Design and energy saving analysis of heavy-duty vehicles ESC-HPS based on a new-type Electromagnetic Slip Coupling

To improve high-speed “road feel” and enhance energetic efficiency of Hydraulic Power Steering (HPS) system in heavy-duty vehicle, a new type energy-saving Electromagnetic Slip Coupling (ESC) used to control the steering pump output flow is presented. The ESC is composed of main motor, vice motor and energy recycle apparatus which can recycle the slip energy. After establishing ESC FEA model, two motors' dynamic characteristics are studied, and designed ESC characteristic validity is verified by bench test. After analyzing ESC assist flow and power conversion, energy consumption under straight driving condition is simulated, and the results show that ESC-HPS saves total energy consumption more than 65% compared to HPS at three typical speed. It indicates that ESC-HPS can realize the variable assist characteristic and reduce the energy consumption significantly.