Blade fixing arrangement for a turbomachine rotor

Claim 1

A turbomachine rotor comprising a drum and at least one stage of blades secured to the outer periphery of said drum, said drum having upstream and downstream annular beads on said outer periphery thereof, an annular groove in said upstream bead, an annular collar on said downstream bead, said collar being provided with peripherally spaced tongues projecting in the downstream direction, a cylindrical bearing surface on said drum adjacent said downstream bead, and an annular groove in said drum on the downstream side of said cylindrical bearing surface, said blades each having a platform provided with upstream and downstream legs on the radially inner face thereof, said upstream leg having an end edge received in said annular groove of said upstream bead on said drum, and said downstream leg having a cylindrical bearing surface at its radially inner end acting on said cylindrical bearing surface of said drum, a central aperture receiving at least one of said tongues of said collar on said downstream bead, and a pair of hooks on the downstream face of said downstream leg, each of said hooks defining a recess in its radially inner face, said rotor including a plurality of arcuate locking plates received in said annular groove of said drum and securing said blades in position, each of said locking plates having first tongues received in said recesses of said hooks on said downstream leg of a blade platform, and second locking tongues at the ends of said locking plate.