| Motorized spindles are one of the most important function components in numerical control turning machines. Compared to the asynchronous motorized spindles, permanent magnet synchronous motorized spindles possess the advantage of no fever on principle, high efficiency, large power density and fast dynamic response, and are widely used in rough and finish turning machining axial parts. To meet the demand of low-speed rough turning and high-speed fine processing, permanent magnet synchronous motorized spindles have to combine low speed high torque characteristics and the weak magnetic speed performance. This demand makes the permanent magnet synchronous motorized spindles motor design hade its own characteristics, such as hoping the rotor’s hole as large as possible, and the rotor core length to be short as much as possible to ensure the shaft’s rigidity, but the rotary inertia is large. At present, the research on permanent magnet synchronous turning spindle is not sufficient, permanent magnet synchronous turning spindle electromagnetic design and performance optimization is urgently needed to study.The MATLAB software is used to compile analysis program for permanent magnet synchronous turning spindle steady-state electromagnetic performance bas ed on the equivalent magnetic circuit method in this paper. Then, a motor which rated power is 20.9 KW, rated speed is 1000 RPM and the pole number is 6 is designed by this program and is optimized from the air gap length, stator winding and rotor magnetic circuit structure and the geometric parameters magnet.To improve the stability of permanent magnet synchronous motorized spindles turning, the effect laws of stator slot width, chute, arc coefficient of the stator and rotor magnetic circuit structure, th e length of the permanent magnet magnetization direction and magnetic bridge insulation thickness to cogging torque are analyzed, the cogging torque of electromagnetic mechanism is revealed, the concrete means to suppress cogging torque are putted forward by optimizing the structure of rotor magnetic circuit and electromagnetic parameters.To optimize the dynamic characteristics of motorized spindles, and improve the machining efficiency, machining precision and machining quality, the motorized spindles system dynamics model are built based on the sine wave inverter power supply. Then the characteristics of this model are analyzed, highly efficient numerical algorithm is putted forward for this model, and realize the simulation of dynamic process based on the MATLAB through independent programming. Use the model to study the motor starting characteristics, speed characteristics and load characteristic. The results show that the S curve acceleration mode is superior to parabolic acceleration mode, and the motor speed ripple, torque ripple are smaller in S acceleration mode; In the same load conditions, the closer to motor’s rated speed, the smaller to motor ’s speed ripple and torque rippleParticipate to build the permanent magnet synchronous turning motorized spindles test bench, and test motorized spindles no-load current under the different speed. Research shows that: the error between the theoretical calculation value and the measured values is less than 15%. Thus it verifies the correct of established system dynamics model in this paper.This paper provides a certain reference value to design and optimize motorized spindles and weak cogging torque. |
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