Securing permanent magnets to a laminated rotor

摘要

A rotor 100 having a first plurality of laminates 110, each including a first plurality of peripheral protrusions 120, and a second plurality of laminates 110', comprising a second plurality of peripheral protrusions 120', the first and second arranged differently around a shaft hole 132 from each other. The protrusions may be asymmetric (figs 2a,b) or may be angularly offset (figs8,9). The rotor further has a plurality of magnets 115, each inserted between the lateral surface of first and second plurality of protrusions, wherein reactive forces operate to hold the plurality of magnets, the reactive forces being caused by deformations of the first and second plurality of protrusions, the deformations enabled based on the insertion of the magnet and the asymmetry of the first and second plurality of protrusions, and/or angular offset between the first and second plurality of protrusions. In respect of angular offset, the retaining force on the magnets is achieved by loosely inserting magnets between the projecting rows and inserting an alignment tool into bores 165,165' which caused the laminations to relatively rotate (offset a,βfig 8,9) as the hole align, moving the protrusions in opposite directions to grip the magnets. Alternatively rotation may be effected by a key engaging a key way formed in the lamination wall of the shaft hole 132, the key way being offset between the first and second lamination type.