Spindle for a machine tool

A spindle for a machine tool for machining a metal workpiece, comprising:

• a. a motor including a stator and a rotor arranged in a spindle housing;
• b. a spindle shaft operationally connected to the motor, the rotor being mounted on an outer surface of the spindle shaft, wherein the motor is configured to drive the spindle shaft for rotation;
• c. a clamping interface for clamping a machining tool, wherein the clamping interface is arranged at one end of the spindle shaft;
• d. a vibration sensing unit for detecting vibration of the spindle arranged in the spindle housing including three vibration sensors for sensing acceleration of the spindle in three linear axes and a vibration sensor circuit configured to process a sensed signal resulting in a vibration signal by amplification, analog-to-digital conversion and filtering;
• e. a crash sensing unit configured to detect that a crash event occurred on the spindle arranged in the spindle housing including three crash sensors for sensing the acceleration of the spindle in three linear axes and a crash sensor circuit configured to process a sensed signal resulting in a crash signal by amplification, analog-to-digital conversion and filtering;
• f. a tool-position monitoring unit for detecting a position of the clamping interface configured to generate a tool position signal, wherein the tool position signal is a digital signal;
• g. a motor temperature sensor for measuring a temperature of the motor arranged closely to the motor on the stator and configured to generate a motor temperature signal;
• h. a bearing temperature sensor for measuring a temperature of a bearing arranged on the bearing for supporting the spindle shaft configured to generate a bearing temperature signal;
• and
• i. a spindle diagnosis module arranged in the spindle housing including a first communication interface configured to communicate with the vibration sensing unit and the crash sensing unit, a second communication interface configured to communicate with the tool-position monitoring unit, a third communication interface configured to communicate with the bearing temperature sensor, a fourth communication interface configured to communicate with external devices arranged outside of the spindle, a processing unit configured to process received sensor signals, and a data storage unit configured to store the received sensor signals.