Intershaft seal assembly with pressure-balanced translatable carrier

Abstract

An intershaft seal assembly for use between a rotatable outer structure and an inner structure within a turbine engine is presented. The assembly includes a primary sealing ring, a translatable carrier, a secondary sealing ring(s), a lower-pressure chamber, a higher-pressure chamber, a first channel(s), and a second channel(s). The primary ring is disposed within and extends from a circumferential groove about the carrier so as to sealingly engage the rotatable outer structure. The primary ring rotates within the groove and with the rotatable outer structure. Each secondary ring is interposed between the carrier and the inner structure. The carrier slidingly contacts the secondary ring(s). The lower-pressure chamber is generally defined by the carrier and the inner structure adjacent to a higher-pressure side. The higher-pressure chamber is generally defined by the carrier and the inner structure adjacent to a lower-pressure side. Each first channel traverses the carrier so that a gas from the lower-pressure side may enter the lower-pressure chamber. Each second channel traverses the carrier so that a gas from the higher-pressure side may enter the higher-pressure chamber. The sum of the translation-resistant forces (F) encountered by the carrier is less than the translation-resistance force (F) encountered by the primary seal ring.