In the hydraulic system of construction machinery, gear pumps and hydraulic pumps are two types of core power components. There are significant differences between the two in working principles, structural characteristics and applicable scenarios, which directly affect the operating performance of the equipment.
From the working principle, the gear pump realizes oil suction and discharge through the rotation of a pair of meshing gears. Other hydraulic pumps represented by plunger pumps change the sealed volume through the reciprocating motion of the plunger in the cylinder hole, and use the distribution plate to control the suction and discharge of oil. The pressure transmission is more direct and can achieve higher working pressure.
In terms of structural composition, the gear pump has a simple and compact structure, mainly composed of active gears, driven gears, pump bodies, end covers and other components. It has a small number of parts, a relatively simple manufacturing process, and a low maintenance cost. The plunger pump contains precision components such as plungers, cylinders, inclined plates, and distribution shafts, and has extremely strict requirements on processing accuracy and assembly process, which also leads to its manufacturing cost being significantly higher than that of gear pumps.
In terms of application scenarios, gear pumps are widely used in auxiliary hydraulic systems with low pressure requirements, such as steering systems and lubrication systems of construction machinery, due to their simple structure and strong anti-pollution ability. Piston pumps can withstand high pressures of more than 30MPa and have a volumetric efficiency of more than 90%. They are often used in main hydraulic circuits, such as the boom and dipper drive systems of excavators, and the bulldozer lifting systems of bulldozers, etc., for heavy-duty conditions.
