Surface Creep of Mineral Oil on Inner Ring of Momentum Wheel Bearing

摘要

Lubricant distribution on the inner ring of an inner-ring rotating bearing may depend on the creep of oil from the bearing raceway up onto the land and subsequent transfer to retainer surfaces. To study creep patterns for a bearing spinning at speeds up to 9000 rpm, a fixture was built so that the motion of the oil could be observed and photographed using ultraviolet stimulated luminescence of the oil. Oil was supplied by and impregnated wick that was allowed to rub against what would normally be the ball track in the raceway (the balls were not present). The oil was observed to migrate up the curved surface until it reached the corner of the raceway. A bead of oil would form at that corner. In on case did oil actually creep across the land. The oil bead thickness was a function of speed, but at 9000 rpm should be approximately 0.12 mm (0.005 in.). (Author)