Topological Optimization Of Butterfly Wing Bionic Cooling Water Channel For High Speed Motorized Spindle

High-speed motorized spindle directly determines the machining accuracy of high performance machine tools as a core component of high-speed machining technology.In the normal operation of high-speed motorized spindle,due to the limitation of internal heat dissipation,it is difficult to dissipate the h eat generated by the two components of the built-in motor and rolling bearing,which will affect the rotation accuracy of the motorized spindle and reduce the service life.In order to improve the heat dissipation limitation of high-power and high-speed motorized spindle,a new type of bionic cooling water channel with butterfly wing is designed based on the micro-structure of butterfly wing as a reference model.The topology optimization of the structure is carried out by taking the minimum mean temperature of the thermal boundary surface of cooling water-stator and the minimum pressure drop energy of cooling water as the objective function.The results show that the heat dissipation performance and depression-potential energy loss of the topologically optimized butterfly wing bionic cooling water channel are further improved and reduced.The specific research results are as follows:(1)Thermal characteristics analysis of high-speed motorized spindle.According to the actual working condition of high-speed motorized spindle,the heat generation of the built-in motor and rolling bearing and the heat transfer in the motorized spindle are analyzed.Heat transfer coefficients of cooling water channel,built-in motor,bearing and air of motorized spindle were calculated by heat conduction theory,and thermal loads of built-in motor and bearing were determined,which were used as thermal boundary conditions of spindle.(2)Structure design of butterfly wing bionic cooling water channel.A new bionic cooling water channel with double cladding was designed based on the microstructure of butterfly wings and the structural similarity theory.The temperature distribution of bionic cooling water channel-stator thermal boundary surface and the pressure drop of cooling water were analyzed according to the thermal boundary conditions of the main shaft.(3)Structural topology optimization of the butterfly wing bionic cooling water channel.In order to avoid the subjective bias of the bionic structure design,the mathematical model of the topology optimization of the butterfly wing bionic cooling channel was established by using the variable density method of topology optimization theory,taking the minimum mean temperature of the thermal boundary surface of the cooling water-stator and the minimum pressure drop energy of the cooling water as the objective function,and the heat dissipation characteristics of the bionic cooling water channel and the flow state of the cooling water after topology optimization were analyzed.(4)Comprehensive performance analysis of the butterfly wing bionic cooling water channel based on topology optimization.Through the finite element simulation analysis,the heat dissipation efficiency of the topologically optimized butterfly wing bionic water channel is increased by 10.1% compared with that of the unoptimized butterfly wing bionic water channel,and the pressure drop potential energy of cooling water is also increased by 44.6%.The results show that the topological optimization of the butterfly wing bionic cooling water channel improves the cooling efficiency and the pressure drop of the cooling water is further improved.The research results of this paper provide a new method and idea for the structural design of high-speed motorized spindle cooling water channel.