There are currently two main types of spindle motors for CNC routers on the market, one is a water-cooled high-speed spindle motor, and the other is an air-cooled high-speed spindle motor. The main difference between these two engraving electromechanical spindles lies in their different cooling methods. The water-cooled spindle uses cooling water to reduce the temperature inside the spindle, while the air-cooled spindle uses fan cooling to control the temperature.
Since the air-cooled spindle of the CNC router integrates the motor into the spindle unit, and the speed is high, a large amount of heat will be generated during operation, which will cause the temperature of the electric spindle to rise, and the thermal and dynamic characteristics of the electric spindle will be deteriorated, thereby affecting the performance of the electric spindle. normal work. Therefore, certain measures must be taken to control the temperature of the electro-spindle to make it constant within a certain value. Machine tools generally adopt forced circulation oil cooling to cool the stator and spindle bearings of the electric spindle. That is, the cooling oil passing through the oil cooling device is forced to circulate outside the spindle stator and spindle bearings to take away the heat generated by the high-speed rotation of the spindle. In addition, in order to reduce the heating of the spindle bearing, it must be lubricated reasonably.
The motors of the air-cooled engraving electric spindle all use AC asynchronous induction motors. Because they are used on high-speed processing machine tools, the speed must be rapidly increased from static to tens of thousands of revolutions per minute or even hundreds of thousands of revolutions per minute. The starting torque is large, so starting The current should exceed the rated current of the ordinary motor by 5 to 7 times. There are two types of drive modes: inverter drive and vector controller drive. The drive control characteristic of the inverter is constant torque drive, and the output power is proportional to the torque. The latest frequency converter of the machine tool adopts advanced transistor technology, which can realize the stepless speed change of the spindle. The drive control of the machine tool vector control driver is constant torque drive at the low speed end, and constant power drive at the middle and high speed end.