Dynamic power matching for wheel loader based on power reflux hydrodynamic transmission system

The power reflux hydrodynamic transmission system (PRHTS) has the advantages of flexible transmission, low-speed torque multiplication, adaptive adjustment of speed ratio to external load, and improved torque converter (TC) transmission efficiency. Therefore, it is highly suitable for wheel loaders. Wheel loaders usually work in harsh environments with complex and changing working conditions, and static power matching makes it challenging to fully utilize wheel loaders’ performance. In response to the above issues, this paper proposes a dynamic power matching optimization design method for PRHTS with capacity adjustment gear (CAG) based on wheel loader. The optimization design method obtains data through V-shaped working condition experiments of the wheel loader, and conducts clustering analysis on the data to obtain high-frequency kinematic segments and their characteristic parameters. On this basis, combined with the analysis of the working principle of PRHTS, the system structural parameters are optimized and designed. Compared with static power matching, the dynamic power matching optimization design method increases the average traction force by 4.9 kN, improves the transmission efficiency by 2.6%, reduces the average fuel consumption rate by 3.66 g (kW·h)−1, and reduces the fuel consumption per V-cycle by 27.7 ml in V-shaped working conditions.