Abstract: In a non-contacting gas seal for a gas turbine engine a seal ring (12) (FIG. 3) is formed from a ring of overlapping segments (16) mounted in a housing (14) on a static component (9) of the engine, and co-operating to define a sealing face (15) which confronts a sealing face (10) on a rotating component (8) to form a seal. The segments overlap and are spaced at their leading ends from the rotating component to define a tapering gap (19) therebetween so that they lift away from the rotating component in operation to ride on a gas film leaving only a very small clearance.In order to ensure that the relative circumferential dispositions of the segments does not alter significantly due to eccentric movements of the rotating component in operation, a dogged ring (34) is provided which is located in the housing by an anti-rotation dog (38) and has spaced dogs (36) engaging each of the segments to prevent circumferential movement thereof while allowing limited radial movement.

Abstract: In a non-contacting gas seal between static and rotatable components of a gas turbine engine, a seal ring (12) (FIG. 4) is composed of a plurality of overlapping segments (16) which co-operate to define a sealing face (15). The segments are located in a housing (14) preferably on the static component with the sealing face (15) confronting a sealing face (10) on the rotating component the arrangement being such that in operation the segments lift away from the rotating component to ride on a gas film leaving a very small sealing clearance therebetween.A secondary seal must be formed between the seal ring and the housing to avoid leakage around the seal ring and this is achieved by a narrow sealing land (23) on the low pressure side-face of each segment being urged into contact with a side-face (22) of the housing by the higher pressure fluid on the opposite side-faces of the segments.

Abstract: U.S. Pat. No. 4,118,079 discloses a fluid bearing in which resilient shells are bent during operation of the bearing in response to changes in pressure of the fluid to make them conform more closely to the confronting surface defining the fluid gap. In the present invention a bearing of this type is used as an intershaft bearing by mounting the shells on one of the rotating shafts the problems associated with centrifugal forces on the shells being turned to advantage by mounting the shells on an external surface of one of the shafts to confront an internal surface on the other shaft. In an application of the invention to a gas turbine engine the two shafts are the high pressure shaft 10 and the concentric inner low pressure shaft 12. The bearing shells 34 of the air bearing 32 are mounted on resilient spring levers 36 on the slower low pressure shaft 12 and their convex surfaces confront the concave internal surface of the high pressure shaft 10, to define the air gap.