Ring for controlling a stage of variable-setting vanes for a turbine engine

Abstract

A control ring for a stage of variable-pitch vanes for a turbine engine includes at least one member for bearing on a casing and means for fixing the member. The member includes a bushing with an axial bore for the passage of the member or an element for supporting the member. A through-slot opens into the bore and allows for substantial radial deformation of the bushing. The member further include an outer thread for screwing the bushing into a complementary thread of a hole in the body, thereby deforming the bushing. The member or support can be mounted and moved inside the bore, to a second position, in which the bushing is radially constrained and is tightly mounted on the member or support, which is thus immobilized in relation to the bushing.

1 . A control ring for a stage of variable-pitch vanes for a turbine engine, comprising an annular body configured to extend around a casing, means designed to be connected to pivots of said vanes, and means that are designed to cooperate with said casing so as to center and guide said body and that comprise at least one member for bearing on the casing that is fixed to the body by fixing means wherein said fixing means comprise at least one bushing which comprises:
 an axial bore for the passage of said member or an element for supporting said member;   a through-slot opening into said bore and designed to allow a substantially radial deformation of the bushing; and   an outer thread for screwing the bushing into a complementary thread of a hole in said body,   said bushing being designed so that when the bushing is screwed in the bushing cooperates with said body so as to substantially radially deform from a first position, in which said member or support can be mounted and moved inside said bore, to a second position, in which said bushing is radially constrained and is tightly mounted on said member or support, which is thus immobilized in relation to the bushing.   
     
     
         2 . The control ring according to  claim 1 , wherein said member or support comprises a cylindrical rod axially engaged in said bore. 
     
     
         3 . The control ring according to  claim 2 , wherein said member comprises at least one pad configured to bear on the casing. 
     
     
         4 . The control ring according to  claim 3 , wherein said pad is rigidly connected to said rod. 
     
     
         5 . The control ring according to  claim 3 , wherein elastically deformable means are interposed between the pad and the body, wherein the deformable means urges said pad against said casing. 
     
     
         6 . The control ring according to  claim 5 , wherein said elastically deformable means comprise at least one compression spring mounted around said rod. 
     
     
         7 . The control ring according to  claim 1 , wherein said bushing comprises at least one substantially frustoconical portion designed to cooperate with a frustoconical portion of said hole in said body for mounting the bushing. 
     
     
         8 . The control ring according to  claim 7 , wherein said bushing comprises a cylindrical portion comprising said outer thread ( 70 ). 
     
     
         9 . A stage of variable-pitch vanes for a turbine engine, comprising an annular row of variable-pitch vanes each comprising a blade and a cylindrical pivot at its radially outer end, the stage further comprising an annular casing comprising mounting holes for the pivots of the vanes, wherein said pivots are connected by levers to a control ring according to  claim 1 . 
     
     
         10 . A turbine engine, comprising at least one control ring according to  claim 1 . 
     
     
         11 . The control ring according to  claim 4 , wherein said pad is formed as a single piece with said rod. 
     
     
         12 . A turbine engine according to  claim 10 , further comprising at least one stage according to  claim 9 . 
     
     
         13 . A turbine engine, comprising at least one stage according to  claim 9 .