High-speed spindle static and dynamic performance analysis and experimental detection

　　Title: High-speed spindle static and dynamic performance analysis and experimental detection
　　Author: Kang Huimin
　　Degree-granting units: Chongqing University
　　Keywords: high-speed spindle;; dynamic analysis;; performance test;; harmonic interference;; thermal model
　　Abstract:
　　High-speed spindle technology as a modern high-speed processing of the core components, a wide range of CNC machining centers and high-performance machine tool spindle, with a multivariable, nonlinear and strong coupling features, its internal electromagnetic Rare earth magnets conversion and spindle exists between the dynamic output performance is very complex interdependence. Therefore, the study how to interpret and control this interdependence has been a high-speed electrical spindle research priorities. However, due to high-speed spindle operation, speed is very high, difficult to make dynamic load test, and because the monopoly of foreign technology, is not yet fully grasp the internal electromagnetic coupling between the spindle and spindle torque output performance between the role of dynamic law, the basis of information on this aspect is also very lack of a serious impact on high-speed spindle technology, in-depth research and engineering applications. For these reasons, the subject from the electromagnetic properties of high-speed spindle, this paper proposes a more complete high-speed spindle dynamic performance testing methods, and through the experimental data and theoretical analysis of the comparison, made the following conclusions:
　　① high-speed spindle dynamic performance testing, including electrical and mechanical parameters of the test parameters of the test. Dynamometer combined with the use of three-phase high-frequency electrical parameters device and other auxiliary equipment, can get high-speed spindle input voltage, current, power factor and output torque, speed and efficiency of mechanical and electrical parameters; through one-way loading and also test the strength and direction of the http://www.chinamagnets.biz/ force displacement can be obtained on the dynamics of high-speed electric spindle rigidity. This high-speed spindle torque and dynamic stiffness of the test are given two kinds of mechanical and electromagnetic testing methods, and pointed out that the use of torque dynamometer test, the load on the mechanical contact with the dynamometer to be addressed spindle and the coupling of the measured dynamic balance problems; but with non-contact eddy current dynamometer, you need to ensure the stability of the magnetic field and load dynamometer side of the electromagnetic heat and timely distribution. When high-speed spindle dynamic stiffness test, the use of a mechanical contact load, to be an effective solution to the loading caused by exposure to wear debris and friction failures and heat dissipation; and electromagnetic loading mode, In addition to the stability of the magnetic field, but also need to consider the interference of the magnetic field of the displacement sensor to prevent data collection failed.
　　② As the high-speed spindle output mechanical energy depends on high-speed spindle air-gap magnetic field of electromechanical energy conversion, so the magnetic field control, high-speed spindle dynamics focus of the study, involving high-speed spindle mathematical model and control selection. Based on the established high-speed spindle features two models: the effective electromagnetic parameters of spindle speed based on the value of the steady-state mathematical model and process-control-based dynamic model. The former to control the air-gap magnetic field for the purpose, when the load changes, by controlling the stator currents to approximate a constant excitation current control, in order to meet the rotor current and load linear relationship. The model fit U / f control mode, the control method is simple, but the control accuracy is not high. The latter were to control the rotor flux and the stator flux for the purpose of their corresponding vector control and direct torque control. This article focuses on vector control for the analysis and testing, describes the speed sensorless vector control principles and under the control of the dynamic performance of high-speed spindle, discusses the changes when the spindle load, the control stability and resistance to outside control of flux interference when the strategy used, and experimentally verified.
　　③ When the spindle of the operating frequency decreases, U / f control input voltage rating should be based on high-speed spindle state stator winding back-EMF voltage of the size of compensation to ensure stability of the magnetic flux at low frequencies; and vector control of excitation current and torque current control accuracy depends on high-speed spindle dynamic mathematical model of coupled voltage decoupling effect. Therefore, this article discusses in detail in the U / f control, how effective low-voltage compensation method, based on experimental data for a specific argument; while the vector under the control of cross-coupled voltage decoupling approach and results were compared the use of experimental verification of high-speed spindle under the control of the vector and anti-disturbance ability to follow dynamic speed accuracy.
　　④ application of the principle of superposition, discussed the harmonic magnetic field generated by the harmonic magnetomotive force to magnetic flux up through the stack effect in the spindle axis of the electromagnetic torque and output speed the way that high-speed spindle static and dynamic performance have serious implications for . And pointed out that the harmonic effects to varying degrees: the lower order of harmonics, the greater the impact; high-speed spindle operation frequency the lower the number the greater the need to suppress harmonics. Therefore, the actual load speed spindle speed is not too low, because the harmonic interference limits the speed of the actual spindle speed range.
　　⑤ applied electric machinery and kinematics, electromagnetic analysis of high-speed spindle thermal and friction causes heat and heat transfer theory based on identified high-speed spindle various parts of the heat transfer coefficient and thermal resistance, thereby establishing a high-speed spindle The overall dynamic thermal model. The results show that the higher the speed, the greater the temperature rise of the spindle; and the amount of air pressure and oil temperature rise of the spindle there is an optimum range of adaptation.
　　In summary, this paper mainly in the high-speed spindle dynamic performance testing methods, steady-state and dynamic mathematical model, control methods and the relationship between mathematical models, cross-coupled voltage decoupling effects and dynamic performance of the spindle Ying Xiang, the overall dynamic thermal model of the spindle and spindle temperature rise to establish the impact of factors has made some theoretical and experimental test results to reveal the structural parameters of high-speed spindle design and electromagnetic variables on the dynamic performance of the spindle mechanism and laws carried out a more systematic analysis and experimental research, to obtain some useful conclusions and test data for high-speed spindle laid the foundation for follow-up study, which has a certain academic significance and social and economic benefits.
　　Degree Year: 2010