Patent ID: 6036413
Filing Date: 2000-03-14
Classification: B23Q,Y10T

Abstract:
In a machine tool for machining a workpiece at speeds of 20,000 rpm's or greater, the combination comprising:a stationary housing;a spindle shaft mounted in the stationary housing and for rotating a tool to machine a workpiece at speeds of 20,000 rpm's or greater;hydrodynamic fluid bearing members fixed in the stationary housing about the shaft for mounting the spindle shaft for rotation about an axis through the spindle shaft for taking axial and radial loads from the spindle shaft;conduits in the housing for delivering and removing liquid bearing fluid from the fluid bearings;seals adjacent the fluid bearings and cooperating with the rotating spindle to stop liquid leakage from the fluid bearings; andat least one of the fluid bearing members including an inclined surface and the shaft having a facing inclined surface with facing sections on the inclined surface of the bearing member having a larger radius of curvature than the radius of the shaft to form hydrodynamic bearing pads having a canted lobe profile and being inclined to the rotational axis of the spindle to take combined and axial loads from the tool.