Patent GB-651589-A (GB)
Title: Improvements in or relating to gas turbine power units and components for such units
IPC: F02C3/10
Filed: 1948-07-29
Abstract: 651,589. Gas turbine plant. WHITE, G., BARR, R. H. H. LEACH, H., and CENTRAX POWER UNITS, Ltd. July 29, 1948, No. 20268. [Classes 110(i) and 110(iii)] [Also in Group XXIV] A gas turbine power plant for road vehicles is shown in Figs. 1, 1A. It comprises an axial-flow air compressor followed by a final centrifugal compressor. The latter delivers air through a'plurality of diffusers to an annular air chamber 12 which encloses a plurality of combustion chambers. The combustion products are delivered to a two-stage turbine 104, 105 which drives the compressors and a following single stage turbine 108 which drives a power shaft 6. The power shaft drives, without a clutch, through a reduction gear and a reversing gear. Fuel and oil pumps and a starting motor are carried by a casing 50. The pumps are driven through worm wheels 47 and the motor drives through the worm shaft 44, which is connected to the compressor rotor by a torsion shaft 46. Air-compressor.-The air inlet 14 is annular, converging inwards from an annular air filter 15. The axial-flow compressor rotor is built up of discs 26 with threaded spigots and sockets 27. The discs are kept from unscrewing by pins 28. The stator blades are held between axially-split rings 35 as described in Specification 624,777 and the rings are enclosed in a split casing 37. The centrifugal impeller 29 delivers to a multiple diffuser, the passages of which are defined by the plane inner walls of casing parts 18, 38 and by the edges of plates 58, Fig. 9, secured between them. The passages are turned into the axial direction by insets 59, 60, Fig. 11, and the projecting parts 60a lie in the air chamber 12 between the combustion chambers. Combustion chambers.-The cylindrical combustion chambers 13 are slidingly mounted on the burners 22 and are secured to connecting chutes 24 which, at their outlets, conform to an annular duct 78 leading to the turbines. The duct is divided by radial ribs into as many passages as there are chambers 13. The chambers 13 are connected by passages 25 and there is a single sparking plug 26. An outer ring 84 guides cooling air on to the chutes 24. Turbines.-The rotors 104, 105, Fig. 1C, carry blades secured in peripheral grooves. The blades are introduced through gaps on the facing sides of the rotors and the gaps are closed by a single block 106 which bridges the rotors. The nozzle blades 94 are riveted to an inner ring 95 and are slidingly constrained by outer platforms 97 and long pins 96. The interstage blades 101 are gripped between rings 99 100 which, with rings 98, 103, fit in an unsplit casing 102. The housing 67 of a bearing 68 is carried by two frusto-conical parts 16, 17 which are bolted to the compressor casing. 'The part 16 is welded to the housing 67 and the part 17 is welded to a ring 69 which 'has a sliding fit on the housing. The inner ring 95 of the nozzle structure is bolted to the ring 69. The duct to the power turbine is defined by inner and outer walls 111, 112. The wall 112 is bolted to the stator of the turbine 104, 105 and the inner wall is supported from the wall 112 by radial ribs 115. Cooling and end thrust balancing. - A chamber 71 behind the impeller 29 is closed by a seal 70 and fills with pressure air that leaks over the edge of the impeller. This air is taken through passages in the pump casing to an external cooler 72 and returned to pipes 72a within the conical part 16 which deliver it to'a chamber A open to the up-stream face of the rotor 104. Air flows over the rotor face: some of it passes into the working fluid stream and some passes between the parts 16, 17 and is evacuated through a device 73 which keeps the pressure in the space between the parts 16, 17 intermediate the pressures in the air chamber 12 and central space within the part 16. This latter space receives air that leaks through the turbine bearing 68 and is evacuated to atmosphere. Air also passes along grooves in the turbine shaft and flows over the down-stream face of the rotor 105.