Patent ID: 7326010

Claim:
A motor spindle for machine tools, the electric motor of the motor spindle having a rotor and stator, the motor spindle comprising: a first modular assembly comprising: a work spindle; said rotor of said motor; a clamping unit for a tool disposed in said work spindle; and axially spaced bearings on said work spindle; a spindle housing assembly comprising: said stator of said motor; a hydraulic ring cylinder; and an internal coolant supply for the tool integrated in said clamping unit and comprising a rotational feedthrough for the coolant provided inside of said hydraulic ring cylinder; said clamping unit being operable by said hydraulic ring cylinder against the force of a spring unit; said hydraulic ring cylinder being configured for releasing said clamping unit, said hydraulic ring cylinder and said rotational feedthrough being disposed in an end of said spindle housing; and said first modular assembly being releasably secured within said spindle housing assembly.