GB1237776A - Electric motor - Google Patents

Abstract

1,237,776. Electric motors. G. QUELLET. 10 Aug., 1968, No. 38336/68. Heading H2A. An electric motor comprises a disc-shaped winding without a magnetic core, the winding comprising at least one coil extending through the full circumference of the winding and having a substantially polygonal shape without radially extending portions. As shown, a continuously rotatable D.C. motor comprises eight stationary permanent magnets 3 and a rotatable winding comprising seven superimposed square coils 9, the coils being mutually angularly spaced by an angle of 2#/7 and being connected to commutator segments 10 contacted by mercury brushes 12. In a modification, the winding is stationary and the magnets rotate. The coils may be made of wire, may be etched or cut out of sheet metal, or may be printed circuits, and may be mounted between two plastics material supports 7, 7<SP>1</SP> as shown, or, alternatively, may be completely embedded in plastics material with a layer of insulating material between adjacent coils. A modification providing limited angular displacement comprises only one coil connected directly to the motor terminals without the use of a commutator. Speed control in the continuously rotating motor or position control in the modified motor is achieved using pulses derived from a photocell 14 co-operating with indicia 13, Fig. 2 (not shown), on the rotor. Alternatively, a controlling signal may be derived from a second winding and commutator similar to those shown.