ADHESION AND COHESION FORCES OCCURRING IN PARABOLICAL MICROBEARINGS

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ADHESION AND COHESION FORCES OCCURRING IN PARABOLICAL MICROBEARINGS

Journal Title: Tribologia - Year 2009, Vol 227, Issue 5

Abstract

This paper presents the influence of adhesion and cohesion forces on the pressure distribution and carrying capacity forces occurring during the lubrication of hydrodynamic, parabolic sidle microbearings. We are considering the microbearing where the attained values of the journal diameter of about 1 millimetre and micro-bearing gap heights have values up to one micrometer. The lubricant in such a thin gap has specific properties, which are different in comparison to the oil in classical bearings. The micro-bearing journal has a parabolic shape in the longitudinal direction. Therefore, during the journal rotation, the centrifugal forces develop that change the adhesion forces in such thin lubricant layer. Magnification of adhesion forces caused by the centrifugal forces gives the changes of internal friction forces between oil particles; hence, the dynamic viscosity in micro-bearing gap height direction changes more than the same case but in cylindrical micro-bearings. This fact implies the new value of hydrodynamic pressure obtained from adhesion and cohesion forces that never occur in cylindrical bearings. The present paper shows the numerical method for the determination of the mentioned additional hydrodynamic pressure caused by the adhesion and cohesion forces in parabolic micro-bearing gaps.<br/><br/>

Authors and Affiliations

Krzysztof Wierzcholski

Keywords

micro-bearings adhesion parabolic journals

EP ID EP517103
DOI -
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