Daimler claims its newly developed Electro-Hydraulic Power Steering (EHPS) system can reduce the fuel consumption of buses.
The fully integrated system replaces the conventional power steering pumps used in all buses with a weight over 7.5 tonnes.
The system will come as an option on all Mercedes-Benz Citaro city buses from mid 2017.
Demand-based actuation of the electric power steering pump, which had previously been powered by the combustion engine, means that steering assist can be used, regardless of the engine speed.
The steering unit consists of a three-phase current synchronous motor, control unit, high-performance electrical system and hydraulic pump in a single housing, and enables simple visual inspections of the power steering fluid reservoir.
Shorter hydraulic pipes ensure that system-based friction loss is reduced within the hydraulic circuit, according to Daimler.
The intelligent control system converts vehicle data to a demand-based actuation of the electrically operated pump, providing the right amount of steering assistance depending on the driving situation.
The system was developed in collaboration with the Engineering Center Steyr GmbH and Co. KG in Austria, and was awarded by judges in the innovation category at the international Busworld 2015 trade fair in Belgium.