A turbocharger bushing of cylindrical shape has at least one recess formed on an inner peripheral surface of the bushing at a position away from at least one end of both ends of the bushing.

A turbocharger includes a rotor shaft that is rotationally driven, a compressor impeller attached to the rotor shaft, and a cylindrical bearing portion that includes an inner cylinder and an outer cylinder, and that supports the rotor shaft in a rotatable manner. A first damping portion is provided between an axial first end portion of the inner cylinder and an axial first end portion of the outer cylinder, and an axial second end portion of the inner cylinder is connected with an axial second end portion of the outer cylinder. A second damping portion is provided between a housing and the axial second end portion. The housing and the bearing portion are fixed by a flange portion provided at the first end portion of the outer cylinder in such a manner as to restrict movement of the flange portion in a radial direction and in an axial direction.

A turbocharger includes a shaft extending along an axis, a compressor wheel coupled to a first end of the shaft, a turbine wheel coupled to a second end of the shaft and having a first diameter; and a bearing housing extending about the shaft. The bearing housing is disposed between the compressor wheel and the turbine wheel. The bearing housing having a thermal dam having a volume extending circumferentially about the shaft and disposed proximate to the second end of the shaft between the compressor wheel and the turbine wheel. The thermal dam has a second diameter extending radially from the shaft. Moreover, the second diameter of the thermal dam is between 1.1 and 1.2 times greater than the first diameter of the turbine wheel.

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 journal bearing includes: a carrier ring; a plurality of bearing pads disposed on a radially inner side of a lower half region of the carrier ring, and configured to support a rotor shaft from below; and a guide metal disposed in an upper half region of the carrier ring, in center with respect to an axial direction of the rotor shaft, so as to cover an upper region of an outer peripheral surface of the rotor shaft.

An exhaust gas turbocharger having a hydrodynamic plain bearing or a hydrodynamic plain bearing, comprising a rotor (10) and a counter-bearing part (50) assigned to the rotor (10), wherein a rotor bearing surface (17.1, 17.2, 17.3) of the rotor (10) and a counter-surface of the counter-bearing part (50) face each other to form a hydrodynamic plain bearing, wherein the rotor bearing surface and/or the counterface, when cut along and through the axis of rotation (R) in sectional view, form(s) a continuous bearing contour forming at least two contour sections (44.1 to 44.3; 53.1 to 53.3) to provide hydrodynamic load capacities in both radial and axial directions, and wherein the counter-bearing part (50) is mounted in a bearing housing (60) or housing part. In order to be able to provide such an exhaust gas turbocharger with a compact and efficient bearing arrangement having a hydrodynamic plain bearing, wherein at the same time the hydrodynamic plain bearing can be easily mounted with a small number of parts, provision is made according to the invention that in that a preferably circumferential gap area (57) for forming a trapped oil film is formed between an outer contour of the counter-bearing part (50) and the bearing housing (60) or the housing part, wherein the gap area (57) is spatially connected to a lubricant guide channel (61), and in that the gap area (57) and the continuous bearing contour of the rotor (10) and/or of the counter-bearing part (50) overlap at least sectionally in the direction of the axis of rotation (R).

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.

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 bearing element includes an inner surface (54) configured to receive a cylindrical shaft (18). The inner surface (54) includes a smooth profile having a plurality of sections (502). Each section (502) having a taper portion (506) between a first arc-span point (512) and a second arc-span point (514), a constant-radius portion (508) between the second arc-span point (514) and a third arc-span point (516), and a transition portion (510) between the third arc-span point (516) and a fourth arc-span point (518). An inner-surface radius dimension (520) changes from an inner-diameter major dimension to an inner-diameter minor dimension at the taper portion (506) and back at the transition portion.

Bearing bushings which are exposed to highly elevated temperatures during operation, corresponding high-temperature-resistant bearing bushings and exhaust-gas turbochargers having at least one such bearing bushing, include an iron material having a material composition which, apart from iron, has at least carbon, silicon, manganese, nickel, chromium, molybdenum and tungsten alloy constituents in certain amounts. This material composition ensures sufficient temperature resistance and self-lubricating properties with simultaneously good machining properties and a moderate price.