Passive self-locking small space docking mechanism for auxiliary operation of mechanical arm

The invention discloses a passive self-locking small space docking mechanism for auxiliary operation of a mechanical arm. The docking mechanism comprises an insertion inner shell, a ball lock outer shell, a ball lock gear, a spring assembly, a ball lock ball, a bearing ball and a check ring. 12 ball locking grooves are uniformly distributed in the outer peripheral surface of the insertion inner shell; six ball lock ball mounting holes and six bearing ball mounting grooves are evenly distributed in the ball lock shell in the circumferential direction. The ball lock gear is connected to the peripheral side of the ball lock shell in a sleeving mode. Six spring assembly mounting holes are evenly formed in the ball lock gear in the circumferential direction, and a bearing ball raceway is arranged on the inner circumferential side of the ball lock gear. A spring assembly is fixedly mounted in each spring assembly mounting hole; the ball lock ball is mounted in the ball lock ball mounting hole in a clearance fit man