Gearboxes for aircraft gas turbine engines, in particular arrangements for journal bearings such gearboxes, and related methods of operating such gearboxes and gas turbine engines. A gearbox for an aircraft gas turbine engine includes: 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 taper roller bearing includes: an inner ring, an outer ring, a plurality of taper rollers, and an annular cage. The cage includes a small-diameter annular portion on one axial side, a large-diameter annular portion on the other axial side, and a plurality of column portions. A radial inner surface of the column portion is provided along a second virtual taper surface that is in the vicinity of a first virtual taper surface including a center line of the plurality of taper rollers, across the entire length in the longitudinal direction of the column portion.

An improved sealed bearing pack for a downhole mud motor is disclosed. More specifically, embodiments of the present invention relate to a mud motor for straight and directional drilling with a sealed bearing pack designed to withstand higher torques, loads, and pressure operations and with a reduced failure rate. In some embodiments, the sealed bearing pack has more lateral support for improved horizontal drilling and extended operational life. Thus, one embodiment includes an adapter housing extending the length of the outer housing and a bearing within the adapter housing for increased support. Additionally, some embodiments include two thrust bearing assemblies for improved operations and reduced failures. Various embodiments include a longer flow sleeve than prior art sealed bearing packs.

Provided is a tapered roller bearing (1) for which a dimensionless number X is defined by the following formula (1) based on a small-diameter-side gap S1 which is a gap between a small-diameter-side annular part (6) of a retainer (5) and a small collar part (2b) of an inner ring (2), a large-diameter-side gap S2 which is a gap between the large-diameter-side annular part (7) and a large collar part (2c) of the inner ring (2), an average roller diameter d, a roller length l, and an outer member angle α. The dimensionless number X falls within a range of 0.69<X<1.12.

A bearing assembly includes a roller bearing connected with a bearing support having a plate-shaped section. The bearing support has a receiving bore for an outer ring of the roller bearing, and the outer ring of the roller bearing is affixed to the bearing support with two affixing plates that are fixed to first and second end sides of the bearing support and that clamp the outer ring at two clamping surfaces. An axial spacing of the first and second end sides of the bearing support is smaller than an axial spacing of the clamping surfaces of the outer ring, and the two affixing plates have a different mechanical strength.

An axial retainment system for a shaft is provided. The axial retainment system includes a cylindrical body extending from an outboard end to an inboard end thereof, and a swaged ridge extending radially outward from the cylindrical body proximate the outboard end. The swaged ridge has an outboard axial surface facing toward the outboard end and extending radially outward and terminating at a radially outward facing circumferential surface. The swaged ridge has an inboard axial surface facing toward the inboard end and extending radially outward from the cylindrical body and terminating at the radially outward facing circumferential surface. The outboard axial surface of the swaged ridge is recessed axially inward from the outboard end of the shaft. The inboard axial surface of the swaged ridge is swaged against, conforms in shape to, and is compressed against a component to be axially retained on the shaft.

An oil bearing structure of a fan includes a shaft seat, a rotating shaft, and an oil bearing. The shaft seat includes a boss. A middle portion of the boss defines a slot. One end of the rotating shaft is inserted into the slot. Another end of the rotating shaft is a free end. The oil bearing is sleeved on an outer periphery of the rotating shaft. An axis of the rotating shaft and an axis of the oil bearing are perpendicular to the shaft seat. An effective length of the oil bearing and the rotating shaft is 50%-70% of a length of the fan.

A rolling bearing includes an outer bearing race and an inner bearing race defining a bearing space therebetween. Rolling elements are mounted in the bearing space. A seal device is at one axial opening of the bearing space and includes a metal ring member with through holes configured such that lubricating oil can pass through the through holes and solid foreign substances cannot pass through the through holes. One of the outer bearing race and the inner bearing race is stationary, and the other is rotatable. The metal ring member is in engagement with the stationary bearing race. A metal or resin sub-ring member, which is a separate member from the metal ring member, is fixed to the rotatable bearing race. Between the metal ring member and the metal or resin sub-ring member, a gap is defined which constitutes a labyrinth seal structure.

An annular cage provided with a taper roller bearing includes: a small-diameter annular portion, a large-diameter annular portion, and a plurality of column portions which link the small-diameter annular portion and the large-diameter annular portion to each other, and further includes roller retaining portions which prevent taper rollers accommodated in pockets from falling out to the outer side in the radial direction. Each of the roller retaining portions has a shape of a protruding beam that is a fixed end on the column portion side and on the small-diameter annular portion side, extends in the circumferential direction and in a column portion longitudinal direction, and is a free end on the tip end side in the extending direction.

A taper roller bearing includes: an inner ring, an outer ring, a plurality of taper rollers, and an annular cage. The cage includes a small-diameter annular portion on one side in a axial direction, a large-diameter annular portion which is positioned on the other side in the axial direction and on a radial outer side of a large flange of the inner ring, and a plurality of column portions which link the small-diameter annular portion and the large-diameter annular portion. The taper roller bearing has a labyrinth structure which suppresses a flow of lubricating oil to the outside of the bearing from the inside of the bearing between the large flange and the large-diameter annular portion.