Hydraulic steering system of vehicle, has first pump as main steering pump and variable displacement vane pump as emergency steering pump

摘要

The system has a first pump (7) as a main steering pump and variable displacement vane pump (2) as the emergency steering pump. A check valve (6) is configured for preventing a discharge flow of the second pump in the reverse direction. The second pump is provided with a rotor having a slot for guiding a wing. The wing and slot has a surface roughness. An independent claim is included for a method for a steering system.