GB399283A - Improvements in or relating to high-tension dynamo-electric machinery - Google Patents

Abstract

399,283. Cores for dynamo-electric machines. ENGLISH ELECTRIC CO., Ltd., 28, Kingsway, London, and CALVERLEY, J. E., Crescent Road, Rowley Park, Stafford. June 20, 1932, No. 17390. [Class 35.] Insulation; machines with two armatures.- In a machine having the armature core insulated from the field core and maintained at the potential of some point on the armature winding, a pole-shoe is insulated from the field core and is maintained at the potential of a point on the armature winding. As shown in Fig. 1, the machine, which has its frame connected either directly or through a resistance 12 to the junction of two armatures 1, 2, has two windings on each armature, the common point of the two windings being connected to the rotor core directly or through a resistance 11 and the four windings are connected in series. The armature cores are 'insulated from the shaft and the pole-shoes 9, which are insulated from the pole cores 8 by insulation 10, are maintained at the same potential as the rotor core by connecting them to the resistance 11 but alternatively they may be maintained at some potential intermediate that of the rotor core and the frame by a connection either to an auxiliary brush on one commutator or to a tapping on a resistance connected across one or more commutators. In the form shown in Fig. 2 the dove-tail projection 9a of the poleshoe extends into a slot formed in the polesections 8a, 8b and insulation 10 extends between the shoe and the pole core. Specification 223,416, [Class 35, Dynamo-electric generators &c.], is referred to.