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:
Apr. 28, 1992
Filed:
Jul. 17, 1990
Katsutoshi Nii, Hitachi, JP;
Kazuhiko Kawaike, Katsuta, JP;
Jun Matsubayashi, Naka, JP;
Satosi Uno, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A sliding bearing an an end ring are mounted on a housing. A magnetic fluid sealing member comprises a permanent magnet and a magnetic fluid. A space is formed between the magnetic fluid sealing member and a lubricating fluid. A shaft has projection member or the end ring forms a spiral groove on an inner peripheral portion. The projection member of the shaft or the spiral groove of the end ring is disposed in an opposite position of the magnetic fluid sealing member. A magnetic fluid flow is disturbed by the projection member of the shaft or the spiral groove of the end ring according to a rotation of the shaft, then a magnetic fluid film is destructed instantaneously and the pressure at the space lowers. Air in the space is discharged from the housing. The scatter degree of the magnetic fluid is made slightly.