A transmission system includes planetary gearing with a ring gear, a plurality of planet gears, a carrier, and a sun gear, a forward clutch operatively connected between the ring gear and carrier, a reverse brake operatively connected between the carrier and a rotationally fixed location, and a control subsystem to switch the transmission system between forward and reverse operational modes in the which the ring gear and the sun gear rotate in the same or opposite rotational directions, respectively. A control subsystem actuation stroke can actuate both the forward clutch and the reverse brake based on a common control signal.

A multi-speed automatic transmission includes a housing, a transmission input shaft, and a plurality of clutches. Different combinations of clutches of the plurality of clutches are engaged to generate different gear ratios corresponding to respective forward speeds of the automatic transmission. The plurality of clutches are positioned within the housing and include a first friction clutch coupled the input shaft and having a first hub, and a second friction clutch having a second clutch hub. The second friction clutch is disposed about the input shaft and radially nested within the first clutch hub such that the second friction clutch is positioned radially between the first clutch hub and the input shaft. The first friction clutch is engaged to generate at least two forward speeds of the transmission and the second friction clutch is engaged to generate seven forward speeds of the transmission including the two forward speeds.

An automatic transmission system includes a housing containing automatic transmission fluid (ATF), a plurality of clutches configured to be engaged to generate gear ratios corresponding to forward speeds of the automatic transmission, wherein one clutch of the plurality of clutches is a friction clutch movable between a disengaged state, an engaged state utilized to create one or more gear ratios of the automatic transmission, and a slippingly engaged state between the disengaged state and the engaged state where the friction clutch is not engaged to create a gear ratio of the automatic transmission, and a controller configured to selectively move the friction clutch to the slippingly engaged state when the friction clutch is not being utilized to generate the one or more gear ratios, such that the friction clutch generates heat from friction to thereby rapidly heat the ATF in the housing and improve operating efficiency of the transmission.

The automatic transmission which includes a third brake element formed by a support member including a first cylindrical portion having a first sliding surface at an outer peripheral surface thereof, a second cylindrical portion having a second sliding surface at an inner peripheral surface thereof and a third cylindrical portion having a third sliding surface at an inner peripheral surface thereof, an inner side piston, inner edge portion of which is in contact with the first sliding surface and an outer edge portion of which is in contact with the second sliding surface and an outer side piston which includes a first piston cylindrical portion, outer edge of which is in contact with the second sliding surface over an entire periphery thereof and a second piston cylindrical portion, outer edge portion of which is in contact with the third sliding surface over an entire periphery thereof.

The present invention provides a control unit. When the control unit performs shifting from a state in which a first shift speed is established by supplying engagement pressures to both hydraulic oil chambers and engaging a predetermined engagement element to a second shift speed by switching engagement and disengagement states of engagement elements other than the predetermined engagement element (Step S1), the control unit reduces the supply of the engagement pressure to one of the two hydraulic oil chambers to a level lower than that in the state in which the first shift speed is established (Step S3).

A gear assembly comprises an axle defining an axis of rotation, a gear mounted to the axle for rotation relative to the axle about the axis of rotation, a pin, and a thrust washer disposed axially adjacent to the gear. The pin is disposed in a portion of the thrust washer and extends into the axle.

A rotorcraft includes a plurality of fan assemblies. Each fan assembly of the plurality of fan assemblies includes a drivetrain having a gearbox with an input shaft and a mast coaxially aligned with the input shaft, and a plurality of electric motors coupled to the input shaft. Each electric motor of the plurality of electric motors is coupled to the input shaft via a sprag clutch.

A rotorcraft includes a plurality of fan assemblies. Each fan assembly of the plurality of fan assemblies includes a drivetrain having a gearbox with an input shaft and a mast coaxially aligned with the input shaft, and a plurality of electric motors coupled to the input shaft. Each electric motor of the plurality of electric motors is coupled to the input shaft via a sprag clutch.

A power transmission device includes a transmission mechanism including a planetary gear set, a first engagement element, and a second engagement element. The first engagement element is a band brake configured to be engaged when the transmission mechanism is in a low gear speed. The second engagement element is a multi-plate friction clutch configured to be engaged when the transmission mechanism is in a high gear speed. The multi-plate friction clutch includes a driven plate and a drive plate. The band brake overlaps with the driven plate and the drive plate of the multi-plate friction clutch in a radial direction.

A kit for modifying an OE vehicle transmission includes a replacement forward piston housing, forward clutch hub and a forward clutch and a replacement direct piston housing, direct clutch hub and a direct clutch. A drum extends between and operably connects the replacement forward piston housing and direct piston housing. The kit includes a replacement sprag shaft. The forward clutch hub and forward clutch and the direct clutch hub and direct clutch are positioned between the forward piston housing and the direct piston housing. At least a portion of the forward clutch and at least a portion of the direct clutch are operably mounted to the drum. The forward piston housing and direct piston housing do not counter rotate relative to one another. A power flow module for an OE vehicle automatic transmission is disclosed.