Spindles are the core component in machine tools. According to machining process, spindles can be applied to lathe, milling, drilling, grinding machines, etc. Equipped with multi-axis controller complex machining shapes can be done. Recently, machine tools have been highly developed in high speed machining. A high speed CNC machine shall be capable of 60m/min feed rate, vibration within 1 G and with spindles rotate at 20000 rpm.