Thermal Analysis of a Ball Screw by ADI Finite Difference Method

The frictional heat generated according to geometric information and operating conditions of a ball screw incurs temperature rise. The thermal deformation due to this temperature rise deteriorates the positioning accuracy of feed drive systems. To compensate for the thermal error due to thermal deformation, the temperature distribution first has to be accurately predicted. In this paper, to predict the temperature distribution regardless of the ball screw model, a parametric temperature prediction simulator is developed using an alternating direction implicit (ADI) finite difference method (FDM). The heat generation rates and convection coefficients of the nut are estimated using the one-body lumped method. Convection coefficients of the shaft surface and thermal contact conductance (TCC) values at the ball screw interface are obtained from previous models. In addition, to verify the validity of the developed simulator, various analyses are performed according to the node size and time interval for several feed speeds. Experiment results confirm the validity of the results obtained.