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:
Jul. 04, 2006
Filed:
Jun. 19, 2002
Rodney Bramel, Bothell, WA (US);
Robert Silbernagel, Seattle, WA (US);
Rodney Bramel, Bothell, WA (US);
Robert Silbernagel, Seattle, WA (US);
Precor Incorporated, Woodinville, WA (US);
Abstract
A non-conductive insulating ring () is inserted between a motor bell () and a motor bearing () that supports a motor shaft (). Stray currents that normally discharge thorough the motor shaft and the motor bearing to the motor bell are prevented due to the non-conductive nature of the insulating ring. Additionally, the motor shaft is grounded to provide a low-impedance alternative path to stray shaft currents. When a fast-switching frequency converter is used to drive the motor shaft, additional arrangements such as a common mode choke, reduction of the switching frequency of the converter, and reduction of the turn-of/off rate of a semiconductor device used in the converter, may be provided to further reduce the stray currents flowing thorough the motor bearings.