GB780392A - Improved support assembly for turbine casings - Google Patents

Abstract

780,392. Turbines. GENERAL ELECTRIC CO. Aug. 8,1955 [Aug. 11, 1954], No. 22811/55. Class 110 (3). An. elastic fluid turbine in which the casing is supported from pedestals carrying the rotor shaft bearings has wedge plates attached to the casing and pedestal respectively with the oppositely inclined surfaces of the wedge plates parallel to one another and a key plate located between the wedge plates which lies substantially in a radial plane through the centre line of the turbine shaft. A turbine casing is supported on two pedestals 2 carrying the bearings 3 of the rotor shaft 1. One of the pedestals is fixed to the foundation 4 while the other is free to slide axially on a sole-plate secure to the foundation. The casing is supported on the pedestals by arms 7, 8. The arms 7 rest freely on the arm 8 which is clamped to the pedestal 2 by a bolt 9, nut 15 and sleeve 14. The upper arm 7 is freed to expand vertically without stretching the bolt 9. The holes 10, 11 in the arms are substantially larger than the bolt 9 to allow for relative movement of the arms 7, 8 and the pedestal 2. Expansion of the lower half of the casing is allowed in a radial direction by a support assembly B, Fig. 4, so that there is no tendency for the casing to expand upwards and so damage the shaft packing. The assembly B comprises two wedge plates 16, 17 and a key plate 18. The wedge plates are attached by screws to the casing and pedestal respectively and located thereon by bosses 19, 22 which engage recesses 20, 23. The key plate 18 is a flat plate having spigots 27, 28 which engage recesses 31, 32 in the wedge plates. The sloped surfaces 25, 26 of the wedge plates are parallel to one another and when the key plate is inserted it lies in a radial plane through the centreline of the shaft 1. The spigots 27, 28 lie in a plane perpendicular to the axis of the turbine so that axial movement of the turbine relative to the wedge plates is prevented whilst allowing radial movement of the arm 8 relative to the shaft 1. To prevent transverse movement of the casing, a lug 36, Fig. 5, on the casing fits into a recess 39 in the pedestal 2. Packing pieces 38 are also provided. Plate 18 may be used as a packing-piece to align the shaft with the casing. The wedge plates may be hardened and the key plate left soft or vice versa and may be made of expensive material to prevent galling and allow of free sliding. In a modification, the upper arm 7 is omitted. In a further modification, either or both of the spigots 27, 28 is on the wedge plates.