精密镗床进给轴差异化主动冷却方法

A differentiated active cooling method for the heat source of the feed axis is proposed to solve the problem of serious heat generation during continuous operation of the double-drive screw feed axis of a precision boring machine, which results in a large thermal error. Firstly, the main heat source parts of the feed shaft are determined to be bearings, motors, and screw nut pairs. The heat generation and heat dissipation mechanisms of the feed shaft heat sources are analyzed. The key boundary conditions are determined, and a thermo-fluid-structure coupling simulation model under active cooling is established. Then, cooling plates with built-in runner are designed and installed at the heat sources, and each cooling plate is respectively provided with a cooling circuit and through the No.4 spindle oil as the coolant. Each cooling circuit is equipped with a separate oil tank for independent temperature adjustment. Finally, heat generation models of heat source for the bearing, motor and screw nut of the feed shaft are established to accurately match the heat generation rate of each heat source to control the temperature of the inlet and outlet coolant in the cooling system, so as to differentially take away the heat generated by the different heat sources to control the temperature of each part and reduce the thermal error. Experimental results show that when the differential active cooling method is used, the maximum thermal errors decrease by more than 58.56% and 34.55%, respectively, compared with the feed axis without cooling and the constant temperature cooling method. At the same time, the stabilization time of thermal error is shortened. These results indicate that the active cooling method of the feed axis can effectively reduce the thermal error of the feed axis.