Dry air filled cavity motor, the stator end winding and rotor cooling machine mainly depends on the air inside. The stator iron loss, stator slot winding through the surface of the casing wells away. The rotor winding and the rotor iron loss resistance loss heat generated by a gas gap directly to the part of the stator core. The case came to the motor outside the water away; the other part to the machine in the air, this part of the heat end winding and the stator to another part of the heat loss of the air resistance and mechanical loss of heat generated by the machine together, the air flow to the stator core, casing and bearing surface, finally through the motor casing and the bearing seat and other parts of the motor to the water away. Because of the poor thermal conductivity of air, heat capacity is small, so well for submersible motor stator winding And the cooling condition of the rotor winding is poor, the temperature rise is relatively high.
