The main fuel pump also has some influence on the damage of auxiliary drum gear coupling. Because the anchor bolts of the main fuel pump of the unit are not well fixed (found afterwards), there is bad meshing between the main and auxiliary screw of the main fuel pump, which causes the load of the auxiliary coupling to be larger than normal, and accelerates the damage of the auxiliary drum gear coupling. Timely detection and treatment will lead to tripping of the unit due to this fault in operation, which will cause the unit to lose its turning after emergency shutdown, and the high temperature during shutdown will lead to serious damage consequences of the unit. Drum-shaped gear coupling has high elasticity (low stiffness, high flexibility). When it bears nominal Torque, the rotation angle is 10 degrees and the maximum torque is 25 degrees. It can reduce the natural vibration frequency of the shafting, change the torsional vibration characteristics of the shafting of the diesel engine power plant, and make the diesel engine not appear dangerous resonance speed in the required speed range. It can absorb and reduce the resonance speed. The fluctuation of output torque of low diesel engine can reduce the knock on the gear face when the torque is changed and prolong the service life of the gear for the power device of diesel engine equipped with reducer gearbox.