An intershaft seal assembly comprises an annular seal ring disposed between a pair of annular runners connected to a hollow outer rotating shaft, and a surface of a co-axial inner rotating shaft. The centrifugal force resulting from rotation of the hollow outer rotating shaft effects engagement of the annular seal ring with the surface of the co-axial inner rotating shaft. The surface may be a radially-inward-facing surface of a retaining arm connected to the co-axial inner rotating shaft.

Systems and methods are presented for sealing a higher pressure fluid cavity from a lower pressure fluid cavity in a rotating machine. The cavities are at least partially disposed between a rotatable shaft and a housing. The seal assembly comprises a runner mounting assembly, a circumferential ceramic runner, a carbon seal ring, and an annular seal member. The carbon seal ring is sealing engaged with the housing and at least a portion of the runner to thereby form a boundary between the higher pressure fluid cavity and the lower pressure fluid cavity. The annular seal member is coupled to the housing axially displaced from the seal ring in the lower pressure fluid cavity. The seal member has a curvilinear face surface that engages the runner.

A circumferential seal assembly capable of separating a gas into two separate flow paths before communication between a rotatable runner and a pair of seal rings is presented. The seal assembly includes an annular seal housing, a pair of annular seal rings, a rotatable runner, and a plurality of groove structures. The seal housing is interposed between a pair of compartments. The seal rings are separately disposed within the seal housing and separately disposed around the rotatable runner. The groove structures are disposed along an outer annular surface of the rotatable runner. A gas is communicable onto the groove structures. Each groove structure includes at least two hydrodynamic grooves that separate and communicate the gas onto the seal rings. Each groove includes steps whereby the depth of at least one adjoining step decreases in the direction opposite to rotation with or without the depth of another adjoining steps increasing in the direction opposite to rotation.

A seal assembly having: a carbon ring annularly extending about a central axis and having an outer face, and a shrink band annularly extending about the central axis, the shrink band having an inner face, the inner face in contact with the outer face of the carbon ring at a contact interface defined therebetween, the inner face of the shrink band protruding axially beyond the contact interface.

A seal ring capable of stabilizing sealing performance while reducing rotation torque. A seal ring 100 has a plurality of first dynamic pressure generation groove 131 and a plurality of second dynamic pressure generation groove 132 on an outer peripheral surface thereof with intervals in the circumferential direction, the plurality of first dynamic pressure generation groove 131 extending from a position close to a first side surface 100A with respect to the center of width in an axial direction to the first side surface 100A and configured to generate dynamic pressure with relative rotation between a housing and the seal ring 100, and the plurality of second dynamic pressure generation groove 132 extending from a position close to a second side surface 100B with respect to the center of width in the axial direction to the second side surface 100B and configured to generate dynamic pressure with the relative rotation between the housing and the seal ring 100.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes at least one side shoulder which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A circumferential seal assembly suitable for forming a thin film between a rotatable runner and a sealing ring is presented. The assembly includes an annular seal housing, a rotatable runner, an annular seal ring, and a plurality of groove structures. Each groove structure includes a groove and an optional feed groove. The groove includes at least two adjoining steps defined by base walls arranged to decrease depthwise. Two adjoining base walls are disposed about a base shoulder. Each base shoulder locally redirects a longitudinal flow to form an outward radial flow in the direction of the annular seal ring. The base walls are bounded by and intersect a pair of side walls. A side wall includes side shoulders which narrows the groove widthwise and locally redirects the longitudinal flow to form a lateral flow in the direction of the other side wall. Outward and lateral flows separately or in combination enhance stiffness of a thin-film layer between the annular seal ring and the rotatable runner.

A sealing device is disposed between a stationary body and a rotating body and is configured to suppress flow of a fluid from a high-pressure side to a low-pressure side. The sealing device includes: a sealing member movably supported by the stationary body in an axial direction and a radial direction of the rotating body; a seal fin extending from the sealing member to the rotating body side; a pressure adjustment space provided between the stationary body and a high-pressure-side end surface of the sealing member; and a communication passage having one end communicating with the low-pressure side and the other end communicating with the pressure adjustment space.

A sealing device includes a plurality of non-contact seals provided along a sealed shaft; a contact seal provided on at least one of two sides of the plurality of non-contact seals; an injection part that supplies purge gas into a first space of spaces arranged in an axial direction of the sealed shaft, the spaces being between the plurality of non-contact seals and the contact seal; and a collector that collects the purge gas from a second space of the spaces between the plurality of non-contact seals and the contact seal, the second space being positioned to be next to the first space in the axial direction.

An intershaft seal assembly for use between a rotatable outer structure and an inner structure within a turbine engine is presented. The assembly includes a primary sealing ring, a translatable carrier, a secondary sealing ring(s), a lower-pressure chamber, a higher-pressure chamber, a first channel(s), and a second channel(s). The primary ring is disposed within and extends from a circumferential groove about the carrier so as to sealingly engage the rotatable outer structure. The primary ring rotates within the groove and with the rotatable outer structure. Each secondary ring is interposed between the carrier and the inner structure. The carrier slidingly contacts the secondary ring(s). The lower-pressure chamber is generally defined by the carrier and the inner structure adjacent to a higher-pressure side. The higher-pressure chamber is generally defined by the carrier and the inner structure adjacent to a lower-pressure side. Each first channel traverses the carrier so that a gas from the lower-pressure side may enter the lower-pressure chamber. Each second channel traverses the carrier so that a gas from the higher-pressure side may enter the higher-pressure chamber. The sum of the translation-resistant forces (F.sub.TTR) encountered by the carrier is less than the translation-resistance force (F.sub.TR) encountered by the primary seal ring.