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.

An assembly is provided for a gas turbine engine. This assembly includes a rotating structure, a stationary structure and a bushing. The rotating structure extends axially along and is rotatable about a centerline. The stationary structure extends circumferentially about the rotating structure. The stationary structure is configured from or otherwise includes stationary structure material with a coefficient of thermal expansion between 10 μin/in-° F. and 15 μin/in-° F. The bushing is radially between the rotating structure and the stationary structure. The bushing includes a mount and a bearing within the mount. The mount is configured from or otherwise includes mount material with a coefficient of thermal expansion between 9 μin/in-° F. and 10 μin/in-° F. The mount material contacts the stationary structure material. The bearing is configured from or otherwise includes bearing material, where the bearing material is engaged with and rotatably supports the rotating structure. The bearing material is or otherwise includes copper.

The shroud can have a wall curved radially outwardly from an axially oriented inlet to an outlet end, a structural member having a flange at the outlet end, and an insert of Greek Ascoloy exposed on an inner face of the wall.

The shroud can have a wall curved radially outwardly from an axially oriented inlet to an outlet end, a structural member having a flange at the outlet end, and an insert of Greek Ascoloy exposed on an inner face of the wall.

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 bearing for a turbomachine variable pitch stator vane pivot mounted in a bore of a casing of the turbomachine and including a bushing integral with the bore and allowing rotation of a pivot rod within the casing, and additionally a ring mounted so as to be integral with the pivot rod inside the bushing and including an outer part providing the stiffening of the ring and an inner part integral with the outer part and providing a damping function.

According to one aspect, a rotating structure comprises a hub having a mounting slot defined by a cavity surface and a body having an anchor structure disposed in the mounting slot. A wear member is disposed between the anchor structure and the cavity surface and the wear member has at least first and second portions of first and second material characteristics, respectively.

According to one aspect, a rotating structure comprises a hub having a mounting slot defined by a cavity surface and a body having an anchor structure disposed in the mounting slot. A wear member is disposed between the anchor structure and the cavity surface and the wear member has at least first and second portions of first and second material characteristics, respectively.