Abstract:

An energy-saving Electromagnetic clutch Electronically Controlled Hydraulic Power Steering System
(E-ECHPS) was proposed with an electromagnetic clutch to control the steering pump for reducing the energy
consumption of hydraulic power steering system (HPS) and improve driver’s feel on high speed road for heavyduty
vehicles. FEA (finite-element analysis) models were established to investigate the dynamical characteristic
curves of main and vice motor in electromagnetic clutch. Based on power changes in electromagnetic clutch,
an energy-saving of the E-ECHPS was analyzed. Energy dissipation and assist characteristic of the E-ECHPS
under steering situation and straight road condition were simulated. The results show that electromagnetic
clutch torque decreases with vehicle speeds increase under steering situation; the E-ECHPS saves energy
consumption more than 71% compared to HPS in the time interval with the vehicle speeds of 10, 40, 80 km/h
under straight road condition. The results indicate that the E-ECHPS can realize the variable assist characteristic
and have significantly better energy efficiency than that of the HPS.

Key words: heavy-duty vehicles, Electronically Controlled Hydraulic Power Steering (E-ECHPS) system, electromagnetic clutch, energy saving, assist characteristic