Embedded PMSM for turning-type electric main shaft

Abstract

The invention discloses an embedded PMSM for a turning-type electric main shaft. The embedded PMSM comprises a rotation shaft, a front bearing, a front end cover, a rear bearing, a rear end cover, a photoelectric encoder, a rotor and a stator. The rotor is of a sectional type inclined pole structure and comprises multiple rotor iron cores which are axially distributed at intervals, a multicolor magnetic pole circumferentially arranged along the rotor iron cores, and each stage of the magnetic pole is arranged in a V-shaped structure and is embedded in a corresponding permanent magnet groove; multiple magnet through holes are correspondingly arranged between each stage of the magnetic pole and the outer circumference of the rotor iron cores; and the stator comprises a cooling pipeline groove disposed in the outer wall of the stator, a stator iron core with multiple stator teeth, and a stator groove formed between adjacent stator teeth. The embedded PMSM provided by the invention has the advantages of high torque density, high power density, rapid response, small air gap magnetic field harmonic waves, high counterelectromotive force sine degree, small torque ripples and wide speed ratio, thereby being suitable for application in a turning-type electric main shaft system for a high-grade numerical control machine tool.

Description

technical field [0001] The invention relates to the technical field of motors, in particular to a permanent magnet synchronous motor used for turning electric spindles. Background technique [0002] Turning electric spindle motors are mainly used in turning CNC machine tools. Turning is a cutting process in which the workpiece is rotated as the main motion and the turning tool is used as the feed motion. Modern turning processing requires high processing precision, which requires high control precision of electric spindle motor, small motor vibration, low torque ripple, and wide speed regulation range. [0003] The existing turning electric spindle motors are mainly divided into two types, namely asynchronous spindle motors and permanent magnet electric spindle motors. [0004] In the prior art, the rotor of the asynchronous spindle motor will generate loss, the efficiency of the motor is low, the rotor generates serious heat, and the life of the bearing is shortened, whic...

AI Technical Summary

Problems solved by technology

[0004] In the existing technology, the rotor of the asynchronous spindle motor will generate loss, the efficiency of the motor is low, the rotor will heat up seriously, and the life of the bearing will be shortened, which will eventually shorten the life of the motor

The power factor of the asynchronous spindle motor is low, the drive capacity is large, and the cost is very high

The torque density and power density of the asynchronous spindle are low, and the volume and weight of the motor are large, which is not conducive to quick start and accurate stop, and the motor responds slowly

Asynchronous spindle motors have large torque fluctuations, large motor speed fluctuations, and low operating stability

The control of asynchronous spindle motor is complicated, and it is not easy to achieve high-precision control

[0005] The permanent magnet synchronous motor used in the electric spindle in the prior art is generally designed as a "one" type permanent magnet structure. This type of motor has a small salient pole ratio, a small reluctance torque, a low torque density, and a large motor volume. The moment of inertia is large, and the response speed is slow during operation. It is not suitable for turning electric spindles that require rapid start-stop and rapid change in speed; and the salient pole ratio of this type of motor is small, and the motor speed ratio is small, so it is difficult to achieve high-speed operation.

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