Gearboxes for aircraft gas turbine engines, in particular to arrangements for journal bearings such gearboxes, and to related methods of operating such gearboxes and gas turbine engines. Example embodiments include a gearbox for an aircraft gas turbine engine, the gearbox including: a sun gear; a plurality of planet gears surrounding and engaged with the sun gear; and a ring gear surrounding and engaged with the plurality of planet gears, each of the plurality of planet gears being rotatably mounted around a pin of a planet gear carrier with a journal bearing having an internal sliding surface on the planet gear and an external sliding surface on the pin.

A floating bush bearing configured to support a rotational shaft rotatably includes: a floating bush body part formed to have a cylindrical shape having an insertion hole through which the rotational shaft is inserted. The floating bush body part includes: an inner peripheral surface; an outer peripheral surface having a greater width dimension than the inner peripheral surface in an axial direction of the floating bush body part; and an axial end surface which connects an end of the inner peripheral surface and an end of the outer peripheral surface, the axial end surface including a vertical surface extending along a direction orthogonal to the axial direction from the end of the outer peripheral surface toward a radially inner side and an oblique surface extending from a radially inner end of the vertical surface toward the end of the inner peripheral surface. The oblique surface has a protruding portion protruding from a virtual line which linearly connects the radially inner end of the vertical surface and the end of the inner peripheral surface.

A machine has a first member; a second member; a third member; a bearing having an inner race mounted to the second member and an outer race mounted to the third member; a damper chamber between the first member and the third member; a fluid outlet in the first member to the damper chamber; a fluid supply flowpath to the fluid outlet; and an unvented chamber open to and locally above the fluid supply flowpath.

An aircraft gas turbine engine (10) comprises a main engine shaft (22, 23), a main engine shaft bearing arrangement (36, 44, 49, 50) configured to rotatably support the main engine shaft (22, 23) and an electric machine (30) comprising a rotor (34) and a stator (32). The rotor (34) is mounted to the main engine shaft (22, 23) and is rotatably supported by the main engine shaft bearing arrangement (36, 44, 49, 50), and the stator (32) is mounted to static structure (46) of the gas turbine engine (10).

A bearing device includes: a bearing housing; a floating metal having a cylindrical shape and disposed in a housing hole of the bearing housing and in which a rotational shaft is inserted; and a positioning pin for positioning the floating metal with respect to the bearing housing, the positioning pin being disposed along a radial direction of the rotational shaft. The positioning pin includes a first oil supply hole formed so as to penetrate the positioning pin and communicating with a first space between an inner peripheral surface of the floating metal and an outer peripheral surface of the rotational shaft, and a second oil supply hole formed inside the positioning pin so as to connect a second space to the first oil supply hole, the second space being disposed between an outer peripheral surface of the floating metal and an inner peripheral surface of the housing hole.

An expansion turbine configured such that even when pressure of process gas steeply changes, the amount of process gas leaking from a gap between an impeller and a cover is made small. The expansion turbine includes a gas supply passage which is connected to any one of a gas supply passage and a gas discharge passage and through which gas is supplied to a region located between a rotor member and a casing member.

A planetary gear train for an aircraft engine, has: a sun gear; planet gear assemblies having main gears meshed with the sun gear, fore lateral gears and aft lateral gears disposed on opposite sides of the main gears and rotating therewith; journal bearings rotatably supporting the planet gear assemblies for rotation about rotation axes, gaps defined between the journal bearings and the planetary gear assemblies; a planet carrier supporting the journal bearings; a fore ring gear meshed with the fore lateral gears; an aft ring gear meshed with the aft lateral gears; and a lubrication system extending within the planet carrier and hydraulically connected to the gaps between the journal bearings and the planet gear assemblies.

The bearing structure includes an insertion member, which is inserted through a pin hole (insertion hole) of a bearing housing (housing) in a direction intersecting an axial direction of a shaft, has one end side inserted between a pair of radial bearing surfaces of a main body portion and another end side inserted through the insertion hole, and has a through hole passing from one end to another end.

A clearance adjusting apparatus to move a thrust bearing of a gas turbine back and forth to adjust a tip clearance of a turbine is provided. The clearance adjusting apparatus includes an adjusting plate disposed to move forward from or rearward to a reference surface, a biasing cylinder disposed to selectively move the adjusting plate back and forth, a stopper disposed to be moved toward the adjusting plate after being moved forward to prevent a rearward movement of the adjusting plate, a position sensor disposed to measure a distance from the reference surface to the adjusting plate, and a controller configured to receive information about measurements from the position sensor and control an operation of the stopper and the biasing cylinder based on the received information.

The invention relates to an exhaust gas turbocharger having a fluid dynamic bearing having a rotor (10) and a counter-bearing part (50) assigned to the rotor (10), wherein a rotor bearing surface of the rotor (10) and a counterface of the counter-bearing part (50) face each other, to form a fluid dynamic bearing, wherein the rotor bearing surface and/or the counterface form(s) a continuous bearing contour when cut longitudinally and through the axis of rotation (R) in sectional view, which bearing contour(s) are formed of at least two contour sections (44.1 to 44.3; 53.1 to 53.3) to generate fluid dynamic load capacities in both the radial and the axial directions, wherein the bearing surface of the rotor (10) is formed by a rotor part (40), which is connected to a rotor shaft (11) and is secured on the rotor shaft (11), and wherein the rotor part (40) is supported relative to the rotor shaft (11) in the area of a support section (14) of the rotor shaft (11). In order to be able to provide such an exhaust gas turbocharger with a compact and efficient bearing arrangement having a fluid dynamic bearing, wherein at the same time the fluid dynamic bearing can be easily mounted using few parts, provision is made according to the invention that the support section (14) and at least one of the contour sections (53.1 to 53.3) of the counter-bearing part (50) at least sectionally overlap in the direction of the axis of rotation (R).