Ball bearing sealing


There are three methods you can use to seal a ball bearing:

The top half of the shaft shows a conventional lip or grease seal that has very limited life and will cut the shaft directly under the lip. See “fretting

The bottom half of the shaft shows a non-contacting labyrinth seal that will not destroy the shaft and works well, as long as the shaft is turning.

Most of these labyrinth designs are not effective when the shaft has stopped, because you a trying to seal with a “hole”.

There are some new design labyrinth seals that incorporate a static O-ring when the shaft has stopped. They are a better choice

The face seal offers positive sealing of both the oil in the bearing case and the water or moisture that is trying to get in.

Some designs are adjustable so that you can make impeller adjustment in open or semi-open impeller configuration.

A fourth option is a face seal design that uses magnets to hold two lapped faces together.

It is not a good idea to locate magnets next to a bearing. Magnets attract metal particles and you do not need fine metal pieces close to the bearing