This equipment eliminated a SAG copper mill gearbox’s maintenance issues resulting from contact lip seals that had a short and unreliable service life.
by George Gillespie, Inpro/Seal

Ease of Installation

Onsite installation in the tight surroundings was accomplished by designing a split seal so that it could be installed in the field without decoupling the equipment. To enable the non-contact bearing isolator to work in the operational flood condition, the seal included a larger, optimal-sized D Groove to handle the volume of oil flowing through the system. The labyrinth seal also incorporated an external drain on the seal.

The external drain was designed to be plumbed back into the gearbox above the sump’s static oil level but below the bearings. This isolated the returning oil so that, on its trip back to the sump, it would not be impeded by the oil located between the bearings and the seal. The returning oil had free flow to the sump, and more important, oil no longer leaked from the gearbox through the seal.

Eliminate Safety Hazards & Save Money

Because the customized seal and drain-back system provide a permanent fix, the time and costs associated with maintaining this gearbox have been greatly reduced. Less scheduled maintenance results in more production time for the SAG mill. The environmental and safety hazards have been eliminated, creating a safer environment for personnel.

The two bearing isolators installed on this gearbox have been in operation for two years. Performance expectations continue to be met, and no signs of leaks have been detected. The representative from the seal manufacturer continues to check-in to monitor the bearing isolator’s performance.