As observant equipment maintenance and reliability
professionals know, some oil-lubricated
bearings have their lube oil levels set to reach the
center of the lowermost (“6 o-clock”) rolling element.
Allowing lube oil to reach the center of the lowermost
bearing ball of, say, a 70 mm bearing is acceptable at
1,500 and 1,800 rpm. So, why are there still oil rings
in some of those bearing housings if, in fact, the oil
covers one-half of the lowermost rolling element?
When used with rolling element bearings at these--for
pumps--relatively moderate speeds, oil rings serve only
to keep the oil well-mixed and to thus avoid hot oil to
“stratify” and float near the top. Then, there are many
rolling element bearings where the oil level is set well
below the bearing and where the oil rings serves another purpose.
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