Fine adjustment self-locking type spiral tensioning device

The utility model relates to the technical field of belt conveyors, in particular to a fine adjustment self-locking type spiral tensioning device which comprises a tensioning roller, a lead screw, a protective leather sheath and a fine adjustment self-locking structure, a bearing seat is arranged in the tensioning roller, a frame is installed at one end of the tensioning roller, one end of the lead screw penetrates through the frame and is inserted into the tensioning roller to be connected with the bearing seat, and the other end of the lead screw is connected with the protective leather sheath. The other end is in threaded connection with the interior of the fine-tuning self-locking structure; the fine adjustment self-locking structure comprises a shell, a worm, a turbine and a bearing, the turbine is installed in the shell through the bearing, and the outer wall of the worm is connected with the outer wall of the turbine in a meshed mode. The operating force is small, the acting force is uniform, the adjus