Optimal design of the gear ratio of a power reflux hydraulic transmission system based on data mining

The power reflux hydraulic transmission system (PRHTS) with a capacity adjustment device presents a high transmission efficiency, a wider range of high-efficiency area (eta >= 75%), low speed, high torque, and adjustable capacity factor to correspond to the various working modes of a wheel loader. Herein, based on the working principle of a capacity adjustment device and cluster analysis of V-pattern working condition data, the shift strategy of a capacity adjustment device was designed. By combining the output characteristics of the PRHTS and V-pattern working condition data analysis, the optimal gear ratio was developed. The simulation results demonstrated that, in a V-pattern working condition, the average transmission efficiency of the PRHTS and traction were improved by 6.94% and 8.74%, respectively, based on the shovel efficiency and fuel consumption which are consistent with the traditional hydraulic transmission system. In traction conditions, the average traction force increased by 20.92%, the dynamic factor increased by 19.75%, and the average constant-speed fuel consumption per 100 km decreased by 11.66%, which considerably improved the power and fuel economy of the wheel loader during traction conditions. (C) 2019 Elsevier Ltd. All rights reserved.