Page 137 - Centrifugal Pumps Design and Application

Vertical Pumps 115

Figure 9-2. Well pump with hollow shaft, electric motor (courtesy BW/IP interna-
1
tional, Inc. Pump Division, manufacturer of Byron Jackson/United™ Pumps).

An alternate well pump design uses a submersible electric motor drive,
which is close coupled to the pump as shown in Figure 9-4. The motor can
either be of the "wet winding" or "dry winding" design. For large motors,
250 HP and up, the preferred construction is the dry winding with the motor
sealed and oil filled [2]. The motor is typically mounted below the pump, so
there will be continuous flow of liquid around the outside of the motor for
cooling. The submersible configuration eliminates the need for a lineshaft