转子静偏心状态下机床电主轴电磁力有限元分析

电磁振动是电磁直驱型机床电主轴不可回避的振动来源,为了抑制电磁振动需要探讨其电磁力的频谱特征。推导了三相异步电主轴的电磁力波计算公式,重点分析了转子偏心状态下的电磁力波特点。基于Ansoft电磁场计算软件,建立了某国产电主轴的电磁场有限元分析模型,获得了电主轴的运行特性曲线。研究了转子在不偏心和偏心状态下的电磁力频谱变化规律,结果表明,静偏心会使电磁力力波成分更为丰富; 偏心的增加不会影响电磁力的阶次和频率分布,但与不平衡磁拉力的幅值和低阶力波幅值成正相关关系,将加剧电主轴的振动。

Finite Element Analysis of Electromagnetic Force in Machine Electric Spindle With Rotor Eccentricity

Electromagnetic vibration is an inevitable vibration source for an electric spindle; therefore, it is necessary to study the frequency spectrum of electromagnetic force in order to suppress electromagnetic vibration. The calculation formula about electromagnetic force of three-phase asynchronous electric spindle was derived and the characteristics of electromagnetic force with rotor eccentricity was analyzed. An electromagnetic field finite element analysis model was built for a domestically produced electric spindle's based on Ansoft software, and a main performance curve of electric spindle was obtained. The variation of electromagnetic force's frequency spectrum with eccentricity and without eccentricity was researched and the results show that the electric spindle with eccentricity produces additional components of electromagnetic force. Increased eccentricity does not influence the order or frequency distribution of the electromagnetic forcebut the increase of eccentricity positively relates to the amplitude of electromagnetic force and low-order force. For this reason, the vibration of electric spindle will be exacerbated.