GB760884A - Mountings for guide blades in axial flow turbines and compressors - Google Patents

Abstract

760,884. Mounting turbine and compressor blades. SULZER FRERES SOC. ANON. Oct. 11, 1954 [Oct. 23, 1953], No. 29191/54. Class 110 (3). In an axial-flow turbine or compressor, a circumferential groove 1 is formed in the stator or casing 2, 2<SP>1</SP> for the reception of blade roots 5 and filling or spacer pieces 7, the groove being wider at least at one point near the bottom thereof than at a point further from the bottom and the maximum length of the blade roots in an axial direction is less than the minimum width of the groove. A spacer ring 10 is inserted between one side wall of the groove and the adjacent sides of the blade roots and is of such a thickness that the blade roots are permitted limited movement in the groove in an axial direction. The circumferential groove may alternatively be formed by suitably-shaped rings mounted on the inner surface of the blade carrier. The casing is formed in two halves 2, 21 and one side 3 of the groove 1 lies in a plane normal to the axis of the machine while the other side lies on the surface of a cone. The sides of the blade roots 5 and spacer pieces 7, also of the half spacer pieces 11, are correspondingly shaped. The spacer ring 10 is also formed in two halves which are disposed between the side of the groove and the sides of the blade roots and spacer pieces which lie in a plane normal to the machine axis. Pins 12 are disposed in short circumferentially-directed bores formed in the ends of the spacer ring halves and the half-spacer pieces 11 to prevent relative circumferential movement of these parts. Also bolts 13 having large heads are screwed into the casing halves 2, 21, the heads engaging recesses 15 formed in the half spacer pieces 11 to prevent circumferential movement of the parts along the groove. The sides of the blade roots may be parallel to the blade chord. Both side walls of the groove could alternatively be formed as fiat surfaces normal to the axis of rotation, one of the surfaces having in it a recess into which correspondingly-shaped projections of the blade roots and filling-pieces engage. Again one of the side walls of the groove could have a circumferential channel into which a wire ring is inserted so that it projects from the channel and fits into corresponding channels in one side of the blade roots and of the filling-pieces. Separate lengths of wire could be used instead of a complete ring.