Design and application of hydrodynamic efficiency control system for high-power bulldozer with hydro-mechanical transmission

To avoid excessive temperature rising and low transmission efficiency of high-power bulldozer when it worked in hydrodynamic operation mode during a long time, hydrodynamic efficiency control system (HECS) was designed and implemented for the high-power bulldozer. Non-causality integrated powertrain model including engine, torque converter and shift clutches was built for bulldozer, and control models of load-delay-acting and heavy-load-prejudging were proposed and realized. The heavy-load working condition of high-power bulldozer was simulated with the control aim of hydrodynamic transmission efficiency, as can be derived that torque converter could operate on ideal high-efficiency level by adjusting engine throttle opening and actively reducing external working load, and the high temperature problem may be resolved effectively.