Structural stator spacers-the key to silent electrical machines

This paper presents a powerful new design aspect to reduce acoustic noise and vibration of electro-magnetic origin for electrical machines, by introducing improved slot wedges referred to as "structural stator spacers". These spacers, by using a very stiff dielectric and nonmagnetic material, a modified shape and small modifications to the stator laminations not only secure the windings and reduce windage losses but also make it possible to increase the stiffness of the stator structure significantly thereby reducing the generation of audible noise. This new method does not incur the significant drawbacks usually associated with other noise reduction methods or interdict other noise control methods. Design models and practical prototypes are detailed which are used to verify the effectiveness of the spacers.