Design and Analysis of a Novel Mechanic- Electronic-Hydraulic Powertrain System for Agriculture Tractors

This paper introduces a mechanic-electronic-hydraulic powertrain system (MEH-PS) composed of an electro-mechanical hybrid system and hydro-mechanical composite transmission according to current mainstream drive and transmission technologies. Firstly, the structural design concept of the system is introduced, and the power and transmission components are selected according to the actual working requirements of the tractor. Then, the principles of various drive modes and transmission modes of the powertrain system are explained, and the speed regulation characteristic curves of the hydro-mechanical transmission (HMT) are given; the speed characteristics, torque characteristics, power split characteristics, and efficiency characteristics of the powertrain system are analyzed. Finally, a tractor simulation and test model was developed to verify its performance under certain operating conditions. Simulation results show that: the tractor acceleration performance is improved, the speed range is wider, the power components and hydraulic components can also meet the requirements, the HMT in a wide range of speed to maintain the average efficiency of above 86%. The bench test results show that: the step-less speed regulation characteristics and efficiency characteristics of the powertrain system are basically consistent with the simulation results.