GB855840A - Improvements in or relating to alternating current generators - Google Patents

Abstract

855,840. Inductor alternators. GENERAL MOTORS CORPORATION. Sept. 5, 1958 [Sept. 11, 1957], No. 28559/58. Addition to 855,551. Class 35. In an inductor alternator having a stationary field member 30 and stator core 22 in the annular air-gap between which an interdigitatedpole inductor 58 rotates as described in the parent Specification, the field winding 32 and stator winding are cooled by air ventilation through apertures in the end wall 28 or by circulated oil. As shown in Fig. 7, the field member consists of coils 32 mounted on the core 30 haying two cylindrical pole parts 36, 38, while the inductor rotor consists of interdigitated magnetic members 60, 62 secured as by brazing to a spacer 64 e.g. of aluminium and serving to carry the generated flux to the stator 22. In the oil-cooled form shown in Fig. 7, oil from a sump 132 is pumped via ducts 120, 122, 124 into the machine casing to cool both windings, whence it is withdrawn at 125, 128 via a cooler 134 to the sump. In a modified construction, Fig. 8, the rotor magnetic members 90, 92 and spacer 94 form part of an engine flywheel. This form may be air-cooled, but as shown is cooled by oil pumped from sump 152 and returned via cooler 151. It is stated that alternators gear-driven by an engine may be cooled by engine oil. The exciting winding may comprise a shunt coil connected across the alternator through a rectifier, and a regulating coil fed through a current or voltage responsive regulator.