One Abstraction Method for Displacement Response in the Sweep-Frequency Testing of Rotating Spindle

Abstract

ion Method for Displacement Response in the Sweep-Frequency Testing of Rotating Spindle Guo Yuzhu1,a*, Chen Tianning1,b, Wang Xiaopeng1,c and Xu Yanfei11 State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, 710049 Xi’an, China aguoyuzhu@126.com, btnchen@mail.xjtu.edu.cn, cxpwang@mail.xjtu.edu.cn Keywords: Rotating spindle; Sweep-frequency measurement; Error separation. Abstract. In the measurement of motorized spindle dynamic performance, the non-contact sweep-frequency excitation is adopted to obtain the displacement response of spindle rotor under high speed rotating. Due to the shape error at measurement section, eccentric error and random vibration, the illusory signals is introduced to the practical measured signal, which makes it difficult to analyze the displacement response. To effectively separate the error, a new method combining template signal and slip filtering is presented. After analyzing the characteristics of displacement response and illusory signals in time-frequency domain, the template signal constructed by the non-superposing portions between response and error is employed to eliminate the error in superposing portions. And a band-pass filter which can slip in time-frequency domain is employed to eliminate the other error. A spindle of CNC milling machine is tested at 7000 r/min, and the analysis result shows that the displacement response can be abstracted successfully from the original signal measured by rotating spindle.