An epicyclic gear train for a turbine engine includes a gutter with an annular channel. A rotating structure includes a ring gear that has an aperture that is axially aligned with the annular channel. Axially spaced apart walls extend radially outward relative to the rotating structure to define a passageway. The passageway is arranged radially between and axially aligned with the aperture and the annular channel. The walls are configured to inhibit an axial flow of an oil passing from the aperture toward the annular channel.

A seal system includes a ceramic component that has a non-core-gaspath surface region that defines a first surface roughness and a core gaspath surface region. A metallic component is situated adjacent the non-core-gaspath surface region. A coating system is disposed on the ceramic component. The coating system includes a silicon-containing layer on the non-core-gaspath surface region and a barrier layer that has a first section on the silicon-containing layer and a second section on the core-gaspath region and that is connected to the first section. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The first section is in contact with the metallic component and the second section serves as an environmental barrier on the core-gaspath region.

A seal system includes a ceramic component that has a non-core-gaspath surface region that defines a first surface roughness and a core gaspath surface region. A metallic component is situated adjacent the non-core-gaspath surface region. A coating system is disposed on the ceramic component. The coating system includes a silicon-containing layer on the non-core-gaspath surface region and a barrier layer that has a first section on the silicon-containing layer and a second section on the core-gaspath region and that is connected to the first section. The surface of the barrier layer has a second surface roughness that is less than the first surface roughness. The first section is in contact with the metallic component and the second section serves as an environmental barrier on the core-gaspath region.

An apparatus has: a first member; a shaft rotatable relative to the first member about an axis; and a seal system. The seal system has a seal carrier having: an axially-extending wall having an inner diameter (ID) surface; and a radially-extending wall having a first surface. A seal is carried by the first member and has: an outer diameter (OD) surface; and a seal face. A seat is carried by the shaft and has a seat face in sliding sealing engagement with the seal face. One or more springs bias the seal carrier relative to the first member so as to bias the seal face against the seat face. At least one of the seal carrier inner diameter (ID) surface and seal outer diameter (OD) surface is formed by a coating.

An apparatus has: a first member; a shaft rotatable relative to the first member about an axis; and a seal system. The seal system has a seal carrier having: an axially-extending wall having an inner diameter (ID) surface; and a radially-extending wall having a first surface. A seal is carried by the first member and has: an outer diameter (OD) surface; and a seal face. A seat is carried by the shaft and has a seat face in sliding sealing engagement with the seal face. One or more springs bias the seal carrier relative to the first member so as to bias the seal face against the seat face. At least one of the seal carrier inner diameter (ID) surface and seal outer diameter (OD) surface is formed by a coating.

An apparatus for oil lubrication of a rotationally fixed connection between two shafts. A first shaft engages with a hollow region of the second shaft. The shafts are operatively connected to each other in a form-fitting manner in the overlapping region. Oil is introduced into a first chamber in the hollow region, which chamber is connected to a second chamber in the hollow region. The second chamber is connectable to a third chamber is arranged in the overlapping region. The fluidic connection between the second chamber and the third chamber is separated above a defined oil volume in the second chamber and above a rotational speed threshold of the shafts via a sealing element. The sealing element is reversibly deformable by the oil volume in the second chamber and the centrifugal force acting thereon and, in the deformed state, seals the connection between the second and third chambers.

An apparatus for oil lubrication of a rotationally fixed connection between two shafts. A first shaft engages with a hollow region of the second shaft. The shafts are operatively connected to each other in a form-fitting manner in the overlapping region. Oil is introduced into a first chamber in the hollow region, which chamber is connected to a second chamber in the hollow region. The second chamber is connectable to a third chamber is arranged in the overlapping region. The fluidic connection between the second chamber and the third chamber is separated above a defined oil volume in the second chamber and above a rotational speed threshold of the shafts via a sealing element. The sealing element is reversibly deformable by the oil volume in the second chamber and the centrifugal force acting thereon and, in the deformed state, seals the connection between the second and third chambers.

A seal assembly for a gas turbine engine having a seal formed of a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the seal and the seal seat each have a sealing surface which together define a sliding seal, and further having a carbon film on the sealing surface of the seal seat.

A seal assembly for a gas turbine engine having a seal formed of a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the seal and the seal seat each have a sealing surface which together define a sliding seal, and further having a carbon film on the sealing surface of the seal seat.

A rotating machine includes a rotating body rotatably supported in a casing; a rotor blade fixed to an outer peripheral portion of the rotating body; a stator blade arranged on a downstream side in a fluid flow direction with respect to the rotor blade and fixed to an inner peripheral portion of the casing; a sealing device arranged between the inner peripheral portion and a front end of the rotor blade; a swirling flow generation chamber provided in the casing on the downstream side from the sealing device along a circumferential direction of the rotating body; and guiding members provided in the swirling flow generation chamber along a radial direction of the rotating body and in the circumferential direction at predetermined intervals. The swirling flow generation chamber has a wall surface located on the downstream side from an edge of the stator blade on an upstream side.