Analysis And Experimental Research For High Speed Hybrid Bearing Motorized-spindle System Thermal Properties

The dynamic and static pressure motorized-spindle system of the liquid uses interior permanent magnet machine as power source,and the dynamic and static pressure bearing as the supporting unit,has many advantages and been well applied.The thermal characteristics of the motorized-spindle system play an important role in ensuring the machining accuracy and working life of the machine.The front and rear bearings and the motor are the main parts of influence the high-speed dynamic and static motorized-spindle system.By analyzing the structure and working principle of machine tools,applying electromagnetic theory,tribology theory and heat transfer theory to analysis the heat source and heat dissipation of machine,building three-dimensional model of motorized-spindle system,combine with theoretical calculation,simulation analysis and experimental verification are good methods to study the thermal characteristics of the liquid motorized-spindle system.To explore the method to improve the law of thermal performance effectively,this thesis will mainly cover the following studies:(1)According to the structure and working principle of the dynamic and static pressure motorized-spindle system,the technical principle of the key parts of the electric spindle system is analyzed,Including cooling system,liquid hydrostatic bearing,high speed motor drive technology,etc.(2)According to the working principle of high speed motorized-spindle and the heat and heat transfer characteristics of each part of the system,the power loss of the spindle and the friction heat generation of the bearing are calculated,and the heat production conditions of hydrostatic bearing,stator and rotor under different working conditions are calculated.(3)CFD simulation software is introduced to solve the problem of fluid thermal analysis,based on 30HD high.speed motorized spindle experimental platform of Hunan University,the theoretical calculation and simulation analysis of the oil film temperature and power consumption of the hybrid bearings has been done,the influence of different bearing parameters on the oil film temperature rise and power consumption of the bearing is obtained.(4)Based on 30HD high speed motorized-spindle experimental platform of Hunan University,the boundary conditions of temperature field and 3D model are determined.Then applying of ANSYS Workbench software to thermal analysis of high-speed motorized-spindle system,and the thermal structure coupling analysis.The experiments were carried out on the experimental platform to verify the thermal characteristics of the high speed motorized spindle system under different operating parameters.(5)Study on the method to effectively improve the law of thermal performance,a new scheme of high speed motorized-spindle system based on ceramic sleeve is proposed and designed,the thermal analysis and thermal structure coupling analysis of ceramic sleeve spindle system with different thickness and material were carried out by using ANSYS Workbench software,it provides reference for the application and advantages of ceramic sleeve.