Motor

• US 4,883,996 A
• Filed: 05/18/1988
• Issued: 11/28/1989
• Est. Priority Date: 05/22/1987
• Status: Expired due to Term

• Current Assignee: Canon Precision Incorporated (Canon Inc.)
• Original Assignee: Canon Incorporated Taiwan (Canon Inc.), Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Aoki, Kanemasa
• Primary Examiner(s): Skudy, R.
• Application Number:
  US07/195,646
• Time in Patent Office: 559 Days
• Field of Search: 310/152, 310/154, 310/254, 310/162, 310/49 R, 310/257, 310/179, 310/40 MM, 310/218, 310/233, 310/261, 310/155, 310/46, 310/89, 310/91, 310/114, 310/258, 354/195.1, 354/400
• US Class Current: 310/154.24
• CPC Class Codes: H02K 16/00 Machines with more than one rotor or stator machines for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts H02K51/00; permanent magnet machines with multiple rotors or stators relatively rotated for vectorially combining the excitation fields or the armature voltages H02K21/029
• CPC Class Codes: H02K 23/04 having permanent magnet excitation

Abstract

A motor having a rotary shaft, a coil wound on an iron core fixed to the rotary shaft, a yoke member, a magnetic flux producing member and commutator means has its yoke member constructed with yoke supporting portions serving as a magnetic path of magnetic flux and four magnetic poles having substantially arcuate shape. Each magnetic pole has a largest dimension of thickness at a center portion thereof and extends outwardly with gradually reduced thickness in accordance with the distance from the central portion. Ends of each magnetic pole respectively oppose corresponding ends of the adjacent magnetic poles with a slight distance therebetween, with the magnetic poles surrounding an outer periphery of the iron core. The magnetic flux producing member includes two rectangular parallelepiped blocks. The motor forms a shape approximate to a rectangle or a square by the two blocks and the four poles and supporting portions, wherein a dimension of thickness of the whole motor is set to a value near a dimension of an outer diameter of the iron core.

Claims

1. A motor having a rotary shaft, a coil wound on an iron core fixed to said rotary shaft, a yoke member, a magnetic flux producing member for magnetizing said yoke member, and commutator means for supplying electric power to said coil,

said yoke member comprising yoke supporting portions serving as a magnetic path of magnetic flux, and four magnetic poles having substantially arcuate shapes and extending from said yoke supporting portions, each magnetic pole having a largest dimension of thickness at a center portion of the magnetic pole, and extending from the center portion toward ends thereof with a gradually reduced dimension of thickness in accordance with a distance from the central portion, the ends of each magnetic pole respectively opposing corresponding ends of adjacent magnetic poles with a slight distance therebetween, said magnetic poles surrounding an outer periphery of said iron core;

said magnetic flux producing member comprising two rectangular parallelepiped blocks, each of said blocks having a north pole and a south pole at the opposite ends thereof, each of said supporting portions being connected and fixed to a respective magnetic pole of each of said blocks;

said motor forming a shape approximate to a rectangle or a square by said two blocks and said four poles and supporting portions,

wherein a dimension of thickness of the whole motor is set to a value near a dimension of an outer diameter of said iron core.

2. A motor according to claim 1, wherein the supporting portions of said yoke member are arcuate and the motor as a whole forms an arcuate shape.