Over time, the hydraulic component industry for oil hydraulics has gained a monopoly in development. Only components for oil hydraulics have been developed. Compared with oil, water as a hydraulic fluid has a better ecological effect, because it does not pollute the environment. Ecology has restarted the development of water hydraulics, which was used in the early days of hydraulics. The development of water hydraulics is progressing, but can it compete with oil hydraulics?

Hydraulic systems are very common in industry and other technical fields. The most frequently used valves for control are sliding directional control valves, which do not have seals on the control pistons. This causes internal leakage. The stability of the leakage is highly dependent on the purity of the hydraulic fluid. The thesis deals with the influence of the purity of the hydraulic oil on the durability and volumetric efficiency of the sliding directional control valve under consideration. As part of the thesis, a hydraulic test rig was designed and assembled, on which three durability tests of a hydraulic 4/3 directional control valve were performed.

Filtering or removing unwanted solid particles from the medium we want to clean, be it different gases or liquids, is a very complex process. This is already evident in the basic terms related to the type, material and shape of the filter and the filtering process. This is especially evident in the in-depth knowledge of the physical background of the liquid passing through the filter, the mechanisms of the elimination of unwanted particles, and in the modelling and simulation of this process.

The Stewart platform allows simulation in six degrees of freedom. It consists of two irregular hexagons connected by six actuators – hydraulic cylinders. The controlled simultaneous retraction or extraction of the piston rods from the tubes of the hydraulic cylinders changes the length of each leg, achieving the movement of the upper moving platform, which is described using a mathematical background.

Efficient filtering is often crucial in the field of machines and devices, as the safe, reliable, and long-term as well economical operation of the entire system depends on the efficiency of the filter. This is especially true for heavily loaded hydraulic devices. In these devices, the efficiency of the filter and the ability to filter depend on various factors.

To control a hydraulic humanoid robot, it is necessary to design and optimize a hydraulic proportional valve with the lowest possible mass and size. The valve for the robot’s rapid movements must not only be compact, but also allow high flow rates while minimizing internal leakage.

In the introduction of the paper, the requirements encountered in modern machines and hydraulic equipment will be stated. The mutual impact between machine requirements, lubricant quality and specifications will be shown.

This paper studies the closed-loop control of an electrohydraulic velocity servo system with the use of the Lyapunov theory of nonlinear systems using integrator backstepping.

Digital transformation brings great technological and business challenges to organizations. It helps to change the patterns of business operations and has the effect of increasing innovation and competitiveness. At the same time, this is a great opportunity to develop and introduce many positive changes to the existing business and process model.

Due to their simplicity and versatility, load-bearing lattice structures allow construction in hard-to-reach areas, as they are easy to transport, easy to install and do not take up much space. Established engineering practice uses a modular structure design where the load-bearing structure is divided into height segments. In the presented study, we question the appropriateness of such an approach.