Pole-piece structure for a magnetic gear

Abstract

The disclosure provides a pole-piece structure for a magnetic gear, comprising a plurality of laminate plates, wherein each plate comprises one or more apertures and an aperture in each plate aligns with an aperture in an adjacent plate to form one or more channels extending from a first end of the laminate plates to a second, opposite end of the laminate plates, wherein a resin cast is provided within each channel to hold the plurality of laminate plates together.

1 . A pole-piece assembly comprising:
 a pole-piece structure comprising a longitudinal axis and one or more channels extending from a first end to a second, opposite end of the pole-piece structure;   a first rotating component; and   a second rotating component;   wherein said pole-piece structure is located between the first and second rotating components;   wherein a solid, substantially non-magnetic material is provided throughout each channel; and   wherein the solid, substantially non-magnetic material comprises cavities at each first and second end, and each of the first and second rotating components comprise lips that extend into the cavities, so as to secure the pole-piece structure in position.   
     
     
         2 . The pole-piece assembly as claimed in  claim 1 , wherein the first and second rotating components are associated with an input shaft or an output shaft. 
     
     
         3 . The pole-piece assembly as claimed in  claim 1 , wherein the first and second rotating components are located at opposite axial ends of a magnetic gear assembly. 
     
     
         4 . The pole-piece assembly as claimed in  claim 1 , wherein the one or more channels extend in a direction parallel or substantially parallel to the longitudinal axis of said pole-piece structure. 
     
     
         5 . The pole-piece assembly as claimed in  claim 1 , wherein each said cavities are provided between a first flange and a second flange, and said lips slot into said cavities between said first and second flanges. 
     
     
         6 . The pole-piece assembly as claimed in  claim 1 , wherein the solid, substantially non-magnetic material is cast or molded into the channels. 
     
     
         7 . The pole-piece assembly as claimed in  claim 1 , wherein the non-magnetic material comprises a resin that is provided throughout each channel, wherein the resin completely fills each channel. 
     
     
         8 . The pole-piece assembly as claimed in  claim 1 , wherein there are no air gaps between each channel and the solid, substantially non-magnetic material. 
     
     
         9 . The pole-piece assembly as claimed in  claim 1 , wherein said pole-piece structure consists of a plurality of laminate plates and said non-magnetic material. 
     
     
         10 . The pole-piece assembly as claimed in  claim 9 , wherein each of said plates comprises a plurality of solid portions arranged alternately with a plurality of substantially hollow portions, and one or more apertures are provided in said hollow portions. 
     
     
         11 . The pole-piece assembly as claimed in  claim 10 , wherein each of said plates are stacked such that said solid portions align so as to form a plurality of magnetic pole-pieces in said pole-piece structure. 
     
     
         12 . The pole-piece assembly as claimed in  claim 10 , wherein said plates are stacked such that said hollow portions align so as to form said one or more channels extending from said first end of the pole-piece structure to said second, opposite end of the pole-piece structure. 
     
     
         13 . The pole-piece assembly as claimed in  claim 9 , wherein each of said laminate plates are formed from a single piece of material. 
     
     
         14 . The pole-piece assembly as claimed in  claim 9 , wherein said laminate plates are held together by said the solid, substantially non-magnetic material. 
     
     
         15 . A magnetic gear assembly comprising:
 the pole-piece assembly as claimed in  claim 1 ;   a plurality of inner permanent magnets; and   a plurality of outer permanent magnets located concentrically with respect to said inner permanent magnets;   wherein said pole-piece structure is located between said inner and outer permanent magnets and modulates the magnetic fields produced by said inner and outer permanent magnets.   
     
     
         16 . A method of securing a pole-piece structure in position, comprising:
 casting or molding a substantially non-magnetic material within each of one or more channels provided in a pole-piece structure, such that a solid, substantially non-magnetic material is provided within each channel, wherein the casting or molding comprises casting or molding cavities at each of a first end and a second end of said one or more channels; and   providing a first rotating component and a second rotating component, each of said first and second rotating components comprising lips which extend into said cavities.   
     
     
         17 . The method as claimed in  claim 16 , wherein the casting or molding cavities comprises casting or molding a first flange and a second flange around each cavity, and said lips slot into said cavities between said first and second flanges. 
     
     
         18 . The method as claimed in  claim 16 , wherein each lip of said first rotating component extends into each cavity at the first end of said one or more channels, and each lip of said second rotating component extends into each cavity at the second end of said one or more channels.