Study on transient lubrication of floating bush in high-pressure fuel pump coupling with camshaft bending vibration

The roller-floating bush-pin (RFBP) structure is one of the critical transmission components in high-pressure fuel pumps for marine diesel engines, and its lubrication performance significantly impacts equipment stability. In this study, a coupled model of camshaft bending vibration and the transient lubrication of the RFBP structure was established, and the time-varying tilt angle of the roller is used as the transmission variable from vibration to lubrication. The coupling model was validated through the experimental bench tests. The interaction mechanism between the camshaft bending vibration and the lubrication characteristics of the RFBP structure was systematically analyzed. Furthermore, the impact of camshaft bending vibration on the RFBP structure lubrication characteristics was compared across varying structural designs and operating conditions. The results show that the camshaft bending vibration adversely affects the lubrication of the RFBP structure, and its influence on the outer film is greater than that on the inner film. The findings of the study provide theoretical support for the dynamic and lubrication design of fuel pump cam mechanisms.