A portal unit is provided. The portal unit includes a deceleration gear train and a housing. The housing includes an inner side wall that is formed with an input opening at a position above a rotation axial line of a driving wheel, an outer side wall that is formed with an output opening at a coaxial position with the rotation axial line of the driving wheel, and an intermediate wall that connects peripheral edges of the inner side wall and the outer side wall. The inner side wall is provided, at a radially outward position of the input opening, with mount bolts for the suspension unit. The mount bolts each include a shaft portion protruding inwardly in a vehicle width direction.

An articulating carriage for moving an object across a surface having a non-planar obstruction to allow movement of the object over the obstruction. The articulating carriage has a walking beam assembly that pivotally supports a pedestal to dispose a support surface thereof above the walking beam assembly. The walking beam assembly has a base plate, wheeled casters and a pair of spaced apart hangers having articulation openings. The walking beam pivots relative to the pedestal. In one embodiment, the pedestal is pivotally mounted on the walking beam assembly. In another embodiment, a pair of walking beam assemblies are connected with a crosstube that pivotally supports the pedestal. In another embodiment, a major crosstube assembly connects a pair of crosstubes to define a carriage having four walking beams. In yet another embodiment, a compound crosstube assembly connects pairs of major crosstube assemblies to define a carriage having eight walking beams.

A half shaft connects to the mounting bracket of the wheel in a splined connection. The straight external spline of the half shaft is modified to a helical or involute external spline, in which the helix angle adopted is small. The mounting bracket of the wheel can be longitudinally advanced by hand assembly only part way onto the half shaft. The rest of the longitudinal advancement during assembly occurs by tightening the nut to completely eliminate the fit clearance between the external spline and its corresponding mating arrangement. Various road tests of vehicles verify that, when using the present invention, the nut does not loosen during use of the vehicle. The invention enables the locking force of the nut to be reduced, and assembly and maintenance are convenient.

A half shaft connects to the mounting bracket of the wheel in a splined connection. The straight external spline of the half shaft is modified to a helical or involute external spline, in which the helix angle adopted is small. The mounting bracket of the wheel can be longitudinally advanced by hand assembly only part way onto the half shaft. The rest of the longitudinal advancement during assembly occurs by tightening the nut to completely eliminate the fit clearance between the external spline and its corresponding mating arrangement. Various road tests of vehicles verify that, when using the present invention, the nut does not loosen during use of the vehicle. The invention enables the locking force of the nut to be reduced, and assembly and maintenance are convenient.

An extendable axle with wheels on a common centerline preferably includes a base housing, a left axle device, a right axle device, a left extension cylinder and a right extension cylinder. The left axle device slides into a left side of the base housing and the right axle device slides into a right side of the base housing. The left axle device preferably includes a base tube, a steering knuckle, a drive motor and a steering cylinder. The steering knuckle is pivotally engaged with an end of the base tube. The drive motor is retained on the steering knuckle. The steering cylinder pivots the steering knuckle. The right axle device is the left axle device rotated 180 degrees. The left extension cylinder extends the left axle device. The right extension cylinder extends the right axle device. The left drive motor and the right drive motor are on the same centerline.

An electric drive unit for a wheel of a motor vehicle, including an electric motor for driving a drive shaft joined to the wheel in a manner resistant to rotation. The drive shaft is disposed coaxial to the rotor of the electric motor and is joined thereto in a rotation-resistant manner. The drive shaft is joined to the rotor of the electric motor in a rotation-resistant and axially moveable manner via a bearing.

An electric drive unit for a wheel of a motor vehicle, including an electric motor for driving a drive shaft joined to the wheel in a manner resistant to rotation. The drive shaft is disposed coaxial to the rotor of the electric motor and is joined thereto in a rotation-resistant manner. The drive shaft is joined to the rotor of the electric motor in a rotation-resistant and axially moveable manner via a bearing.

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.

An axle housing assembly and a method of manufacture. A friction weld may join a spindle to an arm portion of the axle housing assembly. An extension weld may encircle the arm portion. The extension weld may extend from the friction weld in a direction that may extend away from the spindle.