Numerical Simulation and Experimental Examination of an Oldham Coupling

In scroll compressors, Oldham couplings (OCs) have typical been formed of aluminum alloy and have often broken issues due to the high loads which are transmitted from the orbiting scroll. This problem was especially pronounced during flooded start or slug conditions. In this paper, five pcs mass production OCs (standard OC), which are broken during a special slug test are investigated by classifying the ring broken and pin broken. During the investigation, both the quantities and the probabilities of each failure position are counted. Then, Finite Element Method (FEM) is employed in strength calculation for the standard OC and an optimized OC. The Finite Element Analysis (FEA) results explain that the cause of the ring’s breakage is due to high tensile stress and the pin’s breakage is due to high shear stress. After simulation, the authors design a series of strength experiments and DOE tests, with a great number of samples, which includes standard full treatment OC, CNC machined OC, half treatment OC and optimized OC, to verify the FEA results and repeat the failures in slug tests. Further, the author investigates the experiments results and compares the errors group by group. Finally, under the help of numerical simulation and experiment results, two new numerical models for OC strength prediction are proposed and validated by both strength tests and slug tests. The implementation of the prediction models are not only benefit to obtain a stronger OC or ensure it to reach a high reliability level, but also helps the develop engineers to shorten the new OC’s development duration and reduce the fix expense in research activities.