Rotor having an annulus filler

Abstract

An annulus filler for installation between blades, such as fan blades, of the rotor of a gas turbine engine includes a channel which accommodates a post defined between blade slots of the disc. A chocking surface of the annulus filler contacts regions of a contact surface of the post to chock the head of the post within the channel. The annulus filler is thus supported along the axial length of the post, enabling it to withstand circumferential forces generated on rotation of the disc.

1 . A rotor comprising a rotor disc having an array of blade slots each slot retaining a blade root, in which disc posts are defined between adjacent blade slots and annulus fillers are disposed between adjacent blade slots, each annulus filler comprising a body having an airwashed surface and an oppositely disposed chocking surface which contacts a surface of the respective disc post, the disc post having a post formation extending across the axial width of the disc post, and the annulus filler having an annulus filler formation adjacent the chocking surface which abuts both the post formation and the blade root to retain the annulus filler radially with respect to the disc; in which the chocking surface has at least one contact region in contact with the post formation and at least one non-contact region spaced from the disc post formation. 
     
     
         2 . A rotor as claimed in  claim 1 , in which the annulus filler formation comprises a pair of channel walls extending from the chocking surface and defining with the chocking surface a channel which receives the respective disc post. 
     
     
         3 . A rotor as claimed in  claim 2 , in which the disc post comprises a stem and a head with a larger circumferential dimension than the stem. 
     
     
         4 . A rotor as claimed in  claim 3 , in which the channel walls are directed inwardly of the channel and engage beneath the head of the disc post. 
     
     
         5 . A rotor as claimed in  claim 2 , in which the channel walls extend from circumferentially outer edges of the chocking surface. 
     
     
         6 . A rotor as claimed in  claim 2 , in which the channel extends substantially the full axial extent of the disc post. 
     
     
         7 . A rotor as claimed in  claim 1 , in which two of the contact regions are disposed at opposite axial ends of the chocking surface, with the non-contact region, or one of the non-contact regions, disposed between them. 
     
     
         8 . A rotor as claimed in  claim 1 , in which an abutment is provided at one axial end of the disc post, the annulus filler engaging the abutment to limit axial displacement of the annulus filler. 
     
     
         9 . A rotor as claimed in  claim 1 , in which a retaining element is provided at one axial end of the annulus filler, the retaining element being engaged by a support ring which is releasably secured to the rotor disc. 
     
     
         10 . A rotor as claimed in  claim 1 , in which a shear key is fitted to the rotor disc and is accommodated in a recess in the annulus filler. 
     
     
         11 . A rotor as claimed in  claim 1 , in which the body comprises a box section having an outer wall providing the airwashed surface, an inner wall providing the chocking surface, and side walls extending between the inner wall and the outer wall, 
     
     
         12 . A rotor as claimed in  claim 11 , in which the outer wall projects circumferentially beyond the side walls. 
     
     
         13 . A rotor comprising a rotor disc having an array of blade slots, in which disc posts are defined between adjacent blade slots and annulus fillers are disposed between adjacent blade slots, each annulus filler comprising a body having an airwashed surface and an oppositely disposed chocking surface having at least one contact region in contact with the post formation and at least one non-contact region spaced from the disc post formation, and the annulus filler having an annulus filler formation adjacent the chocking surface which engages the post formation to retain the annulus filler radially with respect to the disc. 
     
     
         14 . A rotor as claimed in  claim 13 , in which the channel extends substantially the full axial extent of the disc post. 
     
     
         15 . A rotor as claimed in  claim 13 , in which two of the contact regions are disposed at opposite axial ends of the chocking surface, with the non-contact region, or one of the non-contact regions, disposed between them. 
     
     
         16 . A rotor as claimed in  claim 13 , in which an abutment is provided at one axial end of the disc post, the annulus filler engaging the abutment to limit axial displacement of the annulus filler. 
     
     
         17 . A rotor as claimed in  claim 13 , in which a retaining element is provided at one axial end of the annulus filler, the retaining element being engaged by a support ring which is releasably secured to the rotor disc. 
     
     
         18 . A rotor as claimed in  claim 13 , in which a shear key is fitted to the rotor disc and is accommodated in a recess in the annulus filler.