Armature for an electromotive device

Abstract

An armature apparatus for brushless and brush type electric motors and a manufacturing method for same armature. The armature represents and improved design for electric motors having a rigid, thinwall configuration and high conductor packing density in the magnetic flux air gap that results in motors with higher torque and speed capabilities and the ability to operate at higher temperature than conventional motor designs. The armature is fabricated from pre-machined copper sheet metal parts with an electrical conductor pattern of numerous axially extending conductive bands. These precision machined sheet metal parts are cold rolled to form two work hardened cylinders, each cylinder having a complimentary pattern of electrically conductive bands creating a half-electric circuit. The two cold rolled metal cylinders are sized such that the smaller diameter inner cylinder fits inside the larger diameter outer cylinder. The surface of the inner cold rolled cylinder is over-wrapped with fiber strands, woven in several layers to provide physical spacing and electrical insulation. The fiber wrapped inner cylinder is placed inside the larger outer cylinder radially oriented to ensure that an electrical circuit is created by welding the inner and outer cylinder at the conductor tabs. The surface of this cylinder assembly is over-wrapped with fiber strands, woven in several layers and holding the two cylinders together. The entire armature coil is encapsulated in a potting material to add composite strength and electrical insulation. The result of this assembly is a freestanding, ironless core, inductive armature coil for brushless or brush type electric motors.

1 . An inductive coil for an electromotive device, comprising: 
 a pair of concentric inner and outer sheet metal winding portions separated by a continuous non-conductive fiber strand extending around the circumference of the inner winding portion a plurality of times to form an insulation layer, each of the winding portions comprising a plurality of conductive bands with each of the conductive bands of one of the winding portions being coupled to one of the conductive bands of the other winding portion, the inductive coil being encapsulated with a material that impregnates the winding portions and the insulation layer.    
   
   
       2 . The inductive coil of  claim 1  further comprising a second continuous non-conductive fiber strand extending around the circumference of the outer winding portion a plurality of times.  
   
   
       3 . The inductive coil of  claim 2  wherein the second continuous non-conductive fiber strand forms an outer layer around the circumference of the outer winding, and wherein the material encapsulating the coil impregnates the outer layer.  
   
   
       4 . The inductive coil of  claim 1  wherein the continuous non-conductive fiber strand extends around the circumference of the inner winding portion from one of the inner winding portion ends to the other inner winding portion end.  
   
   
       5 . The induction coil of  claim 4  further comprising a second non-conductive fiber strand extending around the circumference of the insulation layer a plurality of times from one end of the inner winding portion to the other end of the inner winding portion to form a second insulation layer between the inner and outer winding portions.  
   
   
       6 . The inductive coil of  claim 5  wherein the material encapsulating the coil impregnates the second insulation layer.  
   
   
       7 . The inductive coil of  claim 1  wherein each space separating the conductive bands is less than 1.5 time the thickness of every one of the conductive bands.  
   
   
       8 . The inductive coil of  claim 1  wherein the continuous non-conductive fiber strand comprises glass.  
   
   
       9 . The inductive coil of  claim 8  where the continuous non-conductive fiber strand comprises a thickness between 0.00030-0.00075 inch.  
   
   
       10 . The inductive coil of  claim 1  wherein the encapsulation material comprises polyimide.  
   
   
       11 . The inductive coil of  claim 1  wherein each of the winding portions comprises precision machined and rolled copper.  
   
   
       12 . The inductive coil of  claim 1  wherein each of the conductive bands comprises a tensile strength greater than 40,000 psi.  
   
   
       13 . The inductive coil of  claim 1  wherein each of the conductive bands comprises a yield strength greater than 30,000 psi.  
   
   
       14 . The inductive coil of  claim 1  wherein each of the conductive bands comprises a percent elongation less than 20%.  
   
   
       15 . The inductive coil of  claim 1  wherein each of the conductive bands comprises a hardness greater than a Brunell number of 70.  
   
   
       16 . The inductive coil of  claim 1  further comprising an electrically insulated metal flywheel coupled to an interior portion of the induction coil.  
   
   
       17 . The inductive coil of  claim 16  wherein the electrical insulation comprises an anodized outer surface of the flywheel, the anodized outer surface being in contact with the interior portion of the induction coil.  
   
   
       18 . The inductive coil of  claim 17  wherein the metal comprises aluminum.