Abstract: The spring clutch is the key component of the helicopter transmission system,and it is found that its limit torque transmission capacity and failure form can provide the necessary basis for its design.Aiming at the problem of high cost and long cycle of experimental research on clutch torque transmission capacity and failure,The finite element analysis model of the spring clutch was established by using the finite element analysis method.The limit torque and failure form of the clutch under different interface friction,loading mode and speed were simulated.The results show that the increase of the interface friction can reduce the maximum stress of the spring,improve the stress distribution and improve the clutch transmission torque.The lower interface friction causes the spring clutch to fail,and when the interfacial friction reaches the excitation demand,the clutch will fail due to slip over the limit torque.

Key words: spring clutch, limit torque, failure form, finite element method