PUB - Piston Slippers for Robust Water Hydraulic Pumps


A paper on “Piston Slippers for Robust Water Hydraulic Pumps” was published at the 11th International Fluid Power Conference IFK in Aachen.


Water hydraulics are used for applications which require an environmental safety standard for the fluid. In comparison to oil, lubrication with water is a challenging aspect because of the fluid’s lower viscosity. Wear and leakage in water lubricated contacts require lower pressure loads. In order to estimate the possible load carrying capacity in water hydraulics, the tribological contact between the piston slipper and swash plate in axial piston machine and respectively eccentric shaft in radial piston machines is investigated. For this purpose simulations based on the Reynolds-Equation are carried out and analysed.
The results show that the gap height distribution due to manufacturing tolerances between the slipper of a radial piston pump and the eccentric shaft has major impact on the resulting load carrying capacity and the occurring leakage. Furthermore the deformation due to the pressure distribution of slippers made of plastic materials is of the same magnitude as the gap height itself. Therefore the deformation needs to be considered while designing a tribological contact for a water hydraulic pump.

  Deformation of piston slipper due to pressure distribution   Hydrostatic and hydrodynamic pressure distribution