Stepper motor selection considerations - Solutions - Huaqiang Electronic Network

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The holding torque is also called the static torque, which refers to the moment at which the stator locks the rotor when the stepping motor is energized but does not rotate. Since the torque of the stepping motor at low speed is close to the holding torque, the torque of the stepping motor is rapidly attenuated as the speed increases, and the output power also changes with the increase of the speed, so the holding torque is a measure of the stepping. One of the most important parameters of the motor load capacity.

First, choose to maintain torque

The holding torque is also called the static torque, which refers to the moment at which the stator locks the rotor when the stepping motor is energized but does not rotate. Since the torque of the stepping motor at low speed is close to the holding torque, the torque of the stepping motor is rapidly attenuated as the speed increases, and the output power also changes with the increase of the speed, so the holding torque is a measure of the stepping. One of the most important parameters of the motor load capacity. For example, the stepping motor of 1N.m is generally mentioned without explanation, and it can be understood that the holding torque is 1N.m.

Second, choose the number of phases

The two-phase stepping motor has low cost, the step angle is at least 1.8 degrees, the vibration is high at low speed, the torque is fast at high speed, and it is suitable for high speed and low precision and stability requirements; three-phase stepping motor step The angle is at least 1.2 degrees, the vibration is smaller than the two-phase stepping motor, and the low speed performance is better than the two-phase stepping motor. The maximum speed is 30 to 50% higher than that of the two-phase stepping motor, which is suitable for high speed and accuracy and stability requirements. In higher cases, the 5-phase stepping motor has a smaller step angle, and the low-speed performance is better than that of the 3-phase stepping motor, but the cost is high, which is suitable for the middle and low speed sections and requires high precision and stability.

Third, choose stepper motor

Should follow the principle of selecting the stepper drive after selecting the motor first, firstly determine the load characteristics, and then compare the static torque and the moment frequency curve of different types of stepper motors to find the stepping motor that best matches the load characteristics; when the accuracy requirement is high, The mechanical deceleration device is adopted to make the motor work in the most efficient and lowest noise state; avoid the motor working in the vibration zone, if necessary, by changing the voltage, current or increasing the damping; in terms of power supply voltage, it is recommended that the motor be DC 24V-36V, 86 motor adopts DC 46V, 110 motor adopts higher than DC 80V; large inertia load should select motor with larger frame number; when high inertia load and working speed are high, the motor should adopt gradually increasing frequency In order to prevent motor out of step, reduce noise, improve positioning accuracy when stopping; in view of the stepper motor torque is generally below 40Nm, beyond this torque range, and the running speed is greater than 1000RPM, you should consider the choice of servo motor, general AC servo The motor can run normally at 3000RPM, and the DC servo motor can run normally at 10000RPM.

Fourth, select the drive and the number of subdivisions

It is best not to choose the whole step state, because the vibration is larger in the whole step state; try to choose a small current, large inductance, low voltage driver; use a driver larger than the working current, and use subdivision when low vibration or high precision is required. Type driver, high-voltage type driver for high-torque motor to obtain good high-speed performance; in the case where the actual motor speed is usually high and the accuracy and stability are not high, it is not necessary to select a high-dividing number driver. In order to save costs; in the condition that the actual running speed of the motor is usually very low, a large number of subdivisions should be selected to ensure smooth operation and reduce vibration and noise. In short, when selecting the subdivision number, the actual operation of the motor should be considered comprehensively. Speed, load torque range, gearbox settings, accuracy requirements, vibration and noise requirements.