Abstract: An liquid-cooling system for an electrical machine comprises a rotor mounted on a shaft for rotation therewith and defining an axis of rotation, and a stator disposed coaxially with and in opposition to the rotor. The stator has stator windings, the stator windings having an axially-extending portion. The electrical machine further comprises a housing enclosing the stator and the rotor, the housing having an axial end, the axial end having a wall with an inner surface and an outer surface. The electrical machine also includes a cooling tube having a first end and a second end and an embedded portion thereof embedded between the first inner surface and the first outer surface, the embedded portion of the cooling tube located in substantial axial alignment with the axially-extending portion of the stator windings. In another aspect of this design, the inner surface of the wall of the axial end of the housing is substantially flat and is separated from an axial end of the rotor by an air gap.

Abstract: In one embodiment of the present invention, a rotor for an electrical machine comprises a first pole piece and a second pole piece together defining an axis of rotation of the rotor, each pole piece comprising a generally disc-shaped body having a circumference. Each pole piece further has a plurality of angularly-spaced pole fingers extending axially from the circumference of the body of the pole piece. The rotor additionally includes a plurality of permanent magnets, each permanent magnet affixed to a body of a pole piece between two pole fingers of the pole piece.

Abstract: A rotor for an electrical machine according to one embodiment of the present invention comprises a shaft defining an axis of rotation of the rotor, and first and second pole pieces affixed to the shaft for rotation therewith and together defining an interior cavity. The rotor additionally includes a slip ring affixed to the shaft for rotation therewith. Further, the rotor comprises a field-generating coil disposed within the interior cavity, the coil comprising a plurality of turns of electrical wire, the electrical wire further having a section extending to and electrically coupled to the slip ring. Also, the rotor has a retainer disposed exterior to the cavity and adjacent the first pole piece, the retainer comprising a radially-extending channel containing a portion of the section of electrical wire.

Abstract: A rotor for an electrical machine according to one embodiment of the present invention includes first and second individual slip rings mounted on a rotor shaft. A first end of the coil wire for the rotor passes through a first axial passage in the first slip ring and is terminated to conductive material on an axial end of that slip ring. The other end of the coil wire passes through a second axial passage in the first slip ring and through an axial passage in the second slip ring and is terminated to conductive material on an axial end of the second slip ring. The second axial passage of the first slip ring is electrically insulated from the conductive material of that slip ring, so the second wire end does not inadvertently short-circuit to the first conductive material. Also, the first and second slip rings are each designed to cooperate in providing a gap therebetween which provides space to accommodate the termination of the first wire end onto the axial end of the first slip ring.

Abstract: In one embodiment of the present invention, an electrical machine includes a rotor having a rotor stop axially affixed with respect to a shaft of the rotor. The rotor stop has a surface which is machined after assembly of the rotor. The rotor is then assembled into the electrical machine, with the machined rotor stop surface accurately locating the rotor axially within the electrical machine. The rotor stop surface includes at least one groove to prevent the formation of long, continuous machining chips during the machining operation.

Abstract: In one embodiment of the present invention a rotor for an electrical machine comprises a shaft having a radially-reduced portion, the shaft defining an axis of rotation of the rotor. The rotor additionally includes a pole piece having a bore, the pole piece mounted on the shaft for rotation therewith about the axis. Further, the rotor comprises a member located about the shaft in the radially reduced portion and interference fit within the bore of the pole piece. In a second embodiment of the present invention, an electrical machine comprises a rotor which further comprises a shaft defining an axis of rotation of the rotor, a pole piece affixed to the shaft for rotation therewith and a rotor stop slip fit onto the shaft and bearing against the pole piece. The rotor stop also bears against another component of the electrical machine to define an axial position of the rotor within the electrical machine.

Abstract: The present invention provides a rotor for an electrical machine. The rotor comprises first and second pole pieces defining an axis of rotation of the rotor. The first pole piece comprises a body and a plurality of pole fingers extending axially from the body of the first pole piece. The second pole piece comprises a body and a plurality of pole fingers extending axially from the body of the second pole piece, the pole fingers of the second pole piece intermeshed with the pole fingers of the first pole piece. The rotor also comprises a fan affixed for rotation with the first pole piece and the second pole piece, the fan having a plurality of pockets, each pocket containing a permanent magnet.