What is the cause of motor pulley heating?

When the belt is running, the pulley itself will heat up, mainly depending on the temperature. If it is extremely high, it is mainly caused by the belt slip and the two pulleys are not in a straight line. There is also what the electrician said is that the motor is overloaded or the motor bearing is damaged and the temperature is too high to reach the pulley (this may be small). The solution is that if the new machine is hot, it is that the machine design itself has a problem, you have to check the design manual. If it is later hot, you can change the belt and adjust the belt tightness. If the two belts are smashed, turn them off a straight line.