Durability Testing and Simulation Analysis of the Tension Spring Assembly of a 20-ton Excavator

Abstract

A tension spring assembly is a key part supporting the undercarriage track of an excavator. This paper introduces reliability evaluation procedures to ensure the durability of the tension spring assembly. Force data were obtained from a field driving test, yielding equivalent load data acting on the part. After establishing a reliability testing code for the zero failure accelerated life test (ZFAT), a durability test was carried out under axial loading. After the sample satisfied the ZFAT condition of 0.9 million cycles, an additional loading test was repeatedly performed to identify the weakest part. After 1.5 million cycles of loading, the dynamics analysis indicated a disordered spring part. A design modification of the spring was proposed. Numerical simulations were conducted to investigate the weak part of the tension spring assembly, with the results indicating a contact point during the compression step. A modified design for the tension spring is suggested, which can relieve the contact force and improve the durability of the assembly.