Abstract: The disclosure describes a windback device for a circumferential seal within a turbine engine. The windback device includes an annular collar at one end of an annular fluid seal housing, at least one inclined thread, and a plurality of inclined baffles separately disposed along an outer circumferential surface of a rotatable runner. The housing is adapted at another end for an annular seal. The collar has an opening therethrough sized to receive the runner without contact. The annular seal surrounds and sealingly engages the runner. The threads extend from an inner face of the collar toward the runner. The baffles are separately recessed in or raised above the outer circumferential surface of the runner. The baffles are interposed between the runner and threads. Each baffle is separated from the threads via a radial clearance. Threads and baffles direct lubricant away from the annular seal.

Abstract: An intershaft seal system capable of communicating a balanced pressure profile onto forward and aft faces along a piston ring is presented. The 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 or downward and 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 onto each side of the piston ring so as to minimize twist thereof, thus reducing wear along the piston ring and increasing seal life.

Abstract: The disclosure describes a circumferential seal applicable to turbine engines. The circumferential seal includes a ceramic runner, an annular seal ring, at least one tolerance ring, and a pair of sealing rings. The runner is circumscribed about a shaft or a carrier within a recess along the shaft and is bounded by a shoulder and a clamping ring. At least one non-sealing spring mechanism is disposed between and directly contacts the shoulder and the first end of the runner. A second end of the runner directly contacts the clamping ring. In other embodiments, at least one non-sealing spring mechanism is disposed between and directly contacts the second end and the clamping ring and the first end directly contacts the shoulder. An anti-rotation element is attached to the clamping ring, carrier, or shaft and extends into a slot or hole or slot along the runner. The spring(s) applies a biasing force onto the runner toward the clamping ring or shoulder.

Abstract: A segmented intershaft seal assembly for use between inner and outer shafts within a turbine engine is presented. The intershaft seal assembly includes annular end rings, an annular seal element with an inverted “T”-shaped cross section, at least one resilient element, an annular spacer ring, carriers, counterweights, and hydrodynamic grooves. The intershaft seal assembly is secured to the inner shaft. The resilient element(s) biases seal segments away from the inner shaft toward the outer shaft. The counterweights are disposed about the seal segments and substantially negate forces imposed by the seal segments outward toward the outer shaft. The hydrodynamic grooves are disposed along an inner annular surface of the outer shaft and direct fluid onto an outer surface along the seal segments when the outer shaft rotates. The hydrodynamic grooves form a thin-film layer and non-contact seal that separates the seal segments from the outer shaft which otherwise provide a contact-type seal.

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: The disclosure describes a windback device for a circumferential seal within a turbine engine. The windback device includes an annular collar at one end of an annular fluid seal housing, at least one inclined thread, and a plurality of inclined baffles separately disposed along an outer circumferential surface of a rotatable runner. The housing is adapted at another end for an annular seal. The collar has an opening therethrough sized to receive the runner without contact. The annular seal surrounds and sealingly engages the runner. The threads extend from an inner face of the collar toward the runner. The baffles are separately recessed in or raised above the outer circumferential surface of the runner. The baffles are interposed between the runner and threads. Each baffle is separated from the threads via a radial clearance. Threads and baffles direct lubricant away from the annular seal.

Abstract: The present invention relates to a windback device and method of use to prevent lubricant from leaking from a lubricant sump. More specifically, the present invention is comprised of a windback device within a lubricant sump formed from the coupling of an annular sump housing, an annular fluid seal assembly, and a bearing. The annular housing substantially surrounds the runner to form a chamber. The seal assembly is coupled to a sump housing both of which are adapted to receive a rotatable runner such that a sealed chamber is formed around the runner. A plurality of inclined threads extend along an inner face of the windback device and are angled such that lubricant or fluid splashed from the rotating shaft is redirected away from a shaft seal element of the annular fluid seal and through leak off slots leading to the sump housing chamber.

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: 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: 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. 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: 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 segmented intershaft seal assembly for counter-rotating and co-rotating turbine engines is described. The assembly includes a pair of end rings, an annular seal element, and at least one resilient element. At least one end ring has a flange that extends from one side thereof. The flange has a lower annular surface. The seal element includes at least two seal segments. Each seal segment includes a ring segment and a ring flange segment. The ring segment has an upper radial surface. The ring flange segment directly contacts and extends from the upper radial surface forming either a substantially “T”-shaped or “L”-shaped cross section. The seal segments are disposed between the end rings. At least one resilient element biases each seal segment away from the inner shaft so that the upper radial surface contacts the lower annular surface and a portion of the ring flange segment extends beyond the flanges.

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 assembly for counter-rotating and co-rotating turbine engines is described. The seal assembly includes a pair of end rings and a seal element. At least one end ring has a flange, with upper and lower surfaces, disposed along and extending from one side of the ring. The seal element includes a ring, with inner and outer radial surfaces, and a ring flange wider than the ring. The ring flange is disposed along and extends diametrically from the outer radial surface, the latter also contacting the lower surface along at least one flange. The seal element is disposed between the end rings so that the ring flange extends beyond the flanges. The invention avoids the wear and heating problems inherent to intershaft seal systems, thus allowing the seal element to be composed of a temperature resistant metal, metal alloy, or carbon graphite.

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.