GB1310981A - Dynamo-electric machine - Google Patents

Abstract

1310981 Insulation for dynamo-electric machines PAPST-MOTOREN KG 11 May 1970 [14 May 1969] 22691/70 Heading H2A In a dynamo-electric machine the magnetically and electrically active parts of the stator and rotor are completely insulated from any metal parts of the machine accessible to an operator. In the external rotor motor of Fig. 1 a layer of insulation 3 separates the magnetically active part 2 of the rotor, e.g. a hysteresis ring or eddy current ring, from the supporting structure 1 which may be made partly of plastics material. The stator laminations 11 are separated by an insulating layer or tube 14 from an insulating tube 13 carrying bearings for the rotor. In addition the stator end windings 12 are surrounded by a layer of insulation 15. In an internal squirrel cage rotor motor, Fig. 2 (not shown), the ends of a tube of insulating material (27) separating the rotor laminations (26) from the shaft (28) may be extended to lie between the rotor end rings and the motor bearings. The stator laminations (21) are separated from the motor casing by a layer of insulation (23) which also surrounds the stator end windings (22). In a modification (not shown) a stator pole winding is mounted on an insulating former of U-shaped cross-section, the open end of the former being filled with an insulating compound and the legs of the "U" having corrugations to increase the length of the leakage path. In the external rotor motor of Fig. 3 the stator laminations 55 and winding 56 are embedded in cast or moulded insulation 57 anchored in recesses in an insulating tube 54 carrying bearings for the rotor. The magnetically active part 52 of the rotor is mounted in an insulating carrier 51. In the Fig. 2 embodiment the motor casing (24) may be secured to end plates (30) either by a nut and bolt arrangement or by resilient clips engaging recesses in the end plates.