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.

Embodiments of the currently claimed disclosure are directed to methods for inserting an undulated coil assembly in the slots of a hollow core of a dynamoelectric machine. In some embodiments, the method can include positioning at least a first coil portion of the coil assembly around a support member, aligning a guide device with respect to end faces and the slots of the core, feeding the first coil portion from the drum support member along the guide device to insert adjacent superimposed linear portions (LI) of the coil assembly in the slots, engaging the superimposed linear portions (LI) along at least one guide surface during the feeding, and relatively moving the core with respect to the guide assembly device to position the slots for receiving the superimposed linear portions (LI).

A casting coil for a motor assembly, which is formed in a multi-layer structure, includes: a first coil formed to extend in one direction; a second coil bent to extend from an end of the first coil; a third coil bent to extend from an end of the second coil in a direction parallel to the first coil; and a fourth coil bent to extend from an end of the third coil in a direction parallel to the second coil. The first coil, the second coil, the third coil, and the fourth coil form one layer so that a hollow multi-layer structure is formed. A larger magnetic field can be formed by securing a slot filling factor of 50% or more of a stator in the same motor package.

A device and method for producing a plugged wave winding by plugging together first and second wave winding parts. A first receptacle receiving the first wave winding part includes elements for guiding first wave winding part straight wire sections. A second receptacle receives the second wave winding part and has elements for guiding second wave winding part straight wire sections. A device for bending portions of at least one of the wave winding parts is configured to displace one or more of the winding heads directed towards the other wave winding part to plug the wave winding parts together. A relative displacement device pushes and plugs the first and second wave winding parts into one another. The first and/or second guide elements are movable between a position for guiding the straight wire sections and a position for releasing the path of winding heads while plugging into one another.

A coil insertion device includes: a pair of delivery jigs respectively formed with slits into which a pair of side portions of a coil that are parallel with each other can be inserted; and a side portion inserting mechanism configured to push out the side portions inserted into the slits from the slits to insert the side portions into slots of a stator core, the slots facing the slits, the side portion inserting mechanism has: pushing blocks inserted into the slits; and a pushing block moving mechanism configured to move the pushing blocks in a depth direction of the slits.

A stator may include a stator core and a coil. The stator core may include: a first portion; a second portion; and a first intermediate portion interposed between the first portion and the second portion in the axial direction. A first segment conductor and a second segment conductor may overly each other in a circumferential direction of the stator core hr a slot within an area of the first intermediate portion. A first side surface may include a first protrusion provided by the first intermediate portion protruding with respect to the first portion and the second portion. The first segment conductor and the second segment conductor may be held between the first protrusion and a second side surface such that the first, segment conductor and the second segment conductor are connected with each other.

A method to produce rotors or stators of electric machines having radial grooves into which webs of flat windings having parallel webs and winding heads connecting said webs being pulled, wherein a winding is produced on a rotating, strip-shaped flat former shorter than the winding such that windings are pulled off the former and transferred into a linear transfer device, which transports the windings to a removal position at which the windings are transferred into radial grooves of a rotor or of the transfer tool for transfer into radial grooves of a stator, wherein the former, the transfer device, and the rotor or the transfer tool being jointly rotated about an axis of rotation of the former when rotated to form windings.

A method and an apparatus for compact insertion of thick wire multiphase pseudo helical wave winding into a ferromagnetic core of an electrical machine, achieving high fill factor of the core slots, resulting in better heat transfer between the winding and the core, low mass and volume, and overall higher efficiency of electrical machine. An apparatus being fully programmable and physically adaptable to wide range of electric machine dimensions, where process is automated, simple, accurate, reliable and quick, while being suitable for mass production.

A liquid-cooled rotating electric machine may include an inner stator and outer rotor configured to rotate about the stator. A hub may be disposed within the inner stator and a heat exchanger may be disposed in the hub. The heat exchanger may be configured to enable the flow a liquid through it to dissipate heat from the stator.

The invention relates to a method for producing a coil winding (70) for insertion into radially open slots (82) in a rotor or stator (80) of an electrical machine, wherein the coil winding (70) has a wire pack (60) consisting of a number of wires (32), wherein the wires (32) of the wire pack (60) run parallel to one another and are connected to one another in pairs at one end of the wire pack (60), and wherein the coil winding (70) is formed by a flat winding former which can be rotated about an axis of rotation (26). According to the method, the wire pack (60) is fixed on a winding former (26) and winding heads (42) are produced by displacing fixations of the wire pack (60). The winding shaft (26) can be rotated so that, after carrying out the method, a coil winding (70) is present in the form of a wave winding having wires (32) of the wire pack (60) preconnected in pairs at one end. Such a method allows a particularly space-saving coil winding (70) to be produced, which has a particularly high mechanical stability and requires the least amount of installation space in a rotor or stator (80).