Stepper motors are widely used in motion control systems. Many users use the stepper motor, often the feedback stepper motor temperature rise is relatively large, why? How does MOONS’ test the temperature rise of the motor?
First, why is the stepper motor temperature rise relatively large?
Any motor will heat up, but the temperature rise range is different. For stepper motors, the interior consists of a core and winding coils. The winding has resistance, which will cause loss when energized; if the current is not a standard DC or sine wave, the harmonic loss will occur; the core has a hysteresis eddy current that is less than that in the alternating magnetic field. Damage can be 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, so the temperature rise of the stepping motor is relatively large.
Second, the reasonable range of stepper motor temperature rise
The extent to which the motor temperature rise is allowed depends on the internal insulation level of the motor. The general insulation class of the stepper motor is ClassB, so only the internal 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 60 degrees.
Third, the temperature rise test process
- Select the appropriate heat sink according to the size of the motor base and connect the motor to the heat sink. The heat sink size table for each series of motors is shown in the figure below:
- Fix the motor to the bracket through the heat sink. The shaded part between the bracket and the heat sink is a nylon heat shield. See the following figure:
- Place the sensor on the surface of the motor, then drive the motor, test the motor surface temperature and record the data.