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. 23, 1996
Filed:
May. 25, 1994
Shigeya Tanimoto, Aichi, JP;
Mayumi So, Kakamigahara, JP;
Kabushiki Kaisha Toshiba, Kanagawa, JP;
Abstract
In a permanent magnet motor, a stator includes an annular stator core and a plurality of stator windings wound on the stator core so that a plurality of phases are composed. A rotor is rotatably mounted with a predetermined air gap between it and an inner peripheral face of the stator core. The rotor includes a rotor core having a plurality of slots and a plurality of permanent magnets embedded in the slots respectively. Each permanent magnet having a generally arc-shaped cross section is embedded in the slot so that its convex portion is directed toward a rotor axis. Each permanent magnet is magnetized so that directions of easy magnetization are concentrated on a point C at a side of center of curvature thereof. The relation between a distance L between the point C and a center line passing the center of each permanent magnet in the direction of the thickness thereof and a mean radius of curvature R of the permanent magnets is shown by the expression, 1.0.times.R.ltoreq.L.ltoreq.7.5.times.R.