A stator winding includes a plurality of conductors including ducts. The ducts can be connected to a heat pipe or a conduit providing a coolant flow to directly cool the winding. The heat pipe can be connected to a heat exchanger that includes a coolant flow. The stator winding can be produced using additive manufacturing, with hollow ducts extending through leg sections and solid end sections. The heat exchanger can also be additively manufactured. A circuit for driving an electrical machine can be in thermal communication with the heat exchanger, such that the thermal system manages both the stators and the drive circuit.

A stator winding includes a plurality of conductors including ducts. The ducts can be connected to a heat pipe or a conduit providing a coolant flow to directly cool the winding. The heat pipe can be connected to a heat exchanger that includes a coolant flow. The stator winding can be produced using additive manufacturing, with hollow ducts extending through leg sections and solid end sections. The heat exchanger can also be additively manufactured. A circuit for driving an electrical machine can be in thermal communication with the heat exchanger, such that the thermal system manages both the stators and the drive circuit.

A stator includes a stator hub and a plurality of stator teeth extending from the stator hub that define a stator slot having a stator slot base. At least one winding is disposed in the stator slot and the stator also includes a back iron. The winding surrounds the back iron and is held apart from the stator slot base so that a fluid channel is defined between an inner winding portion of the at least one winding so fluid can be passed between the stator slot base and the inner winding portion to cool the inner winding portion.

A stator includes a stator hub and a plurality of stator teeth extending from the stator hub that define a stator slot having a stator slot base. At least one winding is disposed in the stator slot and the stator also includes a back iron. The winding surrounds the back iron and is held apart from the stator slot base so that a fluid channel is defined between an inner winding portion of the at least one winding so fluid can be passed between the stator slot base and the inner winding portion to cool the inner winding portion.

A rotor for an electric motor includes: a rotating element extending along an axis; and a retaining body formed of metal and configured to hold the rotating element from an outer peripheral side, where the retaining body includes: a plurality of annular members annularly surrounding an outer peripheral surface of the rotating element and arranged at intervals in the axis direction; and a plurality of connecting members arranged in a circumferential direction between the annular members adjacent to each other so as to connect the annular members. As a result, a path of eddy current is limited and the eddy current can be reduced.

A rotor for an electric motor includes: a rotating element extending along an axis; and a retaining body formed of metal and configured to hold the rotating element from an outer peripheral side, where the retaining body includes: a plurality of annular members annularly surrounding an outer peripheral surface of the rotating element and arranged at intervals in the axis direction; and a plurality of connecting members arranged in a circumferential direction between the annular members adjacent to each other so as to connect the annular members. As a result, a path of eddy current is limited and the eddy current can be reduced.

A rotary electric device includes a first inverter circuit and a second inverter circuit which control the driving of a motor, and the driving of the motor is controlled by setting a phase of a carrier frequency of the first inverter circuit and a phase of a carrier frequency of the second inverter circuit as opposite phases. The motor includes a stator which includes a plurality of slots, a plurality of coils each of which is inserted into each of the plurality of slots, and a rotor which is provided to be rotatable relative to the stator. In the plurality of coils, one first coil connected to the first inverter circuit and one second coil connected to the second inverter circuit constitute one coil pair, and at least one coil pair is disposed in one slot.

A rotary electric device includes a first inverter circuit and a second inverter circuit which control the driving of a motor, and the driving of the motor is controlled by setting a phase of a carrier frequency of the first inverter circuit and a phase of a carrier frequency of the second inverter circuit as opposite phases. The motor includes a stator which includes a plurality of slots, a plurality of coils each of which is inserted into each of the plurality of slots, and a rotor which is provided to be rotatable relative to the stator. In the plurality of coils, one first coil connected to the first inverter circuit and one second coil connected to the second inverter circuit constitute one coil pair, and at least one coil pair is disposed in one slot.

A pre-fitting nest and a method serve for forming a crown from a plurality of U-shaped electrically conductive hairpins to then be able to install the crown in a machine element of an electric machine, e.g., a stator. Here, an accommodating member has a plurality of grooves in which the legs of the hairpins are accommodated. The grooves are annularly disposed about a center and extend perpendicularly to the plane of the accommodating member. With respect to their size and geometry, they are configured such that in each case a first leg of a hairpin rotates within the groove thus to enable an unconstrained positioning of the second leg of the hairpin in another groove. One or several crowns formed from hairpins are provided for introduction into a machine element and inserted into the machine element.

A pre-fitting nest and a method serve for forming a crown from a plurality of U-shaped electrically conductive hairpins to then be able to install the crown in a machine element of an electric machine, e.g., a stator. Here, an accommodating member has a plurality of grooves in which the legs of the hairpins are accommodated. The grooves are annularly disposed about a center and extend perpendicularly to the plane of the accommodating member. With respect to their size and geometry, they are configured such that in each case a first leg of a hairpin rotates within the groove thus to enable an unconstrained positioning of the second leg of the hairpin in another groove. One or several crowns formed from hairpins are provided for introduction into a machine element and inserted into the machine element.