An axle assembly having a drop gear set and a countershaft transmission. The drop gear set may operatively connect a rotor of an electric motor to a countershaft. The countershaft transmission may operatively connect the countershaft to a drive pinion. The electric motor and the countershaft transmission may be positioned on opposite sides of a differential assembly.

An axle assembly having a drop gear set and a countershaft transmission. The drop gear set may operatively connect a rotor of an electric motor to a countershaft. The countershaft transmission may operatively connect the countershaft to a drive pinion. The electric motor and the countershaft transmission may be positioned on opposite sides of a differential assembly.

An axle assembly having a countershaft transmission. The countershaft transmission may operatively connect a rotor shaft of an electric motor to a drive pinion that may be rotatable about a drive pinion axis. The electric motor and the countershaft transmission may be positioned on opposite sides of a differential assembly.

An axle assembly having a countershaft transmission. The countershaft transmission may operatively connect a rotor shaft of an electric motor to a drive pinion that may be rotatable about a drive pinion axis. The electric motor and the countershaft transmission may be positioned on opposite sides of a differential assembly.

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.

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.

A drive device includes a first clutch mechanism that couples or decouples power transmission systems for front and rear wheels, a first electric motor disposed on a front or rear wheel side and coupled to the first clutch mechanism, a second electric motor disposed on the other of the front and rear wheel sides and coupled to the first clutch mechanism, a second clutch mechanism that couples or decouples the first electric motor and front drive shafts, a planetary gear mechanism that distributes output of the first electric motor to the first and second clutch mechanisms, and a third clutch mechanism that limits a difference between a first rotational element that transmits the output of the first electric motor to the first clutch mechanism and a second rotational element that transmits the output of the first electric motor to the second clutch mechanism.

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.

An inter-axle differential assembly comprising a driving input shaft, a forward differential wheel, a rear differential wheel, a differential spider connected for common rotation with the input shaft and on which differential pinions configured to meshingly engage with said differential wheels are rotatably mounted, and a differential housing to which the differential spider is connected for common rotation. The assembly comprising an output wheel via which torque is transferable to a rear driving axle, and a connection means movable between: an open position which connects the output wheel to the rear differential wheel so that the differential housing can rotate independently of the rear differential wheel, a locking position connecting both of the differential housing and the output wheel to the rear differential wheel, and a disconnecting position connecting the differential housing to the rear differential wheel, so that the output wheel can rotate independently of the rear differential wheel.