Papers by Author: Xiao Dong Yu

Abstract: The dynamic simulation analysis method is adopted to investigate the dynamic damping characteristics of lathe tool with large length to diameter (L/D) ratio. The multi flexible body dynamical simulation model of dynamical damping lathe tool with large length to diameter ratio is built up according to the actual experiment lathe by using the software ADAMS and ANSYS. Simulation analysis of the multi flexible body dynamical model which has been optimized shows that the system damping performance is improved greatly. On this basis the relationship of rubber bush, mass body and vibration absorption cavity is discussed. And the result of the discussion indicates that the shape of rubber bush should be confirmed by repeatedly simulating the model.

Abstract: The pressure field of the clearance oil film of the hydrostatic bearing in varies velocities was simulated based on Finite Volume Method (FVM) by the software of Computational Fluid Dynamics. In this article, a conclusion could be drawn that the viscosity has great influences on the pressure in the heavy hydrostatic bearing and it cannot be neglected especially in high rotating speed. The results of numerical calculations provide internal flow status inside the bearing, which would help the design of the oil cavity structure of the bearing in engineering practice.

Abstract: In order to solve the thermal deformation of the hydrostatic center frame in the heavy type horizontal lathe, a simulation research concerning temperature field of hydrostatic center frame is described. The Finite Volume Method of CFX has been used to compute three-dimensional temperature field of gap fluid between workpiece and bearing pillow. This research theoretically analyzes the influence of angular velocity on the bearing temperature performance according to lubricating theory and computational fluid dynamics, and it has revealed its temperature distribution law of gap oil film. Results indicate that an improved characteristic will be affected by angular velocity easily, and oil cavity temperature increases by gradually with angular velocity enhancing. Through this method, the safety of a hydrostatic center frame can be forecasted, and the optimal design of such products can be achieved, so it can provide reasonable data for design, lubrication, experience and thermal deformation computation for hydrostatic center frame in the heavy type horizontal lathe.

Abstract: A scheme of improving performance of hydrostatic journal support was presented, that is, control journal support pose by controlling flow of four controllable chambers and Coupling various oil film thickness, to assure journal support expected pose; Chamber flow can be regulated by electro hydraulic servo valve-control variable pump according to the surface roughness, load, cutting force, and thermal results of journal support. The mathematical model of the controllable chambers flow, servo variable mechanism and controller were built; the pose control model was established, which contain the kinematics positive and negative solution and control strategy of hydraulic cylinder position feedback; Hardware-in-loop simulation experiment was carried on the electro hydraulic servo test bench by mean of the non-linear relation of film thickness and the hydraulic cylinder displacement. Simulation and Hardware-in-loop simulation experiment results show that the controllable journal support exhibit high oil film rigidity can stably and quickly track the expected goal and can be broadly applied in high precision heavy horizontal machine tool.