Simplifying the manufacturing process for electrical machines

This paper examines production methods for permanent magnet machines and introduces a segmental construction technique in which the stator laminations are split to allow the insertion of pre-wound, tightly packed coils over a section of core back and hence around a single tooth. The technique aims to simplify manufacturing methods, thereby reducing the cost of production, and the need for complex dedicated machinery and/or specialist staff. Another key benefit of the proposed method is that it enables the use of tightly wound coils with good thermal and mechanical properties. A high speed permanent magnet machine has been designed and manufactured using the above technique and is compared to a more conventional design and construction method. Running test results are presented and tentative conclusions drawn concerning the practicality of such a technique.