Polymeric materials used in technical seals – static friction. Determination of frictional resistance apart from durability is a significant issue during the design of the dynamic seals, especially working in reciprocating motion. Friction losses in sealing joints may significantly reduce the whole system efficiency during start-up period. Tribological research of selected sliding couples (a polymeric material on metal) in the static friction have been carried out.

Comparison of efficiency of two hydraulic systems with the throttle controlled actuator. In the paper two hydrostatic systems with a throttle control fed by a fixed pump have been compared. Energy efficiency of hydrostatic systems with hydraulic cylinders controlled by a proportional directional valve has been pointed out. Diagrams of energy efficiency of two hydraulic systems worked at the same parameters have been presented.

The analysis of the external viscous damping influence on the vibrations of the hydraulic cylinder set. The work concerns of the damped transverse vibrations of hydraulic cylinder set. The results of calculations concern the assign of dependence of two first eigenvalues on extension of the hydraulic cylinder including the influence of fluid in the cylinder (or in its surroundings) as a factor of its vibration damping. The influence of size of external damping on the first eigenvalue of system has been introduced.

Design optimization of aerostatic bearing unit applied to the electrospindle for grinding. The main objective of the research was optimization of the flexible membrane thickness used in aerostatic cone bearing of the electrospindle for grinding. The strength analysis module of Autodesk Inventor enables both stress and deformation examination of the assembled mechanical unit. The optimization of the membrane thickness was performed. Objective functions of the optimization were mass minimizing and maximum allowable deformation of the bearing elements.