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. 21, 1992
Filed:
Sep. 01, 1989
Jeffrey A Kordik, Aptos, CA (US);
Applied Motion Products, Inc., Scotts Valley, CA (US);
Abstract
A two phase unipolar brushless direct current motor with asymmetrically arranged pole positions including a rotor portion (12) mounted upon a shaft subassembly (14) and rotating therewith with respect to a stator portion (16). The rotor portion (12) includes a field magnet (22) which is divided into alternately polarized zones (26) and (28) which are of dissimilar sizes, and a commutator magnet (38) to provide for electrical timing. The stator portion (16) includes salient pole positions (44) which are asymmetrically arranged around the circumference of the stator core. A latching hall effect sensor (82) is also provided to act as a commutator triggering element. The motor (10) is characterized in that the asymmetrical arrangement of its magnetic elements prevents there being a zero torque or a detent position. The primary usage of the motor (10) is in digital data storage devices.