Large hydraulic excavators are mainly used in mining and large-scale infrastructure of various large-scale open-pit mines, of which shovel excavators account for the majority. Compared with mechanical cable shovel, hydraulic excavator has the advantages of light weight, wide speed range, good maneuverability and maneuverability, better running track of excavating work, and also has great advantages in reducing operating cost.
The main function of the moving arm hydraulic cylinder is to lift the full load bucket from any possible excavation position to the unloading point. The moving arm hydraulic cylinder must have the lifting ability at the upper or lower limit position and the locking ability provided during excavation.
The excavator generally has long working time, heavy working load, large power consumption and large system calorific value. In the course of operation, the potential energy and kinetic energy loss are large. For the excavator arm, the potential energy recovery is of great significance to prolong the life of the excavator and improve the energy utilization ratio of the excavator. The main methods proposed at present are to use hydraulic transformer to recover potential energy, store energy in accumulator, or directly use accumulator to recover and store energy, and in hybrid excavator, the falling potential energy recovery part of the arm is directly coupled to the motor for power generation recovery, and finally stored in battery in the form of chemical energy. The above method is easy to realize for small hydraulic excavator, but for large hydraulic excavator, because of heavy weight, inertia, high falling potential energy, And hydraulic cylinder flow is very large, energy recovery of the above hydraulic electrical components can not meet the requirements.
Therefore, in the development of large mine hydraulic excavator, the flow regeneration loop is used to reduce the arm, and the proportional regeneration valve is used to realize the flow regeneration, which improves the working speed of the working device, reduces the hydraulic impact, improves the operating performance, reduces the energy consumption of the hydraulic system and improves the working efficiency.