Methods for producing even wall down-hole power sections

Abstract

Embodiments of the present invention provide methods for manufacturing an even-wall rotor or stator that do not suffer from drawbacks of the prior art. Even-wall rotors or stators produced according to those methods are also provided. In one embodiment, a method for manufacturing a rotor or stator for use in a mud motor is provided. The method includes providing a vacuum chamber; providing a metal electrode at least partially disposed in the vacuum chamber; providing a mold disposed in the vacuum chamber; and melting a portion of the electrode with a direct current arc, the molten metal flowing into the mold ring.

1 . A method for manufacturing a rotor or stator for use in a mud motor, comprising: 
 providing a vacuum chamber    providing a metal electrode at least partially disposed in the vacuum chamber;    providing a mold disposed in the vacuum chamber; and    melting a portion of the electrode with a direct current arc, the molten metal flowing into the mold.    
   
   
       2 . The method of  claim 1 , further comprising rotating the mold.  
   
   
       3 . The method of  claim 1 , wherein the mold comprises inner and outer members and the molten metal pours into a space between the inner and outer members.  
   
   
       4 . The method of  claim 1 , wherein the mold has a non-circular profile formed on an inner or outer surface thereof.  
   
   
       5 . The method of  claim 1 , wherein the mold has a substantially hypocycloid profile formed on an inner or outer surface thereof.  
   
   
       6 . A method for manufacturing a rotor or stator for use in a mud motor, comprising: 
 providing a robot having a welding gun;    depositing a layer of metal using the welding gun;    moving either one of the welding gun or the layer away from the other;    repeating the depositing and moving acts until the rotor or stator is formed.    
   
   
       7 . The method of  claim 6 , wherein the layer is deposited onto a base and the method further comprises rotating the base.  
   
   
       8 . The method of  claim 6 , wherein the layer has a non-circular shape.  
   
   
       9 . The method of  claim 6 , wherein the layer has a circular shape.  
   
   
       10 . The method of  claim 6 , wherein the layer has a substantially hypocycloid shape.  
   
   
       11 . The method of  claim 6 , wherein the method is performed in a chamber flooded with an inert or reactive shielding gas.  
   
   
       12 . The method of  claim 6 , wherein the method is performed in a vacuum chamber.  
   
   
       13 . The method of  claim 6 , wherein the layer of metal is deposited by plasma-arc welding.  
   
   
       14 . The method of  claim 6 , wherein the layer of metal is deposited by a step for pinch arc welding.  
   
   
       15 . The method of  claim 6 , wherein the layer of metal is deposited by gas tungsten-arc welding.  
   
   
       16 . The method of  claim 6 , wherein the layer of metal is deposited by flux-cored arc welding.  
   
   
       17 . The method of  claim 6 , wherein the layer of metal is deposited by submerged arc welding.  
   
   
       18 . A method for manufacturing a rotor for use in a mud motor, comprising: 
 rotating a mold having a substantially helical-hypocycloid profile formed on an inner surface thereof; and    pouring molten metal into the mold, wherein centrifugal force caused by the rotation of the mold will press the molten metal under sufficient pressure so that the molten metal will substantially evenly fill the profiled inner surface.    
   
   
       19 . The method of  claim 18 , wherein the mold is in a pressure chamber.  
   
   
       20 . The method of  claim 18 , wherein a longitudinal centerline of the mold is substantially horizontal.  
   
   
       21 . A method for manufacturing a rotor or stator for use in a mud motor, comprising: 
 providing a means for manufacturing the rotor or stator; and    a step for manufacturing the rotor or stator, thereby producing the rotor or stator having a substantially helical-hypocycloid shape.    
   
   
       22 . A rotor or stator for use in a mud motor manufactured by a method, the method comprising: 
 providing a vacuum chamber    providing a metal electrode at least partially disposed in the vacuum chamber;    providing a mold disposed in the vacuum chamber; and    melting a portion of the electrode with a direct current arc, the molten metal flowing into the mold ring.    
   
   
       23 . The rotor or stator of  claim 22 , wherein the method further comprises rotating the mold.  
   
   
       24 . The rotor or stator of  claim 22 , wherein the mold comprises inner and outer members and the molten metal pours into a space between the inner and outer members.  
   
   
       25 . The rotor or stator of  claim 22 , wherein the mold has a non-circular profile formed on an inner or outer surface thereof.  
   
   
       26 . The rotor or stator of  claim 22 , wherein the mold has a substantially hypocycloid profile formed on an inner or outer surface thereof.  
   
   
       27 . A rotor or stator for use in a mud motor manufactured by a method, the method comprising: 
 providing a robot having a welding gun;    depositing a layer of metal using the welding gun;    moving either one of the welding gun or the layer away from the other;    repeating the depositing and moving step until the rotor or stator is formed.    
   
   
       28 . The rotor or stator of  claim 27 , wherein the layer is deposited onto a base and the method further comprises rotating the base.  
   
   
       29 . The rotor or stator of  claim 27 , wherein the layer has a non-circular shape.  
   
   
       30 . The rotor or stator of  claim 27 , wherein the layer has a circular shape.  
   
   
       31 . The rotor or stator of  claim 27 , wherein the layer has a substantially hypocycloid shape.  
   
   
       32 . The rotor or stator of  claim 27 , wherein the method is performed in a chamber flooded with an inert or reactive shielding gas.  
   
   
       33 . The rotor or stator of  claim 27 , wherein the method is performed in a vacuum chamber.  
   
   
       34 . The rotor or stator of  claim 27 , wherein the layer of metal is deposited by plasma-arc welding.  
   
   
       35 . The rotor or stator of  claim 27 , wherein the layer of metal is deposited by a step for pinch arc welding.  
   
   
       36 . The rotor or stator of  claim 27 , wherein the layer of metal is deposited by gas tungsten-arc welding.  
   
   
       37 . The rotor or stator of  claim 27 , wherein the layer of metal is deposited by flux-cored arc welding.  
   
   
       38 . The rotor or stator of  claim 27 , wherein the layer of metal is deposited by submerged arc welding.  
   
   
       39 . A rotor or stator for use in a mud motor manufactured by a method, the method comprising: 
 rotating a mold having a substantially helical-hypocycloid profile formed on an inner surface thereof,    pouring molten metal into the mold, wherein centrifugal force caused by the rotation of the mold will press the molten metal under sufficient pressure so that the molten metal will substantially evenly fill the profiled inner surface.    
   
   
       40 . The rotor or stator of  claim 39 , wherein the mold is in a pressure chamber.  
   
   
       41 . The rotor or stator of  claim 39 , wherein a longitudinal centerline of the mold is substantially horizontal.