Thermal Characteristic Analysis Of Horizontal Boring And Milling Machining Center Spindle Component

The rapid development of technology has brought us new opportunities for machine tool industry, but also new challenges. High-precision CNC machine tools have occupied the basic status of China’s manufacturing industry as well as other related industries. The processing precision of machine tools to achieve is mainly counting on reducing the mismachining tolerance. Meanwhile, thermal deformation of machine tool occupies a large proportion of it. So, it is of great importance to reduce the thermal deformation of machine tool. When it comes to a horizontal boring and milling machining center, we must devote effort to reduce the thermal deformation of the spindle component to improve the machining accuracy for it is the core part of a CNC. Therefore, analysis of thermal characteristics on spindle system contributes a lot to a high machining accuracy. It also has significant theoretical and engineering application value on improving the machining accuracy of a horizontal boring and milling machining center.With the TH6213 horizontal boring and milling machining center spindle component as a research object, this paper analysed the heat source and calculated the heat generated, got the steady and transient temperature distribution and thermal deformation after carrying out a numerical simulation on the spindle、ZF gear box and the spindle box. The result offers a basic theory on structure design of spindle component and optimization of thermal compensation.The main work of this paper is as below:1. Established the finite element analysis model of the key functional parts of boring and milling machining center spindle system and the model was simplified and meshed.2. Analysed the heat source of spindle components and calculated the heat generated as the thermal load, the surface heat convection coefficient as the boundary condition of the thermal characteristics analysis.3. Carried out a finite element simulation analysis on the spindle、ZF gear box and the spindle box and got the steady and transient temperature distribution; The temperature distribution was got and drew a conclusion that the system balanced at the time 9600 s based on the trend of the spindle system thermal line; The max temperature read as 45.456℃ at the location of No.3 bearing, and the TH6213 boring and milling machining center spindle box was proved to be of a thermal symmetric structure.4. A thermal structure coupling analysis on the spindle、ZF gear box and the spindle box was carried and the deformation was got; The machining accuracy was granted because the max deformation of the spindle flat surface was 11.9μm, which is smaller than the limited 50μm; Also, the work reliability of the ZF gearbox was verified as the deformation of the gear meshing position is less than the rated clearance;5. The finite element modeling and simulation analysis was validated to be corrected via temperature measurement experiment; The reasons of mistakes were explored, the model and boundary conditions were revised and finally a fast thermal characteristics simulation model which responded to different speed rapidly was established.The thermal characteristics simulation model of TH6213 horizontal boring and milling machining center could respond rapidly to different spindle speed, and the result offers a basic theory on structure design of spindle component and optimization of thermal compensation.