Rotor blade fixing for turbomachine rotors

A turbomachine rotor having:

• a rotor drum, said drum being provided with
• at least two radially outwardly directed flanges spaced axially apart from each other and defining an upstream drum flange and a downstream drum flange with respect to the direction of flow of gases through said turbomachine rotor,
• a circular row of evenly spaced holes through said downstream drum flange, and
• an annular groove adjacent the base of said downstream drum flange on the downstream side thereof;
• a stage of rotor blades mounted circumferentially on said rotor drum, said stage including a plurality of blade platforms, each of said platforms carrying
• at least two radially inwardly directed flanges spaced axially apart from each other and defining an upstream platform flange and a downstream platform flange cooperating respectively with said upstream and downstream flanges of said drum,
• said downstream platform flange having at least one hole registering with at least one of said holes in said downstream drum flange;
• a generally cylindrical pin projecting through each pair of registering holes of said downstream drum and platform flanges, each of said pins having
• a substantially central radial collar interposed between said downstream drum flange and said downstream platform flange, and
• an annular groove disposed downstream of said collar;
• and
• a plurality of scalloped segments disposed in said annular groove of said drum,
• each of said segments having its radially outer edge defining teeth separated by a plurality of cut-outs, each of said teeth being received in said annular groove of one of said pins to hold said pins and said rotor blades in position radially, axially and tangentially,
• and each of said segments carrying a tongue at each end thereof, one of said tongues extending radially and the other of said tongues being bent at right angles to permit movement of said segment to engage said teeth in said grooves of said pins, said other tongue thereafter being radially straightened to lock said segments, said pins and said rotor blades in position.