Axial turbine for aeronautical applications

1. An axial turbine ( 1 ) for aeronautical applications having an axis of symmetry ( 3 ) and comprising a case ( 8 ) and at least one stator ( 11 ) housed in said case ( 8 ) and comprising a support structure ( 16 , 20 , 21 ) and an array of airfoil profiles ( 33 ) positioned angularly equidistant from one other about said axis of symmetry ( 3 ) and defining respective spaces ( 35 ) therebetween for passage of a flow of gas, and means ( 36 , 37 , 41 , 42 ) for connecting each said airfoil profile ( 33 ) to said support structure ( 16 , 20 , 21 ); characterised in that said connecting means ( 36 , 37 , 41 , 42 ) comprise hinge means ( 36 , 37 , 41 , 42 ) to permit each said airfoil profile ( 33 ) to rotate relative to said support structure ( 16 , 20 , 21 ) about an associated first hinge axis ( 40 ) incident to said axis of symmetry ( 3 ), and in that the axial turbine also comprises angular positioning means ( 50 ) for simultaneously rotating said airfoil profiles ( 33 ) about said respective first hinge axes ( 40 ) by an identical angle of adjustment, and further characterised in that said angular positioning means ( 50 ) comprise actuating means ( 55 ) and synchronising means ( 51 ) interposed between said actuating means ( 55 ) and said airfoil profiles ( 33 ) and further characterised in that said synchronising means ( 51 ) comprise a synchronising ring ( 51 ) that is rotatable about said axis of symmetry ( 3 ) and in that said angular positioning means ( 50 ) also comprise first transmission means ( 72 , 76 ) interposed between each said airfoil profile ( 33 ) and said synchronising ring ( 51 ) and second transmission means ( 58 ) interposed between said actuating means ( 55 ) and said synchronising ring ( 51 ) and further characterised in that said first transmission means ( 72 , 76 ) comprise a control lever ( 72 ) that is radial with respect to the associated first hinge axis ( 40 ) and integral with said associated airfoil profile ( 33 ) and further characterised in that at least one of said first ( 72 , 76 ) and second ( 58 ) transmission means comprise connecting and relative mobility means ( 76 ; 92 ) interposed between each said lever ( 62 , 72 ) and said synchronising ring ( 51 ) to transmit the rotational motion and, in service, to compensate for differences in trajectory/orientation between said synchronising ring ( 51 ) and each said lever ( 62 , 72 ) during rotation and further characterised in that said connecting and relative mobility means ( 76 ; 92 ) comprise a hinge pin ( 78 ; 98 ) interposed between said associated lever ( 62 , 72 ) and said synchronising ring ( 51 ) and having a joint axis ( 80 ) incident to said axis of symmetry ( 3 ) and a spherical head ( 86 ; 99 ) interposed between said hinge pin ( 78 ; 98 ) and one of said associated levers ( 62 , 72 ) and said synchronising ring ( 51 ) and further characterised in that said synchronising ring ( 51 ) is coupled with said case ( 8 ) in a fixed axial position; said connecting and relative mobility means ( 76 ; 92 ) comprising an elongate seat ( 95 ) made in one ( 72 ) of said levers ( 62 , 72 ), and said synchronising ring ( 51 ); and the elongated seat engaged slidingly by said spherical head ( 99 ).

2. Turbine according to claim 1 , characterised in that said hinge pin ( 98 ) is integral with said associated lever ( 62 , 72 ); said elongate seat ( 95 ) being defined by a slot parallel to said axis of symmetry ( 3 ) and carried by said synchronising ring ( 51 ).

3. Turbine according to claim 1 , characterised in that said elongate seat ( 95 ) is defined by a fork ( 94 ).