Gear pump is also called rotor pump. It mainly consists of gear, shaft, pump body, pump cover, bearing sleeve, Shaft end seal and other components. A rotary pump that delivers liquid or pressurizes by relying on the change in working volume and movement formed between the pump body and the meshing gear. Gear pumps have two structures: external meshing and internal meshing. External gear pumps are divided into double gear pumps, three gear pumps and five gear pumps. External gear double gear pumps are the most commonly used. A pair of meshing gears and the pump body separate the suction chamber and the discharge chamber. When the gear rotates, the volume between the teeth separated from each other on the side of the suction chamber gradually increases, the pressure decreases, and the liquid enters the space between the teeth under the action of the pressure difference. As the gear rotates, the liquid between the teeth is brought to the discharge chamber. At this time, the volume between the teeth at the meshing point of the side teeth of the discharge chamber gradually decreases, and the liquid is discharged