Experimental study on microelastohydrodynamic lubrication

The effects of surface irregularities on rolling and/or sliding point conta ct elastohydrodynamic lubrication (EHL) have been surveyed on the basis of direct observations using the due-chromatic optical interferometry techniqu e. A local fluctuation in film thickness caused by surface irregularities d epends strongly on shear flow dominating the EHL conjunction and side leaka ge. The influence of pressure flow has been examined in relation to the loc al entrapment at asperities due to pure squeeze motion. In reciprocating mo tion with a small length of the stroke, EHL films are affected not only by surface irregularities but also by air bubbles produced in the previous str oke. The effects of thickener lumps and groove on grease EHL have also been discussed.