Core slots are provided in an outer circumferential side of a rotor core and extend in an axial direction of a rotor shaft. A rotor conductor is a rod-shaped conductor inserted in each of the slots, and after insertion of the rotor conductor in each slot, a flared portion is formed flaring in a slot-transverse direction, and a propping-apart force occurring between the flared portion and both side wall surfaces of the slot fixes the rotor conductor to the slot. In an inner wall of an outer circumferential side of each slot abutting the flared portion, an unevenness is arranged along the axial direction of the rotor shaft.

A conductor bar of a cage rotor of an asynchronous machine has a longitudinal extension and includes first and second sections in the longitudinal extension. The first section has a hardness which is lower than a hardness of the second section and is realized through soft annealing, brief inductive heating or heating by a flame so as to enable a compression of the first section of the conductor bar by way of axial pressure after axially joining the conductor bar in a slot of a magnetically conductive body of the cage rotor, with the first section abutting an inner wall of the slot of magnetically conductive body of the cage rotor.

The present disclosure in some embodiment provides a hybrid induction motor including dual stators. According to at least one embodiment, the present disclosure provides a hybrid induction motor including a hollow rotor including a single conductor bar which is annularly disposed and spaced apart from a rotation axis by a predetermined distance, an outer stator having an outer stator winding disposed in parallel with an outer circumferential surface of the hollow rotor, and an inner stator having an inner stator winding disposed in parallel with an inner circumferential surface of the hollow rotor.

An electric machine includes a stator and a rotor. The rotor includes stacked laminations forming a rotor core. The rotor rotates relative to the stator about a central axis. The rotor core has an outer diameter. Each lamination includes a plurality of magnet slots. Each magnet slot includes a ferrite permanent magnet located therein, adjacent pairs of the ferrite permanent magnets defining a number of poles. Each of the laminations includes a plurality of non-circular rotor bar apertures spaced about the central axis of the rotor and disposed adjacent to and radially inward of the rotor outer diameter. A non-cylindrical rotor bar is disposed in each respective of the plurality of rotor bar apertures. The rotor bars are formed of a conductive material, wherein at least some of the plurality of rotor bars collectively form a rotor bar cage.

An electric machine includes a stator and a rotor. The rotor includes stacked laminations forming a rotor core. The rotor rotates relative to the stator about a central axis. The rotor core has an outer diameter. Each lamination includes a plurality of magnet slots. Each magnet slot includes a ferrite permanent magnet located therein, adjacent pairs of the ferrite permanent magnets defining a number of poles. Each of the laminations includes a plurality of non-circular rotor bar apertures spaced about the central axis of the rotor and disposed adjacent to and radially inward of the rotor outer diameter. A non-cylindrical rotor bar is disposed in each respective of the plurality of rotor bar apertures. The rotor bars are formed of a conductive material, wherein at least some of the plurality of rotor bars collectively form a rotor bar cage.

A dynamoelectric rotary machine includes a stator, which has a winding system arranged in grooves disposed between teeth of a magnetically conductive body and a winding head on the end faces of the stator in each case. A rotor with a cage ring is arranged rotatably about an axis and during operation of the dynamoelectric rotary machine is in electromagnetic interaction in a motor-driven or generator-driven manner with the winding system of the stator arranged in the grooves by way of an air gap. Comb-type elements are disposed on the end faces of the stator. The comb-type elements assume an extensive intermediate space between the winding system projecting from the end faces of the stator, so that tonal noises which are produced during operation of such an electric machine are at least reduced.

A cage rotor of an asynchronous machine includes a magnetically conductive body having substantially axially running slots with conductors connected to end faces of the magnetically conductive body in an electrically conductive manner by short circuit rings. The short circuit rings have an outer side, an inner side, a front side, and a rear side. A supporting element made of a high-strength material is located at least radially within the short circuit rings, i.e. on the inner face, with the supporting element being connected to the short-circuit ring, at least in one section, with a material fit.

In induction motors, efficiency is improved and a maximum torque is increased. For a magnetic flux density of the stator pole for each phase of an induction motor, a circumferential magnetic flux density distribution is controlled to any distribution state, from a trapezoidal wave-like distribution close to a square wave to a sinusoidal distribution. In particular, motor efficiency in a range of low to medium rotations is improved. The motor structure is designed to reduce the leakage inductance of the rotor windings, and the motor and control thereof are optimized for each other. This increases the maximum torque of the motor more effectively. In addition, the high efficiency of the motor makes it possible to reduce the size of the drive circuit.

A rotor for a rotary electric machine, including: a stack of magnetic laminations each having openings, the superposition of these openings within the stack forming slots, at least some of the openings having, on at least part of their periphery, friction reliefs, electrically conducting bars made of a first material, received in at least part of the slots and coming to bear via at least one principal face against said reliefs.

Methods and systems for cooling an electric motor are provided. An electric motor cooling system, in one example, includes a stator at least partially surrounding a rotor and an inner passage extending axially through the rotor and including an inlet and an outlet. The cooling system further includes an outer passage including an inlet in fluidic communication with the outlet of the inner passage and an outlet in fluidic communication with an inlet of the inner passage and a phase change material in the inner passage and the outer passage.