Non-scrubbing vertical drive unit for a trackless or free roaming vehicle with zero turn radius

A driven wheel apparatus for a vehicle a zero turn radius and limited wheel scrubbing, comprising:

• a mounting plate for attaching the driven wheel assembly to a body of the vehicle;
• a drive motor operable to rotate a drive shaft about a vertical drive axis, wherein the drive motor is pivotally supported upon the mounting plate;
• first and second wheels rotatable about a rotation axis orthogonal to the vertical drive axis;
• a center differential disposed between, and coupled to, the first and second wheels and mated to an output end of the drive shaft to be driven by the drive motor via the drive shaft;
• and
• a rotation gear;
• and
• a steering motor operable to drive an output gear engaging the rotation gear to rotate the rotation gear to steer the driven wheel assembly including rotating the drive motor and the first and second wheels about the vertical drive axis.

A vehicle with a zero turn radius, comprising:

• a vehicle body;
• and
• at least on vertical drive unit comprising:
• a vertical drive motor;
• a drive shaft driven to rotate about a vertical drive axis by the vertical drive motor;
• a differential coupled to an output end of the drive shaft;
• a first wheel and a second wheel each coupled to the differential, wherein the differential is positioned between the first and second wheels, wherein the first and second wheels rotate about a wheel rotation axis that is orthogonal to the vertical drive axis, and wherein the differential is configured such that the first and second wheels are independently rotatable at matching or differing rotation velocities;
• a mounting plate attaching the vertical drive unit to the vehicle body;
• a collar pivotally coupling the vertical drive motor to the mounting plate;
• a rotation gear mated to the collar, wherein the collar, the vertical drive motor, and the differential rotate with the rotation gear;
• and
• a steering motor driving an output gear to rotate the rotation gear about the vertical drive axis to steer the driven wheel assembly.