Study On Thermal Characteristics Of New Laminated Cooling Water Jacket For High-speed Motorized Spindle

High speed spindle system is a key component of precision CNC machine tools,and the thermal deformation caused by temperature rise will seriously affect the machining accuracy and service life of the machine tools.Therefore,the design of a set of efficient cooling system for the effective control of spindle temperature rise and deformation is very significant.In this paper,a new type of cooling water jacket structure based on laminate cooling is put forward by referring to the efficient heat dissipation technology in the aviation field.With the advantage of high convective heat transfer coefficient and enhanced heat transfer by laminate impingement jet and spoiler,the stator of motorized spindle is effectively cooled to improve the heat dissipation effect of motorized spindle and reduce its thermal deformation.The traditional cooling structure of high-speed motorized spindle is studied,the heat generation of motor and bearing inside motorized spindle is analyzed in detail,the calculation formula and applicable conditions of motor and bearing are given,the heat transfer between fixed rotor,the heat transfer between rotor end and surrounding air,and the heat transfer between motorized spindle and surrounding air are analyzed.After verifying CFD numerical simulation method,the flow and heat transfer characteristics of traditional spiral cooling water jacket are simulated and analyzed,and the influence of inlet Reynolds number and initial temperature of coolant on heat transfer of cooling water jacket is analyzed.The surface heat transfer coefficient of cooling jacket under different conditions was obtained.Based on the geometric structure of 150MD24Z7.5 motorized spindle,the steady-state thermal analysis model was established,and its temperature and thermal deformation were calculated.The influence of different cooling conditions on temperature field and thermal deformation field of motorized spindle is studied.Designed the new layer board cooling jacket structure,adopt the method of numerical simulation to study the entrance to the equivalent diameter,hole diameter and disturbed flow column number change influence on BaJuan surface temperature,at the same time changing the inlet Reynolds number and BaJuan heat flow density on shock cavity flow and heat transfer characteristics,the influence of gain has the best cooling effect of cooling jacket structure layer board.The steady-state thermal analysis model of the motorized spindle based on the new cooling water jacket structure is established,the temperature and thermal deformation are calculated,and the simulation results are compared with those of the motorized spindle based on the spiral channelThe functional requirements of the cooling test bed were put forward,and the overall design scheme of the cooling test bed was determined.The test bed was mainly composed of the cooling liquid supply system,the heating system of the test parts,data measurement and data acquisition system.Based on the previous simulation results,the optimal geometric model was selected to design the test section of laminar cooling structure and complete the design of the overall structure and test pieces of the test benchThe conclusions obtained in this paper provide useful reference for further reducing the thermal deformation of high-speed motorized spindle and improving the machining accuracy of precision CNC machine tools...