the axial direction with respect to the casing.