A Groundbreaking Rotary Seal That Redirects Grease To Where It Belongs
CHALLENGE
To cost-effectively prevent grease leakage in a main bearing application that was not designed for traditional seals.
SOLUTION
System Seals developed an abrasion-resistant, helical-style seal that redirects leaking grease back toward the bearing as the turbine rotates.
RESULT
The new VORTEX seal design stopped main bearing leaks in the field and prevented the wind turbine manufacturer from having to redesign the main bearing for new builds. The solution provided significant reductions in overall cost of ownership.
A global wind turbine manufacturer developed a main bearing design that relied on a labyrinth system for grease retention. The principal works well in certain applications. However, a wind turbine is not one of them.
Making matters worse, the bearing ring surface was not designed to accept a traditional rotary seal. A significant machined lead angle created a rough surface, and grease was being drawn away from the raceway.
Grease was leaking from hundreds of wind turbines at an increasing rate, creating an accelerated need for maintenance – from two up to four times per year. The issue severely impacted O&M costs. More significantly, the leaks increased up-tower safety concerns and the risk for bearing failure.
System Seals set out to resolve the issue, and the innovation proved to be revolutionary: System Seals created a helical-style seal that redirects leaking grease back toward the bearing as the turbine rotates. The VORTEX seal was a stroke of genius that led a global wind turbine manufacturer to retrofit all its existing labyrinth seals in the field.
The design was so effective, it afforded the turbine manufacturer a cost-out opportunity by avoiding additional engineering resources and increased costs associated with redesigning the main bearing for new builds. The VORTEX sealing solution lowered O&M costs, decreased up-tower safety risks and drove out costs for new builds.
Since this initial opportunity, the VORTEX profile has been expanded into a family of sizes that retrofit bearing housings currently designed for traditional radial lip seals. This allows the same leak prevention across most major platforms in operation.