Optimum design of headstocks of precision lathes

The optimum designs of headstocks of precision lathes are studied. Three different outer shapes of headstocks are explored. Thermal deformations due to heat generated by spindle bearings are considered. The objective is to minimise the overall deflection of the workpiece at the cutting point. The constraint is to force the fundamental natural frequency much greater than the working frequency in order to reduce dynamic deflections. The design variables include the shape dimensions, the locations of the spindle bearings, the stiffnesses of the spindle bearings, the dimensions of the fins and the locations of the fins. The genetic algorithm is utilised to solve these mixed-variable optimisation problems. Optimum solutions for the three different types of headstocks are found and discussed.