An electric motor for high speed operation use and a rotor which enables use of common parts with electric motors for low speed operation use and which thereby enables reduction of the manufacturing costs. The rotor is provided with a shaft, a rotor core which is fastened to the shaft at the outside in the radial direction and has a first end face at one end in the axial direction and a second end face at the other end in the axial direction, a plurality of conductors which are arranged at the rotor core, and a pair of end rings which are respectively arranged adjoining the first end face and the second end face and which short-circuit the plurality of conductors with each other. The shaft has an outer circumference, while the end rings have outer circumferences which are arranged concentrically with respect to the outer circumference of the shaft.

The invention relates to an electric asynchronous machine (1), in particular an induction machine, comprising:—a cylindrical stator (2) with stator teeth (22) on a stator yoke (21), wherein a ratio between a yoke height (hy1) of the stator yoke (21) in the radial direction and a groove height (hn1) of the stator grooves (23) in the radial direction ranges from 1.75 to 2.5;—a cylindrical rotor (4) with poles (42) on a rotor yoke which are defined by short-circuit windings in a rotor body (41), wherein a ratio between the yoke height of the rotor body (41) in the radial direction and the groove height of the rotor grooves in the radial direction ranges from 2 to 2.75.

A downhole tubing rotator that has a housing configured into a production tubing string in a well in a reservoir, the housing being generally cylindrical with a hollow center and containing a two pole, three phase induction squirrel cage motor operatively connected to a tubing rotator configured to clamp onto a production tubing joint and rotate one or more production tubing joints (but not an entire production tubing string) when the motor is activated. An armor-protected insulated power and control cable connects the motor to a control box positioned at a surface of a reservoir and various sensors provide feedback for the unit. Methods of using this tool are also provided.

A rotor cooling structure includes a turbine blower structure provided on first and second sides of a rotor for an induction motor; a refrigerant passage including a plurality of refrigerant passage inlet openings provided on a bottom surface of the turbine blower structure and a plurality of refrigerant passage outlet openings provided at an axial center of the rotor, which fluidically communicates with the refrigerant passage inlet openings and the refrigerant passage outlet openings and is provided along conductor bars of the rotor; and a plurality of micro groove patterns that hold the refrigerant passage outlet openings and are provided on both axial sides of the rotor on an external periphery of the rotor.

A rotor for an induction motor is provide. The rotor includes a core built with stacks of a plurality of steel sheets and includes a plurality of rotor slots that are radially arranged. The rotor further includes a plurality of conductor bars contained in the plurality of rotor slots, respectively, and end-rings attached to both longitudinal ends of each of the plurality of conductor bars. The rotor further includes at least one slit formed inward from an outer periphery of the rotor along a perimeter of the rotor, wherein the slit has a depth deep enough to form a groove portion in at least some region of each of the plurality of conductor bars.

A squirrel-cage rotor manufacturing method capable of suppressing, at the time of performing die-casting, formation of gaps between closing portions and a rotor core at radially outer parts of rotor slots, or generation of a thermal stress in the rotor core as a result of expansion of the closing portions. The squirrel-cage rotor manufacturing method includes: arranging, through die-casting, conductors into rotor slots that are formed along a radially outer part of a rotor core; and performing the die-casting under a state in which radially outer parts of the rotor slots are closed with closing portions made of the same material as a material of the rotor core.

The invention relates to an electrical machine (1, 51), in particular an asynchronous machine, comprising a stator (2), a rotor (4) which is rotatably mounted about a rotation axis (3) and magnetically interacts with the stator (2) during operation of the electrical machine (1, 51), a shaft (5) on which the rotor (4) is fixed and which has an axial hole (6), and an inflow element (7, 47) which extends into the axial hole (6) such that a coolant (15), in particular a cooling liquid (15), can flow into the axial hole (6) from the inflow element (7, 47). The invention also relates to a cooling system (50) comprising an electrical machine (1, 51) and a coolant circuit (55) for transporting the coolant (15), in particular the cooling liquid (15), through the axial hole (6), and to a vehicle (61) comprising a cooling system (50).

A rotor assembly is provided in which a solid rotor ring is formed at either end of a stack of laminated discs, the solid rotor rings yielding improved electrical and mechanical characteristics in a low weight assembly. The solid rotor rings are fabricated by brazing slugs between the end portions of the rotor bars, the braze joints contacting a large percentage (at least 90%) of the rotor bar end portions.

According to one embodiment, an induction motor includes a stator and a rotor. The stator has a stator coil disposed at a stator core having a plurality of stator slots. The rotor has a rotor core rotatably provided with respect to the stator. The rotor core includes a plurality of rotor teeth and a rotor slot formed between the plurality of rotor teeth and having a rotor conductor disposed therein. The rotor teeth include a teeth main body and a flange. The teeth main body extends in a radial direction of the rotor core. The flange extends in a rotating direction of the rotor core from a distal end of the teeth main body. Then, a recessed surface is formed on at least part of an outer circumferential surface of a radial outer side in the flange.

A rotor fabrication method is provided, along with the resultant rotor assembly. The rotor uses pre-fabricated conductive rotor bars in which the ends have been shaped and sized to fit within corresponding end cap receptacles. After assembly, the structure is compressed, thereby achieving mechanical and electrical coupling between the conductive rotor bars and the end caps. Locking members disposed at either end of the assembly maintain the desired level of axial compressive force on the structure.