Previously, the editor has introduced in detail how to distinguish between servo motors and variable frequency motors. What these two motors have in common is the frequency conversion link. The difference is that the material, structure and processing technology of servo motors are much higher than those of frequency converter drives. AC motor. And today we are going to talk about another new type of motor, which is the stepper motor.
In specific applications, when the terminal load is stable, the action is simple, and basically runs at low speed, it is appropriate to choose a low-cost and easy-to-control stepper servo motor; but when the terminal load has a large fluctuation range, the action is simple, and the speed is basically When running at low speed, if you choose a stepper motor, you will face a series of troubles, so why is this? That's because stepper motors driven by square waves are difficult to eliminate vibration and noise, and will cause out-of-step or overshoot due to torque fluctuations.
In fact, when the terminal load fluctuation range is large, even if it is basically a low-speed operation state, a servo motor should be selected, because after taking into account factors such as efficiency improvement factors, energy saving factors, control accuracy improvement factors, and system stability improvement, you will find that Choosing a higher-priced servo motor actually increases the overall cost. So what are the precautions for replacing stepper motors with servo motors? Let’s find out together below!
1. In order to ensure that the control system does not change much, we should choose a digital servo system, and the previous pulse control method can still be used.
2. Because servo motors have an overload capacity, when selecting this motor, experience can be used to determine the rated torque of the servo based on 1/3 of the output torque of the stepper motor used.
3. The rated speed of the servo motor is much higher than that of the stepper motor. In order to give full play to the performance of the servo, a corresponding reduction device is added to allow the servo motor to operate at a speed close to the rated speed. In this way, you can also choose a smaller power one. motor to reduce costs.
The stepper servo motor uses the principle of electromagnet to convert pulse signals into linear displacement or angular displacement. Every time an electrical pulse comes, the stepper motor will rotate by an angle, driving the machine to move a short distance.
The characteristics of stepper servo motors are as follows:
① Give a pulse and turn a step angle.
② Control the pulse frequency to control the speed of the motor.
③Change the pulse sequence to change the rotation direction.
Since this function of the stepper motor exactly meets the requirements of digital control systems, it is widely used in CNC machine tools, watch industry, automatic recorders and other fields.
中文简体
English
