A method of making an interaxle differential unit. The method may include piercing a workpiece and then ring roll forging the workpiece to form an annular case that is a seamless ring. The annular case may be heat treated before installing an interaxle differential unit gear nest inside the annular case.

A hybrid reflective/refractive HMD includes a structural frame, refractive optical lens elements, and optics housings coupled to the structural frame and positioned in front of a user's first and second eyes. Light-emitting visual sources and reflective optical surfaces are contained in the optics housings. Visual content is transmitted from light-emitting visual sources to the reflective optical surfaces. The visual content is reflected within the reflective optical surfaces at least four times without passing through a refractive optical lens element. The visual content is transmitted to the user's first eye or the user's second eye. Simultaneous with the transmission of the visual content to the user's first eye or the user's second eye, a real-world view of the outside surrounding environment is transmitted to the user's first eye or the user's second eye. The visual content is overlaid onto the real-world view of the outside surrounding environment.

A method of assembling an epicyclic gear train includes providing a unitary carrier that includes spaced apart walls and circumferentially spaced mounts interconnecting the walls, spaced apart apertures provided between the mounts at an outer circumference of the carrier, gear pockets provided between the walls and mounts extending to the apertures, and a central opening in at least one of the walls, inserting an intermediate gear through the central opening and moving the intermediate gear radially into the gear pocket to extend through the aperture, inserting a baffle into the carrier, and inserting a sun gear through the central opening to intermesh with the intermediate gear.

A gear device includes a first double helical gear, a two-step gear, a second spur gear, and an intermediate shaft The two-step gear includes a second double helical gear meshing with the first double helical gear, and a first spur gear on a back surface side of the second double helical gear. The second spur gear meshes with the first spur gear. A housing includes a shaft support hole and a meshing guide groove. The shaft support hole houses one end side of the intermediate shaft. The meshing guide groove meshes the second double helical gear with the first double helical gear by guiding the intermediate shaft along a pitch circle of the second spur gear to a proximity of the shaft support hole while maintaining the first spur gear meshing with the second spur gear. The meshing guide groove rises up at the proximity of the shaft support hole.

An inhibitor switch is attached to a manual shaft with a jig. The jig includes a fitting part and an engagement pin. The fitting part is spline-fitted to an outer periphery of the manual shaft. The engagement pin engages in a positioning hole of the inhibitor switch. The outer periphery of the manual shaft includes a tooth-omitted part formed by omitting at least one of spline teeth. The fitting part includes an insertion hole. The insertion hole includes an inner periphery including internal teeth and an engaging part, wherein the internal teeth meshes with the spline teeth, and wherein the engaging part engages with the tooth-omitted part. The jig is attached to the manual shaft with the engaging part engaged with the tooth-omitted part. The inhibitor switch is rotated about the rotation axis to a position allowing engagement of the positioning hole with the engagement pin.

A gear reduction for a gas turbine engine includes intermediate gears, a single structure establishing a carrier centered on an axis and having a pair of axially spaced apart side walls, axially extending circumferentially spaced connecting structure for connecting the pair of side walls, a central opening in at least one of the side walls, and circumferentially spaced smaller openings spaced radially outwardly of the central opening, with internal surfaces of the circumferentially spaced connecting structure defining intermediate gear pockets that extend away from the central opening to the circumferentially spaced openings. The intermediate gears are receivable through the central opening and are secured in the intermediate gear pockets. A ring gear includes a first ring gear half and a second ring gear half placed on an outer periphery of the intermediate gears such that ring gear teeth of the first and second ring gear halves engage with teeth of the intermediate gears.

Alignment tools and methods are provided for assembling a planetary gear sets. The alignment tools include a handle, and an elongated pin having a tip configured to be inserted through a mounting hole of a housing of the planetary gear set, through a first hole in a first washer, through a bore of a pinion gear between pinion needle rollers arranged in a tubular pattern within the bore, and through a second hole of a second washer. The elongated pin is configured to align the first washer, the pinion gear, the pinion needle rollers, and the second washer during insertion therethrough. The elongated pin is retractable relative to the handle in response to a force being applied to the tip in a first direction along a longitudinal axis of the elongated pin.

A method of assembling an epicyclic gear train includes the steps of providing a carrier having a central axis that includes spaced apart side walls and circumferentially spaced connecting structure defining spaced apart apertures provided at an outer circumference of the carrier, gear pockets provided between the side walls and extending to the apertures, and a central opening in at least one of the side walls, inserting a plurality of intermediate gears through the central opening and moving the intermediate gears radially outwardly into the gear pockets to extend into the apertures, inserting a sun gear through the central opening after the step of inserting the plurality of intermediate gears through the central opening, moving the plurality of intermediate gears radially inwardly to engage the sun gear, and placing a ring gear on an outer periphery of the intermediate gears to engage the intermediate gears after the step of moving the plurality of intermediate gears radially inwardly.

An assembly for acoustically influencing toothed wheels, including at least one first toothed wheel having teeth and one second toothed wheel having teeth, wherein the teeth have flanks, wherein at least one flank of a tooth of the first toothed wheel can be engaged with a flank of a tooth of the second toothed wheel, wherein at least one flank of a tooth of the first toothed wheel forms a contact zone or, in the ideal case, a contact line with an engaging flank of a tooth of a second toothed wheel, wherein the contact zone or the contact line is formed at an angle .sub.Aq, in particular between 5 and 85 or between 95 and 175, in relation to an axis of an undulation, a microangle distribution, and/or a microangle periodicity of the engaging flank of the tooth of the second toothed wheel.

A method of assembling an epicyclic gear train includes providing a unitary carrier that includes spaced apart walls and circumferentially spaced mounts interconnecting the walls, spaced apart apertures provided between the mounts at an outer circumference of the carrier, gear pockets provided between the walls and mounts extending to the apertures, and a central opening in at least one of the walls, inserting an intermediate gear through the central opening and moving the intermediate gear radially into the gear pocket to extend through the aperture, inserting a baffle into the carrier, and inserting a sun gear through the central opening to intermesh with the intermediate gear.