Pumps Wiki Knowledge
Working principle and maintenance of gear pumps
A gear pump is a rotary pump that transports liquid or pressurizes it by relying on the variation and movement of the working volume formed between the pump cylinder and the meshing gears.
（1） Working principle of gear pump:
Gear pump is a type of volumetric pump, consisting of two gears, a pump body, and a front and rear cover to form two enclosed spaces. When the gears rotate, the volume of the space on the disengaged side of the gears increases from small to large, forming a vacuum that sucks in liquid. The volume of the space on the meshing side of the gears decreases from large to small, and the liquid is squeezed into the pipeline. The suction chamber and discharge chamber are separated by the meshing line of two gears.
The pressure at the discharge port of a gear pump completely depends on the resistance at the pump outlet.
（2） Gear pump operation and maintenance
1. Gear pump start:
(1) Before starting, check the sealing of all pipeline flanges and joints.
(2) Disc coupling, no friction or collision sound.
(3) The first startup should inject the conveying liquid into the pump.
(4) Before starting, the valves in the suction and discharge pipelines should be fully opened, and it is strictly prohibited to start with the valve closed.
(5) After verifying the direction of motor rotation, start the motor.
2. Gear pump shutdown:
(1) Turn off the motor.
(2) Close the inlet and outlet valves of the pump.