A rotor for an electric motor includes a rotor core defining a first face, a second face, and an opening extending from the first face to the second face. The rotor also includes an output shaft received by the opening of the rotor core and a valve disposed within a passageway of the output shaft. The valve controls a flowrate of the coolant and is actuated into a fully opened position at a maximum operating temperature of the rotor. The valve includes a stem having a first end portion and a second end portion, a plug disposed at the first end portion of the stem, a valve seat disposed opposite to the plug, and a shape memory alloy actuator that expands to urge the stem of the valve and the plug away from the valve seat and into the fully opened position at the maximum operating temperature.

A rotor for an electric motor includes a rotor core defining a first face, a second face, and an opening extending from the first face to the second face. The rotor also includes an output shaft received by the opening of the rotor core and a valve disposed within a passageway of the output shaft. The valve controls a flowrate of the coolant and is actuated into a fully opened position at a maximum operating temperature of the rotor. The valve includes a stem having a first end portion and a second end portion, a plug disposed at the first end portion of the stem, a valve seat disposed opposite to the plug, and a shape memory alloy actuator that expands to urge the stem of the valve and the plug away from the valve seat and into the fully opened position at the maximum operating temperature.

A motor and a rotating shaft cooling device thereof are disclosed. A rotating shaft of the motor is formed with an annular space. A shaft has a front end and a rear end. The shaft is a blind tube formed with a channel communicating with the annular space through a plurality of nozzles. The distance between the nozzles and the rear end is less than one-half of the length of the shaft. A cooling fluid flows through the nozzles to form a jet array to impinge on the inner wall of the rotating shaft to cool the rotating shaft, and flows back in the annular space to enhance the cooling effect, increase the heat exchange area, and improve the cooling effectiveness of the rotating shaft.

A heat sink (30) for cooling an electric machine (10), includes: a first part of the heat sink (32) in the form of a hollow cylinder, wherein an inner lateral surface includes a groove (34) extending helically with respect to a central axis of the hollow cylinder; a second part of the heat sink (36) in the form of a hollow cylinder, which includes a radially internal fin (38); and a third part of the heat sink (40) in the form of a hollow cylinder, which includes a connecting section (52), in order to accommodate an output shaft (12) of the machine in a rotationally fixed manner. The second part of the heat sink is accommodated, at least partially, in the first part of the heat sink, so that a radially external surface of the second part of the heat sink rests against the groove.

A heat sink (30) for cooling an electric machine (10), includes: a first part of the heat sink (32) in the form of a hollow cylinder, wherein an inner lateral surface includes a groove (34) extending helically with respect to a central axis of the hollow cylinder; a second part of the heat sink (36) in the form of a hollow cylinder, which includes a radially internal fin (38); and a third part of the heat sink (40) in the form of a hollow cylinder, which includes a connecting section (52), in order to accommodate an output shaft (12) of the machine in a rotationally fixed manner. The second part of the heat sink is accommodated, at least partially, in the first part of the heat sink, so that a radially external surface of the second part of the heat sink rests against the groove.

Disclosed are magnetic rotors systems and methods for heating a substrate. The magnetic rotor includes a rotor body and at least one magnet supported on the rotor body. The rotor body is rotatable about an axis. The rotor body also defines a chamber that selectively receives a coolant within the chamber.

Disclosed are magnetic rotors systems and methods for heating a substrate. The magnetic rotor includes a rotor body and at least one magnet supported on the rotor body. The rotor body is rotatable about an axis. The rotor body also defines a chamber that selectively receives a coolant within the chamber.

A magnetic pole piece device disposed between an inner diameter side magnet field and an outer diameter side magnet field of a magnetic gear, includes: an outer circumferential cover member disposed opposite to the outer diameter side magnet field and having a cylindrical shape; an inner circumferential cover member disposed opposite to the inner diameter side magnet field and having a cylindrical shape; and a plurality of magnetic pole pieces disposed at intervals in a circumferential direction between the outer circumferential cover member and the inner circumferential cover member. The outer circumferential cover member includes a plurality of outer circumferential side facing portions facing outer circumferential surfaces of the plurality of magnetic pole pieces, and a plurality of outer circumferential side connecting portions for connecting two adjacent outer circumferential side facing portions of the plurality of outer circumferential side facing portions.

A stator includes: a stator core including an annular yoke portion and a plurality of tooth portions formed on an inner side in a radial direction of the yoke portion so as to be arranged at predetermined intervals in a circumferential direction and protrude toward the inner side in the radial direction; and a winding arranged in slots formed between the tooth portions. The stator includes cooling tubes made of a nonconductive material, extending in an axial direction of the stator, and serving as flow paths for a coolant. The cooling tube has a constant outer shape along the axial direction and has a thickness that changes along the axial direction.

A stator includes: a stator core including an annular yoke portion and a plurality of tooth portions formed on an inner side in a radial direction of the yoke portion so as to be arranged at predetermined intervals in a circumferential direction and protrude toward the inner side in the radial direction; and a winding arranged in slots formed between the tooth portions. The stator includes cooling tubes made of a nonconductive material, extending in an axial direction of the stator, and serving as flow paths for a coolant. The cooling tube has a constant outer shape along the axial direction and has a thickness that changes along the axial direction.