GB396855A - Improvements relating to electromotors - Google Patents

Abstract

396,855. Motors. SIEMENS BROS. & CO., Ltd., Tothill Street, and HUMPHRIES, H. E., 61, Rochester Way, Blackheath, both in London. March 21, 1932, No. 8324. [Class 35.] Motors with unwound iron armatures.-In a single-phase motor of the attracted iron type, the angularly displaced field poles have windings so connected to rectifiers that current flow through one of two adjacent, windings is unhindered and through the other winding is hindered during one half cycle, the conditions being reversed during the next half cycle. As shown, stator poles a, b displaced 90‹ carry windings c, d connected in parallel to a single phase source h in series respectively with rectifiers r<1>, r<2> which may be of the dry plate type. The unwound armature e has a V- or H-shaped section and is formed with cylindrical parts g<1>, g<2> and parts g3, g<4> which determine the direction of rotation and are so inclined that in the position shown, the part g3 presents a broad surface to the pole b and when advanced through 90‹ presents a narrow edge to the pole b, so reducing the counterclockwise torque. The magnetic circuit is completed through the armature spindle f and a yoke in which it is centred, or unwound poles may be placed opposite the poles a, b, separate yokes connecting opposite poles or a common yoke connecting all poles. In a modification, the coils c, d are connected in series and each is shunted by a rectifier. A number of motors may be run in parallel utilizing a single set of rectifiers by connecting their windings to points t.