Linear permanent magnet vernier machines (LPMVMs) have attracted more and more attention last several years due to its high thrust density at low speed, which is very suitable for the direct-drive applications. In this paper, the dual-side toroidal-winding LPMVM with unequal end-teeth width is proposed for the reduction of the detent force and thrust ripple. The detent force reduction in the proposed LPMVM is achieved by optimizing unequal end-teeth width for obtaining the two single-side detent forces with the opposite phase angle. The low thrust ripple can be obtained by selecting the lower detent force under the symmetry three-phase flux linkage condition. The unbalanced magnetic pull in the proposed LPMVM is also discussed in this paper by the finite element analysis (FEA). Compared with the conventional dual-side toroidal-winding LPMVM with the equal end-teeth width, the FEA results shows the detent force is reduced from 63.4 N to 6.3 N and the thrust ripple is reduced from 6.4 % to 2% in the proposed LPMVM.

Detent force， force ripple， linear machine， toroidal-winding， vernier machine.