The mechanical spindle is driven by the spindle motor and the intermediate transmission device (variable speed gear, belt or coupling) to rotate and work. Its output torque and power are large, but the speed, accuracy and stability are relatively poor.

Electric spindle is a new type of spindle component that integrates the functions of machine tool spindle and motor from a structural perspective. It places a high-speed motor inside the spindle component and controls the spindle to obtain the required working speed and torque through a control system. Therefore, it is also known as an internal electric spindle; It eliminates the transmission links of belts, gears, or couplings, achieving "zero transmission" of the machine tool spindle system, which is a major change in the transmission system of CNC machine tools; It overcomes the disadvantages of traditional mechanical spindles such as slipping, high vibration and noise, and large inertia at high speeds, effectively improving the overall performance of spindles at high speeds and possessing irreplaceable advantages over mechanical spindles

1、 Due to the direct drive of the built-in motor, the electric spindle eliminates the need for intermediate variable speed and transmission devices, and has the characteristics of compact structure, light weight, low noise, small vibration, and small moment of inertia. It can achieve high speed, acceleration, and fast start stop at a fixed angle, and has better dynamic accuracy and stability, which can meet the needs of high-speed cutting and precision machining of CNC machine tools; Due to the absence of external forces from intermediate transmission links, the operation of the electric spindle is smoother, and the dynamic load borne by the spindle bearings is smaller, which extends its precision life; By utilizing AC frequency conversion and vector control technology, the electric spindle can achieve stepless speed change within the rated speed range to adapt to the needs of various working conditions and load changes during machine tool operation.

2、 The motor embedded structure of the electric spindle makes it relatively independent from the transmission system and overall structure of the machine tool, forming a relatively complete "spindle unit", thereby promoting the modularization of the machine tool structure. Electric spindle manufacturers form standardized and serialized products based on the characteristics of machine tool usage, structure, performance parameters, etc., for machine tool manufacturers to choose from, changing the traditional "large and comprehensive" production mode of machine tool manufacturers, shortening the research and development and production cycle of machine tools, and better adapting to the rapidly changing market environment. In addition, standardized and serialized electric spindle products are easy to form specialized and large-scale production capacity, thereby promoting the reduction of manufacturing costs.

3、 Some high-end CNC machine tools, such as parallel motion machine tools, pentagonal machining centers, small hole and micro hole machining machine tools, have special requirements for the spindle speed, accuracy, and machine tool structure due to the special processing technology and processing objects. The electric spindle, with its integrated structural design and excellent performance of high speed and high precision, effectively meets the special requirements of certain high-end CNC machine tools.

Electric spindle is one of the three high-tech components of CNC machine tools, including high-speed electric spindle, CNC system, and feed transmission. With the rapid development of CNC technology and cutting tools, more and more mechanical equipment is developing towards high speed, high precision, high efficiency, and high intelligence. The electric spindle has become one of the core functional components suitable for high-performance CNC machine tools. The level and quality of electric spindle technology directly determine and affect the quality, performance, work efficiency, and operational stability of machine tools. Replacing traditional mechanical spindles with electric spindles in some fields is a major trend in the development of the machine tool industry