Development of hybrid EPS

Abstract

Current HPS consists of gear, pump, tank, piping and oil cooler. On the other hand, our Hybrid EPS consists of gear, piping and a special power pack which integrates pump, tank, ECU and motor. Our system is basically the same one of the hydraulic standard like PS system as shown here. Our system, therefore, can be installed with minimum modification of engine compartment.(Fig.1)Similar system so called Hydarulic Electric Power Steering (here after called HEPS) use by several OEMs consists of same as our system. But it uses exactly hydraulic PS gear. Only difference between hydraulic PS and HEPS is how to drive PS pump. HPS uses engine to drive pump. HEPS uses motor to drive pump. Both of them are purely HPS. Our system uses gear with torque sensor. So structure is similar between our Hybrid system and HEPS but clearly different system.