Flux concentrator for ironless motor

Abstract

In one embodiment, a magnet array and ironless winding for a motor is provided which has an array of permanent magnets being arranged such that flux from the permanent magnets reinforce on one side of the array and substantially cancel on an opposite side of the array, the array further includes flux concentrators forming poles on the reinforcing side of the array, and such that a magnetic moment at the poles is oriented generally perpendicular to the reinforcing side of the array, the winding being adjacent to the array and comprising conductor bundles having a generally rectangular cross-section arranged such that a long side of the generally rectangular cross-section is transverse to a direction of magnetic field lines at the poles.

What is claimed is: 
     
         1 .- 31 . (canceled) 
     
     
         32 . A motor comprising:
 a) an inner rotor and an outer rotor with an ironless stator winding therebetween; and   b) the inner and outer rotors each comprise flux concentrators and permanent magnets, the permanent magnets each comprise a pole surface, the pole surfaces of a plurality of permanent magnets face an adjacent flux concentrator, the flux concentrators of the inner and outer rotors being located so as to mutually reinforce flux across the winding.   
     
     
         33 . The motor of  claim 32 , wherein the flux concentrators of the inner and outer rotors are such that the reinforced flux across the winding has substantially a non-fringing density across the winding. 
     
     
         34 . The motor of  claim 32 , wherein the winding comprises turns each having a width, and wherein the flux concentrators of the inner and outer rotors have a width that is substantially a same width as a single winding turn. 
     
     
         35 . The motor of  claim 32 , wherein the flux concentrators of the inner and outer rotors have a width, the permanent magnets of the inner and outer rotors have a width, and the winding comprises turns each having a width such that a non-fringing density of magnetic field lines across the winding has substantially a same width as the width of a single winding turn. 
     
     
         36 . The motor of  claim 32 , wherein the permanent magnets comprise back magnets located on a side of the flux concentrators opposite the ironless stator winding. 
     
     
         37 . The motor of  claim 32 , wherein the flux concentrators of the inner and outer rotors are such that the reinforced flux across the winding has substantially a non-fringing density across the winding. 
     
     
         38 . The motor of  claim 32 , wherein the stator winding comprises Litz wire conductor bundles comprising elongated compressed cross-sections transverse to the direction of the magnetic field across the winding. 
     
     
         39 . A motor comprising:
 a) a dual rotor comprising an inner rotor and an outer rotor each comprising a cylindrical configuration, the inner rotor and an outer rotor being secured together and separated by a gap therebetween;   b) an ironless stator winding between the inner rotor and the outer rotor;   c) the inner and outer rotors each comprise flux concentrators and permanent magnets, the permanent magnets each comprise pole surfaces, the pole surfaces of the permanent magnets adjacent to a flux concentrator face the adjacent flux concentrator so as to provide reinforcing magnetic flux through the adjacent flux concentrator, the flux concentrators of the inner and outer rotors being located so as to provide mutually reinforcing flux across the stator winding; and   d) wherein the stator winding comprises Litz wire conductor bundles comprising elongated compressed cross-sections transverse to the direction of the magnetic field across the winding.   
     
     
         40 . The motor of  claim 39 , wherein the permanent magnets comprise back magnets located on a side of the flux concentrators opposite the gap, wherein the back magnets and corresponding flux concentrators both have a same width. 
     
     
         41 . The motor of  claim 39 , wherein the winding comprises turns each having a width, and wherein the flux concentrators of the inner and outer rotors have a width that is substantially a same width as a single winding turn. 
     
     
         42 . The motor of  claim 39 , wherein the flux concentrators of the inner and outer rotors have a width, the permanent magnets of the inner and outer rotors have a width, and the winding comprises turns each having a width such that a non-fringing density of magnetic field lines across the winding has substantially a same width as the width of a single winding turn. 
     
     
         43 . The motor of  claim 39 , wherein the stator winding comprises Litz wire conductor bundles comprising elongated compressed cross-sections transverse to the direction of the magnetic field across the gap. 
     
     
         44 . A motor comprising:
 a) a dual rotor comprising an inner rotor and an outer rotor each comprising a cylindrical configuration with an ironless stator winding in a gap therebetween; and   b) the inner and outer rotors each comprising a permanent magnet arrays comprising:
 (1) a plurality of flux concentrators; 
 (2) a plurality of permanent magnets, each having a magnetic moment such that the magnetic moment of each of the permanent magnets adjacent to a flux concentrator either all point in a direction toward an adjacent flux concentrator or all point in a direction away from an adjacent flux concentrator; and 
 (3) wherein the plurality of flux concentrators of the inner rotor opposing the plurality of flux concentrators of the outer rotor across the gap so as to provide reinforcing magnetic fields across the gap. 
   
     
     
         45 . The motor of  claim 44 , wherein the flux concentrators of the inner and outer rotors are such that the reinforced flux across the winding has substantially a non-fringing density across the winding. 
     
     
         46 . The motor of  claim 45 , wherein the plurality of permanent magnets comprise a plurality of back magnets each adjacent to a respective one of the plurality of flux concentrators on a side opposite the gap 
     
     
         47 . The motor of  claim 46 , wherein the magnetic moments of adjacent permanent magnets are orthogonal. 
     
     
         48 . The motor of  claim 46 , wherein the stator winding comprises Litz wire conductor bundles comprising elongated compressed cross-sections transverse to the direction of the magnetic field across the gap. 
     
     
         49 . The motor of  claim 44 , wherein the winding comprises turns each having a width, and wherein the flux concentrators of the inner and outer rotors have a width that is substantially a same width as a single winding turn. 
     
     
         50 . The motor of  claim 44 , wherein the flux concentrators of the inner and outer rotors have a width, the permanent magnets of the inner and outer rotors have a width, and the winding comprises turns each having a width such that a non-fringing density of magnetic field lines across the winding has substantially a same width as the width of a single winding turn.