Effect of Motor Shaft Eccentricity on the Performance of a High-Speed Magnetic Fluid Sealer

Abstract

The objective of the study is to develop recommendations for accounting during the design stage and the feasibility of operating a magnetic fluid seal with a significant eccentricity of the rotating shaft relative to stationary pole attachments. This goal is achieved through conducted experi-mental research, the selection of necessary equations, boundary conditions, assumptions, and physical properties of the magnetic fluid when constructing a numerical mathematical model of the working gap of the magnetic fluid seal. The most important results of the study include ob-tained and analyzed distributions of the magnetic field, velocity field, and pressure in the mag-netic fluid, as well as the evaluation results of the impact of absolute and relative shaft misa-lignment in the magnetic fluid seal, centrifugal forces arising during shaft rotation, on the re-tained pressure drop by the seal. A significant reduction in the retained pressure drop occurs at an eccentricity of up to 40% of the working gap, and with further increases in eccentricity, the rate of pressure drop reduction slows down. The significance of the results lies in the potential utilization of the provided numerical model, as well as the outcomes of physical and mathemati-cal experiments, in the development of a magnetic fluid seal operating with significant misa-lignment between the rotating shaft and the housing. The dimensionless dependencies obtained allow for consideration, during the design stage, of the reduction in retained pressure drop with shaft eccentricity, taking into account the magnitude of the working gap, magnetic induction, and linear velocity.

Keywords

• magnetic fluid
• magnetic fluid seal
• eccentricity
• pressure drop
• numerical modeling.