1. Why does the stepper motor heat up? Insulated Terminals,Terminals,High-quality insulated terminals Taixing Longyi Terminals Co.,Ltd. , https://www.lycopperlugs.com
Any motor will heat up, but the degree of heat is different. For various stepper motors, the interior consists of a core and a winding coil. The winding has resistance, and the power will generate loss. The loss is proportional to the square of the resistance and current. This is the copper loss we often say. If the current is not a standard DC or sine wave, harmonic loss will occur. The core has hysteresis. The eddy current effect also causes loss in the alternating magnetic field, and its magnitude is related to material, current, frequency, and voltage. This is called iron loss. Both copper loss and iron loss are manifested in the form of heat, which affects the efficiency of the motor. Stepper motors generally pursue positioning accuracy and torque output, the efficiency is relatively low, the current is generally large, and the harmonic components are high, and the frequency of the alternating current also varies with the rotational speed. Therefore, the stepping motor generally has a fever condition, and the situation is more general. The AC motor is serious.
2, the reasonable range of stepper motor heating? .
The extent to which the motor is allowed to heat up depends mainly on the internal insulation rating of the motor. Internal insulation properties are destroyed at high temperatures (above 130 degrees). Therefore, as long as the internal temperature does not exceed 130 degrees, the motor will not be damaged, and the surface temperature will be below 90 degrees. Therefore, the stepper motor surface temperature is normal at 70-80 degrees. The simple temperature measurement method is useful for point thermometers. It can also be roughly judged: it can be touched by hand for more than 1-2 seconds, not more than 60 degrees; it can only be touched by hand, about 70-80 degrees; a few drops of water quickly It is 90 degrees or more.
3, stepper motor works differently, and the heat is different.
In the case of constant current drive technology, the stepper motor maintains a relatively constant current at static and low speeds to maintain constant torque output. When the speed is high to a certain extent, the internal back EMF of the motor rises, the current will gradually decrease, and the torque will also decrease. Therefore, the heat generated by the copper loss is related to the speed. Generally, the heat is high at static and low speeds, and low at high speeds. However, the change in iron loss (although the proportion is small) is not always the case, and the whole heat of the motor is the sum of the two, so the above is only a general case.
4. Does the stepper motor heat affect the working life of the stepper motor?
Although the motor heat does not generally affect the life of the motor, it is not necessary for most customers. However, severe fever can have some negative effects. If the thermal expansion coefficient of each part of the motor is different, the structural stress changes and the small change of the internal air gap will affect the dynamic response of the motor, and the high speed will easily lose the step. In some cases, excessive heating of the motor, such as medical equipment and high-precision test equipment, is not allowed. Therefore, the necessary control of the heating of the motor should be carried out. Our stepper motor is used on steel robots. The ambient temperature is more than 100 degrees and it is working normally.
5, the solution to the heating problem of stepper motor?
If the stepper motor driver has an automatic half-flow mode, try to make it work in a semi-flow state, because the stepper motor has the largest total heat generation.
If the load torque range allows, the motor rated current can be reduced, such as 5A motor, let it work in 4A state;
Choose a low-resistance, low-current stepper motor to reduce copper loss and iron loss.
Install a fan to force heat dissipation.