1. The ambient temperature of the DC geared motor is too high.
2. The motor is stuck, causing the current to increase and the temperature to rise.
3. The insulation of the rotor or stator coil of the DC geared motor is aging and the temperature rises.
4. The motor bearing is short of oil. The high temperature of friction causes the temperature to rise.
5. The DC geared motor is running overloaded. The temperature rises.
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