​Working principle of gear pump

The working principle of the gear pump mainly relies on the spatial changes of the meshing gears in the pump cylinder. These spatial changes cause the liquid to be sucked in and discharged. 12

A gear pump usually consists of two gears, a pump body and a front and rear cover. The two gears rotate in the pump body to form two closed spaces. As the gears rotate, they create a larger space on the disengagement side, which increases in volume from small to large, creating a vacuum that sucks in liquid. In contrast, the volume of the space on the meshing side changes from large to small, forming a high pressure that squeezes the liquid into the pipeline. The suction and discharge processes are separated by the meshing line of the two gears. The discharge pressure of the gear pump depends on the resistance at the pump outlet.

In order to maintain the smoothness of gear transmission and ensure the strict isolation of the suction and discharge chambers and the continuity of liquid delivery, the overlap coefficient of the gears is usually greater than 1, so that in the gear meshing, before the front pair of gears exits the mesh, the next pair of gears Already engaged. In this way, during the period when the two pairs of gears are meshed at the same time, part of the liquid is trapped in the closed liquid cavity formed by the gears. The volume of this closed liquid chamber changes with the rotation of the gear. When it decreases, it will squeeze the liquid, and when it increases, it will cause a partial vacuum. These phenomena may cause vibration and noise in the gear pump.

Gear pumps are widely used in hydraulic systems. They use the principle of gear meshing and are divided into external meshing and internal meshing gear pumps according to different meshing forms. The external gear pump consists of a driving tooth and a driven tooth, and a sealed volume space is formed by the sealing of the front and rear cover plates. The driving wheel rotates with the motor and drives the driven wheel to follow. The closed volume of the gear on the side that exits the mesh increases, forming an oil suction chamber. The hydraulic oil enters the oil suction chamber of the gear pump from the oil inlet and flows out of the Unicom pressure oil chamber. Mouth discharge. In this way, the hydraulic oil is continuously sucked in and discharged, thereby converting the kinetic energy output by the motor into the pressure energy of the hydraulic oil.