Patent GB-760518-A (GB)
Title: Improved gas turbine
Inventor: WOSIKA LEON R
IPC: F02C7/04
Filed: 1954-04-28
Abstract: 760,518. Gas turbine plant; axial flow compressors. SOLAR AIRCRAFT CO. April 28, 1954, No. 12289/54. Classes 110 (1) and 110 (3). [Also in Group XXXIV] A compact, small dimension gasturbine plant shown in perspective in Fig. 1, comprises a compressor 33 (see also Figs. 3 and 4), having an outlet scroll 34 and arranged coaxially with a turbine (see also Fig. 5), having an inlet scroll 36, the scrolls being interconnected by a laterally offset combustion chamber 35 in which the gas flow is in the opposite direction to the flow in the compressor. The turbine rotor is carried in bearings in a housing 54 connecting the two stators, the bearing 128 adjacent the turbine allowing longitudinal movement and the more remote bearing 69 taking thrust. Fluid pressure means are provided for confining the hot working fluid to the periphery of the turbine rotor and the bearings are thermally shielded from the heat of the scrolls. A stub shaft 72 with longitudinal splines engaging splines in the two rotors constitutes a driving connection free of thrust. Axial flow compressors.-The compressor rotor comprises a number of blade carrying discs mounted on a cylinder 77, the adjacent ends of the disc hubs making spigot-and-socket connections one with another. Circumferential rows of rivets 171 passing through the connections secure the discs to one another and to the cylinder 77. A casting 92 secured to one end of the cylinder is provided with a hub 93 carried in a roller bearing 94 and making a splined connection with a hollow shaft 96 connected through gears 97 with a power take-off 104. A casting 75 provided at the other end of the rotor has a hub 74 carried by a thrust bearing 76 and internally splined to receive the stub shaft 72. A casting 65 secured to one end of the stator constitutes an air inlet scoop, provided with guide vanes 68, and a housing for the thrust bearing 76. Sheet metal guide vanes 162, shown in perspective in Fig. 11, have flanges spot-welded to rings 160, 163, the assembly being held in position in the casting 65 by screws 164. The scroll at the outlet end of the compressor is made up from an outer part 89 secured by a flange 86 to the gear-box 88 and an inner part 91 forming a shaft chamber 84 with an end wall 95 housing the bearing 94. The scroll includes a diffuser 85 and makes labyrinth seals 106, 109 with the casting 92 and the last rotor disc respectively. Air intakes.-The inlet end of the compressor is surrounded by a silencer 32 consisting of three arcuate abutting sections 38, 40, 39, Fig. 1. Each section comprises sheet metal elements constituting end walls 43, 44, Fig. 4, and arcuate top and bottom walls 41, 42. Radial plates 45 inserted between the intermediate section 40 and the end sections 38, 39 are secured to the compressor casing and the adjacent flanges of the walls of the sections. The opposed ends of the end sections are spaced apart to leave a recess for the combustion chamber 35. The ends are provided with closure members 56 and are supported from the compressor casing by plates 57. Perforated aluminium sheets extend between the plates 45, and between the plates 45 and members 56, and carry suitable silencing material to define concentric silencers 58 in the axially directed air flow. Mounting combustion chambers.-The inlet end of the combustion chamber 35, Fig. 6, makes a slip joint with the outlet from the compressor scroll. A metal bellows 119, secured to a flange 120 on the scroll carries a closure plate 121 having arms 121a secured by longitudinally adjustable rods 123 to the combustion chamber. The bellows communicates with the scroll through ports 122, and is centred by means of a tube 127 secured to the closure plate 121 and engaging an aperture in a boss 125 on the scroll. The outlet end of the combustion chamber is coupled to the turbine inlet scroll 36, Figs. 1 and 4, by a ring 114 removably secured to the chamber and scroll by clamps 114a. Axial flow turbines.-The turbine rotor, Fig. 5, comprises a bladed wheel 129 welded to a hollow shaft 70 and a bladed wheel 131 secured by bolts 131a to the wheel 129. The stator casing is made in two halves 134a, 134b which communicate respectively with the inlet scroll 36 and an outlet scroll 37. The casing carries a partition 138 separating the wheels and making a labyrinth seal 139 with an annular flange on the wheel 129. Compressed air for starting is admitted through a coupling 137 to the intermediate stator vanes 136. A casting with an outer annular wall 140a connected to an inner annular wall 140b by radial ribs is secured to the housing 54 and, by an annular sheet metal member 141, to the stator. The annular walls make labyrinth seals 142, 143 with an annular member on the turbine shaft 70 and an annular flange on the wheel 129 respectively. The gases leaving the second turbine stage pass into a bell 152 opening into the exhaust scroll. Lubricating and cooling arrangements.-The lower part of the gear-.box 88 forms an oil reservoir 159, Fig. 17, and contains an oil pump 158 which delivers oil to a nest of finned tubes 31 (see also Figs. 1 and 4), arranged in the inlet to the air silencer 32 and connected in parallel between inlet and outlet headers 62. Oil flows from the outlet header to the gears, the compressor bearings 94, 76 and the turbine bearings 69, 128, and is returned from the bearings to the reservoir by connections 175, 179. The oil from bearings 76, 69, 128 is collected in a dry sump 178'. A fan 100, Figs. 3 and 6, secured to the compressor rotor, draws air through apertures 98 in the gear case 88 into the shaft chamber 84 and then through bores 99 in the end wall 95. The air is discharged through outlet ports 103 in the scroll casing. The circulating air cools the oil reservoir in the gear-box, the bearing 94 and the air in the scroll casing. A labyrinth seal 105 is made with the fan 100. Compressed air leaking from the last compressor stage 107 through seal 109 passes through duct 111 and metering plug 1121 to a pipe 112 leading to a chamber 144, Fig. 5, formed between the sheet metal member 141 and the turbine wheel 129. The turbine stator and its inlet and outlet scrolls are airjacketed by casings 145, 150, and a fan 148 mounted on the turbine wheel 129 supplies air to the jackets. The fan sucks air through an opening 149 in the wall 140b from the space between the casing 145 and the housing 54 to cool the bearing 128 and the wheel 129. A blower 153 mounted on the turbine wheel 131 draws air through the annular member 54 and discharges it through a passage 155 into the exhaust gas stream. Resilient spacing members 151 are arranged in the exhaust scroll jacket and an outlet 157 from the jacket is provided by spacing members 158. The action of the blower draws air from the jacket. The casing of the air silencer and the supporting plates 57 are of bright metal.