数控铣床电主轴故障诊断及仿真分析

针对数控铣床高速电主轴故障分析和诊断的需要,避免因主轴结构设计不合理而产生的故障,进行了基于噪声和小波变换监测原理的电主轴故障诊断仿真分析和动态特性分析方法研究。结果表明,小波变换能有效地把机床噪声信号变换到时频域,得到电主轴工作状态下的时间和频率信息,从而区分出主轴在正常工作下的噪音和故障状态下的工作噪音,诊断出机床电主轴的故障信息。通过模态分析得到了电主轴的固有频率、振型和临界转速,有效避开了电主轴固有频率,并为高速电主轴结构设计和轴承最佳预紧力的确定提供了分析依据。

Fault Diagnosis and Simulation Analysis of Motorized Spindle of CNC Milling Machine

In view of the needs of fault analysis and diagnosis of high speed motorized spindle in CNC milling machine,the fault diagnosis is avoided that it is because of the unreasonable design of the spindle structure.The simulation analysis and dynamic characteristic analysis method of the spindle fault diagnosis based on the principle of noise and wavelet transform monitoring are carried out.The results show that the wavelet transform can effectively transform the noise signal of the body to the time frequency domain,and get the time and frequency information of the working state of the spindle,thus the noise of the spindle under normal work and the working noise in the fault state are separated,and the fault information of the spindle of the machine tool is diagnosed.The natural frequency ,vibration mode and critical speed of the motorized spindle are obtained by modal analysis,which effectively avoids motorized spindle inherent frequency,and provides analysis basisfor design of high-speed motorized spindle strueture and the determination of the optimum pretension force of the bearing.