Cause of motor heating

For any motor icluding sevomotor spindle motor, brushless dc motor,etc,It is normal to heat up during operation, and the same is true for stepper motors.
The interior of the stepper motor is composed of an iron core and a winding coil. The resistance of the operation and maintenance winding exists, and the current flowing through the motor will cause loss.
The loss is proportional to the square of the resistance and the current, which is called "copper loss". In addition, there is a hysteresis eddy current effect in the iron core, and losses will also occur in the alternating magnetic field. Its size is related to material, current, frequency and voltage, which is called "iron loss". Both copper loss and iron loss will be expressed in the form of heat, affecting the efficiency of the motor. Because stepping motors generally pursue positioning accuracy and torque output, they have low efficiency and large current.
The harmonic component is high, and the alternating frequency of the current also changes with the speed, so the stepper motor generally generates heat.

The maximum temperature the motor can withstand

The allowable degree of motor heating mainly depends on the internal insulation level of the motor. Only at high temperature (above 130 degrees), the internal insulation performance will be destroyed. So as long as the internal temperature does not exceed 130 degrees and the surface temperature is below 90 degrees, the motor will not be damaged.
Therefore, it is normal for the surface temperature of the stepper motor to be 70-80 degrees, which can be roughly judged by a spot thermometer. This normal heating will not affect the life of the stepper motor.

Solutions to motor overheating

3.1 Check whether the current setting of the driver is appropriate. If the setting is too high, the current can be reduced appropriately, and at the same time, the half-current hold function of the driver is turned on.

3.2 Check whether the driver is overloaded or overheated, and if necessary, increase heat dissipation measures or replace a higher power driver.

3.3 Check whether the stepper motor has been working for too long, if so, consider increasing the cooling time or using a fan for heat dissipation.

3.4 Check whether the ambient temperature is too high, increase ventilation or lower the working temperature if necessary.

3.5 Check the power cord and its connecting wires: Check the power cord and its connecting wires to ensure that there is no high impedance in them, so as not to affect the flow of current and make the stepper motor hot.