关键词: 螺纹连接；飞轮壳；摩擦系数；轴向力；表面质量

Abstract: In order to study the rear mount bracket bolts loose and the crack of the flywheel housing for a heavy vehicle, a strength analysis is conducted on the flywheel housing, and the assembly torque of the suspension support bolts is recalculated, at the same time, the friction coefficient, axial force, and surface quality of the support bolts are tested. The result shows that surface quality of mount bracket is poor, and axial clamp force can′t resist external load leads, the mounting bolts gradually loosen during the use of the vehicle, which leads to fatigue cracking of the flywheel housing. Therefore, the quality rectification of the surface quality of the feet was carried out, after the full verification of the market, the fault is finally solved, which provides ideas for the solution of similar problems.

Key words: Threaded connection; Flywheel housing; Friction coefficient; Axial force; Surface quality