ANALYSIS OF WEAR FAILURE MECHANISM AND PERFORMANCE DEGRADATION PREDICTION OF AVIATION FUEL GEAR PUMP

The gear pump is widely applied in aircraft fuel systems due to its reliable performance and low cost. It is one of the most critical components in the aircraft fuel control system. However, the failure mechanism of airborne gear pumps is complex due to the challenging operating conditions, including wide temperature ranges, varying load sequences, and strong vibrations. This paper focuses on the wear failure mechanism of the floating bearing in aviation fuel gear pumps and constructs its degradation process model. First, a dynamics model is established to demonstrate that floating bearings primarily experience two-body wear under airborne operating conditions. Next, the wear failure mechanism of the friction pair, composed of the fuel gear pump gear end face and the thrust bearing, is analyzed based on the two-body wear model, establishing the relationship between wear and leakage. Subsequently, the degradation process model is constructed based on the leakage model of the gear pump. Finally, the accuracy of the proposed model is verified using real test data.