DC MACHINE WITH LIQUID METAL SWITCH Russian patent published in 2012 - IPC H02K23/04 H01R39/30 

FIELD: electricity.

SUBSTANCE: closest analog of the proposed DC machine (DCM) is a DCM with a mechanical switch, a collector with sliding brush contacts. The mentioned machine has some disadvantages in its structural design, consisting in the fact that it comprises rotary anchor winding and collector, on the surface of which several pairs of brush contacts are sliding continuously in process of operation of this machine. It results in intense wear of sliding and contacting parts due to sliding friction, and accordingly to narrowing of the application field of such machine as a result of sparking that occurs. Besides, rotary anchor windings to a certain extent limit the angular speed of its rotor. In the design of the proposed DCM the anchor winding is fixed, and an inducer rotates, comprising permanent magnets and a central magnetic conductor installed on a common rotation shaft, at the same time a liquid metal switch is applied, which consists of neighbouring dielectic bases of four cylindrical metal reservoirs that are somewhat filled with electroconductive fluids, and such bases have holes for free insertion of a rotation shaft, and in the first two reservoirs that are connected accordingly to direct and reverse wires of anchor winding, on a rotation shaft there is one electroconductive disc installed on each one, slightly submerged into the specified fluids with sharp edges, every of which is electrically connected to according diametrally arranged pairs of metal sectors of two adjacent combined discs, also installed in the next two reservoirs connected accordingly to positive and negative terminals of outer DC voltage source. As DC voltage is supplied to a liquid metal switch, currents leaking through windings of the anchor winding will start interacting with the magnetic field of the inducer. Then the rotor will start rotating, and after a half-turn, instead of the first ones, the next metal sectors of combined discs will be submerged in the electroconductive fluids, and each disc will already be electrically connected to other metal discs of the switch. As a result, in the anchor winding there will be a current of another direction opposite to the initial one. But since at that time the permanent magnets of the inducer shift places, directions of electromagnet forces acting at the rotor will remain unchanged. In the generator mode when rotating all discs of the metal switch by an external motor synchronously to the inducer, positive and negative half-waves of the induced AC current of the anchor will always arrive to one and the same according terminals of the electric output of DCM, and at the same time DC current will be leaking in the external circuit.

EFFECT: significantly longer service life of the machine, expansion of its application field and increased reliability in operation.

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