With long time experience in adopting such kind of stepper motor for our plasma cutting machine. it shows good quality, reliability performance.
Guarantee that high precision driving, durable working life and strong torque. We could give helpful suggestion to select a suitable model for any kind of plasma cutting machine.
Keeping torque concept：
The holding torque refers to the moment at which the stator locks the rotor when stepper motor is energized but does not rotate. It is one of the most important parameters of a stepper motor. Usually, the torque of the stepper motor at low speed is close to the holding torque. Since the output torque of the stepper motor is continuously attenuated as the speed increasing, the output power also changes with the increase of the speed, so the holding torque becomes one of the most important parameters to measure stepper motor. For example, when people say that a 2N.m stepper motor, it usually means a stepper motor maintaining a torque of 2N.m.
The detent torque refers to the moment at which the stator locks the rotor when the stepper motor is not energized. Detent torque has no unified translation method in China, which is easy to misunderstand. Because the rotor of reactive steper motor is not made of permanent magnet material, it does not have DETENT TORQUE.
Stepper motor accuracy:
The accuracy of a general stepper motor is 3-5% of the step angle and does not accumulate.
Stepper motor’s external temperature:
If the temperature of the stepper motor is too high, the magnetic material of the motor will be demagnetized firstly, resulting in a torque drop and even out of step. Therefore, the maximum temperature of the motor surface should depend on the demagnetization point of the magnetic material of different motors; In general, the demagnetization of the magnetic material is above 130 degrees Celsius, and some even above 200 degrees Celsius, so the stepper motor’s external temperature is completely normal at 80-90 degrees Celsius.
The reason why stepper motor’s torque decreases with the rotate speed increasing:
When the stepper motor rotates, the inductance of each phase winding of the motor will form a back electromotive force; the higher the frequency, the larger the back electromotive force. Under its influence, the motor decreases with increasing frequency (or speed), resulting in a drop in torque.
Why stepper motor can’t be launched when its pulse frequency is higher than a certain value?
The stepper motor has a technical parameter: No-load launching frequency, that is a pulse frequency with which the stepper motor can launch in no-load conditions. If the pulse frequency is higher than this value, the motor cannot launch and lost or blocked may occur. In the case of loading, launching frequency should be lower. If the motor is to be rotated at a high speed, the pulse frequency should have an acceleration process, that is, the starting frequency is low, and then rise to a desired high frequency (the motor speed is increased from a low speed to a high speed) at a certain acceleration.
Method for mitigating vibration and noise of two-phase hybrid stepper motor:
The large vibration and noise of stepper motor at low speed is its inherent shortcoming. Generally, the following solutions can be adopted for mitigating:
A. If the stepper motor works in resonance, the resonance can be avoided by changing the gear ratio and other mechanical transmissions;
B. Using a drive with subdivision, this is the most common and easiest method;
C. Change a stepper motor with smaller step angle, such as a three-phase or five-phase stepper motor;
D. Switching to AC servo motor can almost completely overcome vibration and noise, but the cost is higher;
E. A magnetic damper is added to the motor shaft. This product is available on the market, but the mechanical structure changes greatly.