Electro-hydraulic systems: the best combination of hydraulics and electrics

29th Nov 2023 - 11:51AM

Publish Date: 02/09/2022

The electrification of the global commercial vehicle segment will gain serious momentum over the next 10 to 20 years, according to a study by ACT Research which predicts that 24 percent of commercial vehicle demand (Class 4 to Class 8 trucks, including transit, coach, school and refuse trucks) in the US, and medium and heavy-duty vehicles in Europe, China and elsewhere in the world, will be all-electric in the future. The report forecasts this number to rise to 28 percent in 2031, and further to 53 percent by 2035.

“This growth in fully electrified and hybrid commercial vehicles presents excellent long-term opportunities for electro-hydraulic steering systems (EHS), which supply hydraulic pressure via a fully electronic and software-controlled electric motor, in combination with a high performance and low noise hydraulic gear pump (e-pump) unit. This does not draw power from the engine and reduces parasitic losses in steering systems,” states Concentric Hydraulics Engineering Director, Matthias Fuchs. Concentric is well known as a leader in hydraulic gear products including pumps, motors, power packs and flow dividers for mobile equipment.


“On a conventional truck or bus, as well as for many off-highway applications, the hydraulic power assistance for the steering comes from an internal combustion (IC) engine driven pump, following the engine speed. Typically, the pump is dimensioned to provide power steering function even at the idle speed of the IC engine, so it is constantly running at full capacity and consuming power from the engine. The controllability of an EHS system reduces the power drain and so increases efficiency in IC vehicles and machines.

“In addition, in a hybrid application, the conventional power steering system cannot be used since the IC engine is turned off when the vehicle is operating in pure electric mode. EHS systems are able to assist here, as they can be used for both hybrid and electric platforms, helping to reduce energy consumption by utilising – power on demand – technology,” he continues.

“This is of particular significance, as energy saving and efficiency are key focuses in the development of new heavy-duty vehicles, in particular in steering systems, where according to Mordor Intelligence, more than 70 percent of the fuel consumed by a conventional hydraulic power steering (HPS) system is unnecessary and can be avoided.”

As an expert in hydraulics with deep knowledge and experience in transportation markets, Concentric’s EHS system has been designed, developed and tested over many years for use in a range of on-road and off-road commercial vehicles globally.

“The Concentric EHS unit replaces the traditional power steering pump, providing only the required power on demand and is able to operate during the electric mode for hybrid applications,” Fuchs states. “Our EHS system has been proven over time to operate well in harsh environments, winning production nominations with established OEMs entering the electric vehicle market.”

The compact Concentric system offers power savings through its pressure-on-demand and variable speed control capability, delivering the primary benefit of reduced energy consumption – up to 50 percent in certain applications. Typically placed close to the steering gear, it also allows for reduced installation costs.

The requirement for less noise pollution in urban areas can also be catered for, with the option of low-noise pump technology, as well as direct electronic control features through Controller Area Network (CAN) Bus communications.

“And while Concentric has a rich history in power-on-demand hydraulic steering solutions since 2014, as the first provider to introduce electro-hydraulic systems for steering, we are also continually looking for new opportunities for innovation. Recently, Concentric developed and introduced a new generation of low noise internal gear pumps, which provide an additional up to 30 percent noise reduction from the previous generation. Currently Concentric is leveraging our deep knowledge for 24V  technology experience to develop and launch a high voltage unit for heavy duty on and off road applications.”


The organisation has also recently announced steps to facilitate integration between its own offerings and that of Engineered Machined Products (EMP), acquired by Concentric in 2021, providing a ‘one face to the customer’ approach for all Concentric products, including EHS technology.

“The acquisition of EMP has been a key part of Concentric’s electrification strategy, as EMP’s product portfolio, technological know-how, and strong relationships have helped to accelerate our growth in electrical products.”
Concentric’s EHS products and newly developed wide range of CAN controllable e-water and oil pumps are suitable for truck, bus, construction and mining equipment applications. Alongside group companies EMP and LICOS, the organisation will showcase a wide range of hydraulic gear pumps and gear motors, which are designed for high performing, heavy duty applications, as well as hydraulic power units with integrated hydraulic valve and sensor functions. In addition to the hydraulic products, Concentric will display the various types for low and high voltage electric water (e-WP) and electric oil (e-OP)pumps and the recent development of high voltage cooling fan modules for hybrid and fully electric commercial vehicle applications at the upcoming BAUMA 2022 trade fair, taking place from 24 to 30 October at the Trade Fair Centre Messe München in Munich, Germany. The Concentric group can be found in Hall 4, on stand 537.


Media contact – Lynne McCarthy – [email protected]


Listed on the NASDAQ OMX Stockholm exchangeConcentric AB is an innovator in flow control and fluid power, supplying proprietary systems and components to the world’s truck, agricultural machinery, construction equipment and industrial applications end-markets. The company has a global manufacturing presence including in the UK, USA, Germany, Sweden, India and China. Concentric’s focus is to develop world class technology with innovative solutions that meet the sustainability needs of its customers. In addition to its acquisition of LICOS Trucktec GmbH, a leading producer of water pumps and electromagnetic fan clutches for the truck industry, the Group acquired both Allied Enterprises, LLC, a US manufacturer of transmission products for the construction, agricultural, material handling and stationary power market, and Engineered Machined Products, Inc. (EMP), a leading US producer of electric and mechanical water and oil pumps, electric fans, thermal management systems and precision machined components, further strengthening Concentric’s capabilities.

Listed on the NASDAQ OMX Stockholm exchange, Concentric AB is an innovator in flow control and fluid power, supplying proprietary systems and components to the world’s truck, agricultural machinery, construction equipment and industrial applications end-markets. The company has a global manufacturing presence including in the UK, USA, Germany, Sweden, India and China. Concentric’s focus is to develop world class technology with innovative solutions that meet the sustainability needs of its customers. In addition to its acquisition of LICOS Trucktec GmbH, a leading producer of water pumps and electromagnetic fan clutches for the truck industry, the Group acquired both Allied Enterprises, LLC, a US manufacturer of transmission products for the construction, agricultural, material handling and stationary power market, and Engineered Machined Products, Inc. (EMP), a leading US producer of electric and mechanical water and oil pumps, electric fans, thermal management systems and precision machined components, further strengthening Concentric’s capabilities.