Patent Number: 6,166,470

Title: Brushless DC motor

Abstract: A brushless DC motor, whose stator (10) is a combination of stator yokes (11, 16). a bobbin (14) on which a magnetic field coil (15) is wound and to which terminal pins are provided, and a base plate (20). The stator (10) is fixed to the base plate (20) by a protrusion (12c) provided on the bobbin (14) or by a flange (18a) formed on a bearing. The widths of magnetic poles (11a, 16a) of the stator, which are measured in the circumferential direction of the stator, are smaller than the width of one of the poles of a rotor magnet (5). Thereby, the position of a stable point is a maximum excitation torque position. Further, a magnetic pole sensing element (21) is provided at a place which is shifted in the circumferential direction from the middle position of one of the magnetic poles of the rotor magnet (5).

Inventors: Miyazawa; Hiroshi (Suwa, JP), Matsuzawa; Kinya (Suwa, JP), Ito; Norio (Suwa, JP), Soya; Yasushi (Suwa, JP), Saito; Koichi (Suwa, JP)

Assignee: Seiko Epson Corporation

International Classification: H02K 3/52 (20060101); H02K 29/06 (20060101); H02K 3/46 (20060101); H02K 29/08 (20060101); H02K 1/14 (20060101); H02K 1/18 (20060101); H02K 21/22 (20060101); H02K 1/27 (20060101); H02K 5/22 (20060101); H02K 037/14 ()

Expiration Date: 12/26/2017