Slow-running synchronous AC motor - has two coaxial stator coils with phase-shifting transformer to supply one of latter

摘要

The motor has the stator poles regulated in the rotating field cycle, with the coil (12) of the second stator (4) supplied by the secondary of a transformer having its primary coupled across the AC network supplying the first stator coil (7). The transformer has a transfer ratio of 1:1, so that it acts purely as a phase shifter. The rotor (5), lying between the two stators, (3, 4) has pole teeth at spaced points around its periphery, or pole teeth around its full periphery of reduced height. Each of the stators (3, 4) has a relatively thick-walled core sleeve secured to a stator ring adjacent the rotor (5), the stators (3, 4) fixed via screws (19) to the respective halves (1, 2) of the motor casing. The motor may be used to drive an electric timepiece.