Non-Contacting Face Seal Application: Gearbox
The Gearbox in a commercial aircraft engine had multiple locations with carbon face seals experiencing high leakage and seal failures. Technetics’ Qualiseal® Technology was called upon to find a solution to reduce time and expense due to maintenance downtime.
Operating Conditions
- High speed (up to 27,000 rpm)
- Gearbox oil (MIL-R-23699)
- 5 psid
Determining Cause and Failure Modes
- High heat generation of seals caused oil to coke
- Abrasive coke particles became embedded in sealing faces causing excessive leakage and wear
- Seals had to be replaced on the wing before scheduled maintenance of the gearbox due to excessive leakage
Technetics’ Qualiseal® Technology Solution
- Designed a new non-contacting carbon face seal with hydrodynamic features on the mating ring to reduce heat generation
- The new design allows for maintenance-free seals before the gearbox is pulled for scheduled maintenance
- Final design solution required NO COST INCREASE over the original product
