A vehicle includes three pairs of wheels, each pair being spaced apart in a right-left direction, three differential gears, respectively corresponding to the three pairs of wheels, and an engine that generates a rotation to be transmitted to the three pairs of wheels through the three differential gears. The engine is located rearward of a front differential gear that is any one of the three differential gears and is fixed to the front differential gear.

Methods and systems for an epicyclic gear mechanism that includes a primary differential assembly to selectively drive the fore secondary differential assembly and the aft secondary differential assembly. The fore secondary differential assembly selectively drives one or more fore interfaces (e.g., output gears), whereas the aft secondary differential assembly selectively drives one or more aft interfaces (e.g., output gears). Each of the primary differential assembly, the fore and aft secondary differential assemblies, and the interfaces rotate about a common central axis. The primary differential assembly drives the fore secondary differential assembly via a first sun gear, and drives the aft secondary differential assembly via a second sun gear, both of which rotate about the common central axis. Further, one or more actuators are to activate or deactivate in order to drive or be driven by a selected interface.

Methods and systems for an epicyclic gear mechanism that includes a primary differential assembly to selectively drive the fore secondary differential assembly and the aft secondary differential assembly. The fore secondary differential assembly selectively drives one or more fore interfaces (e.g., output gears), whereas the aft secondary differential assembly selectively drives one or more aft interfaces (e.g., output gears). Each of the primary differential assembly, the fore and aft secondary differential assemblies, and the interfaces rotate about a common central axis. The primary differential assembly drives the fore secondary differential assembly via a first sun gear, and drives the aft secondary differential assembly via a second sun gear, both of which rotate about the common central axis. Further, one or more actuators are to activate or deactivate in order to drive or be driven by a selected interface.

Methods and systems for nacelle door electromechanical actuation may include a power distribution unit comprising a motor and differential gears; and a plurality of electromechanical actuators, each coupled to an output of a corresponding one of the differential gears. Each of the electromechanical actuators may include a configurable brake and a mechanical output, where the power distribution unit may provide mechanical torque to one of the electromechanical actuators via the motor and the differential gears based on configuration of the configurable brakes in each of the electromechanical actuators. At least one of the configurable brakes may be an electrically configurable brake. At least one of the configurable brakes may be a mechanically configurable brake. The differential gears may include two or more differential gears for receiving an input torque and supplying an output torque to one of a plurality of outputs of the differential gears.

Methods and systems for nacelle door electromechanical actuation may include a power distribution unit comprising a motor and differential gears; and a plurality of electromechanical actuators, each coupled to an output of a corresponding one of the differential gears. Each of the electromechanical actuators may include a configurable brake and a mechanical output, where the power distribution unit may provide mechanical torque to one of the electromechanical actuators via the motor and the differential gears based on configuration of the configurable brakes in each of the electromechanical actuators. At least one of the configurable brakes may be an electrically configurable brake. At least one of the configurable brakes may be a mechanically configurable brake. The differential gears may include two or more differential gears for receiving an input torque and supplying an output torque to one of a plurality of outputs of the differential gears.

A hybrid drivetrain is provided. The hybrid drivetrain comprises a power source, a transmission, and a tandem axle assembly. The transmission includes a primary clutch and is drivingly engaged with the power source. The tandem axle assembly includes a first axle and a second axle and is drivingly engaged with the transmission. One of the transmission and the tandem axle assembly includes a first motor generator in electrical communication with a battery. The first motor generator and the primary clutch facilitate operating the hybrid drivetrain as a hybrid drivetrain in a plurality of operating modes. The hybrid drivetrain may further comprise second and third motor generators in electrical communication with the battery to facilitate operating the hybrid drivetrain in a plurality of operating modes.

An automatic torque transmission with one or more stages, where each stage has a number of available gear ratios. There is a planetary gear train comprising a planet gear on a planet gear carrier, a sun gear, and a ring gear, wherein an input to the planetary gear train is through the planet gear carrier, and wherein the planet gear is configured to drive the sun gear at higher speed and lower torque, and the ring gear at lower speed and higher torque. There is a first differential gear train having a first input side, a second input side, and an output, wherein the sun gear is coupled to the first input side of the first differential gear train and the ring gear is coupled to the second input side of the first differential gear train, thereby combining two inputs into a single output. A brake clutch is configured to be selectively coupled to the ring gear, to provide selective braking of the ring gear so as to selectively transfer drive from the ring gear to the sun gear. A one-way clutch is configured to be selectively engaged or disengaged from the sun gear, to selectively prevent rotation of the sun gear in one direction. The output of the differential gear train is coupled to either another stage of the transmission or to an output differential gear train. The output differential gear train is configured to be locked for forward drive or coupled to a housing for reverse drive. With the one-way clutch disengaged the sun gear will freewheel by rotating in reverse, with no output.

Methods of controlling a tandem axle assembly in a vehicle, the tandem axle assembly including an inter-axle differential (IAD), one or more side gears, and a front tandem axle assembly having a pair of front tandem axle half shafts selectively connected to a pair of front tandem axle wheel hub assemblies. When a determined speed of the vehicle is greater or equal to a predetermined speed, the IAD may be locked, the tandem axle wheel hub assemblies may be disconnected from their respective tandem axle shafts, and/or the IAD may be moved out of engagement with the one or more side gears. When a determined speed of the vehicle is less than a predetermined speed, the IAD may be unlocked, the tandem axle wheel hub assemblies may be connected to their respective tandem axle shafts, and/or the IAD may be engaged with the one or more side gears.

Methods of controlling a tandem axle assembly in a vehicle, the tandem axle assembly including an inter-axle differential (IAD), one or more side gears, and a front tandem axle assembly having a pair of front tandem axle half shafts selectively connected to a pair of front tandem axle wheel hub assemblies. When a determined speed of the vehicle is greater or equal to a predetermined speed, the IAD may be locked, the tandem axle wheel hub assemblies may be disconnected from their respective tandem axle shafts, and/or the IAD may be moved out of engagement with the one or more side gears. When a determined speed of the vehicle is less than a predetermined speed, the IAD may be unlocked, the tandem axle wheel hub assemblies may be connected to their respective tandem axle shafts, and/or the IAD may be engaged with the one or more side gears.

Disclosed is a travel control apparatus for a four-wheel drive vehicle in which the states of engagements between a drive output part for secondary drive wheels and left and right secondary drive wheel axles are each changed to a torque transmission state or a torque transmission interruption state. The ratio of rotational speed of the drive output part to the average of rotational speeds of primary drive wheels is greater than 1. When the engagement states corresponding to the secondary drive wheels on the outer and inner sides of a turning locus have been set to the torque transmission state and the torque transmission interruption state, respectively, the engagement state having been set to the torque transmission state is changed to the torque transmission interruption state upon determination that an accelerator pedal is not operated and the magnitude of lateral acceleration is equal to or greater than a predetermined threshold.