Oil trapping characteristics of external meshing cosine gear pump

In order to ensure smooth meshing and operation of the gears in the gear pump, strict separation and sealing of the high and low pressure oil chambers, and even and continuous oil supply to the pump, the overlap degree of gear meshing (generally taken as:==1.1~1.3) is required, which means that before the previous pair of teeth disengages, the next pair of teeth enters meshing again. Therefore, during this period, there are two pairs of teeth meshing at the same time, forming a closed volume between the two pairs of teeth that is not connected to the suction and pressure oil chambers. When the gears continue to rotate, the size of the closed volume will change, which is called oil trapping phenomenon.