A global approach for the study of forces developed by a tubular linear moving magnet

Abstract

A global approach for the study of forces developed by a tubular linear moving magnet actuator for a low speed and high force application is described. We used here an easy analytical approach made with the Ampere's law to give the field distribution done by permanent magnets in the airgap. In order to calculate the effort developed by the moving part we used the Laplace force which takes into account the field distribution calculated previously and the current distribution on the stator. The results are validated extensively by comparison with finite element analysis. The analytical field solutions allow the prediction of the thrust force. This facilitates the characterization of tubular machine topologies and provides a basis for comparative studies, design optimization, and machine dynamic modeling.

Comparison, With an Analytical Optimization Process, of Two Synchronous Halbach Permanent Magnet Machines, for a Direct Drive Stick Application

“…In the tubular MMA, the translator is composed of PM with a Halbach magnetization (as in [7]), fixed to a tubular magnetic circuit. This structure is an evolution of the structure presented in [8] where the PMs are only magnetized radially. This change improves the power density and therefore the expected performances of the actuator, as demonstrated in [9].…”