Patent ID: 8827609
Filing Date: 2014-09-09
Classification: B23Q,F16C,Y10T

Abstract:
1. A spindle device for a machine tool that includes: a housing; a spindle that holds a tool and that is rotationally driven; a front rolling bearing via which a front portion of the spindle, which is close to the tool, is supported by the housing; and a rear rolling bearing via which a rear portion of the spindle, which is distant from the tool, is supported by the housing, the spindle device further comprising: preload application means for applying a preload to the front rolling bearing; damping application means for applying a damping force to the rear rolling bearing, the damping application means including a hydrostatic bearing fitted to an outer periphery of a sleeve, which sleeve is fitted to an outer ring of the rear rolling bearing; a rotation stopper which extends through the hydrostatic bearing to prevent the sleeve from rotating with respect to the housing while permitting movement of the sleeve in a radial direction with respect to a rotation axis of the spindle; and control means for controlling the damping force that is applied by the damping application means based on at least one of a type of the tool, a machining condition for machining performed using the tool, a load that is applied to the spindle, and a vibration that is generated in the spindle.