Electrically Powered Hydraulic Steering


Electrically Powered Hydraulic Steering (EPHS) by ZF TRW is an innovative steering technology that allows a conventional hydraulic steering system to run without an engine driven pump. This can be used on conventional petrol and diesel vehicles as well as hybrid and electric vehicles.  The level of assist provided by EPHS can be varied depending on the vehicle speed and rate of steer, giving a tailored steering feel and  substantial fuel savings over traditional hydraulic power steering.  Without the need for a direct connection to the engine an EPHS pump can also ease packaging issues as it can be positioned virtually anywhere in the engine bay, or in any other convenient location where it can be connected to the steering rack.

To learn more about Conekt’s EPHS products or to request a CAD model, please contact us.

Summary

Advantages
• Multi-speed steering assist based on steering rate and vehicle speed
• Reduced steering effort at dry park and low speed
• Improved controllability at high speed
• Reduced vehicle fuel consumption (typically -0.2 litres / 100 km ECE-cycle)
• Reduced development time and cost
• Compact dimensions, easy to package and install

Sample Technical Specification for 100-C*
• Motor Pump Unit Integrated unit comprising an electric motor, a hydraulic pump, an electronic control unit (ECU), and reservoir
• Electric Motor Brushless PMAC rotor with inner rotor, sinusoidal commutation
• Pump Outer gear pump with constant displacement volume
• Pump Flow 12.0 l/min
• Maximum System Pressure 120 bar
• Speed Control Multi-speed, steering rate and vehicle speed (with sensors)
• Hydraulic Power 1000 W
• Maximum Current @ 13.5 V 115 A
• Stand-by Current <2.5 A
• Operating Temperature Range -40ºC to 105ºC
• Weight (dry) 5 kg
 

* Other motor pump units are available depending on application requirements