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. 16, 1996
Filed:
Mar. 14, 1995
Thomas G Van Sistine, Menomonee Falls, WI (US);
Ronald P Bartos, Menomonee Falls, WI (US);
William L Mehlhorn, Greenfield, WI (US);
Timothy H Houle, Wauwatosa, WI (US);
A. O. Smith Corporation, Milwaukee, WI (US);
Abstract
A switched reluctance motor includes a rotor mounted for rotation about an axis, and having a plurality of rotor poles, and a stator surrounding the rotor and including first, second and third stator phases. The motor also includes energizing means for sequentially energizing the stator phases with an energy source to cause rotation of the rotor, based on rotor position information, the energizing means causing one phase to be energized and then deenergized to near a zero current level prior to a point where the rotor pole breaks away from the stator pole. The energizing means further includes limited current turn on means connected to switch operating means for operating a switch on the one phase to permit flow of limited current through the one phase after it reaches a near zero current level but before the break away point. The motor further includes circuit means connected to the one phase for permitting the limited current to circulate through the one phase; and current sensing means for sensing the amount of current in the one phase and for determining when the current exceeds a predetermined regenerative current threshold at about the break away point, the energizing means being connected to the current sensing means to use this excess regenerative current information at about the break away point for rotor position information.