Performance Investigation of a Novel Multi-tooth Switched-flux Linear Motor

A multi-tooth switched-flux linear motor (MTSFLM), with a novel armature structure, is proposed. In its armature the height of permanent magnets (PMs) is not the same as that of iron cores, which is different with conventional switched-flux motor (SFM). Firstly, a MTSFLM with the same tooth-slot parameters as the corresponding rotatory motor is showed, pointing out that its coil areas is much smaller than that of the rotatory form. The MTSFLM with 2.5 times high armature is discussed then to enlarger slot areas. Secondly, it is pointed out that MTSFLM with higher armature may lead to serious saturation if the height of iron core and the height of PMs are still kept the same as conventional design. A MTSFLM with shorter PMs, than the height of corresponding iron cores, in armature is proposed. And the height optimization of the PMs is then investigated to produce optimum output characteristics. Thirdly, the unique impacts of yoke height and gap distance on optimum PMs height value are discussed. Finally, a prototype with optimized structure parameters is presented. The measured back-EMF, detent force data are compared with those from FEM, and the result curves validated aforesaid analyses.