Method and apparatus for connecting turbine rotors

Abstract

Connecting rotors in rotary machines, particularly turbines, is generally described. Some aspects of the invention provide for a simplified attachment rotors to each other and/or other components of a turbine assembly, such as, drive shaft, using friction fit.

What is claimed is: 
     
         1 . A turbine assembly including:
 a first turbine rotor having a disc and at least one blade attached to the disc; and   a second turbine rotor having a disc and at least one blade attached to the disc,   wherein the first and second turbine rotors are attached to each other via only a friction fit.   
     
     
         2 . The assembly of  claim 1 , wherein the first and/or second turbine rotor is boreless. 
     
     
         3 . The assembly of  claim 1 , wherein a self-locking tapered fit joint provides the friction fit between the rotors. 
     
     
         4 . The assembly of  claim 1 , wherein the discs of the first and second rotors are free of any holes or openings arranged in an axial direction. 
     
     
         5 . The assembly of  claim 1 , wherein the discs of the first and second turbine rotors include complementary annular engagement surfaces that engage with each other via a friction fit. 
     
     
         6 . The assembly of  claim 5 , wherein the annular engagement surfaces are tapered. 
     
     
         7 . The assembly of  claim 6 , wherein the annular engagement surface of the first turbine rotor tapers so that a circumference of the engagement surface decreases with distance away from the disc. 
     
     
         8 . The assembly of  claim 7 , wherein the annular engagement surface of the second turbine rotor tapers so that a circumference of the engagement surface increases with distance away from the disc. 
     
     
         9 . The assembly of  claim 5 , wherein the annular engagement surfaces extend in a generally axial direction relative to a respective disc. 
     
     
         10 . The assembly of  claim 5 , wherein the annular engagement surface of the first turbine rotor is on a first side of the disc, the first turbine rotor further including a second annular engagement surface on a second side of the disc opposite the first side, the second annular engagement surface being arranged for frictional engagement with a complementary engagement surface of a drive shaft of the turbine assembly. 
     
     
         11 . The assembly of  claim 10 , wherein the drive shaft comprises a stub shaft that includes the complementary engagement surface. 
     
     
         12 . The assembly of  claim 11 , wherein the stub shaft is made of a ceramic material. 
     
     
         13 . The assembly of  claim 5 , further comprising:
 a third turbine rotor having a disc and at least one blade attached to the disc, the third turbine rotor being attached to the second turbine rotor via only a friction fit, the third turbine rotor being attached to the second turbine rotor on a side of the second turbine rotor that is opposite the first turbine rotor.   
     
     
         14 . The assembly of  claim 13 , wherein the third turbine rotor is boreless. 
     
     
         15 . The assembly of  claim 13 , wherein the disc of the third turbine rotor is free of any holes or openings arranged in an axial direction. 
     
     
         16 . The assembly of  claim 1 , wherein the rotors are made of a ceramic material, such as silicon nitride or silicon carbide, or of a metal. 
     
     
         17 . The assembly of  claim 1 , wherein the rotors are arranged for operating temperatures of up to about 1400 degrees Celsius. 
     
     
         18 . The assembly of  claim 1 , wherein the rotors are arranged for rotary speeds up to about 26,000 rpm. 
     
     
         19 . (canceled) 
     
     
         20 . A method for operating a turbine assembly, including:
 providing first and second turbine rotors each having a disc and at least one blade attached to the disc; and   attaching the first and second turbine rotors to each other via a friction fit.   
     
     
         21 - 41 . (canceled) 
     
     
         42 . A turbine rotor including:
 a disc having an engagement surface arranged to frictionally engage the disc with another turbine rotor disc or a shaft of a turbine assembly; and   at least one blade attached to the disc.   
     
     
         43 - 49 . (canceled)