Bearings are contained within a housing from which a shaft extends. The shaft entry into the housing offers an opportunity for dust and moisture to enter the bearing. The shaft seal closes the gap between the housing and shaft. Choosing the appropriate shaft seal and seal configuration to protect against the penetration of dust and moisture is critical to bearing life.
Bearing housing seals for dusty environments are traditionally oil seals. NBR oil seals are the most common and allow for some flexing of the shaft. To keep out dust when putting a lip seal into place, ensure the sealing lip faces outward.
The lip oil seal, while selected mainly for sealing the shaft to housing gap, is typically an unsatisfactory sealing device. Over time, the lip causes fretting corrosion of the shaft (the gouge seen under the lip when it slides off the shaft). Moisture on the shaft capillaries is drawn past the lip, and water sprayed directly at the lip seal blows past the seal and into the bearing. Oil seals are rarely replaced in installed equipment even though the seal is a perishable component and should be replaced routinely.
Extreme Bearing feature a specially developed centrifugal seal contained within a housing in order to prevent wear on the shaft through abrasion by an emulsion of sand or dust and water.
The gaps between the lips and the stator of the centrifugal seal must be sealed to keep out dust and water. To improve bearing life for centrifugal shaft seals, use an automatic lubricator. Only a small quantity is necessary when slowly flushed into the bearing cavity to force dust and moisture away from the elements.
Typical Extreme Bearing application with exposure to salt water, a lot of sand and small pieces of shell.
AVAILABLE IN METRIC AND IMPERIAL (INCHES) SIZES