Deep well pump is made of motor and pump. It is a kind of pump that sucks and transports water into underground water well. It is widely used in farmland irrigation, industrial and mining enterprises, urban water supply and drainage, sewage treatment and so on. Because the motor is submerged at the same time, the structure requirement of the motor is more special than that of the general motor. Its motor structure is divided into four types: dry, semi-dry, oil-filled and wet.