Locking fine adjustment mechanism of small two-dimensional rotary table

A locking fine adjustment mechanism of a small two-dimensional rotary table comprises a locking ring assembly, a spring assembly, a locking fine adjustment hand wheel assembly and a base. A threaded hole is formed in one end in the base, the spring assembly is fixed to the base in a threaded connection mode, an unthreaded hole is formed in the other end in the base, and the locking fine adjustmenthand wheel assembly is arranged in the unthreaded hole of the base in a clearance fit mode. The locking ring assembly is in clearance fit with a main shaft, and the main shaft can rotate freely in anon-locking state. When a hand wheel locking nut is rotated, a hand wheel limiting sleeve, a pin shaft, a cam shaft and a cam can be driven to rotate, a cam lift curved surface pushes an ejector rod to do reciprocating motion, a fan-shaped locking block, a first locking block and a second locking block are further pushed to complete the locking action of the main shaft, and therefore the locking function is achieved. When