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. 23, 1991
Filed:
Aug. 30, 1990
Keith I Hoemann, Jefferson County, MO (US);
Scott E Eckles, St. Louis County, MO (US);
Emerson Electric Co., St. Louis, MO (US);
Abstract
A permanent magnet rotor for an electric motor includes longitudinally extending main rotor field and sensor field sections, the sensor field section being substantially shorter than the main rotor field section and being disposed at one end thereof. The sensor field section is magnetized in circumferentially disposed parallel strips of alternating magnetic polarity around the rotor. The main rotor field section has longitudinally extending strips of alternating magnetic polarity which are skewed in a predetermined pattern. The predetermined pattern includes a first portion in which each longitudinally extending strip runs generally at a first predetermined non-zero angle with respect to the longitudinal axis of the rotor, a second portion in which each longitudinally extending strip runs generally at a second predetermined non-zero angle with respect that axis, and a third portion in which each longitudinally extending strip runs generally at the first predetermined non-zero angle with respect to the axis. The first and second angles are opposite in sign.