GB739300A - Improvements relating to the exhaust cone assemblies of gas turbine engines - Google Patents

Abstract

739,300. Jet propulsion gas turbine plant. ARMSTRONG SIDDELEY MOTORS, Ltd. June 1, 1954 [July 3, 1953], No. 18446/53. Class 110 (3). [Also in Group XXXIV] In a gas turbine exhaust cone assembly comprising inner and outer casings connected by aerofoil spokes, a shaft bearing at the rear end of the turbine is supported by a diaphragm having, in cold conditions, an interference fit in the inner casing in the region of the spokes, and a plurality of angularly-spaced pins are provided to locate the diaphragm relative to the inner casing in all directions except the generally radial direction. The arrangement allows the inner casing to expand freely radially but maintains the concentricity and alignment of the diaphragm and inner casing. The exhaust cone shown comprises an outer casing formed in two parts 30, 31 connected to the turbine stator casing support 33, an inner casing 17 which carries a conical extension 24 and spokes 25 connecting the parts 17, 31. The rear turbine bearing 13 is carried by a diaphragm 11 formed with a rim 16 which has, in cold conditions, an interference fit with a ring 18 attached to the inner casing 17. Screws 21 mounted in the rim 16 have a plain pin portion 22 which engage the ring 18. The screws 21 are arranged truly radially in the end view of the diaphragm but in the axial section shown are slightly inclined to the radial. This arrangement allows the inner casing to expand freely radially and also facilitates the drilling of the screw holes. The rings 16, 18 may also be made of a lighter construction. The chamber enclosed by the inner casing 17 and conical extension 24 is open to atmosphere and is insulated from the hot gases by lagging 27, 28.