Using Finite Element Analysis (Fea) To Estimate Reed Frequency Of Vertical Motors For Pump Applications

Abstract

Vertical motor/pump systems that run close to the motor reed frequency may experience significantly high vibration levels, which can damage the motor as well as the entire pump system. These damages can result in costly repairs of the motor/pump, therefore accurate prediction of motor reed frequency will enable a more cost- and performance-effective pump base design and will extend system life. A recent trend has shown that end users are requesting more accurate prediction of motor reed frequency (+/- 10%), enabling better pump base design with less potential for base rework. This study describes the utilization of Finite Element Analysis (FEA) as a tool in the prediction of vertical motor reed frequency and its correlation with extensive bump test results. Preliminary analysis first identified parameters that affect motor reed frequency. It was then followed by sensitivity studies, which further examined the impact of each parameter. One of the critical parameters is the stator core modulus. Because of its laminated structure, the core modulus is not uniform, which has a significant effect on motor reed frequency. The critical parameters were calibrated against existing test data using design of experiments. Lastly, they were used to verify future motor performance. This paper discusses the background behind the analysis, the FEA verification process as well as test validation.