PROCEDE ET DISPOSITIF DE MAINTIEN D'UN JEU CONSTANT ENTRE PARTIES FIXES ET MOBILES D'UNE TURBINE

L'INVENTION CONCERNE UN PROCEDE ET UN DISPOSITIF DE MAINTIEN D'UN JEU CONSTANT ENTRE PARTIES FIXES ET MOBILES D'UNE TURBINE, EN PARTICULIER ENTRE LES POINTES DES AUBES MOBILES 18 D'UNE TURBINE DE MOTEUR A TURBINE A GAZ ET LE BANDAGE ENVIRONNANT 23 RENFERMANT UN CONDUIT THERMIQUE ANNULAIRE D'EGALISATION DE TEMPERATURE 25, LA DILATATION OU LA CONTRACTION THERMIQUES DUDIT BANDAGE ETANT REGLEES PAR UN COURANT D'AIR REFRIGERANT DONT LE DEBIT EST DOSE PAR UN DISTRIBUTEUR 41 ACTIONNE PAR UNE UNITE DE COMMANDE 40 EN FONCTION DUDIT JEU MESURE PAR UN ODOMETRE ELCTRIQUE 39.LE DISPOSITIF ASSURE LE MAINTIEN DUDIT JEU PAR DES MOYENS MECANIQUES REDUITS A LEUR PLUS SIMPLE EXPRESSION. A gas turbine engine has a turbine which includes an annular array of rotary aerofoil blades surrounded by an annular shroud member. All or a major portion of the annular shroud member is constituted by a heat pipe. A distance measuring device is provided to measure the clearance between the tips of the rotary aerofoil blades and the shroud member and its output is monitored by a control unit. The control unit is adapted to control a valve which regulates the flow rate of cooling air directed onto the heat pipe. The arrangement is such that the temperature of the heat pipe is maintained at a level which is consistent with the clearance between the rotary aerofoil blade tips and the annular shroud member being within a predetermined range of values.