| Demands for good-performance machine tool increase. Joints in machine tools will affect their dynamic and thermal characteristics largely. So it is a precondition of forecasting and improving performances of machine tools to study the dynamic and thermal characteristics of joint. Based on the project of"Develop of the High-speed High Precision Numerical Control Centerless Grinder", the dynamic and thermal characteristics of fixed joint are studied.1. The means produced by Ji-cun-yun-xiao is used to study the dynamic characteristics of real joint. The spring-damp elements are used to simulate the joint that is in unit area, and FEA method and experiments are applied to identify its dynamic parameters. The influential factors in the parameters are discussed based on the researches on different joints.2. Considering the effects of joints, dynamic analyses of subassemblies in grinder are carried out with Pro/E and ANSYS. The effects of joints on the dynamic characteristics of machine tool are studied to improve the precision of computer simulation.3. An analytic thermal contact resistance model based on classical heat conduction theory and the advanced M-B fractal model is developed under some hypotheses. Compared with related experiments and other's results, the model has good identity. It can be used to calculate the thermal contact resistance of joints. The influential factors in the resistance are discussed based on the model.4. Thermal analysis of grinding machine housing is carried out, considering the effects of thermal contact resistance, the viscosity temperature characteristics of grease and the stiffnesses of bearings, and compared with experiments. Temperature distribution and thermal deformation of the housing during working are analyzed.
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