Systems & Components: Fluid technology for off-highway applications – hydraulic systems on mobile machines are becoming increasingly intelligent 

Hydraulic and electro-hydraulic systems for the off-highway market of today and tomorrow will be at the centre of Systems & Components, which will take place from 10th to 16th November alongside Agritechnica 2019.

The challenges for fluid technology are substantial in the agriculture, construction and forestry sectors, where it is used not only for manoeuvring heavy loads at height, but also for drive systems on the machines themselves. Exhibitors taking part in Systems & Components in Hanover, Germany, will present an impressive cross-section of equipment, from current trends to technological innovations, for original equipment manufacturers to flexibly adapt their solutions to the needs of their customers.

Frankfurt/Main, Germany, 24th October 2019 – Systems & Components exhibitors from the hydraulics sector continually redefine both efficiency and comfort in the daily work routine of agricultural, construction and forestry machines equipped with modern drive, suspension and steering systems. The solutions that will be on display in mid-November at Hanover’s Exhibition Grounds will provide improved handling and increased efficiency, delivered through innovations such as hydraulic wheel hub motors as an additional drive. This is suitable equipment when a vehicle primarily moves on paved roads and only temporarily requires increased traction when off-highway or as a traction aid on steep ramps. A press of a button in the cabin is all that is needed to activate the additional drive.

All-wheel drive at the press of a button

Hydrostatic gearboxes differ considerably from the permanent all-wheel drives with a conventional drive shaft. They are the state-of-the-art for heavy off-highway vehicles, where a high-pressure pump connected to one or more hydraulic motors is at the heart of the drive system. The mechanical power of the diesel engine is converted into hydraulic power by the pump, and transmitted to the drive axles via differential gears. Here, the latest developments combine two and three-stage planetary gears with axial-piston hydraulic motors to form individual and modular stepless drive packages for machines for the agriculture, construction and forestry sectors.

Depending on the driving conditions, only as much torque as is actually required for traction is delivered to the part-time drive on the front axle. This is managed by an intelligent control system using sensors that detect the slip, weight and angle of inclination of the vehicle. The optimum design of the high-pressure pumps and motors not only improves the efficiency of the drive, it also clears the way for downsizing the diesel engine. Depending on the vehicle configuration, the payload advantage compared to a conventional all-wheel drive is up to 750kg. Added to this are fuel savings gained when the system is switched off and the non-driven wheels rotate freely.

Full power with less loss 

Hydraulic systems on mobile machinery is a natural area of focus when manufacturers want to improve fuel economy. For this reason, the focus of many exhibitor stands at Systems & Components will probably be on the presentation of the latest generation of load-sensing technologies. These promote a control principle for demanding hydraulic applications in an open circuit where the oil flow is divided and exactly adjusted according to current pressure and volume requirements.

Step by step, the signal lines, which today are often still hydraulic, are being replaced by an electronic control system that dynamically adjusts the maximum pressure to individual implements and functions. As a result, no implements stop or operate in an unforeseen manner, even when the diesel engine is at full capacity. The driver can concentrate on the task at hand, and define the characteristics of the working hydraulics by selecting the respective mode on a touch-screen. This results in fuel savings and a higher handling capacity, which is especially apparent in machines with complex tasks and changing applications.

However, this alone is still not enough. To ensure the highest efficiency of driving and working hydraulics at reduced engine speeds, intelligent networking with the diesel engine control system via corresponding function modules is required. The hydraulic system signals the expected load requirement in advance to the diesel engine, which then operates proactively to avoid major fluctuations. This means both systems can work together to reduce fuel consumption and exhaust emissions by up to 20 percent.

Digitisation as a driver for innovation

What does the future hold? The Internet of Things (IoT) is becoming increasingly relevant for mobile machinery, which means the competition between electro-mechanics and fluid technology will continue to increase. Practically every exhibitor at this year’s Systems & Components is looking for ways to sound out the opportunities of digitisation for themselves and their products. The technology suppliers are confronting this competition by capitalising more strongly on the networking of hydraulics and electronics to increase the power density of their drives and to further optimise controllability.

Already today, hydraulic valves record their switching processes and pumps determine their load spectrum. In preparation for cloud-based services, machine manufacturers are integrating sensors that measure the pressure, volume flow and temperature. These not only support accurate remote diagnosis, they also serve to continually improve the components. In the future, electro-hydraulics will probably play a central role in many applications, like those used in powerlift control systems. The physical advantages of fluid technology are combined with digital control, while also forming the basis for assistance systems that decrease the strain on the driver and increase the safety of the vehicle. This enables manufacturers to reduce their development and assembly costs by shifting previous hydro-mechanical functions to the control software. Furthermore, large parts of the hydraulic pipe network is eliminated, which results in reduced maintenance effort and costs.

Showcase for off-highway innovations

When the quantity and diversity of the innovations presented at Systems & Components are considered, it becomes apparent that fluid technology is a dominant topic at Hanover. Advanced modular drive technology, implemented in hydrostatic systems, forms the heart of stepless, power-split gearboxes for the off-highway market. Exhibitors will score points with a broad range of hydraulic components and systems that promise added dynamics, reliability, operating comfort and productivity for mobile machines like wheeled or tracked excavators, self-propelled foragers and combine harvesters.

The offerings on the trade fair stands will include pumps with even more compact dimensions and improved efficiency; hydraulic motors; valve technology; gears; and electronics for open- and closed-loop circuits. The diversified term of intelligent networking will be applied to a large number of exhibitor’s developments, but they all have one thing in common – smart components that communicate with each other and are the key to consistent system integration. Visitors can also learn about the potential digital systems have, and where the industry is today, in the “Future Lounge”, the trade forum of Systems & Components in Hall 17.