A wind turbine drive train component (22) comprising a rotating shaft (61) with a radial seal (50) is provided. The radial seal (50) comprises a stationary part and a rotating part. The stationary part comprises a ring (51) with an inner edge and an outer edge, the inner edge being configured for contactlessly surrounding the shaft (61). The rotary part comprising a disc (52), coaxially connected to the shaft (61) for rotation therewith and comprising a flange (53) that wraps around the outer edge of the ring (51). The radial seal (50) further comprises an annular air lock gap (55) for containing an amount of lubrication fluid (64) and thereby closing off the air lock gap (55) when the rotary part rotates at a rotational speed above a predetermined threshold speed, the annular air lock gap (55) being formed by an inner surface of the flange (53), an outer part of the opposing parallel surface of the disc (52) and the outer edge of the ring (51).

A seal assembly includes a plurality of arcuate seal bodies spaced about a central axis and coupled to form an annular seal disposeable within a housing first chamber. Each seal body has an inner circumferential sealing surface for sealingly against a rotatable member outer surface and an axial end having a radial sealing surface sealingly engageable with a housing radial surface to separate the first chamber and a second housing chamber. One or more lift ramps extend outwardly from the body inner surface and generate an outwardly directed force on the seal body when the inner member rotates within the seal. An elongated projection extends axially from the body end, has radially inner and outer surfaces, and is disposeable within the housing second chamber. The projection outer surface is exposable to fluid pressure within the second chamber to generate a pressure differential between the projection inner and outer surfaces.

A seal assembly includes a plurality of arcuate seal bodies spaced about a central axis and coupled to form an annular seal disposeable within a housing first chamber. Each seal body has an inner circumferential sealing surface for sealingly against a rotatable member outer surface and an axial end having a radial sealing surface sealingly engageable with a housing radial surface to separate the first chamber and a second housing chamber. One or more lift ramps extend outwardly from the body inner surface and generate an outwardly directed force on the seal body when the inner member rotates within the seal. An elongated projection extends axially from the body end, has radially inner and outer surfaces, and is disposeable within the housing second chamber. The projection outer surface is exposable to fluid pressure within the second chamber to generate a pressure differential between the projection inner and outer surfaces.

A seal for reducing leakage about a rotating shaft having an axis includes a rotating component configured to be positioned radially outward from and surround the rotating shaft, and including a rotating cylinder defining an annular oil chamber for receiving oil. The seal also includes a static component including a sealing plate configured to extend into the annular oil chamber such that the oil fills a gap between the sealing plate and the rotating cylinder to reduce air leakage between the rotating component and the static component in response to rotation of the rotating component.

A seal for reducing leakage about a rotating shaft having an axis includes a rotating component configured to be positioned radially outward from and surround the rotating shaft, and including a rotating cylinder defining an annular oil chamber for receiving oil. The seal also includes a static component including a sealing plate configured to extend into the annular oil chamber such that the oil fills a gap between the sealing plate and the rotating cylinder to reduce air leakage between the rotating component and the static component in response to rotation of the rotating component.

A hydraulic seal arrangement for a rotating machine, the hydraulic seal arrangement comprising: an annular housing around a shaft having an axis of rotation, the shaft and the annular housing being relatively rotatable; the annular housing further comprising a sealing fluid zone at a radially outer portion of the housing; a fin extending radially from the shaft into the annular housing, at least a portion of the fin extending radially into the sealing fluid zone; wherein sealing fluid is centrifugally accelerated, in use, before being directly introduced into the sealing fluid zone by a sealing fluid inlet, to generate a swirl component upon introduction.

A hydraulic seal arrangement for a rotating machine, the hydraulic seal arrangement comprising: an annular housing around a shaft having an axis of rotation, the shaft and the annular housing being relatively rotatable; the annular housing further comprising a sealing fluid zone at a radially outer portion of the housing; a fin extending radially from the shaft into the annular housing, at least a portion of the fin extending radially into the sealing fluid zone; wherein sealing fluid is centrifugally accelerated, in use, before being directly introduced into the sealing fluid zone by a sealing fluid inlet, to generate a swirl component upon introduction.

A rotating machine having a rotor mounted to rotate in a casing and bearing at least a plurality of impellers is provided. The machine may include at least one seal ring disposed radially between the rotor and the casing and mounted to move radially in a seal support of the casing, and wherein it includes a damping system for the seal ring disposed radially between the seal ring and the seal support. The damping system is configured to damp the seal.

A rotating machine having a rotor mounted to rotate in a casing and bearing at least a plurality of impellers is provided. The machine may include at least one seal ring disposed radially between the rotor and the casing and mounted to move radially in a seal support of the casing, and wherein it includes a damping system for the seal ring disposed radially between the seal ring and the seal support. The damping system is configured to damp the seal.

A bearing isolator seal provides enhanced coupling and stability of the rotor to the shaft, without undue seal enlargement, by including a plurality of drive O-rings in a common retention groove. In embodiments, the isolator seal accommodates axial rotor misalignment up to a maximum permitted axial misalignment, which can be at least 0.025. Embodiments include a labyrinth passage between the rotor and the stator configured to expel fluid by centrifugal force. Embodiments include a shut off feature that takes advantage of axial misalignment. Some embodiments include a unitization feature that holds the rotor and stator together during assembly. The unitization feature can include chamfers on rotor and stator extensions that facilitate assembly and disassembly when sufficient force is applied.