| The spindle system is an important part of the high-speed CNC machine, whichhas a direct impact on the accuracy and reliability of the CNC machine. The spindlesystem contains the spindle, the bearings, the transmission installed in the spindle, thefasteners and other components.As we all know, the research about properties of spindle system is highlyconcerned by scholars, and they mainly focus on how to establish the dynamic model ofrotor-bearing system, how to calculate of the dynamic stiffness of rolling bearing, andanalyze the critical rotation speed and main mode. Main contents of the thesis are asfollows:(1) This article investigates the model of single angular contact ball bearings andthe methods to calculate it’s dynamic stiffness. What’s more, the article investigatesthe model of a double row angular contact ball bearing (being in a back-to-backarrangement, face-to-face, tandem) via a three dimensional stiffness matrix.(2) According to summarize the previous identification methods, the thesispresents the identification approach of dynamic contact parameters forspindle-bearing joint base on frequency response function. The joint region iscomplex, which include the joint surface of bearing rollers-bearing inner ring,bearing rollers-bearing outer ring, inner ring-shaft and outer ring-housing. Itsstiffness plays an important role in dynamic characteristics of spindle assembly ofmachine tool.(3) Using the method, we can get the joint parameters of the certainspindle-bearing system experimental setup. Combine214unit is used to verify thevalidity of the method. Finally, The influence of the quality of joint region force onthe parameters of spindle-bearing joint is also introduced.(4) Finally, an experimental platform for testing dynamic characteristics ofspindle–bearing system is designed. The experiment verifies the validity of theidentification method. So, it can provide a theoretical basis for the prediction ofdynamic properties and spindle system structure optimization. |
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