GB345137A - - Google Patents

Abstract

345,137. Alternating- current motors. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Soc. Generale de Constructions Electriques et Mecaniques (Alsthom); 146, Avenue des Champs Elysees, Paris.) April 24, 1930, No. 12697. Convention date, April 25, 1929. [Class 35.] Machines with two armatures.-An alternating- current motor has secondary windings on the stator 10 and rotor 2 and primary windings 9, 8 co-operating therewith on a freely rotating intermediate member 7, the two primary windings being fed from the same set of slip rings 19. The rotor 2 which carries a single or double squirrel-cage winding is mounted on the driven shaft 1 and rotates at a speed which is the sum of the speeds of the fields set up by the primary windings. The stator 10 has a winding which can be closed through resistances or through brushes on a commutator 15 connected to an additional winding on the member 7. The commutator winding may be combined with the winding 9. Power factor correction and speed regulation may be obtained by adjusting the commutator brushes, or the commutator may supply continuous current to the winding 11 so that the elements 7, 10 function synchronously. A single or double squirrel-cage winding may be provided on the stator. In a modification, Fig. 3, for use with bi-polar circuits the diameter of the apparatus is reduced by disposing the rotor 2 and stator 10 axially in line surrounded by the two-part member 7. In another modification, Fig. 4 (not shown), the rotor of a machine of normal construction carries a primary winding and is coupled to the outer primary member of a second motor, the rotor of which drives the load.