Hydraulic excavator track supporting wheel oil leakage fault analysis

•Failure mechanism of track travelling unit of hydraulic excavator.•Whole excavator experiments were carried out.•Non-linear finite element analysis of the supporting wheel was carried out.•Determine the two working conditions and load values of the supporting wheel with the highest force through the simulation results.•A test rig was set up to analyse the failure of the strut wheel sealing assembly. In order to explore the specific reasons for the oil leakage of the supporting wheel, and to determine the specific location of the oil leakage of the supporting wheel, this paper carries out the excavator machine test and the finite element simulation analysis of the supporting wheel assembly, and designs and manufactures the supporting wheel test bench. It was found that the lubricant was leaking from the gap between the supporting wheel body and the axle seat. Through further tests, it was finally determined that the floating seal rubber ring had undergone plastic deformation during the working process of the supporting wheel, resulting in oil leakage from the supporting wheel. The results of the study also emphasized the importance of temperature on the seal failure of the support wheel. An improvement programme for the seal failure of the support wheel was also proposed.