Structure analysis of centrifugal pump

The centrifugal pump is designed according to the principle of centrifugal force, the high-speed rotating impeller blade drives the water to rotate, the water is thrown out, so as to achieve the purpose of conveying. There are many kinds of centrifugal pumps, which can be divided into civil and industrial pumps from the use. From the transport medium can be divided into clean pumps, impurity pumps, corrosion resistant pumps and so on.

Centrifugation is actually the manifestation of inertia of objects, such as the water droplets on an umbrella, when the umbrella slowly rotates, the water droplets will follow the umbrella rotation, this is because the friction between the umbrella and the water droplets as a centripetal force to the water droplets. But if the umbrella spins faster, this friction is not enough to keep the water droplets moving in a circle, then the water droplets will break away from the umbrella and move toward the outer edge, just like pulling a rock with a rope in a circle. If the speed is too fast, the rope will break and the rock will fly away. This is called centrifugation.

The basic structure of the centrifugal pump is composed of six parts, respectively: impeller, pump body, pump shaft, bearing, sealing ring, stuffing box.

1, The impeller is the core part of the centrifugal pump, it has high speed and large output force, the blade on the impeller plays a main role, the impeller should pass the static balance experiment before assembly. The inner and outer surfaces on the impeller should be smooth to reduce the friction loss of the water flow.

2, The pump body is also called the pump shell, it is the main body of the pump. It plays the role of supporting and fixing, and is connected with the bracket for mounting bearings.

3, The role of the pump shaft is to connect the coupling and the motor to pass the torque of the motor to the impeller, so it is the main component of transferring mechanical energy.

4, The bearing is set on the pump shaft to support the pump shaft components, there are two kinds of rolling bearings and sliding bearings. During the operation of the pump, the temperature of the bearing is up to 85 ° C and generally runs at about 60 ° C, if it is high, it is necessary to find the reason (whether there are impurities, whether the oil is black, whether the water is in) and timely treatment.

5, Sealing ring is also known as leakage reduction ring. In order to increase the backflow resistance and reduce internal leakage, delay the service life of the wheel and the pump shell, the sealing ring is installed at the inner edge of the pump shell and the external aid of the impeller, and the sealing gap is maintained between 0.25 and 1.10mm.

6, The packing box is mainly composed of packing, water seal ring, packing cylinder, packing gland, water seal tube. The function of the stuffing box is mainly to close the gap between the pump shell and the pump shaft, so that the water in the pump does not flow outside and does not let the outside air enter the pump. Always maintain the vacuum in the pump! Special attention should be paid to the inspection of the stuffing box during the operation of the pump, and the stuffing should be replaced after 600 hours of operation.

7, The axial force balancing device in the centrifugal pump operation process, because the liquid is at low pressure into the impeller, and at high pressure out, so that the pressure on both sides of the impeller is unequal, resulting in the axial thrust pointing to the entrance direction, will cause the rotor axial movement, wear and vibration, so the axial thrust bearing should be set up in order to balance the axial force.