GB453022A - Improvements in or relating to self-starting low-speed synchronous motors - Google Patents

Abstract

453,022. Alternating-current motors. JANZEN, O., 20, Hillmannstrasse, Hermsdorf, Berlin. Aug. 31, 1935, No. 24380. Convention date, Sept. 29, 1934. [Class 35] The salient shaded poles of the synchronous stator component of an induction starting synchronous motor have two groups of teeth, the tooth or teeth in one group being displaced relatively to the tooth positions of the other group by half the rotor tooth pitch and the numbers of teeth in the two groups are made unequal, in addition, or alternatively, the cross-sections of iron in the pole sections corresponding to the two groups are made unequal. In the form shown in Fig. 3, the stator has four shaded poles 21, 22 for asynchronous operation surrounded by a conducting drum rotor 7 and arranged axially adjacent four toothed poles 23, 24 which co-operate with the toothed rotor component 2. The asynchronous and synchronous stator components have common energizing windings 4 and common shading coils 5. In the form shown in Fig. 6, the teeth 19 of the long cylindrical rotor co-operate with toothed poles 13 which are provided at each end of the rotor, and the squirrel cage rotor-winding 20 cooperates with the other poles 15 which extend the whole length of the rotor.