Abstract: A seal structure is provided having a configuration with a very small seal gap between a relatively stationary seal member and a complementary surface on a movable (rotatable) member (such as a rotating shaft) adjacent to which the stationary seal member is mounted. The stationary seal member is movable toward and away from the movable seal member so as to vary the seal gap therebetween. The seal is effective in applications where an incompressible fluid is provided on the high pressure side of the stationary seal member so that leakage along the seal gap is of an incompressible fluid into a lower pressure region on the other side of the seal gap. A sealing dam is provided on the stationary seal member on its sealing face adjacent the low pressure end of the seal gap. A plurality of elongated pads are formed on the sealing surface of the stationary seal member on the high pressure side of the sealing dam, extending perpendicularly to the direction of leakage flow along the seal gap.

Abstract: A method and system for cooling a gas turbine engine in conjunction with an improved gas bearing face seal assembly. The gas turbine engine has a multi-stage compressor which discharges compressor discharge air for expansion by a combustor. A cavity which is aerodynamically linked to a turbine stage on its downstream end is formed by a metal structure the upstream end of which is connected to a seal which substantially inhibits the flow of compressor discharge air into the cavity. A conduit links an intermediate stage of the multi-stage compressor to the cavity for purposes of cooling the cavity and the turbine stage components located downstream of the cavity.

Abstract: A circumferential seal arrangement has one or more expanding carbon rings and a rotating runner concentric to and radially outside of the carbon rings. Cooling oil is injected directly onto the outer circumferential surface of the runner and also in the direction of the bearings. The runner shields the seal interface from the cooling oil. To facilitate scavenging of oil from the cavity between the bearings and seal assembly and thereby further reduce the amount of oil reaching the seal interface, a disk pump is mounted on the main shaft between the runner and the bearing. As the main shaft rotates,, the disk pump slings oil adhering on its surfaces into an annular oil purge channel. The sealing arrangement also incorporates a discourager which forms a barrier to direct oil leaking through the seal interface to an overboard drain.

Abstract: A gas bearing face seal assembly for a gas turbine engine having improved sealing characteristics. The assembly can include support means which concentrically position a face seal member with respect to a seal radius, while permitting translation of the face seal with respect to a rotating sealing surface and radial growth of the seal member with respect to the housing. A clearance control ring means can be included to reduce and maintain radial clearance between the face seal member and a housing surface. The face seal member may be pressurized radially outwardly, and can include improved vent channel and vent passage means.

Abstract: A labyrinth seal for use in a gas turbine engine and placed between adjacently lying differently pressurized compartments where leakage may occur from the higher to the lower pressure compartment, the seal includes a stationary annular abradable shroud and a rotor with teeth and with channels formed between adjacent teeth, a pumping passage formed in the rotor for supplying an additional pressure component during rotation from the lower pressure compartment into the channel lying between the last pair of teeth downstream toward the lower pressure compartment.

Abstract: A piston ring seal for squeeze film dampers includes radial fluid vent passages through the ring section leading from the outer circumferential face of the ring through the inner circumference of the ring to the ring groove. A combination step ring and step groove prevents incorrect assembly.

Abstract: A ring seal having a continuous circumferentially extending and radially facing outside diameter seal dam positioned adjacent the upstream, axially facing, high pressure side of the ring seal. The seal dam is aerodynamically connected to a downstream axially facing, low pressure side of the ring seal by axial vents. A plurality of radially extending upstream face vents on the high pressure side of the ring seal are aerodynamically connected to a corresponding axially facing upstream transverse sealing dam. A plurality of radially extending, downstream face vents on the low pressure side of the ring seal are aerodynamically connected to a corresponding axially facing, downstream transverse sealing dam.

