Device for axial securing of blade feet of a gas turbine disk

Claim 1

A gas turbine having an axial securing device for the roots of the blades of the rotor disc of the gas turbine which permits the blades to be readily disengaged from the rotor disc, said gas turbine comprising: (a) a rotor disc having an upstream front face, a downstream rear face, a radially outer rim, a plurality of axial notches in the radially outer rim, an axially projecting flange on the upstream front face, and a circumferential, radially outwardly open score on the radially outward surface of said axially projecting flange; (b) a front cowl removably fitted on the upstream front face of said rotor disc; (c) a plurality of rotor blades, each of said plurality of rotor blades having a blade root which is axially slidably disposed in a corresponding one of said plurality of axial notches and a project which extends axially forwardly and radially inwardly from the upsteam front face of the associated one of said plurality of rotor blades; (d) at least two ring segments slidably disposed in said circumferential score and circumferentially movable therein, said ring segments having a radially outwardly projecting collar which extends radially outwardly farther than said plurality of projections extend radially inwardly, said ring segments and said circumferential score being positioned such that the front surface of said radially outwardly projecting collars abut against the rear surfaces of said plurality of projections, thereby preventing rearward axial movement of said rotor blades, when said ring segments and said projections are circumferentially aligned, the sum of the lengths of said ring segments being less by at least the circumferential width of one of said axial notches than the circumference of said circumferential score, whereby said ring segments can be slid into a position in said circumferential score permitting at least one of said rotor blades to be disengaged from said rotor disc; and (e) a locking element carried by the downstream rear face of said front cowl, said locking element selectively engaging said ring semgents to prevent circumferential movement thereof and to circumferentially fix said ring segments in position to engage said plurality of projections, thereby preventing rearward axial movement of said rotor blades.