Design and testing of a high force density linear electromagnetic actuator

This paper describes the design and testing of a high force density linear electromagnetic actuator which explores magnetic gearing technology. The actuator integrates a magnetic screw with a rotary motor and is designed for active vehicle suspension. The actuator has superior high thrust force density derived from magnetic gearing and is free from mechanic jamming. It has, therefore, great potential in number of applications. To circumvent the difficulties in realizing helically magnetized magnetic structure, discrete, parallel-magnetized magnets are deployed along a helical profile in both components of the integrated magnetic screw. The electromagnetic performances are assessed by time-stepping finite-element analysis (FEA) and the FE results are validated by experiments based on a prototype machine.