Hydraulic excavator has many structures and degrees of freedom. The number of hydraulic action elements is large and the action required is very complex, so the hydraulic system is required to be very high. In order to achieve these requirements, hydraulic systems must adopt various measures, summarized, including the following points.
1.The control performance of excavator is high, the fine operation requires fretting, the high productivity requires fast action, the speed regulation range is wide, the operation resistance changes greatly and the power variation range of various working conditions is large. Therefore, the speed regulation of each action element is good.
2.Excavator operation requires each hydraulic acting element to act independently, but in most cases, it requires each acting element to cooperate with each other to achieve composite action. In addition, the boom, stick, bucket, slewing and walking almost all need composite action, and the composite action has a wide range, complex and diverse forms. At the same time, it requires good composite handling performance, which can reasonably distribute the common action time The flow and power of each hydraulic element.
3.Excavator as production equipment, long working time, large energy consumption, requires high efficiency of hydraulic system, reduce energy consumption and emissions, make the total heat generation small, hydraulic oil temperature should not be too high, for all hydraulic components and pipelines are required to reduce energy consumption, so energy saving measures should be fully considered in hydraulic system.
4.It is very important to improve the production efficiency of excavator. The hydraulic system should consider matching well with the engine and make full use of the full power of the engine.
5.The working condition of excavator is bad, the load change is violent, and the impact vibration is large, which requires the reliability and durability of hydraulic components.