Modelling radial lip seal friction - A multi-scale mixed lubrication approach

verfasst von

B. Wennehorst, T. Engelke, G. W.G. Poll

Abstract

In continuation of earlier investigations into lubricant film formation and the frictional characteristics of radial lip seals, further measurements of the seal under-lip temperature are performed. Utilizing the measured film thickness profiles and the actual lubricant viscosity the viscous lubricant friction component is computed. Comparison with the total measured friction torque clearly indicates that there is an additional boundary friction component which is nearly independent of rotational speed. Based upon these experimental results a multi-scale mixed lubrication approach is proposed allowing for the estimation of radial lip seal friction. Viscous heating is modelled assuming a constant lubricant film thickness being of the order of the combined contact roughness, while speed-independent boundary friction is accounted for by an empirically determined boundary friction coefficient. Micro-scale frictional heat generation is coupled to the actual macro-scale sealing system assembly utilizing an empirically determined relationship between seal under-lip temperature and specific friction loss, thus allowing the calculation of the actual lubricant viscosity. Starting from a first temperature estimate, frictional heat and seal under-lip temperature are computed iteratively until a converged solution is obtained yielding the under-lip temperature and friction torque as a function of the operating conditions and seal-specific parameters. The applicability of the approach is demonstrated for different seal materials, lubricant viscosities and realistic sliding speeds. It is furthermore illustrated how the relationship between seal under-lip temperature and specific friction loss could be derived from thermal finite element analysis or conjugate heat transfer analysis of the sealing system.

Organisationseinheit(en)

Institut für Maschinenkonstruktion und Tribologie

Typ

Aufsatz in Konferenzband

Seiten

207-226

Anzahl der Seiten

20

Publikationsdatum

2011

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Erdkunde und Planetologie (sonstige)