Abstract: A squeeze film damper assembly includes a piston ring and groove seal combination. The piston ring is proportioned with respect to its groove to generate a pressure wave in an annular ring space which closely approximates the pressure generate in the annular squeeze film space, thereby improving piston ring sealing. The radial dimension of the ring space is matched to the radial dimension of the squeeze film space. The assembly can include channels interconnecting the squeeze film space and ring space at corresponding angular positions in the annular spaces, with means for restricting circumferential flow between the angular positions.

Abstract: A hydro-lift seal for the bore region of a seal segment having a shallow groove inlet on the high pressure side of the seal segment. The shallow groove inlet is aerodynamically connected to a shallow groove which extends in the direction of rotation of a seal race, the seal race being connected to a rotating shaft. The shallow groove is aerodynamically connected to a deep groove which has an interface region which is perpendicular to the shallow groove and a region which is parallel to the shallow groove. A vent groove located on the low pressure side of the seal segment is parallel to that region of the deep grove which is parallel to the shallow groove. A plurality of venting holes is located in the vent groove which connect the vent groove to the high pressure side of the seal segment.

Abstract: A squeeze film damper assembly includes a piston ring and groove seal combination. The piston ring is proportioned with respect to its groove to generate a pressure wave in an annular ring space which closely approximates the pressure generate in the annular squeeze film space, thereby improving piston ring sealing. The radial dimension of the ring space is matched to the radial dimension of the squeeze film space. The assembly can include channels interconnecting the squeeze film space and ring space at corresponding angular positions in the annular spaces, with stand-offs for restricting circumferential flow between the angular positions.

Abstract: An axial thrust force-compensating apparatus is provided in a gas turbine engine having relatively rotatable first and second structures. The axial thrust force-compensating apparatus includes a first annular part mounted to the first engine structure and having an annular end surface, a second annular part mounted to the second engine structure and having an annular end surface which opposes and faces toward the end surface of the first annular part, and a primary hydraulic pressure balance mechanism for providing separate outer and inner fluid flows to the respective outer and inner regions between the end surfaces at pressures responsive to the amount of separation existing between the end surfaces at those regions. The separate fluid flows at the pressures produce a film of fluid flowing between and in contact with the respective end surfaces which generates primary compensating moment forces acting on the end surfaces to maintain the end surfaces in generally parallel relationship.

Abstract: In a gas turbine engine including first and second differentially rotating members coaxial with each other, a low pressure region disposed about the first and second differentially rotating members, and an annular gas flowpath disposed within the first and second differentially rotating members defining a high pressure region, a method and apparatus for preventing fluid leakage between the first and second rotating members. An annular carrier is coupled to the first rotating members such that the annular carrier is coaxial with the first rotating member. The annular carrier is sandwiched between a first race and a second race with the first and second races coupled to the second rotating member. The second race is urged toward the first race such that leakage of a fluid from the high pressure region to the low pressure region is not substantially increased by frictional wear of any of the annular carrier, first race and second race.

Abstract: A fluid transfer seal for transferring hydraulic fluid between differentially rotatable components, such as between the stator and rotor of a gas turbine engine. A circumferential channel is formed about the stator with a fluid passageway connecting the channel to a fluid supply reservoir in the stator. An annular seal carrier is positioned within the channel such that opposite sides thereof are in sliding contact with sidewalls of the channel for inhibiting fluid escape around the carrier. Radially outer and inner circumferential slots are formed on the carrier with apertures through the carrier for coupling fluid between the slots. Outer circumferential grooves are formed around the carrier on opposite sides of the outer slot. Seal rings are positioned in the grooves in contact with the carrier and the rotor for preventing fluid escape along the carrier-rotor interface.

Abstract: An assembly is disclosed for automatically balancing thrust on the rotor of a gas turbine engine. An annular chamber axially positioned relative to the rotor is adapted to receive pressurized hydraulic fluid and apply it to the rotor. The force thereby applied to the rotor is regulated by sensing changes in axial rotor thrust and delivering hydraulic fluid to the chamber at a pressure sufficient to balance axial forces acting on the rotor.