A concept for the sustained assessment of sliding surfaces based on Merkel Counter Surface Parameters (MCPs) takes into account the specific requirements involved in hard-soft contacts.

Seal counterfaces have usually been assessed on the basis of parameters for metal-to-metal contacts.

However, as a piston and rod seal in hydraulic systems always involves a hard-soft contact, the result obtained for counter-surface assessment in terms of abrasivity, long-term behaviour and oil deposits provides restricted information.

This is leading to greater friction and more rapid wear of the sealing elements in tribological systems.

With MCPs, surface profiles are registered according to the tried-and-tested contact-stylus process.

This is the first time, however, that the parameters relevant for hard-soft contacts are derived from the Abbott Firestone curve.

The parameters defined therein - core peak-to-valley height Rk, peak height Rpk, Rpkx and groove depth Rvk, Rvkx - make it possible to obtain an accurate description of surfaces as seal counterfaces.

As a result, essential properties of the surface topography can now be determined with accuracy in the field of sealing technology.

These include the peaks being responsible for abrasive properties and wear potential; the profile core governing long-term behaviour; and the recesses influencing the conveyance of media - as leaks and/or hydrodynamic lubricating film.

Click on the link at right-hand side of the page for more information.

< Prev		Next >