A bearing isolator is a non-contact, non-wearing, permanent bearing protection device. It has a rotor and a stator, and the two are unitized, so that they don’t separate from one another while in use. Typically, the rotor turns with a rotating shaft, while the stator is pressed into a bearing housing. The two components interact to keep contamination out of the bearing enclosure and the lubricant in. Bearing isolators do not require lubrication or any particular shaft finish or condition.

The best bearing isolators are made of metal, usually bronze, and they utilize a vapor-blocking feature, which inhibits the free transfer of vapor contamination when the rotating equipment is cycled on and off.