Rotor formed of multiple metals

Abstract

A rotor for a machine under this disclosure could be said to include a hub having a plurality of blades extending radially outwardly of the hub. At least one of the hub and the plurality of blades is formed of at least two metal materials. The two metal materials are selected to have different thermal expansion coefficients such that the overall rotor will be more resistant to forces it may experience as temperature or speed increases. There are layers of each of the two metal materials, with an intermediate gradient wherein the two materials are mixed. Alternatively, a shape memory alloy may be used. A method is also disclosed.

What is claimed is: 
     
         1 . A rotor for a machine comprising:
 a hub having a plurality of blades extending radially outwardly of said hub;   at least one of said hub and said plurality of blades is formed of at least two metal materials, the two metal materials being selected to have different thermal expansion coefficients such that the overall rotor will be more resistant to forces it may experience as temperature or speed increases, and there being layers of each of the two metal materials, with an intermediate gradient wherein the two materials are mixed.   
     
     
         2 . The rotor as set forth in  claim 1 , wherein an electric motor is connected to drive the motor. 
     
     
         3 . The rotor as set forth in  claim 1 , wherein there are voids within a body of at least one of said hub and said blades formed. 
     
     
         4 . The rotor as set forth in  claim 3 , wherein said voids are formed by a lattice structure. 
     
     
         5 . The rotor as set forth in  claim 3 , wherein said voids are formed within each of said hub and said plurality of blades. 
     
     
         6 . The rotor as set forth in  claim 1 , wherein the two metal materials are utilized to form at least said plurality of blades. 
     
     
         7 . The rotor as set forth in  claim 6 , wherein the two metal materials are selected such that said blades bend upon exposure to heat in a direction that opposes a bending centrifugal force on the blades. 
     
     
         8 . The rotor as set forth in  claim 1 , wherein the two metal materials form at least a tip of the blades to resist deformation due to centrifugal force. 
     
     
         9 . The rotor as set forth in  claim 1 , wherein the hub is formed of the at least two metal materials positioned to resist bending of the hub in a direction towards the blades. 
     
     
         10 . The rotor as set forth in  claim 1 , wherein the two metal materials also form at least a part of said hub. 
     
     
         11 . The rotor as set forth in  claim 10 , wherein the hub has a fuse that will be caused to fracture should the hub be exposed to at least one of a force, or speed that is beyond predetermined desired maximum. 
     
     
         12 . The rotor as set forth in  claim 1 , wherein there are a plurality of sandwiched portions of the at least two metal materials which are sandwiched together. 
     
     
         13 . The rotor as set forth in  claim 12 , wherein there is at least a third metal material positioned between a layer of a first metal material and said second metal material with a thermal expansion coefficient of said third metal material being intermediate the thermal expansion coefficients of the first and second metal materials, and there also being a gradient between the first and third metal materials and the second and third metal materials. 
     
     
         14 . The rotor as set forth in  claim 1 , wherein there is at least a third metal material positioned between a layer of a first metal material and said second metal material with a thermal expansion coefficient of said third metal material being intermediate the thermal expansion coefficients of the first and second metal materials, and there also being a gradient between the first and third metal materials and the second and third metal materials. 
     
     
         15 . A rotor for a machine comprising:
 a hub having a plurality of blades extending radially outwardly of said hub;   at least one of said hub and said plurality of blades formed of a shape memory alloy, such that the at least one of the hub and the plurality of blades resist deformation as the rotor is exposed to an increased temperature or speed.   
     
     
         16 . A method of forming a rotor comprising the steps of:
 laying down material in layers to form an intermediate body, and of a first metal material;   forming a layer of a second metal material in contact with a portion formed of the first metal material, the two metal materials being selected to have different thermal expansion coefficients such that the overall rotor will be more resistant to forces it may experience as temperature or speed increases, and there being layers of each of the two metal materials, with an intermediate gradient wherein the two materials are mixed.   
     
     
         17 . The method as set forth in  claim 16 , wherein there are voids formed by a lattice structure within a body of the rotor. 
     
     
         18 . The method as set forth in  claim 17 , wherein said voids are formed within each of a hub and a plurality of blades in the rotor body. 
     
     
         19 . The method as set forth in  claim 16 , wherein the two metal materials having different thermal expansion coefficients. 
     
     
         20 . The method as set forth in  claim 16 , wherein there is at least a third metal material positioned between a layer of a first metal material and said second metal material with a thermal expansion coefficient of said third metal material being intermediate the thermal expansion coefficients of the first and second metal materials, and there also being a gradient between the first and third metal material and the second and third metal material.