The pressure and flow of oil cylinder and motor are required to change with the change of resistance and working speed. The special requirements of excavator hydraulic system are as follows:
1. Stepless speed regulation, and all actions are reversible.
2. The overload protection of each working oil cylinder is good, and the braking and speed limiting of walking device and slewing mechanism are reliable. The boom must be prevented from falling rapidly due to its own weight.
3. Carry out compound action to shorten operation cycle time and make full use of engine power.
4. The left and right tracks are driven respectively.
5. There must be measures for pressure release, sudden drop or overflow of high pressure liquid in the hydraulic system.
6. The engine emission of excavator should meet the emission limit of exhaust pollutants.
The applicable conditions of hydraulic excavator operation are as follows:
1. The hydraulic system is complex, and all actions are driven by hydraulic motor. Professional maintenance team and perfect maintenance equipment and facilities must be equipped, and parts supply should be timely, reliable and complete.
2. The hydraulic equipment relies on the hydraulic oil to transfer the force to realize all kinds of excavation actions, and the system is required to be sealed and clean. Only when the daily protection is in place can the superior performance of the excavator be brought into full play.
3. In winter, due to the high viscosity of hydraulic oil, it is easy to cause slow action and low efficiency when starting the excavator, which lasts for nearly half an hour, so the special hydraulic oil must be used in winter operation. Compared with mechanical excavators, hydraulic excavators have better digging characteristics, so the suitable materials are basically the same as mechanical excavators. When mining and loading high bench materials, the effect of hydraulic front shovel is better than backhoe, while when mining and loading thin layered materials, the effect of hydraulic backhoe is better than front shovel, but the mining height of hydraulic backhoe is small.
