What is the reason for the broken double head screw of dowty retarder?

Whether the installation of the stud bolts of the dowty retarder meets the requirements has a great internal relationship to ensure the normal operation of the dowty retarder and improve the service life of the double headed bolt.What is the reason for the broken double head screw of dowty retarder?

The main reason of double head bolt fracture of dowty retarder is that the bolt is loose with the whole body or Lei nut, resulting in the uneven stress of stud bolt. Under the rolling of vehicle, the load stress is concentrated, the bolt is sheared up and down, and the fatigue damage accumulation for many times, which causes the generation and propagation of cracks and the fracture of bolt. This kind of fracture accounts for more than 80% of the total number of fractures (under normal fastening condition, when the vehicle rolls the dowty retarder, the force it bears is transmitted on the stud bolt and rail).

Another reason is that the dowty retarder installation does not meet the requirements, and the spare parts are inspected carelessly, which brings hidden dangers; the maintenance and inspection work is not kept up with, the bolts are corroded, and the tightening torque exceeds the silver limit of stretching, causing fracture.