The cleanliness of the motor shell wrapped by the mechanical part is beneficial to the heat dissipation of the motor, and the winding is damaged due to too high temperature.
Lubricate the bearings regularly-after a long time, the shaft will die and the winding will burn out seriously.
Wait, that's what you learned.
The maintenance of the circuit part covers the lines and windings, and its main purpose is to protect the windings relatively carefully.
In short, it is not allowed to damage the winding, because every time the winding burns out, the magnetic field lines of the motor stator will be lost, so that the performance and efficiency of the motor will be reduced every time the motor winding is rewound.