Bearing Isolators: Contacting vs. Non Contacting

Bearing Isolators: Contacting vs. Non Contacting

The purpose of a bearing isolator is to prevent leakage of the bearing lubrication while also protecting the bearing lubrication from external contamination. The two basic types of bearing isolators are contacting (positive seal) and non-contacting (labyrinth). The fundamental difference between the two technologies is:

• The contacting IsoMag bearing isolator is a positive sealing device with the seal face closing force provided by magnetic energy.

• The non-contacting bearing isolator is a labyrinth device that relies on close clearances between a stationary and rotating component.

Both technologies work well in applications where the equipment shaft is horizontal and the bearing lubrication method is a bearing sump where the lubrication is “splashed” within the bearing housing.

However, the positive seal provided by the contacting IsoMag bearing isolator provides superior performance in additional services such as:

• Flooded lubrication – gearboxes

• Forced circulation – pumps and steam turbines

• Vertical installations – gearboxes, motors, pumps, mixers, agitators, etc.

• Oil mist systems – pumps, motors and other rotating equipment

• Stand-by conditions – pumps and other rotating equipment

• Submerged – pumps, motors

• Rock and roll – marine pumps

The concern about using contacting IsoMag bearing isolators vs. non-contacting has been with potential limits on operating life (wear of the seal faces) and heat generation due to the friction at the contacting seal faces. Neither of these issues are factors for non-contacting bearing isolators. However, now comes patented technology from IsoMag that provides a positive seal with exceptional operating life (100,000 hours) and virtually no heat added to the bearing temperature.

As the pioneers in the use of magnetic energy to advance bearing isolator technology, IsoMag continues to be on the forefront of innovation to continuously extend rotating equipment meantime between repair (MTBR).

For more information on IsoMag bearing isolator technology click here.