Apparatus for soldering the winding to the commutator of an electric machine

An apparatus for soldering the wires of the rotor winding of an electric machine to its commutator. The apparatus comprises a tank with molten solder and heaters, a magneto-hydrodynamic pump for the solder, a device for holding the rotor, and a device for the protection of the molten solder from oxidation. The device for holding the rotor comprises a base in the shape of a hollow cylinder with holes and having a chamfered bottom part of the internal surface thereof in which there is movable disposed a replacement nozzle, which is made up of a sleeve and a rotor holding case rigidly connecting together. The nozzle reciprocates in the base. The commutator of the rotor to be solder is inserted into the case. Between the sleeve and the case there is formed a ring-shaped duct, connected with a booster zone which directs the molten solder toward the commutator. To the upper part of the base there is attached a device for the protection of the molten solder from oxidation; such device comprises a hood with a central hole and a gas distributor, connected to a source of inert gas. When there is no rotor inside the case, the nozzle is lifted by the molten solder under the action of the Archimedes' forces, and the molten metal is returned into the bath thereof in the tank through the holes in the base, while the sleeve is sealed against the hood to avoid the flowing out of inert gas provided above the molten solder.