Abstract:

This article classifies many direct-acting electromagnetic mechanisms from the perspective of the number of equivalent working gaps and the series-parallel relation between the permanent magnet magnetic potential and the coil magnetic potential.Based on the equivalent magnetic circuit,the calculation models of the working gap magnetic flux and the electromagnetic force that works on the moving iron core are established.Then,this paper analyzes the characteristics of the electromagnetic force curves of various electromagnetic mechanisms and the relations between the coil ampere-turns and the working gap magnetic flux,the initial electromagnetic force when the moving iron core is at the release position.On this basis,a calculation model of the critical coil ampere-turns corresponding to the maximum initial electromagnetic force of the direct-acting electromagnetic mechanism with permanent magnet is built.The research conclusions have certain guiding effect on the reliability design of the direct-acting electromagnetic mechanism with large output force requirements.

Key words: electromagnetic mechanism, electromagnetic force, coil amper turns, magnetic circuit