Research on yokeless double-sided multi-tooth flux-switching linear motor

Abstract

Purpose

Due to the advantages of direct driven, high thrust density, and high efficiency, flux-switching linear motor (FSLM) is required for many applications, including aerospace and automotive. However, the vibration caused by detent force and difficulties in the assembly produced by the large normal force become the barriers that restrict its development. The paper aims to discuss these issues.

Design/methodology/approach

In order to improve the electromagnetic performance of double-sided multi-tooth FSLM (DMTFSLM), a yokeless DMTFSLM with moving primary is proposed and compared with normal DMTFSLM. Moreover, with theoretical analysis, the selection principle of slot-pole number combination is obtained. DMTFSLMs with four slot/pole combinations, 6s/16p, 6s/17p, 6s/19p, 6s/20p, are analyzed based on finite element analysis model. Finally, several parameters of this yokeless DMTFSLM have been optimized to obtain the better performance.

Findings

In yokeless DMTFSLM, it is found that the asymmetry of Back-EMF caused by the end-effect is eliminated, which leads to a better thrust force performance in comparison with the normal structure. The small attractive force between the secondary and the primary makes it easier for assembly and also can reduce the friction, which is more suitable for high-speed application. In addition, the best slot-pole combination rule is found through a simple theoretical analysis.

Originality/value

The yokeless DMTFSLM has excellent electromagnetic performance, such as high thrust density, negligible normal force, and small force ripple. It is a strong candidate for high-precision device.

Citation

Lu, Q., Li, H., Huang, X. and Ye, Y. (2016), "Research on yokeless double-sided multi-tooth flux-switching linear motor", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 35 No. 2, pp. 832-843. https://doi.org/10.1108/COMPEL-12-2015-0438