Optimization analysis on the transmission characteristics of multipurpose power transmission device

Abstract A multipurpose power transmission device integrating the hydrostatic, hydro-mechanical and mechanical transmission is designed. This paper mainly discusses the transmission characteristic optimization problem of multipurpose power transmission device from the respective of speed regulation characteristic, shift strategy, and efficiency improvement. In accordance with the design requirements, the kinematic and kinetic analysis for the drive system is performed, the assembly schemes and relevant parameters of power transmission device should be analyzed, and the speed regulation characteristic curve can be obtained. According to the evaluation indexes of shift quality, the shift strategy of power transmission device involving clutches and brakes during the whole speed regulation process, and the best switch time of each component can be found. The hydrostatic system efficiency expression can be derivatized from the efficiency model of pump- control-motor system, and the efficiency of multipurpose power transmission device can be obtained by efficiency definition method; the fitting curves of hydrostatic system efficiency are determined by experimental data, and the efficiency of hydro-mechanical composite power transmission system can be got by conversion mechanism method. The results show that the shift quality of power transmission device can be improved greatly by controlling the switch sequence of clutches and brakes reasonably.