A gas turbine engine for an aircraft configured with an engine core that has a turbine, a compressor, and a core shaft connecting the turbine to the compressor. A fan located upstream of the engine core, that has a plurality of fan blades. A gearbox arranged to receive an input from the core shaft and to output to the fan so as to drive the fan at a lower rotational speed than the core shaft. The gearbox being an epicyclic gearbox having a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. The gearbox having an overall gear mesh stiffness, and wherein the overall gear mesh stiffness of the gearbox is greater than or equal to 1.05×10.sup.9 N/m and less than or equal to 8.0×10.sup.9 N/m.

An engine core including a turbine, compressor, and a core shaft connecting the turbine and compressor; a fan located upstream of the engine core including a plurality of fan blades; and a gearbox. The gearbox is arranged to receive an input from the core shaft and to output drive to the fan to drive the fan at a lower rotational speed than the core shaft. The gearbox is an epicyclic gearbox and includes a sun gear, a plurality of planet gears, ring gear, and planet carrier to the mounted planet gears. The planet carrier has an effective linear torsional stiffness and the gearbox has a gear mesh stiffness between the planet gears and the ring gear. A carrier to ring mesh ratio of:

[00001]$\frac{\begin{array}{c}\mathrm{the}\mathrm{effective}\mathrm{linear}\mathrm{torsional}\\ \mathrm{stiffness}\mathrm{of}\mathrm{the}\mathrm{planet}\mathrm{carrier}\end{array}}{\begin{array}{c}\mathrm{gear}\mathrm{mesh}\mathrm{stiffness}\mathrm{between}\\ \mathrm{the}\mathrm{planet}\mathrm{gears}\mathrm{and}\mathrm{the}\end{array}}$

An article of manufacture comprises a first component having a first mating surface and a second component having a second mating surface. The first component may include an aperture having internal splines or gear teeth, and/or an outer perimeter having external splines or gear teeth. The first and second components are disposed such that a gap is provided between the first and second mating surfaces. Brazing material is disposed between the first and second mating surfaces so as to mechanically couple the first and second components. The first component may be made of a powdered metal or a non-powdered metal, and the second component may be made of the other of such two metals. In one embodiment, the first component may be a planetary carrier plate portion having internal splines and the second component may be a planetary carrier spider portion.

A planetary gear with a sun wheel, a hollow wheel and a planetary carrier on which a planetary wheel is rotatably mounted. In the axial direction on a first side of the planetary carrier, the sun wheel and hollow wheel include connection areas for coupling the sun wheel and hollow wheel to rotatable or torque-proof areas of an engine. The planetary carrier has a connection area for attaching to rotatable or torque-proof areas of the engine on its opposite second side. The structural component stiffnesses of the sun wheel, planetary carrier, the hollow wheel and the planetary wheel are adjusted to each other such that, during operation they have twistings in the axial direction of the planetary gear that respectively qualitatively correspond to each other between the connection areas and side areas facing away from the connection areas due to the respectively applied torques.

An epicyclic gear assembly includes a carrier that includes a first plate axially spaced from a second plate. At least one epicyclic gear set is located between the first plate and the second plate. The first plate is configured to rotate with an output of the epicyclic gear assembly. A first bearing race is attached to the first plate for supporting a first bearing. A second bearing race is attached to the second plate for supporting a second bearing.

An output frame is connected to a portion of a radially outer portion of a carrier, the portion being closer to a front plate than to a rear plate. The carrier has a first region as an external force transmission path between front pin support surfaces and the output frame, and a second region as the external for transmission path between rear shaft support surfaces and the output frame, and a stiffness with respect to a twist force of the first region and a stiffness with respect to the twist force of the second region are equal to each other. In the front plate and the rear plate, a stiffness with respect to a radial tensile force applied to the front pin support surfaces and a stiffness with respect to the radial tensile force applied to the rear shaft support surfaces are equal to each other.

The present invention relates to an equidirectional transfer universal transmission formed by connecting an equidirectional transfer case, a commutator, and an actuator. One of five types of planetary gear trains is used for the equidirectional transfer case, the component corresponding to a term having a maximum absolute value of a coefficient in a motion characteristic equation is used as an input end, and the other two components are respectively used as an inner output end and an outer output end. The commutator includes fourth types of quill shaft commutators and a non-quill shaft commutator, which are set by respective methods. One of two types of single-layer planetary gear trains is used for the actuator. The present invention includes methods for setting respective components of the equidirectional transfer case and the actuator, and includes a connection method. According to the present invention, an output shaft is controlled to revolve around an actuator shaft by inputting a revolving speed, a forward moment and a reverse moment are balanced during revolving, the output shaft has no unidirectional bearing moment, and a revolving control device has a simple structure.

A high ratio traction drive transmission includes a sun roller, a traction ring, a plurality of traction planets in contact with the sun roller and the traction ring, at least one reaction roller in contact with at least one of the traction planets, and a carrier assembly coupled to at least one of the traction planets and the at least one reaction roller. The sun roller has a first longitudinal axis and the traction ring is aligned coaxially with a second longitudinal axis, wherein the first longitudinal axis is radially offset from the second longitudinal axis.

A gas turbine engine for an aircraft has an engine core having a turbine, compressor, and core shaft connecting the turbine and compressor; a fan upstream the engine core, the fan having fan blades; and a gearbox. The gearbox receives an input from a core shaft and outputs drive to a fan to drive the fan at a lower rotational speed than the core shaft. The gearbox is an epicyclic gearbox and has a sun gear, planet gears, ring gear, and planet carrier on which the planet gears are mounted. The gearbox has a gear mesh stiffness between the planet gears and the ring gear and a gear mesh stiffness between the planet gears and the sun gear. The gear mesh stiffness between the planet gears and the ring gear divided by that between the planet gears and the sun gear is in the range from 0.90 to 1.28.

A gas turbine engine for an aircraft including an engine core including a turbine, compressor, and core shaft connecting the turbine and compressor; a fan located upstream of the engine core including a plurality of fan blades; a gearbox that can receive input from the core shaft and can output drive to the fan at a lower rotational speed than the core shaft, an epicyclic gearbox including a sun gear, planet gears, a ring gear, and a planet carrier on which the planet gears are mounted; and a gearbox support. A first gearbox support shear stress ratio:

[00001]$\frac{\begin{array}{c}\mathrm{torsional}.Math..Math.\mathrm{shear}.Math..Math.\mathrm{stress}.Math..Math.\mathrm{of}.Math..Math.\mathrm{the}.Math..Math.\mathrm{gearbox}.Math..Math.\mathrm{support}.Math.\\ \mathrm{at}.Math..Math.\mathrm{maxiumum}.Math..Math.\mathrm{take}.Math..Math.\mathrm{off}.Math..Math.\mathrm{conditions}\end{array}}{\mathrm{radial}.Math..Math.\mathrm{bending}.Math..Math.\mathrm{stiffness}.Math..Math.\mathrm{of}.Math..Math.\mathrm{the}.Math..Math.\mathrm{gearbox}.Math..Math.\mathrm{support}}$

is less than or equal to 4.9×10.sup.1 m.sup.−1, and/or a second gearbox ratio:

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