Electric motor with permanent magnet rotor and wound stator - has excitation winding and rotor speed sensing winding for feedback control

摘要

The motor has a cylindrical permanently magnetic rotor rotating inside the laminated stator core. The assembly is enclosed in a cylindrical housing. The stator field windings which produce the driving field are located to face the curved surface of the rotor and are grouped diametrically opposite one another. A second set of coils is situated in the centre of each group to detect the speed, at which the rotor magnetic field is rotating with respect to the stator, and thus to generate a voltage proportional to the rotor speed. The stator coils may be arranged coaxially in the stator slots.