液压系统中常用的泵结构分为：齿轮泵、叶片泵和柱塞泵3种。齿轮泵：体积较

Hydraulic systems commonly used pump structure is divided into: a gear pump, vane pumps and piston pumps 3 kinds. <br>Gear Pump: smaller, simpler structure, strict cleanliness requirements of oil, the price is cheaper; but by the shaft unbalanced force, badly worn, leaking large. <br>Vane Pump: double-acting pumps and divided into single-acting pumps. This pump flow uniform, smooth operation, low noise, high operating pressure and volumetric efficiency than gear pumps, complex structure than the gear pump. <br>Piston: high volumetric efficiency, low leakage, can work at high pressure, most of the power for the hydraulic system; however, complicated structure, high precision machining and materials, expensive, high oil cleanliness requirements.

The pump structure commonly used in hydraulic system is divided into: gear pump, blade pump and plunger pump 3 kinds.<br>Gear pump: smaller size, simple structure, oil cleaning requirements are not strict, the price is cheaper;<br>Blade pump: divided into dual-acting blade pump and single-acting blade pump. This pump flow is uniform, running smoothly, noise is low, the pressure and volume efficiency is higher than the gear pump, and the structure is more complex than the gear pump.<br>Plunger pump: high volume efficiency, small leakage, can work under high pressure, mostly used in high-power hydraulic system, but the structure is complex, material and processing accuracy requirements are high, expensive, high cleanliness of oil requirements.

The commonly used pump structure in hydraulic system is divided into gear pump, vane pump and plunger pump.<br>Gear pump: small volume, simple structure, lax requirement on oil cleanliness, low price; but the pump shaft is seriously worn and leaked due to unbalanced force.<br>Vane pump: divided into double acting vane pump and single acting vane pump. The pump has the advantages of uniform flow, stable operation, low noise, higher working pressure and volumetric efficiency than gear pump, and more complex structure than gear pump.<br>Plunger pump: it has high volumetric efficiency, small leakage, can work under high pressure, and is mostly used in high-power hydraulic system; however, it has complex structure, high requirements for material and processing accuracy, expensive price, and high requirements for oil cleanliness.