Blade cluster having an offset axial mounting base

Abstract

The stage of a turbine or of a compressor having a plurality of blades which are mounted on a rotor and/or a stator of the stage. The blades are combined into a number of blade clusters as integral components which are each composed of at least two blades and which are each equipped with one shared blade mount for mounting the cluster on the rotor or stator.

1 - 8 . (canceled) 
     
     
         9 . A stage of a turbine or of a compressor comprising:
 a rotor or stator;   blades mounted on the rotor or stator, the blades being combined into a number of blade clusters as integral components each composed of at least two blades, each blade cluster equipped with one shared blade mount for mounting the blade cluster on the rotor or stator.   
     
     
         10 . The stage as recited in  claim 9  wherein the blade mount includes an axially extending dovetail groove or tongue for connection to a corresponding dovetail tongue or groove, respectively, on the rotor or stator. 
     
     
         11 . The stage as recited in  claim 10  wherein the dovetail connection is configured in a decentralized location between the at least two blades. 
     
     
         12 . The stage as recited in  claim 11  wherein the dovetail connection is offset circumferentially from a central location between the at least two blades. 
     
     
         13 . The stage as recited in  claim 12  wherein the circumferential offset is equal to approximately one half of a blade pitch, the direction of the offset corresponding to the direction of the action of force of the blades. 
     
     
         14 . The stage as recited in  claim 9  wherein the blade mount is the dovetail groove formed on the blade cluster, and the corresponding tongue is formed on the rotor or stator. 
     
     
         15 . The stage as recited in claim  8  wherein each blade cluster has three blades. 
     
     
         16 . The stage as recited in  claim 14  wherein the corresponding tongues are formed in one piece with the rotor or the stator. 
     
     
         17 . The stage as recited in  claim 9  wherein the dovetail groove has the form of a fir tree and forms a plurality of radially spaced apart undercuts for each lateral face.