Spindle device for machine tool

摘要

The damping property of a rear rolling bearing (133) is adjusted by controlling a damping force that is applied by damping application means (5, 134) based on, for example, the type of a tool (T). Thus, it is possible to provide the optimum damping properties for various tools that differ in natural vibration, and to suppress the generation of chattering of the various tools. As a result, it is possible to increase the cut amount per unit time to increase the productivity.

主权项

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.