The reasons for the fracture of the elastic coupling bolt are as follows:
According to related calculations, the safety factor of the coupling bolt is too low, which is a cause of bolt fracture. After an in-depth and careful analysis of the coupling damage on the test site, the reasons for the bolt fracture are analyzed as follows:
(1) Coupling bolts are matched with bolt holes on flange and diaphragm
The gap is too large and the size is not uniform. The node has a large displacement after loading, which causes the diaphragm to buckle and deform, and the diaphragm does not play a good role in the transmission torque process.
(2) The positioning sleeve holes of the diaphragm have obvious incomplete finishing traces, and the roughness is above 25. The positioning sleeve hole is too rough, which obviously damages the surface of the coupling bolt, and induces multi-source fatigue fracture of the bolt, and no anti-corrosion measures are taken on the bolt positioning surface. For the new bolts distributed by the coupling manufacturer, the rust marks can be clearly seen on the positioning surface.
(3) There are obvious circumferential rotation and bite marks on the surrounding surfaces of the five bolt holes matching the middle section of the coupling and the positioning sleeve, indicating that the compression positioning sleeve is loose. When the coupling is working normally, the positioning The sleeve rotates obviously, and the tightening torque is not enough.