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:
May. 01, 1990
Filed:
Aug. 29, 1989
Manabu Shiraki, Kanagawa, JP;
Sumio Ishii, Kanagawa, JP;
Shicoh Engineering Co., Ltd., Kanagawa, JP;
Abstract
A disk-type single-phase brushless motor wherein a reluctance torque having a sufficient magnitude can be generated to assure self-starting and continued rotation of the motor and production of disagreeable noises is minimized. The motor comprises a stator yoke mounted in an opposing relationship to a magnet rotor with an axial air gap left therebetween. The magnet rotor has an equal circumferential pole width .theta.. The stator yoke has a cutaway portion formed therein for enabling self-starting of the motor. The cutaway portion has a specific shape including a first radially extending edge and a second edge extending in a predetermined angular relationship from an inner end of the first edge to an outer circumferential edge of the stator yoke. The stator yoke is positioned at a predetermined angular position relative to a coreless armature coil so that the first edge thereof may be angularly spaced by a predetermined angle from a position at which a maximum starting torque is produced in the direction opposite the direction of rotation of the rotor.