Moving magnet linear actuator with self‐holding functionality

Abstract

Electromagnetic design of a moving magnet frictionless linear actuator with self-holding functionality for mechanical gear shifting in a transmission application is presented. The actuator consists of a tubular magnetic circuit with stationary armature and axially moving rotating permanent magnet assembly with radial magnetisation in the air gap. The armature contains a two-piece magnetic core with a space for a winding. The effects of armature slot opening and magnetic circuit materials on the self-holding force and the acting force are studied in the whole moving range. The designed moving magnet linear actuator improves the performance of the vehicle by enabling shift times below 50 ms with no energy consumption between the shifts. (a) Magnetic flux, position 0 mm and current 0 A, (b) Magnetic flux, position 5 mm and current 0 A, (c) Magnetic flux, position 0 mm and current 2.5 A, (d) Magnetic flux, position 5 mm and current 2.5 A

Research on the Axial Force of Conical-Rotor Permanent Magnet Synchronous Motors with Turbines

“…The output performances at different load conditions is listed in Table 3, which shows there is a quite small difference (≤5%) between the simulated and measured results. Based on the above analysis, the axial magnetic force only has a greater increase with the increase of d-axis current, which confirms the previous analysis and conclusions in Equations (12) and (13).…”

“…It can be seen from Figure 11 that when α is small, FZ increases slowly with a small axial displacement, and when α is larger, FZ decreases linearly with the axial displacement. As can be seen from Figure 12, the axial magnetic force has only a quite slight increase with the increase of q-axis current, which confirms the previous analysis and conclusion in Equations (12) and (13). In addition, the magnetic axial force will increase with id.…”

“…According to Equations (12) and (13), once the CR-PMSM rotates, an axial magnetic force will be produced, and it will change with the stator current.…”

“…Research indicates that the value of the axial force depends on the PM air gap flux density and the d-axis current, besides the geometry. Equivalent magnetic circuit models under open circuit condition (OCC) are often used to investigate electric machines [10][11][12][13][14].…”

Unsymmetrical bistable multimagnetic circuit permanent magnet actuator for high‐voltage circuit breaker application: analysis, design, and dynamic simulation

“…To improve the efficiency, total weight, and losses, the above PMA with a trapezoidal permanent magnet is studied in [18]. Moreover, the E-type cylindrical bistable PMA with quasi-Halbach magnetised tubular PM mover is presented and optimised to adjust the long stroke [19][20][21].…”