Abstract:

A new hydraulic system was built for the wheel loader ZL50 to save its energy consumption. The energy-saving principle of the constant pressure hydraulic system was described and a new secondary regulation component hydraulic transformer(HT) was introduced. A mathematical model was established for the displacement and pressure of the HT, and the simulation was performed for the HT under its port plate control angle -90°~90° to analyze its displacement and pressure characteristics. A new hydraulic system was built on this basis and its working process was analyzed and compared with the original hydraulic system to reveal its energy-saving potential. The parameters of the main components of the new hydraulic system were defined by the power consumptions of the loader under different operating conditions. The simulation under main pump speeds 0~2200 r/min indicates that the installation power of the new system was reduced to 43% of the original system, showing the clear energy-saving benefit.

Key words: hydraulic transmission and control, constant pressure hydraulic system, hydraulic transformer, secondary regulation, loader ZL50, energysaving