Latest seal designs help to boost bearing life
January 1st 2006

The costs associated with premature bearing replacement as a result of failure due to contamination can be considerable.

A rolling bearing subject to contamination may require replacement at a point in its lifecycle that is a mere fraction of the life expectancy that would otherwise be achieved if operating in a clean environment.

In addition to being forcibly injected by means such as highpressure hosedowns, contamination in the form of moisture can be drawn into rolling bearings by the vacuum created as bearing internal air pockets cool after machines shut down.

Moisture saturates the grease lubricant, congregating around the points of contact between balls and raceways and exposing these areas to developing corrosion.

Where contamination is from dust, the overall result - bearing failure - is the same.

NSK says the key to determining the impact of contaminated operating conditions on bearing service life is an analysis of rolling bearing failure modes through individual bearing examinations combined with consideration of bearing replacement history and applied loads.

Problems can be overcome using bearings protected with sealing appropriate to the environment. NSK offers Triple-Lip and Flinger seals and, for high speed applications, the noncontact labyrinth V-seal that is said to eliminate seal lip friction.

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