1. Why do the submersible pumps used in refineries often need maintenance and their service life is not ideal? I believe that under the liquid pump users are aware that the liquid pump motor in the liquid surface, the pump wheel in the liquid surface, the middle through the long axis connection, the long axis is divided into several sections, the motor drives the long axis of the pump wheel rotation , Thus withdrawing the liquid. The deeper the tank or the deeper the tank is buried in the ground, the longer the long axis of the submerged pump. The longer the long axis, the deeper the depth of the submersible pump wheel swing amplitude. This swing is an important reason that submerged pumps often require maintenance. In the submerged pump can often hear a loud noise, the sound emitted by the motor, long axis swing sound. Long axis swing loss of a lot of energy, the rotation of the bearing is not in a straight line, but a cone-shaped rotation, the shaft and bearing material requirements are relatively high, bearing life is shorter, resulting in higher maintenance frequency. Submerged pump motor above the liquid level, motor cooling only contact with the outside air to reduce the temperature. The life of the motor directly determines the life of the submerged pump. Submersible pump can solve these problems? Submersible pump motor is not on the surface, but below the surface. The motor is a submersible motor that is connected to the pump wheel as a potential liquid. First, the submersible pump bearing is very short, no long axis, there will be no swing problem, almost no energy loss, smooth operation, the sound is small. Second, the submersible pump motor is the core technology of this pump. This type of motor is called a submerged motor or a shielded motor. There is a gap between the stator and the rotor of the motor, which is about the thickness of an A4 paper. The oil flows through it and serves two purposes. One is to cool the motor , Almost all the motor can only flow through the outside of the motor to achieve the cooling effect, thus protecting the motor life. Submersible pump motor fluid inside the characteristics of this motor doubled the life. Second, the liquid flow through the gap between the stator and the rotor, the bearing play a good role in lubrication. Motor and bearing problems have been effectively resolved, so that submersible pump does not require maintenance, low failure rate. Service life of up to ten years, shelf life of three years.