A machining method for forming an opening through a workpiece, serving as a green compact, by moving a milling tool in a radial direction relative to the workpiece is provided. The milling tool includes a first milling tool and a second milling tool. The method includes a pre-machining step of using the first milling tool, and forming the first sidewall surface by rotating the first milling tool so as to cause cutting edges of the first milling tool to cut the workpiece from the acute angle corner to the obtuse angle corner, while leaving a cutting allowance on the second sidewall surface; and a post-machining step of using the second milling tool whose cutting edges are reversed from the cutting edges of the first milling tool, and forming the second sidewall surface by rotating the second milling tool so as to cause the cutting edges of the second milling tool to cut the cutting allowance from the acute angle corner to the obtuse angle corner.

An engine for an aircraft includes an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan having a plurality of fan blades; and a gearbox. The gearbox is an epicyclic gearbox and comprises a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. The radial bending stiffness of the planet carrier is equal to or greater than 1.20×10.sup.9 N/m, and/or the tilt stiffness of the planet carrier is greater than or equal to 6.00×10.sup.8 Nm/rad. A method of operation of such an engine is also disclosed.

A planetary gear apparatus for a power transmission apparatus including a transmission housing includes a sun gear provided on a first shaft, first and second planet carriers rotatably supporting pinion gears gear-engaged with the sun gear, and a ring gear gear-engaged with the pinion gears, where an internal circumference of the sun gear is spline-engaged with an external circumference of the first shaft, where first and second support shafts are fixed to first and second side surfaces of the ring gear, respectively, where the first support shaft is rotatably supported by a supporting frame fixed to the transmission housing, interposing a first bearing, where the second support shaft is rotatably supported by the transmission housing, interposing a second bearing, where the first planet carrier is rotatably supported by the first support shaft interposing a third bearing, and where the second planet carrier is fixedly connected to a connection end portion of a second shaft.

A planetary gear apparatus for a power transmission apparatus including a transmission housing includes a sun gear provided on a first shaft, first and second planet carriers rotatably supporting pinion gears gear-engaged with the sun gear, and a ring gear gear-engaged with the pinion gears, where an internal circumference of the sun gear is spline-engaged with an external circumference of the first shaft, where first and second support shafts are fixed to first and second side surfaces of the ring gear, respectively, where the first support shaft is rotatably supported by a supporting frame fixed to the transmission housing, interposing a first bearing, where the second support shaft is rotatably supported by the transmission housing, interposing a second bearing, where the first planet carrier is rotatably supported by the first support shaft interposing a third bearing, and where the second planet carrier is fixedly connected to a connection end portion of a second shaft.

A planetary gearbox for a wind power installation includes a planetary carrier having a first and second carrier cheeks, planetary gears mounted rotatably on the first and second carrier cheeks via bearing pins, respectively, an internal gear meshing with the planetary gears, with an assembly clearance being configured between a cheek external diameter of the first and second carrier cheeks and an internal diameter of the internal gear, and a planetary carrier spider configured to position the first and second carrier cheeks at a defined spacing with respect to one another. The planetary carrier spider has a radially outwardly pointing outer side which extends at a greater spaced-apart relation radially inward from a radially inner tip circle radius of an internal toothing system of the internal gear than the first and second carrier cheeks and which is arranged radially outside with respect to an internal diameter of the planetary gears.

An electrically-actuated variable camshaft timing (VCT) device, comprising: an input configured to receive rotational force from an electric motor; an output configured to couple with a camshaft of an internal combustion engine; a planet gear having radially outwardly extending gear teeth configured to engage ring gears and a radially-inwardly-facing surface; a planet pin, supporting the planet gear, having an outer surface and an axis of rotation about which the planet gear rotates; and a spring applying force in a substantially axial direction along the axis of rotation that moves the planet gear in a radial direction.

A mechanical gearbox for an aircraft turbomachine includes a sun gear having an axis (X) of rotation, a ring gear around the sun gear, and planet gears meshed with the sun gear and the ring gear. Each planet gear has a first toothing meshed with the sun gear and a second loathing meshed with the ring gear. The first toothing includes a series of upstream teeth and a series of downstream teeth located on either side of a plane (H) perpendicular to the axis (X) of rotation of the sun gear. The second toothing includes a series of upstream teeth and a series of downstream teeth located on either side of the plane (H) and separated from one another by the first toothing, these teeth being parallel to one another and to the axis (Y) of rotation of the planet gear.

A gearbox comprises a differential gear train. The differential gear train comprises a ring gear assembly, a sun gear assembly, and a planetary carrier assembly connected to a planetary gear mechanism. The planetary carrier assembly comprises side plates. The side plates combine with gears to form high-pressure volume units and low-pressure volume units, and a throttle channel is connected between two volume units. The high-pressure volume unit is constructed in a meshing zone of the gears. All high-pressure volume units are connected and communicated with each other by means of a high-pressure oil channel on the planetary carrier assembly. The gearbox can reduce the volume of the high-pressure volume unit, simplify the structure and process, and improve the transmission efficiency and reliability

A component includes a metallic substrate having a tribological surface and a coating. The coating includes a first layer disposed on the tribological surface and a second layer disposed on the first layer. The first layer includes titanium, chromium, or a diamond-like carbon (DLC). The second layer includes a disulfide.

To reduce assembly man-hours of a planetary gear device by devising a structure of a carrier, disclosed is a carrier of a planetary gear device 1 is formed with a gear housing space for housing a sun gear and a planetary gear. The gear housing space is formed between a pair of gear support parts rotatably supporting the planetary gear by a gear support shaft. The pair of gear support parts are integrally connected by a plurality of beams. The beam has a virtual plane orthogonal to a rotation axis of the sun gear as an x-y plane, and a radial direction of a direction extending radially from the rotation axis along the x-y plane is formed along a radial direction at a radially outer position of the sun gear. The planetary gear is located between the beams.