The spindle is in the field of CNC machine tools in recent ten years of the spindle and the spindle motor integration of the new technology, it is of high speed CNC machine tools "core" components, its performance directly determines the performance of high-speed processing machine. The spindle has the advantages of compact structure, light weight, small inertia, small vibration, low noise, fast response and other advantages, can reduce the gear, simplifying the machine shape design, easy to realize spindle positioning is a kind of ideal structure of high speed spindle. High speed CNC machine tool spindle as the key component, its performance determines the whole of the high speed machine tool machining precision and the production efficiency to a great extent, so the industrial countries are very concerned about the research and development of high speed electric spindle, have invested heavily, well-equipped processing and testing equipment, the establishment of environmental temperature, clean assembly the formation of a lot of electric spindle professional production base. The design and manufacture technology of electric spindle in our country has just started, and the scale of mass production has not yet been formed. The performance indexes of motorized spindle have a wide gap with those in other countries. In order to speed up the development and application of high speed machining technology in our country and accelerate the upgrading of NC machine tools, it is suggested to further organize the technical research, and realize the specialization and mass production of electric spindle at an early date. Electric spindle work not only high speed, but requires a very high angular velocity and angular acceleration, fast stopping at the specified location, the manufacture and control of the structure design, put forward very strict requirements and bring a series of technical problems, such as electric spindle cooling, lubricating and precision control etc.. In the design, we must properly solve these problems, in order to ensure the stable and reliable high-speed operation of spindle, to achieve efficient precision machining. As a key component of electric spindle machining center, it will be the machine tool spindle and the AC servo motor shaft will be made one, spindle motor stator and rotor spindle components directly into the interior, and through the dynamic balance correction, with good accuracy and stability of rotary, forming a perfect high speed spindle unit, also known as the built-in electric spindle, which no longer uses the belt gear pair, so as to realize the machine tool spindle system of Zero drive, power rotor direct drive spindle operation.

Since the spindle is a high speed and precise component, it is necessary to maintain it regularly. The electric spindle is regularly maintained as follows:

1. the axial runout of the spindle is generally 0.002mm (2 mu m), and is detected 2 times a year.

2. radial spindle taper bore beat of the general requirements for 0.002mm (2 m), detection of 2 year.

3. electric spindle mandrel distal (250mm) radial runout is generally required: 0.012mm (12 mu m), 2 times a year testing.

4. butterfly spring tightening force requirements: 16~27KN (to HSK63 as an example) 2 times a year testing.

5. when the cutter sticks, the extension distance is: 10.5 + 0.1mm (take HSK63 as an example), 4 times a year