Small synchronous motor with permanent magnet rotor - has meander type winding on printed circuit strip as coreless stator

摘要

The synchronous motor is of the relatively slow speed type, with a large number of poles, employed in the direct drive of timing devices, counters, and recording apparatus. The elimination of ferromagnetic coupling between stator and rotor reduces noise and vibration. A meander type winding on a printed circuit strip is used. On a strip of insulating material (4) the windings (3, 3a) are printed, typically one or each side, with the required number of poles. The disc rotor (1) has a corresponding number of permanent magnet poles on its periphery (2). The stator windings are typically 90 deg. apart electrically to give facilities for reversal and predetermined direction of rotation.