In recent years, various demands to machine precise micro parts and/or molds used in advanced industries such as automobile, aircraft, medial and electronics for instance. These parts are produced by ultra-precision machine tools. In order to machine the precise micro structures, high speed spindle must be a key component that determines the machining accuracy of the parts. Thus, the spindle of the ultra-precision machine tools for machining the precise micro structures needs high rotational accuracy, high bearing stiffness and high-speed spindle rotation. To meet the requirements, the spindles supported by hydrostatic bearings are in general used for the ultra-precision machine tools. The spindle supported by the hydrostatic bearings achieves better rotational motion with low friction by non-contact support of the rotor. However, even in the spindle supported by the hydrostatic bearings, heat generations due to the power loss cannot be avoided. The power loss is mainly due to the pressure drop of the lubricating fluid and the viscous friction of the lubricating fluid.
展开▼
