Abstract: A combined labyrinth/brush seal is provided in a seal between rotating and stationary components. The seal includes a plurality of arcuate sealing segments, each having one or more labyrinth teeth extending radially toward the surface of the rotating component. As original equipment or retrofit, a brush seal is provided among the labyrinth teeth in a slot formed in the sealing face of the seal segment. In one form, backing and/or forward plates for the brush seal have a tongue extending into an axially extending groove of the seal segments to prevent relative radial movement of the brush seal and seal ring segments. The end faces of the brush seal and seal ring segments may be bored and filled with weld material to prevent relative circumferential movement. Where a single radially extending slot is provided in the sealing ring segment, the brush seal may be stitch-welded to the seal ring segment along opposite sides of the brush seal.

Abstract: A brush seal, which may be used in gas or steam turbine rotor applications, includes a packet of bristles attached to a seal housing. A seal member is slideably-attached to the seal housing, has a planar first surface portion parallel to, and slideably in contact with, a first surface of the seal housing, and has a planar second surface portion which is parallel to, and slideably in contact with, a first side of the bristle packet. A mechanical spring is positioned in compression between the seal housing and the seal member.

Abstract: A variable clearance packing ring includes a plurality of circumferentially extending segments disposed in a generally dovetail-shaped slot in the stationary component of a machine having a rotor rotatable about an axis, the packing ring including an arcuate seal face in opposition to the rotor and axially extending flanges within the dovetail slot. Pins project axially from opposite sides of the stationary component for location between the flanges and sealing faces of the segments. A centering ring is mounted on the pins for each segment and has a coefficient of thermal expansion greater than the coefficient of thermal expansion of the segment.

Abstract: A steam turbine having a shaft and a first (e.g., high-pressure) turbine section. A first embodiment also includes a first bearing longitudinally spaced apart from the first turbine section and further includes a first brush-seal assembly, having bristles, longitudinally positioned between the first turbine section and the first bearing and radially positioned proximate the shaft. The steam turbine is devoid of any backup seal to the bristles. In a second embodiment, a second brush seal assembly is positioned between the first and second (e.g., intermediate-pressure) turbine sections which lack any intervening bearing.

Abstract: A combined labyrinth/brush seal is provided in a seal between rotating and stationary components. The seal includes a plurality of arcuate sealing segments, each having one or more labyrinth teeth extending radially toward the surface of the rotating component. As original equipment or retrofit, a brush seal is provided among the labyrinth teeth in a slot formed in the sealing face of the seal segment. In one form, backing and/or forward plates for the brush seal have a tongue extending into an axially extending groove of the seal segments to prevent relative radial movement of the brush seal and seal ring segments. The end faces of the brush seal and seal ring segments may be bored and filled with weld material to prevent relative circumferential movement. Where a single radially extending slot is provided in the sealing ring segment, the brush seal may be stitch-welded to the seal ring segment along opposite sides of the brush seal.

Abstract: Bucket covers for the buckets of a rotating component of a turbomachine are in radial opposition to a stationary component containing a circumferentially extending brush seal having bristles extending into engagement with sealing surfaces of the covers as the covers rotate by the bristles. The leading edges of the covers for the buckets in the plane of rotation and in the plane containing the brush seal have ramps or rounded surfaces which minimize the wear on the bristles and degradation of the performance of the seal as the bucket covers are rotated past the brush seal.

Abstract: A hybrid seal segment and a rotary machine (such as a steam or gas turbine) containing such hybrid seal segment. The machine has a rotor, a stator casing, and the hybrid seal segment. The annular hybrid seal segment has a circumferentially-extending channel between axially-spaced-apart first and second labyrinth-seal segments which are attached to a radially-outwardly located mounting block which is circumferentially offset from the labyrinth-seal segments. A brush-seal segment is positioned in the channel.

Abstract: A labyrinth brush seal combination for a rotating machine comprising an arcuate segment of predetermined axial extent carrying a plurality of axially spaced, circumferentially and radially extending tapered seal teeth, and at least one circumferentially extending array of discrete bristles carried by the segment at a predetermined axial location therealong and projecting beyond the radial extent of the teeth, the bristles having an elongated, flexible carrier strip slidably and removably received within a slot in the segment.

Abstract: A rotor and stator assembly having a rotor and a stator with opposing surfaces defining an air bearing and an air dam of an aspirating face seal. In a first embodiment, the air bearing and the air dam are axially offset. In a second embodiment, the rotor has an axially extending protuberance located radially between the air bearing and the air dam. The axial offset and the protuberance each act to divert the air flow (e.g., compressed gas or combustion gases in a gas turbine or steam in a steam turbine) in a direction transverse to the air flow direction through the air bearing and the air dam, thus isolating the air flows from the air bearing and the air dam which improves seal performance.

Abstract: A seal assembly and a rotary machine, such as a steam turbine, containing the seal assembly. A casing circumferentially surrounds a rotor and includes a circumferential channel open to the rotor. Seal segments are circumferentially arrayed in the channel and are movable between radially inward and outward positions. Circumferentially adjacent seal segments have circumferentially opposing surface grooves. A resilient and imperforate member is engaged in the grooves of circumferentially-adjacent seal segments circumferentially urging apart such segments and providing sealing between such segments.

Abstract: A brush seal which, among other applications, may be used for sealing a steam leakage gap between the shrouded free end of steam-turbine buckets (blades) of a steam-turbine rotor and a circumferentially surrounding steam-turbine stator. In a first embodiment, the brush seal includes first and second bristle packets having, respectively, first and second bristles, wherein the second bristles are more abrasive than the first bristles. In a second embodiment, the brush seal includes a bristle packet having bristles which are more abrasive proximate their free ends than not proximate their free ends.

Abstract: A brush seal which, among other applications, may be used for sealing a steam leakage gap between a steam turbine rotor and a steam turbine casing. A brush seal backing plate has a surface which includes adjacent first and second areas. First and second bristle packets contact and generally cover, respectively, the first and second areas. A first anti-hysteresis plate is positioned between and contacts the first and second bristle packets, is aligned generally perpendicular to the backing plate, and is proximate and generally spaced apart from the backing plate. The anti-hysteresis plate restores the bristles which would otherwise become set in a non-sealing position against the backing plate because of transient events such as thermal differential growth or relative movement of the rotor and casing.

Abstract: A brush seal which, among other applications, may be used for sealing a steam leakage gap between the shrouded free end of steam-turbine buckets of a steam-turbine rotor and a circumferentially surrounding steam-turbine stator. In a first embodiment, an unflexed brush seal includes bristles having a generally straight first portion secured to a backing plate and a coextensive and generally straight second portion with a free end. The second portion makes a greater angle, than that of the first portion, with respect to a directed reference line. In a second embodiment, the first and second portions are curved, wherein a tangent line to the second portion makes a greater angle than a tangent line to the first portion.

Abstract: A brush seal is comprised of arcuate seal segments having ends cut in a radial direction with bristles "canted" at an approximate 45.degree. angle relative to radii of the segments, leaving triangular regions adjacent one end of each segment devoid of bristles at the segment interfaces. The brush seals are retrofit into conventional labyrinth seals with the backing plate for the bristles comprising a labyrinth tooth profile extending fully 360.degree. about the seal, including those areas where bristles are not present. The sealing capacity is not substantially degraded, while affording significant sealing improvements over conventional labyrinth seals. Additionally, when retrofit into labyrinth seals with radial movement, the individual labyrinth seal segments are free to move radially independently of one another during transients.