[Technical problem] To provide a power transmission mechanism for a four-wheel drive vehicle in which a prime mover is disposed at a low position to lower the center of gravity of the vehicle while a driving path from a transmission to a front wheel differential mechanism is also shortened. [Solutions] In a power transmission mechanism for a four-wheel drive vehicle, the power of a prime mover is transmitted to a front wheel differential mechanism which is disposed in front of the prime mover, and to a rear wheel differential mechanism which is disposed behind a transmission, through the transmission which is disposed behind the prime mover. The transmission comprises a front and rear wheel drive shaft that extends along the longitudinal direction of the vehicle body. The transmission is arranged separately from the prime mover and a rear axle drive device. The rear end portion of the front and rear wheel drive shaft is connected to an input shaft of the rear wheel differential mechanism. The front end portion of the front and rear wheel drive shaft is connected to an input shaft of the front wheel differential mechanism via a front wheel power transmission shaft that extends along the longitudinal direction of the vehicle body and passes through the space beneath the prime mover. The front wheel differential mechanism, the prime mover, the transmission, and the rear wheel differential mechanism are arranged along the longitudinal direction of the vehicle body at the center of the vehicle width of the vehicle.

An off-road vehicle, including: an engine body having a cylinder and a crankshaft that extends in a horizontal direction; and a transmission disposed adjacent to the engine body in a direction orthogonal to an axial direction of the crankshaft in a horizontal direction, in which the cylinder has a center axis inclining to an opposite side to a direction in which the transmission is disposed in a horizontal direction or extending horizontally to the opposite side.

The present disclosure provides methods for adjusting steering angle and articulation angle in an auto articulation operation of a work vehicle. The percentage of travel of a steering joystick of the work vehicle at least partially determines a steering desired angle change, which can be used to calculate a steering desired angle and an articulation desired angle change. The difference between the steering desired angle and a steering angle detected by a steering angle sensor is used to adjust the steering angle. The articulation desired angle change can be used to calculate an articulation desired angle. The difference between the articulation desired angle and an articulation angle detected by an articulation angle sensor is used to adjust the articulation angle.

An engine system comprising: a housing having an accommodating cavity; a crankshaft part, a speed change mechanism and a transmission shaft are provided in the accommodating cavity; and a first motor and a second motor are located outside the accommodating cavity and provided on the housing. The crankshaft part is provided in the accommodating cavity and outputs first power. The first motor comprises a first motor shaft which is connected to an output end of the crankshaft part to convert the first power into electric energy. The second motor comprises a second motor shaft and is configured to output second power according to electric energy. The speed change mechanism is drivingly connected to the second motor shaft without connecting the output end of the crankshaft part. The transmission shaft is connected to an output end of the speed change mechanism. Also disclosed is an all-terrain vehicle.

An apparatus and methods are provided for a rear portal trailing arm assembly for a vehicle rear suspension. The trailing arm assembly comprises a CV joint hub for coupling with a transaxle and a wheel hub for coupling with a rear wheel. A gear transfer case extends rearward from the CV joint hub to an axle case and functions similarly to a rear trailing arm. Forward mounts facilitate coupling the gear transfer case to the chassis such that the trailing arm assembly pivots vertically with respect to the chassis. A rearward mount facilitates coupling a strut with the gear transfer case to control the vertical motion of the rear wheel. Multiple gear assemblies are meshed within the gear transfer case. An axle is coupled with the meshed gear assemblies and housed within the axle case, such that torque applied to the CV joint hub is communicated to the wheel hub.

A portal gear box assembly for an all-terrain vehicle includes a portal gear box housing with a set of gears contained therein, and a plurality of heat-radiating fins extending from the housing wall and effective to radiate heat from the housing at a faster rate than would be radiated in the absence of the fins. The fins may extend outward or inward from the housing, and may be formed integrally with one or more of the walls of the housing, or may be removably attached to the housing. Preferred fins comprise a generally rectangular, planer surface extending radially from a wall of the housing.

A portal gear box assembly for an all-terrain vehicle includes a sealed portal gear box housing having an interior housing space that contains a set of gears for linking an axle to an output shaft. An expandable space is in fluid communication with the interior housing space, and is adapted to allow pressurized fluid contained in the interior housing space to flow into the expandable space, thus expanding the volume of the expandable space and reducing the pressure within the interior housing space. The expandable space may be provided in the form of a bellows whose volume can be changed by expansion or contraction of a fluid contained therein. A fluid is contained within the portal gear box housing and within the expandable space.

The expandable space may be mounted externally to the portal gear box housing, and may be connected to the portal gear box housing by a conduit effective for allowing fluid to pass between the portal gear box housing and the expandable space. The expandable space and its connecting conduit are effective for allowing air to flow from within the portal gear box housing to the expandable space when an increased air pressure within the portal gear box is encountered, thus mitigating against a build-up of air pressure within the portal gear box housing.

A fuel system comprising a fuel tank, a mixing volume configured to mix fuel vapor and air, the mixing volume comprising an outlet configured to be fluidly coupled to an engine, and a fuel vapor line configured to fluidly couple the fuel tank to the mixing volume.

A utility vehicle includes a rear suspension assembly which has a trailing arm generally extending longitudinally. Also, the rear suspension assembly includes an upper radius rod extending in a generally lateral direction relative to a centerline of the vehicle. Additionally, the rear suspension assembly includes a lower radius rod extending in a generally lateral direction relative to the centerline of the vehicle. The rear suspension assembly further includes a suspension member configured to control toe of the at least one rear ground-engaging member.

All-terrain vehicle systems and methods configured for attachable tools and implements are disclosed. An example embodiment includes: an All-Terrain Vehicle (ATV) frame configured with a void; a modular Power Take-Off (PTO) system removably installable in the ATV frame in the void; and a cargo bed removably installable at a rear portion of the ATV frame.