Mechanism for adjusting track gauge of track chassis

The invention relates to the technical field of track chassis of rotary drilling rigs, in particular to a mechanism for adjusting the track gauge of a track chassis. The mechanism comprises track frames, positioning pins, front connecting rods, widening oil cylinders, a lower vehicle frame and rear connecting rods, wherein a guide wheel is arranged at one end of each track frame, and a driving wheel is arranged at the other end of each track frame; a plurality of thrust wheels are arranged under each track frame; a caterpillar track is wound at the periphery of each track frame; bearing chain wheels are also arranged between each caterpillar track and a frame body; the track frames, the front connecting rods, the lower vehicle frame and the rear connecting rods are connected to form a parallelogram through pin shafts; a cylinder barrel end of each widening oil cylinder is hinged with the lower vehicle frame; a piston rod end of each widening oil cylinder is hinged with one track frame; and a locking shaft pin and a positioning pin hole are arranged on a convex corner of each front connecting rod. The mechanism avoids the sliding friction of the original structure, can ensure that the gravity center position of a transport state of a drilling rig is relatively reasonable at the same time, and can also be structurally implemented easily.