Axial flux machine manufacture

Abstract

We describe a method of manufacturing a stator of an axial flux permanent magnet machine, the machine having a stator comprising a stator housing defining a chamber comprising a set of coils wound on respective stator bars and disposed circumferentially at intervals about an axis of the machine, and a rotor bearing a set of permanent magnets and mounted for rotation about said axis, and wherein said rotor and stator are spaced apart along said axis to define a gap therebetween in which magnetic flux in the machine is generally in an axial direction, the method comprising: providing first and second radial walls for said stator housing; providing inner and outer side walls for said stator housing; assembling said first and second radial walls and said inner and outer side walls around said set of coils to form a stator assembly, wherein said assembling further comprises: providing one or more collapsible elements between said side walls and one or both of said first and second radial walls; and attaching said side walls to said first and second radial walls, wherein said attaching comprises controlling one or both of a spacing and a degree of parallelism of said first and second radial walls by controlling the collapse of said one or more collapsible elements.