METHODS FOR PRODUCING EVEN WALL DOWN-HOLE POWER SECTIONS
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 acts of:
depositing a layer of metal or alloy using a robot having a welding gun, wherein the layer:
is a cross-section of the rotor or stator,
has a non-circular shape, and
is deposited by arc welding;
moving either one of the welding gun or the layer away from the other; and
repeating the depositing and moving acts until the rotor or stator is formed.
2 . The method of claim 1 , wherein the layer is deposited onto a base and the method further comprises rotating the base.
3 . The method of claim 1 , wherein the layer has a substantially hypocycloid shape.
4 . The method of claim 3 , wherein robot moves the gun along a path corresponding to the shape while depositing the layer.
5 . The method of claim 4 , wherein the layer is deposited onto a base and the method further comprises rotating the base after each layer is deposited, thereby forming a substantially helical-hypocycloid shape.
6 . The method of claim 1 , wherein the method is performed in a chamber flooded with an inert or reactive shielding gas.
7 . The method of claim 1 , wherein the method is performed in a vacuum chamber.
8 . The method of claim 1 , wherein the layer is deposited by plasma-arc welding.
9 . The method of claim 1 , wherein the layer is deposited by pinch arc welding.
10 . The method of claim 1 , wherein the layer is deposited by gas tungsten-arc welding.
11 . The method of claim 1 , wherein the layer is deposited by shielded metal arc-welding or flux-cored arc welding.
12 . The method of claim 1 , wherein the layer is deposited by submerged arc welding.
13 . The method of claim 1 , wherein the metal or alloy is nonmagnetic.
14 . The method of claim 1 , wherein the metal or alloy is high strength.
15 . A rotor or stator manufactured according to the method of claim 1 .