What Are Oil Pump Gears?

The working principle of oil pump gears mainly relies on the meshing of two or more rotating gears, which change the volume of the working chamber through the rotation and meshing of the gears, thereby achieving the suction and discharge of liquids. This working principle makes the gear pump a volumetric pump, whose flow rate is basically independent of the discharge pressure, and there is pulsation between flow rate and pressure. There is no inlet valve or exhaust valve, and the structure is simpler than that of a reciprocating pump. It is easy to manufacture, easy to maintain, reliable to operate, has a large flow rate, and is more uniform than a reciprocating pump. Gear pumps can be divided into external meshing gear pumps and internal meshing gear pumps based on the arrangement of gears. 

In an external gear pump, two gears are located on the outside of the pump, usually one gear (drive wheel) is connected to a mechanical or electric power source, while the other gear rotates accordingly. The liquid enters the pump through the inlet and is then pushed to the outlet by the gear. When the driving gear rotates, it causes other gears to rotate along with it, drawing liquid into the pump and discharging it to the outlet.

The internal meshing gear pump includes two or more gears that rotate within a sealed pump housing. Generally speaking, there is a driving gear (drive wheel) that rotates through a mechanical or electric power source. When the driving gear rotates, it causes other gears to rotate accordingly. The liquid enters the pump casing through the inlet and is discharged to the outlet as the gears rotate. Internal meshing gear pumps have advantages such as compact structure, small size, and light weight. Moreover, due to the gears rotating in the same direction, the relative sliding speed is small, and the wear is slight, resulting in a longer service life of the pump.

The working principle of a gear pump can be summarized as the following key steps: gear rotation, gear meshing, liquid discharge, and continuous operation. The gear pump repeatedly repeats these steps to provide continuous fluid flow. Gear pumps are widely used in various hydraulic systems and engineering, including but not limited to the automotive industry, presses, excavators, tractors and other machinery.