Turbine blades

Abstract

A turbomachine apparatus for driving a compressor is disclosed. The turbomachine apparatus contains at least one rotor stage and at least one retaining element. The at least one rotor stage contains a plurality of blades and is configured to rotate about an axis. The at least one retaining element is configured to retain the at least one rotor stage with the blades thereof at least partly or wholly in radial compression during rotation thereof.

1 . A turbomachine apparatus comprising:
 at least one rotor stage wherein the rotor stage comprises a plurality of blades and is configured to rotate about an axis; and   at least one retaining element wherein the retaining element is configured to retain the rotor stage with the blades thereof at least partly or wholly in radial compression during rotation thereof.   
     
     
         2 . A turbomachine apparatus as claimed in  claim 1  wherein the at least one retaining element is configured to support a centrifugal load on the at least one rotor stage. 
     
     
         3 . A turbomachine apparatus as claimed in  claim 1  wherein the at least one retaining element is a shroud ring. 
     
     
         4 . A turbomachine apparatus as claimed in  claim 1  wherein the at least one retaining element is formed of a circumferentially-reinforced fiber material. 
     
     
         5 . A turbomachine apparatus as claimed in  claim 1  wherein the at least one retaining element is formed of carbon-carbon. 
     
     
         6 . A turbomachine apparatus as claimed in  claim 1  wherein the at least one retaining element is configured to force the plurality of blades into radial compression. 
     
     
         7 . A turbomachine apparatus as claimed in  claim 1  wherein the plurality of blades is formed of a ceramic material. 
     
     
         8 . A turbomachine apparatus as claimed in  claim 7  wherein the ceramic material is silicon nitride. 
     
     
         9 . A turbomachine apparatus as claimed in  claim 1  wherein the at least one rotor stage further comprises a hub. 
     
     
         10 . A turbomachine apparatus as claimed in  claim 9  wherein the plurality of blades is fixed to the hub. 
     
     
         11 . A turbomachine apparatus as claimed in  claim 1  wherein the plurality of blades and the at least one retaining element are separately formed components. 
     
     
         12 . A turbomachine apparatus as claimed in  claim 11  wherein the blades and the at least one retaining element are joined by diffusion bonding or brazing. 
     
     
         13 . A turbomachine apparatus as claimed in  claim 1 , wherein the at least one rotor stage further comprises a hub and wherein the plurality of blades and the hub are separately formed components. 
     
     
         14 . A turbomachine apparatus as claimed in  claim 13  wherein the blades and the hub are joined by diffusion bonding or brazing or other suitable material joining process. 
     
     
         15 . A turbomachine apparatus as claimed in  claim 1  wherein the turbomachine apparatus comprises a gas turbine. 
     
     
         16 . A turbomachine apparatus as claimed in  claim 15  wherein the gas turbine is configured to run on helium or another inert fluid. 
     
     
         17 . A turbomachine apparatus as claimed in  claim 15  wherein at least one of the at least one rotor stages is adapted to receive gas, such as helium, at around 1200K. 
     
     
         18 . A turbomachine apparatus as claimed in  claim 1  wherein the plurality of blades is configured to withstand a compressive load applied thereto by the at least one retaining element. 
     
     
         19 . A turbomachine apparatus as claimed in  claim 1  wherein the blades are configured to withstand the operational temperature of the turbomachine apparatus without substantial degradation due to temperature. 
     
     
         20 . A turbomachine apparatus as claimed in  claim 1  which comprises a contra-rotating turbine.