A gas turbine engine for an aircraft has an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor, the turbine being the lowest pressure turbine of the engine and the compressor being the lowest pressure compressor of the engine; a fan located upstream of the engine core; and a gearbox that receives an input from the core shaft and outputs drive to the fan. The engine core further has three bearings arranged to support the core shaft, and two rearward bearings, and wherein the forward most rearward bearing has a bearing stiffness defined by the radial displacement caused by the application of a radial force at the axial centerpoint of the bearing, and wherein a stiffness ratio of the bearing stiffness at the forward most rearward bearing to the minor span is in the range from 0.08 to 0.5 kN/mm.sup.2.

A gas turbine engine for an aircraft has an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor, the turbine being the lowest pressure turbine of the engine and the compressor being the lowest pressure compressor of the engine; a fan located upstream of the engine core; and a gearbox that receives an input from the core shaft and outputs drive to the fan. The engine core further has three bearings arranged to support the core shaft, and two rearward bearings, and wherein the forward most rearward bearing has a bearing stiffness defined by the radial displacement caused by the application of a radial force at the axial centerpoint of the bearing, and wherein a stiffness ratio of the bearing stiffness at the forward most rearward bearing to the minor span is in the range from 0.08 to 0.5 kN/mm.sup.2.

There is provided a composite oil seal having an electric corrosion prevention function. The composite oil seal includes: a seal main body configured to seal an interior of a motor housing in a state of being mounted to a shaft in the motor housing; and a ground path mounted to the seal main body. The ground path is configured to electrically connect the shaft to the motor housing to allow current induced in the shaft to flow to the motor housing. ( )

A torque transfer device is provided to transfer torque from a torque tool to a torque limiter device, the torque transfer device comprising a torque limiter connection member adapted for connection to the torque limiter device; a first joint; a second joint; and a tool connection member adapted for connection to the torque tool, wherein the first joint and the second joint are configured to lock responsive to activation of the torque tool to transfer a reaction torque generated by the torque tool to the torque limiter device, and wherein the first joint and the second joint are configured to unlock responsive to deactivation of the torque tool to enable rotation between the torque tool and the torque limiter device along a first axis and a second axis different from the first axis.

A bearing damper element includes a ring mounted between a rotating object and a supporting object which supports the ring. The ring includes at least three slits through the thickness of the ring in the axial direction and at a distance of the radial inner and outer surface of the ring. At least half of the slits have one or more damping parts with a maximum width of 0.5 millimeters, whereby the damping parts are concentric and do not overlap.

An apparatus for localized patterned surface hardening for light-weight alloys to increase wear resistance under lubricated contact is provided. The apparatus includes a first metallic structure and a second metallic structure. The second metallic structure includes a contact surface and is disposed in lubricated contact with the first metallic structure at the contact surface, wherein the second metallic structure is constructed with a lighter-than-steel material and wherein the contact surface includes a localized surface hardened pattern.

A bearing assembly can support a rotating shaft on a vehicle structure and can include a rolling element bearing that has an inner race configured to be press fit on the rotating shaft. An outer race can surround the inner race and be configured to be mounted on the vehicle structure. A plurality of rolling elements can be located between the inner race and the outer race. A retaining ring can be configured to be press fit on the rotating shaft and abut the inner race when the rolling element bearing and the retaining ring are press fit on the rotating shaft. The press fit between the retaining ring and the rotating shaft can contribute to the press fit between the inner race and the rotating shaft such that the retaining ring and the rolling element bearing together distribute a load input by the rotating shaft to the vehicle structure.

The present invention relates to internal combustion engines, and discloses a double-cylinder internal combustion engine. The double-cylinder internal combustion engine of the present invention adopts a curved groove ball bearing mechanism to replace crank-connecting rod mechanisms since traditional internal combustion engines have a complicated structure, high material requirements, high processing difficulty, and the inertia effect and noises thereof are hard to be eliminated. Two inner rings of the curved groove ball bearing mechanism are fixedly connected, and a valve mechanism and an ignition mechanism are driven through a gear pair, so that the two sets of cylinders and pistons reciprocate in opposite directions to automatically balance reciprocating inertia thereof. Compared with the prior art, the present invention has simple motion forms which only consist of the rotary motion and the reciprocating motion, and low noises are produced. The inertia of the reciprocating motion is automatically offset, causing small vibrations.

The present invention relates to internal combustion engines, and discloses a double-cylinder internal combustion engine. The double-cylinder internal combustion engine of the present invention adopts a curved groove ball bearing mechanism to replace crank-connecting rod mechanisms since traditional internal combustion engines have a complicated structure, high material requirements, high processing difficulty, and the inertia effect and noises thereof are hard to be eliminated. Two inner rings of the curved groove ball bearing mechanism are fixedly connected, and a valve mechanism and an ignition mechanism are driven through a gear pair, so that the two sets of cylinders and pistons reciprocate in opposite directions to automatically balance reciprocating inertia thereof. Compared with the prior art, the present invention has simple motion forms which only consist of the rotary motion and the reciprocating motion, and low noises are produced. The inertia of the reciprocating motion is automatically offset, causing small vibrations.

Disclosed is an electronic motor with two bearings. The motor is structured so that, when loaded, the majority of the load (e.g., a radial load) is borne by one of the bearings. The bearing that bears a greater load may be larger and, thus, better suited for a heavy load. In some embodiments, the larger bearing may include rolling elements that have respective radii larger than respective radii of rolling elements of the other bearing by a ratio of at least 1.5 (150%). In some embodiments, the larger bearing may have an outer race with a radius that is greater than a radius of the outer race of the smaller bearing by a ratio of at least 1.5. In some embodiments, the motors may include a third bearing between the two bearings. The third bearing may reduce vibration in the motor.