04206374 is referenced by 68 patents and cites 5 patents.

A synchronous motor, in particular a stepping motor, with two coaxial stator sections which are each provided with a ring coil and with two circular systems of teeth, which are shifted by half a tooth pitch relative to each other. The two stator sections are shifted by a quarter tooth pitch relative to each other. In addition, the motor comprises an axially magnetized permanent-magnetic ring which is disposed between the two stator systems, for magnetizing the two systems of teeth of the stator sections with mutually the same polarity. The two systems of teeth of each stator section are constituted by annular parts which are provided with teeth at the inner circumference. The annular parts form part of the magnetic circuit which surrounds the annular coil and are disposed concentrically in such a way that the axial distance between the teeth of both systems is at least a few times greater than the air gap between stator and rotor.

Title
Synchronous motor
Application Number
5/808784
Publication Number
4206374
Application Date
June 22, 1977
Publication Date
June 3, 1980
Inventor
Bernardus H A Goddijn
Eindhoven
NL
Agent
Robert S Smith
Assignee
U S Philips Corporation
NY, US
IPC
H02K 37/17
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