Thermo-mechanical analysis of a machine tool with hydrostatic bearings

Thermal behaviour is a key factor affecting the operating status of high performance hydrostatic (HS) bearings of rotational axes of machine tools (MT). This paper introduces a novel model developed for transient thermo-mechanical analysis of hydrostatic guideways with a surrounding MT structure. In contrast to common approaches to HS bearing design, which only consider the static load carrying capacity, the new model enables detailed prediction of the bearing thermal stability under various operating conditions. An analytical description of the HS bearing heat generation coupled with a MT finite element (FE) model enables calculation of heat transfer, conduction and especially thermal deformations of the entire MT structure affecting the working accuracy of the machine tool.