Strength Simulation and Experimental Analysis of the Connecting Rod Structure of 922F Excavator Working Device

The working device of the excavator is a three degree of freedom arm structure, where the connecting rod structure bears random and variable cyclic loads during excavation operations. In order to accurately evaluate the strength of the excavator connecting rod structure, three typical force bearing postures are determined for the 922F excavator as the research object. The dynamic model of the excavator is established on the MotionView software platform; then the maximum load on the connecting rod is calculated by using the locking pressure of the oil cylinder. Based on the finite element model of the excavator working device, the stress distribution of the connecting rod structure is simulated and calculated. Applying the same load to the connecting rod structure, the structural stress tests are conducted through the SDS500 testing machine. The results show that the error between the structural stress obtained from the experiment and the simulated stress is within 5%, and the safety factor of the connecting rod structure under ultimate load is 1.34. The connecting rod structure of this model of excavator has abundant strength and can be optimized for design.