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 prosthetic elbow includes a fixed member structure and a powered gearbox mechanism housed in a housing structure for rotating the forearm portion to varying angular positions. The powered gearbox mechanism includes a motor attached to the housing structure, a planetary frictional drive connected to a motor shaft of the motor and the housing structure, and a strain wave gear set having an input driven by the planetary fictional drive and an output attached to the fixed member structure, where the powered gearbox mechanism is configured to convert an output of the motor into a rotation of the housing structure relative to the fixed member structure, thereby causing the rotation of the forearm portion to varying angular positions relative to the upper arm. The fixed member structure and the housing structure each are connected to one of a forearm portion and an upper arm portion and rotatable relative to one another about an axis of rotation of the forearm portion.

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.

A planetary gearbox, a splined sleeve, a gas turbine engine with a planetary gearbox and a method for producing a torque-proof connection between a planetary carrier and a support element. The splined sleeve is formed with an outer substantially cylindrical shell surface area and an inner conical shell surface area, and is inserted between the planetary carrier and the support element for creating the torque-proof connection. The diameter of the inner conical shell surface area decreases in the axial direction, starting from an end of the splined sleeve in the direction of a second end of the splined sleeve. The outer cylindrical shell surface area is formed in a stepped manner. The outer cylindrical shell surface area comprises a first cylindrical section and a second cylindrical section which has a diameter larger than the diameter of the first cylindrical section. Between the sections, a conical area is provided.

A gas turbine engine for an aircraft includes an engine core with a turbine, a compressor, and a core shaft connecting the turbine and compressor; a fan upstream of the engine core including a plurality of fan blades; and a gearbox that receives an input from a gearbox input shaft portion of the core shaft and outputs drive to a fan shaft so as to drive the fan at a lower rotational speed than the core shaft, the gearbox being an epicyclic gearbox including a sun gear, a plurality of planet gears, a ring gear, and a planet carrier arranged to have the plurality of planet gears mounted thereon, and wherein the sun gear receives input from the core shaft. At cruise conditions the torque on the core shaft is greater than 10,000 Nm and a ratio of core shaft stiffness to core shaft torque is within a specified range.

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.

The invention provides a transmission mechanism for an electric drill and the electric drill including the transmission mechanism. The transmission mechanism includes a primary planet carrier, a gear assembly, a secondary planet carrier, and a secondary gear assembly. The gear assembly comprises a primary gear ring and a primary gear set located in the primary gear ring. The primary gear set has two primary planetary gear sets mounted on the primary planetary gear shaft. The secondary planet carrier is provided with secondary planetary gear shafts and an output shaft. The secondary gear assembly includes a secondary gear ring and a secondary planetary gear set. The secondary planetary gear set is pivotably mounted on the secondary planetary gear shafts, an outer side of the secondary planetary gear set engages with the secondary gear ring, and an inner side of thereof engages with the sun gear.

A window covering includes a housing, a covering material, a spindle, and a driving device. The spindle and the driving device are provided at the housing. The driving device includes a motor having a shaft, and an epicyclic gearing decelerating device having an input end and an output end connected to the shaft and the spindle, respectively. Whereby, the spindle can drive the covering material to expand or to collapse. The epicyclic gearing decelerating device includes a ring portion and at least a planet gear assembly which is coupled between the input end and the output end. The planet gear assembly includes a plurality of planet gears having a Shore A durometer hardness of 45-90, which is rotatable along the fixedly provided ring portion. While being driven to move, a lower end of the covering material moves at a speed higher than 65 mm per second.

An external mechanism for endoscope includes: an abutment surface that is a first surface configured to cover a knob arranging surface at which a second bending operation knob is arranged in an operation portion of an endoscope; a wheel configured to engage with the second bending operation knob arranged at the knob arranging surface; a motor configured to generate a driving force for rotating the wheel; a housing case that houses the wheel and the motor; a case attaching/detaching and fixing section for detachably attaching the housing case to the operation portion of the endoscope; and a locking member provided at the housing case and configured to be locked on the knob arranging surface of the endoscope and a large-diameter portion end face adjacent to the knob arranging surface in the operation portion of the endoscope.

A shifting device for a transmission is disclosed. The shifting device comprises a transmission shaft, a shift gear being mounted thereon, wherein the shift gear is configured with a connecting hub which is axially displaceable relative to the transmission shaft, wherein the connecting hub has an internal toothing in engagement with an external toothing of the transmission shaft, so that the shift gear is drive-connected to the transmission shaft in an axially displaceable manner therewith. A latching device is further provided, the shift gear being axially displaceable thereby into a plurality of latching positions. The latching device comprises a spring-pretensioned setting pin displaceably mounted radially to the transmission shaft and in engagement with a setting shaft rotatably mounted in the transmission shaft, such that the setting shaft and the setting pin can be brought out of an unlocked position into a locked position and vice-versa by rotating the setting shaft.