Hydraulic systems are characterised by high power density, and may be used for very precise control. Sweden is a leading nation in the development of hydraulic equipment, such as equipment for the construction, forestry, and mining industries, and is also a leader in the manufacturer of components such as pumps, motors and valves. These applications require engineers with expertise in several areas: mechanics, fluid dynamics, electronics, control technology, etc.
Energy losses in the hydraulic systems are responsible for a large part of the fuel consumption in machines such as wheel loaders, excavators and forestry machines. With the new system concept, it is possible to reduce fuel consumption by more than 30%.
Energy efficient hydraulics
The requirements of higher energy efficiency are important in the use of hydraulic systems. Much of our research is therefore focussed on energy efficient hydraulic systems with low metering losses, and systems with energy recovery. It is important in these applications to retain the high degree of control. Another important area is noise control in hydraulic systems. A major source of noise and vibrations in a hydraulic system are the pumps. We have pioneered methods to measure and simulate flow pulsations in the pumps (which is considered to be a good measure of the sound level). This has resulted in several innovations and methods to significantly reduce noise.
In our lab, there is a full hydraulic transmission for equipment such as wheel loaders, where new control algorithms can be tested in a laboratory environment. A technology known as “hardware-in-the-loop (HWIL )” uses new research findings. We also have available a test set-up for the measurement of flow pulsations in the hydraulic pumps and motors. Flow pulsation is used to validate new solutions for pumps and motors. Several rigs are available in which students can test and analyse hydraulic phenomena.