A bearing assembly for supporting a drive shaft of an electric drive motor includes at least one inner ring, at least one outer ring, and a plurality of rolling elements disposed between the inner ring and the outer ring. The bearing assembly is an angular contact ball bearing, and the plurality of rolling elements include a first row of rolling elements and a second row of rolling elements. Also a shaft assembly supported by the bearing assembly and an electric motor including the shaft assembly.

A journal shaft for a journal bearing assembly of an aircraft engine includes a shaft body extending along a longitudinal axis. The shaft body has a radially outer surface and a radially inner surface radially spaced apart from the longitudinal axis to define an inner cavity. An oil pocket is defined in the radially outer surface. One or more passages extend through the shaft body from the radially inner surface to the oil pocket to provide fluid communication between the inner cavity and the oil pocket. The oil pocket includes a radially inner base surface and interconnecting transition surfaces extending between the radially inner base surface of the oil pocket and the radially outer surface of the shaft body. The interconnecting transition surfaces form a fluid-dynamically smooth and edgeless transition to the radially outer surface of the journal shaft.

The present invention relates to a grease composition which can impart excellent durability to a bearing used under a high-speed rotation condition with a DN value of 100,000 or more, wherein the grease composition contains a base oil (A) and a urea-based thickener (B), and particles containing the urea-based thickener (B) in the grease composition satisfy requirement (I) that the particles have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method. The grease composition is used for a bearing used under a high-speed rotation condition with a DN value of 100,000 or more.

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.

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 tire testing device includes a road surface, a carriage capable of traveling along the road surface in a state where a test tire is in contact with the road surface, and a guide mechanism configured to guide movement of the carriage. The guide mechanism includes a rail, and a runner. The runner includes a first roller that rolls on an upper surface of a head of the rail, and a second roller that rolls on a lower surface or a side surface of the head of the rail. The tire testing device includes a first guide mechanism and a second guide mechanism. In the first guide mechanism, the rollers except for the first roller are disposed only on one side of the rail, and in the second guide mechanism, the rollers except for the first roller are disposed only on an other side of the rail.

The present invention relates to a grease composition which can impart excellent durability to a bearing used under a high-speed rotation condition with a DN value of 100,000 or more, wherein the grease composition contains a base oil (A) and a urea-based thickener (B), and particles containing the urea-based thickener (B) in the grease composition satisfy requirement (I) that the particles have an arithmetic mean particle diameter of 2.0 μm or less on an area basis when measured by a laser diffraction scattering method. The grease composition is used for a bearing used under a high-speed rotation condition with a DN value of 100,000 or more.

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.

Disclosed herein is a sliding member having an alloy overlay layer that comes into sliding contact with a counterpart member thereof and has improved fatigue resistance. The sliding member comprises a base material layer and an alloy overlay layer formed on the base material layer, in which the alloy overlay layer has a soft metal phase made of tin and precipitated in a metallic matrix phase made of aluminum, and when an average aspect ratio of the soft metal phase is defined as A, and its standard deviation is defined as A, A+A is 3.0 or less. In this case, the soft metal phase has a shape close to a sphere without elongating in a certain direction.

A rolling bearing including a cage is provided. The cage includes, on its outer peripheral surface, a plurality of ridges protruding radially outwardly, and circumferentially spaced apart from each other. The ridges extend in the axial direction or in an oblique direction or directions relative to the circumferential direction. The ridges are capable of coming into contact with the inner peripheral surface of the outer ring through lubricating oil.