Electronically controlled commutator-free DC motor - has several flat coils between rotor and prismatic framework on whose interior lie flexible circuit boards with rotor position sensors

摘要

The motor includes the rotor (10) which may comprise one or several magnets (13) with alternate poles or may entirely comprise a permanent magnet. The framework (15) with its faces parallel to the motor axis surrounds the rotor and forms part of the motor casing. The rotor diameter is such that the smallest distance between the rotor and the framework is less than the thickness of the stator coils (18) and it has a flat section to allow insertion between the coils. Discs (16) enclose the ends of the carcass. The PCB is initially flat but may be folded around the side walls and at least one end. The sensors used are typically Hall effect sensors. ADVANTAGE - Simpler mfr., easier miniaturisation with externalising control circuits.