GB1344144A - Rotor for a dynamo-electric machine and process for producing the same - Google Patents

Abstract

1344144 Coils for dynamo electric machines JECO CO Ltd 11 Oct 1971 [12 Oct 1970] 47200/71 Heading H2A A core-less rotor for a dynamo-electric machine comprises arrays of conductors on the inner and outer surfaces of a hollow cylindrical insulating support, the conductors being inclined in opposite directions to the rotor axis on the two surfaces and being electrically interconnected at the ends of the support. In the motor shown, part of the rotor periphery forms a commutator engaged by brushes 19, the rotor being mounted between a ferromagnetic casing 11 and a stator permanent magnet 12. The rotor is mounted on an insulating support 17 secured to the rotor shaft 15. In a modification, Fig. 1B (not shown), a separate commutator is formed on the support 17. The rotor may be made using printed circuit assemblies or a slitted copper sheet adhered to or embedded in a sheet of plastics material. In one method of assembly, a sheet bearing parallel conductors is cut to form a parallelogram having two opposed sides parallel to the conductors. This is folded over, with the conductors on the outside, to form a trapezium which is then rolled up to form a cylinder. The conductor ends may be electrically connected by dipping in a solder bath to form one complete coil. In another method, the parallelogram is folded over several times to form a multiple-ply trapezium before the latter is rolled up to form a cylinder. This provides a multi-pole rotor. In a further method, parallelograms of different length are superimposed on one another and then rolled up with the shorter (or shortest) one on the inside. In this method, soldering is required at both ends of the rotor.