Four-phase hybrid type stepping motor

• US 4,385,247 A
• Filed: 04/17/1981
• Issued: 05/24/1983
• Est. Priority Date: 07/02/1980
• Status: Expired due to Term

• Current Assignee: Oriental Motor Company Limited
• Original Assignee: Oriental Motor Company Limited
• Inventors: Satomi, Hirobumi
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US06/255,258
• Time in Patent Office: 767 Days
• Field of Search: 310/49, 310/162-165, 318/696, 318/685
• US Class Current: 310/49.33
• CPC Class Codes: H02K 37/18 of homopolar type

Abstract

A four-phase hybrid type stepping motor is disclosed, which comprises a rotor and eight stator poles each formed on a plane facing to an outer side surface of the rotor with a plurality of stator teeth, wherein a pitch between a center of the stator teeth of the first one of the eight stator poles and a center of the stator teeth of the fourth stator pole, a pitch between the center of the stator teeth of the fourth stator pole and a center of the stator teeth of the seventh stator pole and a pitch between the center of the stator teeth of the seventh stator pole and a center of the stator teeth of the second stator pole are common and equal to τ_c defined as follows: ##EQU1## where Z_R is the number of the rotor teeth and N is an integer close to 3·Z_R /8.

Claims

1. A four-phase hybrid type stepping motor comprising a rotor, eight stator poles are formed on a plane facing to an outer side surface of said rotor with a plurality of stator teeth arranged with a common pitch τ

_s, opposing ones of said stator poles being paired and being separated from each other by 180°

, and a plurality of windings wound in heteropolar on the four pairs of said stator poles, wherein a pitch between a center of said stator teeth of a first one (1₁) of said stator poles and a center of said stator teeth of a fourth one (1₄) of said stator poles, a pitch between said center of said stator teeth of said fourth stator pole and a center of said stator teeth of a seventh one (1₇) of said stator poles and a pitch between said center of said teeth of said seventh stator pole and a center of said stator teeth of a second one (1₂) of said stator poles are common and equal to τ

_c, said pitches τ

_s and τ

_c being set so that they satisfy the following equations;

##EQU4## where τ

_R is a pitch of teeth of said rotor, Z_R is the number of the teeth of said rotor and N is an integer close to 3·

Z_R /8.

2. A four-phase hybrid type stepping motor as claimed in claim 1, wherein said windings are wound in monofilar.

3. A four-phase hybrid type stepping motor as claimed in claim 1, wherein said windings are wound in bifilar.