Japanese Auto major Nissan has developed world’s first and very innovative power steering system for its upcoming Hybrid car Nissan Fuga Hybrid which is due for its launch in year 2011. We have already covered technical article on the two most popular power steering systems – Electric Power Steering VS Hydraulic Power Steering.
This new technology called the Electro-hydraulic Steering System combines the best of both these technologies to make it a wonderfully energy efficient and pleasure to drive system.
What Is Electro Hydraulic Steering System ? How Does Electro Hydraulic Power Steering Work ?
As you can see in the above diagram, the steering rod is powered with a hydraulic system just like any other Hydraulic Power Steering system, but a major difference is that in conventional Hydraulic system, the Hydraulic System will extract power from the engine, which lowers the total power output of the car and decreases the fuel mileage of the car slightly. On the other hand, in this electro hydraulic power steering system, the power to the hydraulic system is delivered by an electric motor and not the engine directly. This means that the engine load does not change as the power is being delivered by battery and motor.
Another added advantage is that the electric motor gets operated and controlled by the ECU unit which controls the motor very precisely by accurately monitoring the steering force, vehicle speed and steering angle. This added intelligence makes the system very comfortable to drive and improves the handling & feel to a great extent.
A short Extract from the press release from Nissan
For the first time in the world, an Electro-hydraulic Power Steering system has been adopted in which the motor is activated only when the driver is steering. The system is smaller than traditional power steering systems, which was achieved by integrating multiple parts. It offers the advantages of both types of steering – the natural and smooth steering of hydraulic power steering and the improved fuel efficiency of electric power steering – combined to create a balanced system fitting the Nissan Fuga and Infiniti M’s luxury sport sedan buyers’ needs.
source – Nissan
Also Read – Electric Power Steering VS Hydraulic Power Steering.