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:
Jun. 06, 1995
Filed:
Aug. 05, 1993
Hirofumi Aritsubo, Sanda, JP;
Toshihiko Fuse, Sanda, JP;
Nippon Pillar Packing Co., Ltd., Osaka, JP;
Abstract
A shaft seal device comprises two mechanical seals for sealingly separating a sealed fluid region from an atmospheric region. A shaft is rotatable about an axis and extends through a casing from a sealed fluid region to an atmospheric region. The mechanical seals separate the sealed fluid region and the atmospheric region by a purge region formed between the mechanical seals. Each mechanical seal comprises a first seal ring fixed on the shaft and a second seal ring slidable in the axial direction and pressed against the first seal ring. The mechanical seal separating the sealed fluid region from the purge region is a contact type seal so that the fluid pressure of the sealed fluid region acts as a back pressure on the second seal ring. The mechanical seal separating the atmospheric region from the purge region is non-contact type seal so that the fluid pressure of the purge region acts as a back pressure on the second seal ring. The purge fluid region is charged with a gas such as nitrogen at a pressure lower than the pressure in the sealed fluid region.