Patent ID: 8757302

Claim:
An irrigation system comprising: a central pivot; a series of mobile towers connected to the central pivot and to one another by support structure, each mobile tower having a drive tube, a drive motor, and a drive shaft driven by the drive motor; and at least one track assembly for supporting at least one of the mobile towers above a ground to be irrigated by the irrigation system, the track assembly comprising: a hinge plate for attachment to one end of the drive tube; a mounting bracket pivotally attached to the hinge plate; a gearbox assembly and rotatable drive wheel hub attached to the mounting bracket; a drive wheel attached to the drive wheel hub; a rotatable tension wheel hub attached to the mounting bracket and spaced from the drive wheel hub, the tension wheel hub being shiftable relative to the mounting bracket and the drive wheel hub; a tension wheel attached to the tension wheel hub; a track belt trained over the drive wheel and the tension wheel and driven by the drive wheel to propel the mobile tower; structure for adjusting a pivot angle of the mounting bracket with respect to the mobile tower to achieve a desired turning radius or tow for the track assembly; and structure for adjusting a mounting angle of the gearbox assembly on the mounting bracket to further adjust the turning radius or tow of the track assembly.