It is an object of the present invention to provide an electric motor for an electric vehicle with an improved cooling capacity by causing coils wound around a stator to serve as a tubular heat pipe type heat transfer device. An electric motor for an electric vehicle includes a stator 11, coils 12 wound around at least the stator, and a rotor 13 being rotated by an induction field developed around the coils 12. In one embodiment of the invention the coils 12 are formed of a tubular container 121 which is filled with a working fluid which vibrates in an axial direction of a tube by nuclear boiling generated at a high temperature portion of the coils 12. The coils themselves are arranged as a non-looped tubular heat pipe type heat transfer device.
A conductor of a stator coil 18 is formed of oxygen free copper and the conductor end acting as a neutral point of the stator coil 18 is protruded from a coil end portion 18b and the tip end of the conductor end is bonded from above by arc welding to configure a neutral connection portion 20.
A cooling system for an electrical machine includes at least one set of heat-conducting inserts positioned so as to transmit heat from at least one part of the winding in the stator to a heatsink. The heatsink may be the frame of the machine itself, but could also be a coolant pipe mounted at one or both ends of the stator. One form of insert is arranged between windings to draw heat away from the sides of the poles. Another form of insert is arranged on the ends of the poles to draw heat from that region.
A rotating machine which includes a stator having a number of field winding slots, a number of field windings disposed in each of the field winding slots, at least two of the field windings have an outer jacket; and a number of conductive wires disposed within and enclosed by the outer jacket such that longitudinal passages are defined between the conductive wires. A pump circulates a coolant into and from the rotating machine through the longitudinal passages. Preferably, the rotating machine includes a housing that has a cavity for acceptance of the stator therein. The housing and stator define and second plenums at first and second ends of the stator. The coolant enters the rotating machine into the first plenum and exits the rotating machine from the second plenum.
An electric motor including a motor portion, a cooling portion and a plurality of heat pipes is provided. The motor portion includes a stator and a rotor that when energized with electric current causes the rotor to rotate. The motor portion comprises a motor frame that encloses the rotor and stator from exterior elements. The cooling portion is adjacent the motor portion and exterior of the motor portion. In various embodiments it defines a fluid chamber containing a quantity of fluid that is prevented from contacting interior of the motor portion. The plurality of heat pipes within the motor portion extend from the motor portion to the cooling portion such that the fluid contacts the heat pipe within the cooling portion in order to remove heat from the heat pipe.
A stator assembly including a plurality of stator coil assemblies and a stator coil support structure constructed of a non-magnetic, thermally-conductive material. The stator coil support structure includes an axial passage for receiving a rotor assembly and a plurality of channels positioned radially about the axial passage. Each channel is configured to receive one or more of the stator coil assemblies.
