The drive function of compact loader applications typically relies on closed-circuithydrostatic transmission as a mature solution. This study adapts an innovative concept termed Electronified Open Circuit Drive (eOC-D), incorporating three open-circuit units,one pump to drive two motors, offering stepless speed control for the hydrostatic transmission. This innovative eOC-D concept is derived from the electronified open-circuit (eOC) unit by Rexroth. With four-quadrant capabilities in terms of displacement and speed, the eOC unit can smoothly transition from negative to position displacement, functioning as both a pump and a motor. Consequently, the eOC-D concept enhances drive performance through advanced electronic control of pressure, flow, torque, and power. In addition, the eOC-D approach leads to a significant reduction in component costs when compared to the closed-circuit architecture. To prove the concept, a simulation model is developed in the Simulink environment utilizing the lumped-parameter method with a 67kW power-rated compact loader as reference machine. Through simulations, the eOC-D system is sized considering an optimal combination of pump, motor, and gearbox. The performance of energy efficiency and dynamic response is evaluated from simulation. With baseline measurements as inputs, the eOC-D system demonstrates higher efficiencies and faster response compared to the baseline The efficiency improvement ranges from 5% to 10%, while the response time sees a reduction of over 50%.
Posted on 2026-4-20 19:24:56