Bearing seal with backup device

摘要

A bearing seal assembly includes a pair of segmented circumferential e.g. carbon ring seals (54, 56) to contain oil in the bearing compartments of a gas turbine engine or other mechanical device. The pair of seals, an oil-side seal (54) and an air-side seal (56), are axially-spaced between the oil and the air in the housing. Air at an elevated pressure is introduced between the seals (54, 56). This elevated air pressure urges the seals (54, 56) axially apart from one another and radially inward to improve the seal. A backup seal (76) is provided adjacent either the oil-side seal (54) or the air-side seal (56). In the event of failure of either the oil-side seal (54) or the air-side seal (56) which results in the loss of air pressure, the backup seal (76) will provide at least a minimum level of seal between the oil compartment (26) and the air in the housing.