At present in the CNC cutting machine products, many product components, need to be carefully maintained and selected, how to reasonably select CNC cutting machine, especially the emerging CNC cutting machine products, more is the need to face CNC cutting machine products and performance is aware, otherwise in case of problems, It's very difficult to handle. The drive unit includes two parts of the drive unit and the motor, and the selection of the drive unit is mainly driven by the choice of the drive device, because the motor is a generic part and the performance gap exists only in different manufacturers and models.
Drive motor can be divided into: Reactive stepper drive motor, hybrid (or permanent-magnet reactive) stepper drive motor and servo-driven motor three major categories. The rotor of the reactive stepper drive motor has no winding, and the reaction moment of the stator winding of the excitation is realized by stepping. Hybrid stepper motor rotor with permanent magnet, from the excitation and permanent magnet generated by the electromagnetic torque to achieve the step-run. The stepper motor is controlled by the pulse, changing the order of power can change the direction of the motor rotation, change the frequency of the pulse can change the speed of the motor rotation. Stepper motor has a certain step-distance precision, no cumulative error. But the efficiency of stepper motor is low, the ability of dragging load is not great, the pulse equivalent cannot be too large, the speed of adjustment is not big. The current stepper motor can be divided into two-phase, three-phase, five-match children, commonly used is five-phase stepper motor. In the past a long time, stepper motor accounted for a huge market, but the current is gradually replaced by servo motor.
The current commonly used servo motor is AC servo motor, in the NC cutting machine motor shaft end equipped with photoelectric encoder, through the detection of rotor angle for frequency control. From the lowest speed to the highest speed, servo motor can smooth operation, torque fluctuation is small. The servo motor has a long overload capacity, a smaller moment of inertia and a large plugging torque. Servo motor has a small start-up frequency, can be very fast from the minimum speed to speed up to the rated speed.
The use of AC servo motor as a driving device can be the same as the DC servo motor to form a high-precision, high-performance half-closed loop or closed-loop control system. Because the AC servo motor is brushless structure, the child does not need to repair, the volume is relatively small, to help increase the speed and power. At present, the DC servo motor has been replaced by a large area. After the advent of the All-digital AC servo system using a fast microprocessor and a dedicated digital signal processor (DSP), the original hardware servo control becomes the software servo control, some advanced algorithms in modern control theory are realized, which greatly improves the performance of the servo system, so the servo unit can greatly enhance the production efficiency and manufacture precision, but the price of servo-driven unit is also higher. With the gradual upgrading of servo control technology, the current servo drive unit is becoming the main force of the driving unit, and the price of servo-driven unit is decreasing gradually.