In the shipbuilding industry, there are stern shaft sealing device and coupling sealing device on the ship transmission shaft system. The stern tube is connected with the stern shaft through sleeve coupling.           A copper sleeve is sleeved on the outside of the stern tube, and a stern shaft front seal is installed on the stern tube connected with the stern shaft. The sleeve coupling 3 and the front seal of the stern shaft are fixed on the transmission shaft system with perforated hexagon bolts. When in use, the perforated bolt will loosen with the operation of the ship's transmission shaft. Therefore, in order to ensure the safety of ship operation and prolong the service life of the hull, it is necessary to take protective measures for the perforated bolt. At present, the shipyard's anti loosening method for perforated bolts is generally to fix every two adjacent perforated bolts with iron wire, that is, after the steel wire passes through one bolt hole, fold the steel wire together and screw it into a twist, then the steel wire passes through another bolt hole adjacent to it, and finally screw the joint of the steel wire. This method has achieved certain results in preventing bolt loosening in the field of ship construction, but it has the following defects:

1) Heavy workload and long construction period;

2) Because the iron wire only tightens two adjacent bolts with holes, the overall anti loosening function of bolts in the same radial range cannot be guaranteed, and the anti loosening quality is poor.