Study on thermal behavior of an improved motorized spindle with water-lubricated hydrodynamic spiral groove bearings

Abstract

The machine tool spindle supported by oil lubricated hydrostatic bearings suffers from high temperature rise when running at high speed. To overcome this issue, an improved motorized spindle supported by water-lubricated hydrodynamic spiral groove bearings is proposed in this study. The thermal model for the motorized spindle including heat generation model and heat dissipation model is established by aid of finite element method. A test prototype for the motorized spindle and an experimental device are developed to carry out the test of spindle thermal behavior. The temperature field and thermal deformation field of the motorized spindle are investigated by numerical simulation and experimental measurement. Finally, a comparative study of thermal behavior is conducted between the proposed spindle with herringbone groove journal bearings (HGJBs) and the replacement spindle with plain journal bearings (PJBs). The result indicates that the water-lubricated hydrodynamic spiral groove bearings can decrease the temperature rise of motorized spindle; and the thermal design for the proposed motorized spindle supported by HGJBs is effective.