GB191120709A - Improvements relating to the Operation of Electrical Machines of the Induction Type. - Google Patents

Abstract

20,709. Price, W. A. Sept. 19. Alternating-current induction machines.-The current passing through an induction machine connected to a source of direct current through a reversing commutator is regulated by connecting together the rotor and commutator by mechanical or other equivalent connexion so as to maintain definite relations between the speed of the rotor and the frequency of the alternating currents. The commutator and rotor shafts may be geared together through ordinary toothed wheels, and the current thereby maintained constant through a large range above and below synchronism. If the shafts be ,connected together by epicyclic gearing so as to maintain a constant difference between their speeds the current taken by the motor will be inversely proportional to the speed. The commutator c may be driven by an independent auxiliary motor r, by changing the speed of which the induction motor M may be controlled. In order to keep the difference in the speeds of the axles A, a small, they are connected together by straight and crossed belts, the pulleys p<1>, q<1> running on opposed free-wheel clutches and the pulleys p<1>, q being smaller .than the pulleys p, q<1>. In order to start up the induction motor, the mechanical connexion must be such as to permit of the commutator being run independently of the rotor.