1. For various stepping motors, the inside is composed of iron core and winding coil. The winding has resistance, and the power will generate loss. The magnitude of the loss is proportional to the square of the resistance and current. This is what we often call the copper 陨. If the current is not a standard DC or sine wave, it will also produce harmonic loss; the core has hysteresis The eddy current effect, in the alternating magnetic field, also produces losses, the size of which is related to material, current, frequency, voltage, which 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, low efficiency, relatively large current, high harmonic content, and alternating current frequency with speed. The AC motor is serious.
2, the reasonable range of engraving machine stepper motor heating to the extent of motor heating, mainly depends on the internal insulation level 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, and can also be roughly judged: the hand can be touched for more than 1-2 seconds, not more than 60 degrees; the hand can only touch, about 70-80 degrees; a few drops of water quickly It is more than 90 degrees.
3, stepper motor heating with speed changes with constant current drive technology, stepper motor at static and low speed, the current will remain relatively constant 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 the general case.
4. Although the motor heat does not generally affect the life of the engraving machine 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 heat of the advertising engraving machine motor should be controlled as necessary.
