A seal assembly includes a carbon seal that has a sealing surface. A seal seat has a sealing surface and is positioned for rotation relative to the carbon seal. A diamond-like carbon coating at least partially forms the sealing surface on the seal seat.

A split ring seal has: a first circumferential end and a second circumferential end; an inner diameter surface and an outer diameter surface; a first axial end face and a second axial end face. A circumferentially distributed first plurality of open channels are along the first axial end face. A circumferentially distributed second plurality of open channels are along the second axial end face.

A fan system of a turbine includes a fan mid shaft made of a coated steel material configured to extend along a center axis of a turbine. The fan mid shaft having an inner diameter surface. The fan system includes a dry film lubricant that is configured to be applied to at least a portion of the inner diameter surface of the fan mid shaft.

A method of operating a variable vane for a gas turbine includes the step of locating a first bushing at least partially surrounding a first trunnion that extends from a first end of the variable vane. The first trunnion includes an outer surface that has a plurality of troughs. The first bushing includes a plurality of peaks that extend inward from an inner surface. Relative movement is produced between the first bushing and the first trunnion to form a carbon transfer film between the first bushing and the first trunnion.

A method of operating a variable vane for a gas turbine engine includes the step of locating a first bushing adjacent a first trunnion on a variable vane. At least one of the first bushing or the first trunnion include a first plurality of surface irregularities. Relative movement is produced between the first bushing and the first trunnion to form a carbon transfer film between the first bushing and the first trunnion.

A gas turbine engine, has: an annular gaspath extending around a central axis, the annular gaspath defined between a first casing and a second casing, the first casing defining pockets; and a variable guide vane assembly having: variable guide vanes circumferentially distributed around the central axis, the variable guide vanes having airfoils extending into the annular gaspath and extending between first and second pivot members at respective first and second ends of the airfoils, the variable guide vanes rotatable about respective spanwise axes, bushings received within the pockets of the first casing, the first pivot members of the variable guide vanes rollingly engaged to the bushings, and resilient members disposed radially between surfaces of the first casing and the bushings relative to the spanwise axes, the resilient members in abutment against both of the surfaces of the first casing and the bushings.

A seal assembly for a gas turbine engine includes a seal composed of a nickel-based superalloy; a component in contact with the seal and defining a seal-counterface; and a coating on the seal at the seal-counterface, wherein the coating is a ternary oxide.

An abradable powder composition is includes a metal component, a lubricant component, and a polymer component. A portion of the metal component is wrapped in the lubricant component to achieve high lubricity and abradability. The abradable powder composition can be used to form an abradable seal coating provided for use in a turbo machinery having a housing and a wheel having multiple blades. The housing houses the wheel which rotates therein. The seal coating is formed on the inner walls of housing adjacent where the wheel blades pass during their rotation. When the wheel is rotated such that the blades contact the seal coating, it is abraded to form a close fit gap. The abradable seal coating preferably does not produce significant wear of the blade tips or transfer abradable material significantly to the blade tips upon being abraded.

A rotor assembly for a gas turbine engine according to an example of the present disclosure includes, among other things, a rotor that has a hub carrying one or more rotatable blades. The rotor is mechanically attached to a shaft, and an annular seal is carried by the shaft. The annular seal includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer and arranged to establish a sealing relationship with the rotor. The second layer includes a solid lubricant that has molybdenum trioxide (MoO3). A method of sealing for a gas turbine engine is also disclosed.

A bushing for a stator vane assembly of a gas turbine engine has a tubular member that is coaxial about a longitudinal axis and that extends a length between a first axial end and a second axial end. The tubular member has an outside circumferential surface thereon and an inside circumferential surface therein and is manufactured from a cobalt based alloy, a nickel based alloy, a graphite material, a cermet material or an alloy matrix comprising titanium, aluminum, niobium, manganese, boron, and carbon and a solid lubricant being dispersed in the alloy matrix. A portion of the inside circumferential surface and/or a portion of the outside circumferential surface has a wear resistant material thereon.