Research on High Pressure Resistant Linear Variable Differential Transformer with Magnetic Ring

Abstract

Aiming at the problems of traditional linear variable differential transformer (LVDT) with poor linearity and small stroke length ratio, a new kind of structure with magnetic ring was presented. The finite element simulation models of the before and after improved LVDT were established. The structural static analysis of pressure pipe was simulated by ANSYS to study the pressure capacity. For researching the effect of magnetic ring on the characteristics of LVDT, the transient electromagnetic field was simulated by Ansoft. The results show that the maximum deformation of pressure pipe appears at the unfixed end and the value is 2.7μm at 30MPa. After the magnetic ring is added in the bobbin, the LVDT’s magnetic field distribute is greatly improved. Comparing with the unimproved LVDT’s characteristics, the linearity of improved LVDT increases 5.6 times, the stroke length ratio improves 2.5 times and the sensitivity has a slight reduction. So the global Characteristics of LVDT is promoted a lot.