Analysis of Surface Damage of Rubber Seal Ring Used in Aircraft Engine Fuel Accessories

The O-shaped seal ring as the key component that plays a vital role in the safety work of the fuel accessory of the aero-engine. In this paper, the O-shaped seal rings used by aviation engine fuel accessories were subjected to macro and microscopic observation, FTIR, DSC and TGA analysis, and the fracture morphology and thermophysical properties between the same batch of unused and used seal rings were compared. The analysis results show that the surface damaging of seal ring by used 550 h is mainly due to the following three reasons. First of all, the seal ring overload cracking caused by mechanical damage. Secondly, due to excessive pressure to form extrusion cracking, and the fatigue cracking caused by cyclic action of oil pressure. Besides, stress aging cracking caused by the combined action of load and environment. According to the corresponding damage mode, it is proposed to pay attention to the direction of the seal, change the structure of the sealing ring installation slot, and replace the perflurane rubber seal ring during assembly.