A drivetrain for an aircraft includes an engine, a driveshaft to receive rotational energy from the engine and a gearbox including a multistage planetary gear system to receive rotational energy from the driveshaft. The multistage planetary gear system includes an integral multistage ring gear system having flanged and cantilevered ends. The integral multistage ring gear system forms a first stage ring gear at the cantilevered end and a second stage ring gear interposed between the flanged end and the first stage ring gear. The multistage planetary gear system includes a first stage sun gear, first stage planet gears and a first stage carrier. The first stage planet gears mate with the first stage ring gear. The multistage planetary gear system includes a second stage sun gear, second stage planet gears and a second stage carrier. The second stage planet gears mate with the second stage ring gear.

Separate structural units for an inner gear and a housing of a planetary gear device include an inner gear with a first raised portion formed on the outer peripheral surface of the inner gear, where the first raised portion extends towards in a direction that is inclined with respect to the axial direction of the inner gear. A housing includes a second raised portion formed on an inner peripheral surface, where the second raised portion extends in a direction that is inclined in respect to the axial direction. The housing contains the inner gear such that there is a gap formed between the inner peripheral surface of the housing and the outer peripheral surface of the inner gear. Movement of the inner gear within the interior of the housing is limited through linear contact of the first raised portion and the second raised portion.

A ring gear assembly includes a ring gear, a gear box case, and a set of bolts. The ring gear includes a set of gear teeth inside the ring gear and arranged in a circle around the ring gear axis. The ring gear further includes a set of flanges arranged along at least one side of the ring gear. Each flange has a respective flange bolt hole therethrough, and each flange bolt hole has a respective bolt axis that is oriented perpendicular to the ring gear axis. The gear box case has a set of gear box bolt holes therethrough, each gear box bolt hole corresponding to a respective one of the flange bolt holes. Each of the bolts passes through a respective one of the gear box bolt holes and its corresponding flange bolt hole to fasten the ring gear to the gear box case.

The support structure comprises a main body, a base part, and a ring gear having internal teething. The main body has at least one axle element for rotatably mounting the at least one gear wheel, or at least one connection point for an axle element for rotatably mounting the one gear wheel. The ring gear is mounted with an axial end on the base part and is designed to be used as an outer gear wheel of a planetary gear drive. The internal teething of the ring gear has a plurality of tooth elements which extend in each case from a tooth foot to a tooth head in the radial direction relative to a centre axis of the ring gear. An intermediate space, exposing a region of the tooth head at least of individual tooth elements or a number thereof, is provided between the internal teething and the base part.

Provided is a method for producing a gear including an intermediate product forming process of solidifying a fluid material to form a gear intermediate product, and a tooth forming process of cutting the gear intermediate product to form teeth.

It has been found that duplex monolithic parts can be manufactured in high volume at low cost by using powder metal technology to mold and sinter an inner component of the part into an outer component of the part. This technique reduces the cost of manufacturing intricate metal products by taking advantage of the attributes of powder metal technology in making the inner component of the part. The outer component of the part can be wrought machined, stamped or forged, or made by double press double sinter or forging a powder metal component of the part. In any case, this technique can beneficially be used in making a wide variety of toroid parts, such as gears, clutches, sprags, bearing races, one-way diodes, and the like.

A baitcaster for retrieving a fishing line includes a spool, and a compound gear set. The spool is configured to be driven to take up the fishing line. The compound gear set includes a ring gear, first planet gears, second planet gears, and a second shaft. The ring gear is configured to receive an input torque from a first shaft. The first planet gears are driven by the ring gear. The second planet gears are driven by the first planet gears. The second shaft is driven by the second planet gears and is configured to drive the spool to take up the fishing line.

The relates to a method for producing and machining a cylindrical hollow body constructed of aluminium or an aluminium alloy and for arranging said hollow body in a motor vehicle transmission. The hollow body is produced by a casting process such that the hollow body has an inner and an outer lateral surface and has teeth in at least one sub-region of the inner lateral surface. For machining, the hollow body is centrally clamped. The hollow body is arranged in the vehicle transmission by tooth flanks of the internal teeth. In the disclosed method according to the disclosure, the hollow body is centrally clamped at a tip diameter of the internal teeth. The disclosure further relates to a corresponding cylindrical hollow body and to a corresponding vehicle transmission.

Provided is a double-flexspline harmonic reducer, comprising a strong flexspline (3), a weak flexspline (2) and a wave generator (1). The strong flexspline (3) and the weak flexspline (2) are coaxially fixed in an axial direction and a radial direction, and teeth which can be engaged with each other and are different in the number thereof are provided on the strong flexspline (3) and the weak flexspline (2) respectively. The wave generator (1) causes the weak flexspline (2) to undergo non-circular elastic deformation and then to partially engage with the strong flexspline (3), and a contact portion of the strong flexspline (3) and the weak flexspline (2) undergoes non-circular elastic deformation under a radial pressure from the weak flexspline (2). A wall thickness of the strong flexspline (3) is greater than or equal to 2 times and less than 5 times that of the weak flexspline (2).

Vehicle steering systems are disclosed. An example apparatus disclosed herein includes a first gear, a first pinion engaged with the first gear, a second pinion fixed to the first gear, a second gear engaged with the second pinion, and a third pinion fixed to the second gear, the third pinion to engage with a steering rack of a vehicle.