An electric motor includes a shaft, and a stator disposed around the outer periphery of the shaft and including a plurality of slots extending toward the shaft. A plurality of coil units are arranged respectively in the plurality of slots. The coil units are each formed of a plurality of wires connected in parallel. One of the coil units that is arranged in at least one of the plurality of slots formed in the stator includes a plurality of winding groups that are connected in series and that have a different number of turns from each other. The winding groups are arranged in the slot in descending order of the number of turns in the direction toward the shaft.

A rotary transformer is provided. The transformer has a stator and a rotor. The stator has a stator core and the rotor has a rotor core sleeved in the stator core. An air gap is defined between an inner side wall of the stator core and an outer side wall of the rotor core. During rotation of the rotor, a length S of the air gap along a circumferential direction of the transformer and a mechanical rotation angle θ of the rotor satisfy a sinusoidal function relationship containing third-harmonic components, and the length changes periodically according to the functional relationship to define a shape of the rotor core. As a result, the output signal amplitude and measurement accuracy of the position of the rotary transformer can be improved under the same maximum and minimum air gaps.

A rotary transformer is provided. The transformer has a stator and a rotor. The stator has a stator core and the rotor has a rotor core sleeved in the stator core. An air gap is defined between an inner side wall of the stator core and an outer side wall of the rotor core. During rotation of the rotor, a length S of the air gap along a circumferential direction of the transformer and a mechanical rotation angle θ of the rotor satisfy a sinusoidal function relationship containing third-harmonic components, and the length changes periodically according to the functional relationship to define a shape of the rotor core. As a result, the output signal amplitude and measurement accuracy of the position of the rotary transformer can be improved under the same maximum and minimum air gaps.

A stator for a rotating electrical machine is disclosed, the stator comprising a plurality of stator slots (22) each of which accommodates a plurality of coils (40) of stator windings (18). Radial air gaps (46) are present between the coils of adjacent stator slots as the coils extend out of the stator slots. Insulating means (42, 54, 84) are provided between the coils of a stator slot as the coils extend out of the stator slot. The radial air gaps (46) are defined between the insulating means of the coils of adjacent stator slots. This can allow radial air passages to be formed through the windings, while ensuring sufficient electrical insulation between the coils of a stator slot.

A stator for a rotating electrical machine is disclosed, the stator comprising a plurality of stator slots (22) each of which accommodates a plurality of coils (40) of stator windings (18). Radial air gaps (46) are present between the coils of adjacent stator slots as the coils extend out of the stator slots. Insulating means (42, 54, 84) are provided between the coils of a stator slot as the coils extend out of the stator slot. The radial air gaps (46) are defined between the insulating means of the coils of adjacent stator slots. This can allow radial air passages to be formed through the windings, while ensuring sufficient electrical insulation between the coils of a stator slot.

An electric motor having has a rotor and a stator with a stator core as well as an insulation assembly, which extend along a common longitudinal axis from a first end face to a second end face of the stator. The stator core is formed with bars arranged uniformly distributed on the circumference to accommodate conducting wires wound into coils. The insulation assembly has a first insulation element, second insulation elements, and a third insulation element. The first insulation element is arranged between conducting wires and the stator core; a respective second insulation element is arranged in an intermediate space formed between coils arranged to fit closely to one another; and the third insulation element is arranged on an inner side of the stator, the inner side pointing inward in the radial direction, in a manner so as to seal the inner side.

A coil attachable to a tooth extending to one radial side of the tooth from an annular core back surrounding a central axis of a motor includes a first winding body including a first wound flat wire, and a second winding body including a second wound flat wire, that is located on a radial side of the first winding body, and that is connected to the first winding body. When N is a freely-selected integer of 1 or more, and M is a freely-selected integer larger than N, the first winding body is an N-layer winding body aligned and wound in two rows aligned in a radial direction, and the second winding body is an M-layer winding body aligned and wound in two rows aligned in the radial direction.

A coil attachable to a tooth extending to one radial side of the tooth from an annular core back surrounding a central axis of a motor includes a first winding body including a first wound flat wire, and a second winding body including a second wound flat wire, that is located on a radial side of the first winding body, and that is connected to the first winding body. When N is a freely-selected integer of 1 or more, and M is a freely-selected integer larger than N, the first winding body is an N-layer winding body aligned and wound in two rows aligned in a radial direction, and the second winding body is an M-layer winding body aligned and wound in two rows aligned in the radial direction.

Reliability of a rotating electrical machine is enhanced. A stator of a rotating electrical machine includes: a stator core being provided with teeth and slots on a cylindrical inner side surface of the stator core; a plurality of winding wires being each arranged inside each of the slots; and slot liners being each arranged respectively between an inner wall of each of the slots and each of the plurality of winding wires, each of the slot liners has a sheet-like first insulating substrate, a second insulating material layer being disposed on at least one surface of each of the slot liners, and an adhesive layer which expands between the first insulating substrate and the second insulating material layer by processing, the second insulating material layer is provided with a through-hole which communicates a side of the first insulating substrate with the inner wall of each of the slots, and each of the slot liners is disposed inside each of the slots in such a way that the second insulating material layer is provided on a side closer to the inner wall of each of the slots than the first insulating substrate.

Reliability of a rotating electrical machine is enhanced. A stator of a rotating electrical machine includes: a stator core being provided with teeth and slots on a cylindrical inner side surface of the stator core; a plurality of winding wires being each arranged inside each of the slots; and slot liners being each arranged respectively between an inner wall of each of the slots and each of the plurality of winding wires, each of the slot liners has a sheet-like first insulating substrate, a second insulating material layer being disposed on at least one surface of each of the slot liners, and an adhesive layer which expands between the first insulating substrate and the second insulating material layer by processing, the second insulating material layer is provided with a through-hole which communicates a side of the first insulating substrate with the inner wall of each of the slots, and each of the slot liners is disposed inside each of the slots in such a way that the second insulating material layer is provided on a side closer to the inner wall of each of the slots than the first insulating substrate.