The Dynamic Model of a Linear Electromagnetic Motor for a Laboratory Shaker

Abstract

For setting up linear movement (translational or reciprocating) with a specified frequency, rack, screw or more complex gears are most often used. The presence of an additional kinematic link results in increased losses, degraded reliability, increased noise, and pooper weight and dimension indicators. An alternative option is to use a linear electromechanical converter. The article presents the results of numerical simulation of a linear electromagnetic motor (also known as a linear inductor motor) based on the finite element method. An linear inductor motor is designed to drive a laboratory shaker applied in medicine. A mathematical model of the physical processes of linear inductor motor operation is presented. A term for considering the viscous friction force is introduced into the equation of motion, which makes it possible to improve the accuracy of the calculations. Three-dimensional models of an linear inductor motor are considered: a single-sided one (for the action of a one-sided electromagnetic force and a two-sided one (for the case of alternately acting oppositely directed electromagnetic forces). Various design options are analyzed, and the most suitable one is proposed based on the analysis results. Temporal dynamic characteristics of the linear inductor motor model for the case of operation in the regions of resonant and off-resonant frequencies are obtained, their analysis is performed, and recommendations for further improvement of the design are given. The possibility of using the considered motor for driving a laboratory shaker is qualitatively assessed.