Research On The Solid-thermal Coupling Characteristics Of High-speed Motorized Spindles

With the rapid development of modern manufacturing,people have higher and higher requirements for the machining accuracy of CNC machine tools.As the core component of CNC machine tools,electric spindles have a solid-thermal coupling characteristic that affects the accuracy of machine tools.Based on the theories of heat transfer,thermoelasticity,and friction mechanics,this paper analyzes the solid-heat coupling mechanism of the electric spindle unit,and proposes an improvement plan for the electric spindle cooling system based on the solid-heat coupling characteristics.The results are as follows:Based on the Jones bearing model,a load-displacement model for angular contact ball bearings that comprehensively considers thermal effects and centrifugal force effects was established,and the solid-thermal coupling mechanism of the bearing was analyzed.First,the calculation of contact angle,contact load and thermal displacement was carried out,and on this basis,the mutual influence relationship among the speed,preload,bearing thermal displacement and bearing parameters was analyzed.Based on the theory of heat transfer and friction mechanics,a solid-thermal coupling calculation model of the electric spindle based on the bearing and the motor was established.On this basis,the transient temperature field of the electric spindle and the thermal deformation caused by it were obtained,and the solid-thermal coupling mechanism of the electric spindle was obtained by analyzing the coupling influence relationship between the temperature change of the electric spindle and the structural deformation.Based on ANSYS simulation software,a solid-thermal coupling simulation analysis of the electric spindle was carried out.The solid-thermal coupling simulation results of the electric spindle were compared with the theoretical analysis results,and the accuracy of the solid-thermal coupling calculation model of the electric spindle is verified.Based on the solid-heat coupling characteristics of the electric spindle,the cooling structure of the electric spindle unit was analyzed,and an improvement plan for the cooling channel was proposed.The deformation of the internal structure of the electric spindle is improved,and the solid-heat coupling characteristics of the electric spindle are optimized.