Thermal structure design optimization and temperature control for worm gear grinding machine using flood cooling technology

Abstract

For the worm gear grinding machine using flood cooling technology, the coolant absorbs the grinding heat in the machining process and flows on the machine bed, which directly affects the relative position between tool and workpiece. The existing thermal structure analysis and the temperature control research lack in-depth research on thermal problems related with the coolant flowing along the machine bed. In order to reduce the thermal deformation of the machine bed, this paper proposes a novel structure with double-layer coolant channel to improve the thermal characteristics of the machine bed, and the cooling fluid is controlled to maintain an even temperature distribution of machine bed through this structure. In addition, based on a comprehensive analysis of the machine bed heat sources and boundary conditions, a more accurate coolant convection heat transfer coefficient distribution was obtained by using CFX software, and a flow-thermal-structural multi-field sequential coupling finite element thermal characteristic analysis model was established to study the thermal characteristics of the machine bed. The results show that the maximum prediction error of the model is less than 6.77% compared with the experimental data under the same working conditions. The temperature distribution of the proposed machine bed structure is more uniform than that of the original one. The maximum temperature difference is reduced by 1.7 °C, which shows that this method can effectively reduce the relative deflection between the workpiece column and the column. The proposed machine bed structure decreases the thermal deformation’s sensitivity to the temperature of the coolant and has a high adaptability to external temperature fluctuations.