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:
Mar. 11, 1997
Filed:
Jun. 20, 1994
Shuji Takahashi, Yonago, JP;
Nidec Corporation, Kyoto, JP;
Abstract
There is disclosed a brushless motor in which an oil-impregnated sleeve bearing is inserted in a bearing holder having a cylindrical shape with a closed bottom, and a rotating shaft is inserted in the oil-impregnated sleeve bearing in such a manner that the rotating shaft may freely rotate. With this arrangement, it becomes possible to prevent lubricant from leaking out without increasing either the number of component elements or the number of assembling steps. The oil-impregnated sleeve bearing comprises an inner and outer layers. An oil seat is disposed on the oil-impregnated sleeve bearing at the open-end side of the bearing holder. The percentages of voids are set such that the percentages of voids become lower in the order of the oil seal, the outer layer, and the inner layer. With the above arrangement, the lubricant can be prevented from leaking out through a gap of the bearing, and therefore reduction of life due to the leakage of lubricant can also be prevented.