Abstract: An intershaft seal system capable of communicating a balanced pressure profile onto forward and aft faces along a piston ring is presented. Seal system includes forward and aft mating rings and a piston ring. Mating rings include a plurality of divergent flow grooves adjacent to the piston ring. Each divergent flow groove includes a pair of grooves which intersect at and are substantially symmetric about an apex. The piston ring includes channels which direct a fluid from a high pressure region upward, downward, or directly through the piston ring and onto the divergent flow grooves. The divergent flow grooves separate the fluid in a symmetrically divergent fashion prior to communication onto the piston ring. The divergent flow grooves communicate a substantially symmetric pressure force along the radial width of the piston ring so as to minimize twisting thereof, thus reducing wear along the piston ring and increasing seal life.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. Each additional groove may contain a pocket. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. Each additional groove is an axial bore groove extending perpendicularly to a longitudinal axis of the seal ring segment in fluid communication with the dead end circumferential groove so as to direct fluid flow generated from a rotating shaft into the dead end circumferential groove.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. A plurality of radial dams disposed along the surface in an outward radial arrangement from the circumferential darn is provided to improve the stiffness of the thin film.

Abstract: An intershaft seal system capable of communicating a balanced pressure profile onto forward and aft faces along a piston ring is presented. Seal system includes forward and aft mating rings and a piston ring. Mating rings include a plurality of divergent flow grooves adjacent to the piston ring. Each divergent flow groove includes a pair of grooves which intersect at and are substantially symmetric about an apex. The piston ring includes channels which direct a fluid from a high pressure region upward, downward, or directly through the piston ring and onto the divergent flow grooves. The divergent flow grooves separate the fluid in a symmetrically divergent fashion prior to communication onto the piston ring. The divergent flow grooves communicate a substantially symmetric pressure force along the radial width of the piston ring so as to minimize twisting thereof, thus reducing wear along the piston ring and increasing seal life.

Abstract: A force balanced seal for use with a rotor in the turbomachine has a member in opposed facing disposition to the rotor with a face dam portion of the member having a surface parallel with the sealing surface of the rotor, a groove in the member facing the rotor and bounding the face dam surface, an air bearing surface in the member facing the sealing surface of the rotor, a second passageway through the member from the air bearing surface to a radially outwardly facing surface of the member and a first passageway through the member from the groove to a member surface facing oppositely from the air bearing surface. An operating clearance between the seal and rotor is maintained by a closing force, exerted through a plurality of springs, and an opposing opening force created by pressurized air venting through the second passageway to the first passageway.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. A plurality of radial dams disposed along the surface in an outward radial arrangement from the circumferential darn is provided to improve the stiffness of the thin film.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. The secondary seal ring is disposed between and contacts the primary seal assembly and housing structure so as to form a bore seal and a face seal therewith.

Abstract: An improved air-riding seal system for turbine engines is presented. The seal system includes a movable primary seal assembly, a stationary secondary seal assembly, and at least one structure to increase the stiffness of a thin film between the primary seal and a rotating component. The primary seal assembly includes an annular seal ring and an arcuate support arm. The annular seal ring has a cross section that is substantially L-shaped and a surface with a step face and a circumferential dam. The arcuate support arm has a tooth at one end adjacent to an outermost circumferential surface along the seal runner, which could include an optional notch. The tooth and outermost circumferential surface are separated by a gap. The secondary seal ring is disposed between and contacts the primary seal assembly and housing structure so as to form a bore seal and a face seal therewith.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. Each additional groove may contain a pocket. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. Additional grooves are contained on the shaft-side face of each sealing ring segment. The additional grooves direct and create pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. Each additional groove is an axial bore groove extending perpendicularly to a longitudinal axis of the seal ring segment in fluid communication with the dead end circumferential groove so as to direct fluid flow generated from a rotating shaft into the dead end circumferential groove.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: A circumferential seal system for sealing a high pressure region from a low pressure region separated by a runner with an outer circumferential surface and a seal ring disposed about the outer circumferential surface is described. The seal system includes a plurality of groove sets separately disposed along the outer circumferential surface. Each groove set further includes at least two grooves. At least one groove within each groove set exerts a lifting force via a fluid from the high pressure region onto the seal ring as the runner translates with respect to the seal ring along an axis substantially perpendicular to the rotation of the runner. The continuous feed of fluid onto the seal ring ensures a thin film between the seal ring and the runner regardless of their relative arrangement during axial excursions of the runner resulting from conditions within a turbine engine.

Abstract: The present invention relates to circumferential seal ring segments positioned around a rotating shaft so as to prevent fluids from leaking from a lubricant sump during both low and high pressure conditions. The circumferential seal is comprised of a plurality of adjoining annular ring segments facing the rotating shaft. Each sealing ring segment includes a dead end circumferential groove on a shaft-side face of each sealing ring such that, when the segments are joined, the circumferential dead end groove of each segment extends arcuately in the direction of shaft rotation. At least one additional groove is contained on the shaft-side face of each sealing ring segment. The additional groove(s) directs and creates pressurized air within the dead end circumferential groove, either directly or indirectly maintaining a seal between the ring segments and the shaft. A bleed hole may also be provided to create a seal between each sealing segment.