The Strength Calculation And Optimization Of ESP's Shafts With Finite Element Method

The ESP's shafts are the critical parts of ESP, and their strength design will directly influence the other capacities of ESP. In this paper, the load status for different shafts is analyzed after introducing their structures, and the several dynamic models are established under analyzing the status of load. The strength of the shafts is calculated with three-dimensional finite element method by ANSYS software. The mesh generation is automatic, and we use the method to generate 10-node or 20-node elements. Because it is hard to mesh for small angularity in the body, especially spline, so we have to simplify these parts. We adapt two methods to simplify them, and choice the better one to calculate the strength of the shafts. Above all, we also optimize the shafts structure.For pump shafts, the results reveal that the stress in the spline is higher than the other parts of the shaft, and the highest stress is at bottom and terminal of the spline. In fact, the broken of shafts is at the same position; it demonstrates that the calculation is right. For motor shafts, the highest stress is at the boundary between the key groove and the ring groove; the next one is at bottom and terminal of the spline. According to the results, the φ17.4mm shaft is insecurity, the φ22.2mm and φ30.2mm shafts are security. For the φ30.2mm shaft, there are still larger over measure to load.The strength is increased by optimization. For?φ17.4mm shaft, the strength is increased by enlarge the inner dimension of the spline; for φ30.2mm shaft, the strength is increased by adjust the structure at the boundary between the key groove and the ring groove, the highest stress of the shaft is at bottom and terminal of the spline after optimization.In national, it is the first time to calculate the strength of ESP's shafts accurately with the finite element method. It hurdles localizations of the traditional methods in engineering, and has great significance for optimizing the structures of shafts, increasing the capacities of shaft's load, even the design ofwhole systems.