高速电主轴谐波转矩产生机理及对主轴振动的影响
Formation Mechanism of Harmonic Torque and Effect on Vibration of High-speed Motorized Spindle

高速电主轴的动态特性受轴承和高频谐波电磁力矩的共同影响，为了将两者的特征频率分离以便采取相应的控制方法，从气隙磁场的波形出发，利用傅里叶变换求出各次谐波磁动势，进而导出稳态谐波电磁转矩和脉动谐波电磁转矩的计算公式，得出稳态谐波转矩只影响主轴的转矩输出能力，脉动谐波转矩会导致系统产生周期性振动，且脉动频率为6的整数倍基波频率的结论。据此不仅可轻易分辨出由轴承运动和谐波电磁转矩所产生的振动频率及各自对系统动态性能的影响程度，而且可以根据系统的动态需求，采取有选择性的控制方法。最后以170MD15Y20型高速电主轴为例，对此结论进行了验证。
The dynamic performance of high speed motorized spindle was governed by both bearing and high frequency harmonic torque. Aiming at extracting their characteristic frequencies for proper control, the calculation formulae for steady and ripple harmonic electromagnetic torque were derived from different electromagnetic force on the basis of Fourier Transform of the waveform of the air gap magnetic field. The conclusion was that the steady harmonic torque only affected the output torque of the spindle when the ripple harmonic torque generated periodical vibration with frequency of integer multiple of six times fundamental frequency. Based on the above-mentioned results, it is easy to extinguish the vibration frequency from the bearing and that from the harmonic torque, as well as their effect on the dynamic performance of the spindle system. In addition, the different control methods can be applied as the system dynamic requirement. Finally, the conclusion has been validated via an experiment on a 170MD15Y20 high speed motorized spindle