Patent GB-736800-A (GB)
Title: Improvements in or relating to stationary blade rings of axial flow turbines or compressors
IPC: F01D25/16
Filed: 1952-07-10
Abstract: 736,800. Turbine and compressor stators. DE HAVILLAND ENGINE CO., Ltd., HALFORD, F. B., CLARKE, G. F., and BARRETT, A. W. E. Sept. 21, 1953 [July 10, 1952], No. 17415/52. Classes 110 (1) and 110 (3). A stationary blade ring assembly for an axial flow compressor or turbine comprises coaxial outer and inner blade supporting rings, hollow blades supported from these rings in a manner permitting linked movement of each blade relative to at least one of the rings in the direction of the length of the blade and links extending through some or all of the blades each connected at its ends to the outer and inner supporting rings in a manner preventing radial movement between each end of the link and the supporting rings so that the links can be placed in tension or compression and maintain the rings approximately concentric with each other. The nozzle ring of a gas turbine shown comprises an outer blade supporting ring formed by an outer annular part A and an inner cylindrical part A<SP>1</SP>. The part A forms part of the main outer structure of the turbine unit and is bolted to the casing B, by which the outlet ends of the combustion chambers are 'supported, and the outer casing C of the turbine. The inner part A<SP>1</SP> which is located between two flat plates A<SP>2</SP> , A<SP>3</SP> is formed with a series of slots each of approximately the contour of the blades J. One end face of the part A<SP>1</SP> constitutes a locating face for one end of the hollow shroud ring E for the first row of turbine rotor blades. Radial splines E<SP>1</SP> allow for free radial expansion and contraction of the shroud ring E. The inner blade supporting ring consists of an inner part F which is bolted to the main inner bearing supporting structure G and an outer part H of channel cross-section which is formed with a series of slots similar to those in the member A<SP>1</SP>. The ends of the blades J make a sliding fit in the slots in the members A<SP>1</SP> and H. Links K pivoted at one end to split lugs A<SP>4</SP> formed on the members A, have at the other end a rotatable screw-threaded sleeve L which engages a boss F4 so that by rotating the sleeve L the links K may be given any desired degree of tension or compression. The pivotal axis of the pins K<SP>2</SP> may be as shown inclined to the plane passing through the pin and containing the axis of the blade ring or alternatively be normal to such a plane. The central portion of each of the links K, Fig. 2, fits closely to the inside surfaces of the blades J and acts as a strut between the sides of the blades. The surfaces of the links are grooved at K<SP>5</SP> to form cooling air passages through which cooling air passes from the ports M to the ports M<SP>2</SP>. In a modification, the link K divides the space inside the blades into two chambers. In the arrangement the cooling air flows into the chamber adjacent the trailing edge of the blade through transverse grooves in the link K into the chamber adjacent the leading edge and leaves through the ports M The blade material may differ from that of the links. Reference has been directed by the Comptroller to Specification 582,152.