Polyphase induction motor with large capacity and high torque density

Abstract

The invention relates to a polyphase induction motor with large capacity and high torque density. The polyphase induction motor comprises a stator, a rotor and a machine foundation, wherein the stator and the rotor are sealed inside the machine foundation. The polyphase induction motor is characterized in that: the phase number of stator windings is a multiple of 5; no electric connection exists between each phase of winding; each phase of the winding has an independent lead; 5 phases are taken as one basic unit inside which neutral points of 5 phases of the windings are connected together; the stator windings have a full-pitch collective form; a stator core adopts an axial segmental structure. The polyphase induction motor realizes great improvement on the torque density through the technology such as polyphase design, non-sine power supply, evaporative cooling technology, rotary sealing technology, a constant resistance agitation friction welding process, and the like. The efficiency of the induction motor is also improved while the rotor air gap shearing force is simultaneously increased.

Description

technical field [0001] The invention belongs to the field of structural design of induction motors, in particular to a multi-phase induction motor with large capacity and high torque density. Background technique [0002] The AC drive system has a series of advantages such as fast speed regulation, flexible layout, and high efficiency. It has been widely used in ship propulsion and other fields. However, with the continuous improvement of space constraints and power requirements in these special applications, traditional motors have It becomes the bottleneck restricting the further application of the AC drive system, therefore, it is necessary to invent a propulsion motor with high torque density. [0003] Induction motor is the most widely used type of propulsion motor due to its simple structure and reliable operation. Compared with the synchronous motor, the induction motor rotor does not have an excitation winding, and the AC excitation needs to be provided by the stato...

AI Technical Summary

Problems solved by technology

[0006] With the increase of the torque density of the induction motor, on the one hand, the electromagnetic size is greatly reduced, even if the air gap similar to the synchronous motor is adopted, the power factor of the motor will not be significantly affected; on the other hand, the loss density of the motor is also increasing , the traditional air cooling method has been difficult to meet the requirements of heat dissipation and low noise, so a new efficient cooling method is required

[0007] In terms of processing technology, traditional induction motor rotor end plates and guide bars usually use intermediate frequency welding and other welding methods. These welding methods require the use of solder with a resistivity much larger than the rotor guide bar itself, which inevitably increases the contact resistance, which will not only increase Loss, more importantly, there is also the possibility of local heat causing expansion and fracture of the end plate, so it is necessary to study a new processing technology

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