Why 1, the motor heat for a variety of stepper motor, the internal is composed of iron core and the windings.
Winding resistance, electricity will produce loss, the loss is proportional to the square of the size and the resistance and current, this is what we call the copper meteorite, if current is not a standard dc or sine wave, will also produce harmonic loss;
Core has hysteresis eddy current effect, also can produce loss in the alternating magnetic field, its size and material, voltage, current, frequency, this is called iron losses.
Copper loss and iron loss will be displayed in the form of heat, which affects the efficiency of the machine.
Stepper motor general pursuit of position precision and torque output, the efficiency is low, the current is compared commonly big, high harmonic components, the frequency of the alternating current is also change with speed, thus stepping motor are widespread fever, than the general ac motor serious condition.
2, the reasonable range of motor heating motor heating allows to what extent, mainly depends on the internal motor insulation class.
Internal insulation at high temperature (
More than 130 degrees)
Will be destroyed.
So as long as within no more than 130 degrees, the motor will not damage, while the surface temperature under 90 degrees.
So, step motor surface temperature in 70 -
80 degrees are normal.
Simple useful point thermometers, temperature measurement method can also be roughly judge: can touch 1 - by hand
More than 2 seconds, no more than 60 degrees;
Can only touch with the hand, around 70 -
Drop a few drops of water gasification quickly, more than 90 degrees.
3, along with the speed change motor fever using constant current drive technology, stepping motor under static and low speed, the current will remain relatively constant, to maintain constant torque output.
High speed to a certain extent, the motor internal counter potential, current will gradually decrease, the moment will decline.
Therefore, because of the copper loss of fever is related to the speed of the story.
Generally high fever when static and low speed, high speed low fever.
But the iron losses (
Although the smaller percentage)
Situation does not change, but the motor of the fever is the sum of the two, so the above is just normally.
4, the influence of tropical to electrical heating although generally will not affect the life of the motor, for most customers don't need to ignore.
However, serious fever can bring some negative effects.
Internal parts such as motor thermal expansion coefficient of different lead to the change of structural stress and internal air gap of tiny change, affects the dynamic response of the motor, high speed will be easy to out of step.
And as some situation does not allow excessive heating of the motor, such as medical equipment and high-precision test equipment, etc.
So the control of the heating of the motor should be necessary