Nenewtonská termální analýza elastohydrodynamického mazání perfluoropolyetherových kapalin s vysokou hustotou

Non-Newtonian thermal elastohydrodynamic lubrication analysis of perfluoropolyether fluids with high density

conference paper

en

Perfluoropolyether (PFPE) fluids with high density are the liquid lubricating oils which possess outstanding thermal stability and extremely lower vapor pressure. Owing to such excellent physical properties, these fluids have been adequately employed for many satellite equipments as lubricants in vacuum environments. In regard to the PFPE fluids, the rheological properties in elastohydrodynamic lubrication (EHL) and the rolling contact fatigue life of ball bearings have been investigated. In the present investigation, a non-Newtonian thermal EHL analysis was performed under the lubricating conditions with the PFPE fluids. The PFPE fluids are Fomblin, Demnum and Krytox. In the numerical analysis, a point contact which was constructed by a pair of steel ball and glass disk was simulated. The solid-liquid phase distribution in the fluid film was estimated from the local temperature and the phase transition temperature. In addition, when the maximum Hertzian pressure and the entrainment velocity were raised to 1.5 GPa and 10 m/s, respectively, its effects were discussed based on the obtained analytical results.

Perfluorpolyetherové (PFPE) kapaliny s vysokou hustotou jsou kapalné mazací oleje, které mají vynikající tepelnou stabilitu a extrémně nízký tlak nasycených par. Vzhledem k těmto fyzikálním vlastnostem, jsou tyto kapaliny používány pro zařízení ve vesmíru a jako maziva ve vakuových podmínkách. V této studii byla provedena nenewtonská termální analýza elastohydrodynamicky mazaného kontaktu s tekutinami PFPE . Byly studovány kapaliny Fomblin , Demnum a Krytox. Numericky byl simulován bodový kontakt reprezentovaný párem ocelové kuličky a skleněného disku. Přechod mezi pevnou a kapalnou fází maziva byl odhadnut z lokální teploty a teploty fázového přechodu. V příspěvku jsou diskutovány výsledky pro podmínky maximálního Hertzova tlaku 1,5 GPa a unášivou rychlost 10 m/s.

Perfluoropolyether (PFPE) fluids with high density are the liquid lubricating oils which possess outstanding thermal stability and extremely lower vapor pressure. Owing to such excellent physical properties, these fluids have been adequately employed for many satellite equipments as lubricants in vacuum environments. In regard to the PFPE fluids, the rheological properties in elastohydrodynamic lubrication (EHL) and the rolling contact fatigue life of ball bearings have been investigated. In the present investigation, a non-Newtonian thermal EHL analysis was performed under the lubricating conditions with the PFPE fluids. The PFPE fluids are Fomblin, Demnum and Krytox. In the numerical analysis, a point contact which was constructed by a pair of steel ball and glass disk was simulated. The solid-liquid phase distribution in the fluid film was estimated from the local temperature and the phase transition temperature. In addition, when the maximum Hertzian pressure and the entrainment velocity were raised to 1.5 GPa and 10 m/s, respectively, its effects were discussed based on the obtained analytical results.

point contact numerical solution, phase diagram

2013

09.05.2013

Society of Tribologists and Lubrication Engineers

Detroit

978-1-62993-289-7

Society of Tribologists & Lubrication Engineers Annual Meeting & Exhibition 2013 / Proceedings of a meeting held 5-9 May 2013, Detroit, Michigan, USA.

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169–171

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