US Patent 6881033 Impeller

An impeller includes a plastic disc, an annular array of vanes, a rotation support and regions of permanently magnetisable material. The plastic disc has an upper face and a lower face. The vanes are spaced around the periphery of the disc and extend from the upper face of the plastic disc. The rotation support is axially located and aligned through the disc. The regions of permanently magnetisable material encapsulated within said plastic disc for the formation of an annular array of magnetic poles.