Rotor assembly

Abstract

A rotor assembly includes a substantially cylindrical support structure having at least one first region, and at least one second region. At least one rotor coil is positioned within each first region of the substantially cylindrical support structure. Each rotor coil includes a pair of distal end portions and a convex center portion, and the average mechanical density of the convex center portion is substantially equal to the average mechanical density of the distal end portions. The average mechanical density of the at least one first region is substantially equal to the average mechanical density of the at least one second region.

1 . A coil comprising: 
 a pair of distal end portions; and    a center portion positioned between the pair of distal portions, the average mechanical density of the center portion being substantially equal to the average mechanical density of the distal end portions.    
   
   
       2 . The coil of  claim 1  wherein the center portion has a convex shape.  
   
   
       3 . The coil of  claim 1  further comprising a mandrel positioned within an interior region of the coil.  
   
   
       4 . The coil of  claim 3  wherein the mandrel occupies a portion of the interior region of the coil and is constructed of a material having a mechanical density that is greater than the average mechanical density of the first and second regions.  
   
   
       5 . The coil of  claim 4  wherein the mandrel includes removed portions.  
   
   
       6 . The coil of  claim 3  wherein the mandrel occupies the interior region of the coil and is constructed of a material having a mechanical density that is substantially equal to the average mechanical density of the first and second regions.  
   
   
       7 . The coil of  claim 6  wherein the mandrel includes removed portions.  
   
   
       8 . The coil of  claim 3  wherein the mandrel is constructed of a material chosen from the group consisting of stainless steel, aluminum, phenolic, and copper.  
   
   
       9 . The coil of  claim 3  wherein the mandrel includes a pair of distal end portions spaced by a pair of convex center portions.  
   
   
       10 . The coil of  claim 9  wherein the periphery of the distal end portions of the mandrel are defined by a first radius, and the periphery of the convex center portions of the mandrel are defined by a second radius that is larger than the first radius.  
   
   
       11 . The coil of  claim 3  wherein the mandrel is an elliptical mandrel.  
   
   
       12 . The coil of  claim 1  wherein the coil is a racetrack-type coil.  
   
   
       13 . The rotor of  claim 1  wherein the coil is a saddle-type coil.  
   
   
       14 . The coil of  claim 11  wherein the saddle-type coil is configured such that the lines of magnetic flux produced by the saddle-type coil are perpendicular with a surface of the substantially cylindrical support structure and radially aligned toward an axial centerline of the rotor assembly.  
   
   
       15 . The coil of  claim 1  wherein the coil is a superconducting coil.  
   
   
       16 . The coil of  claim 15  wherein the superconducting coil includes one or more high temperature superconducting windings.  
   
   
       17 . The coil of  claim 1  wherein the coil is a rotor coil.