GB1217070A - Improvements in or relating to gas turbine engines - Google Patents

Abstract

1,217,070. Gas turbine plant and combustion chambers. ROLLS-ROYCE Ltd. July 17, 1968, No.33974/68. Headings F1G and F1L. A gas turbine engine comprises a compressor 14 supplying air to combustion equipment 37 for combustion with fuel at substantially constant volume, a power turbine 84 driven by the combustion products and a further turbine 104 driven by the gases leaving the power turbine and itself driving the compressor 14. Air from the centrifugal compressor 14 enters an annular chamber 30 which has disposed at its downstream end four equi-angularly spaced rotary disc valves 42 each mounted on a respective hollow shaft 44 driven by a shaft 46 and reduction gearing 50, 52 &c. from the compressor shaft 16. Each rotary disc has a port therein to control the flow of air from chamber 30 to the inlet 36 of one of four generally spherical combustion chambers 37 and the flow of combustion products from the outlet 39 to the multi-stage power turbine 84. The latter drives the output shaft 126 of a land vehicle through gearing 114, 116 &c. Gases leaving the power turbine 84 enter an annular plenum chamber 100 and thence drive the further turbine 104 connected to compressor 14 before exhausting at 110. Leakage at the faces 68, 70 of each valve disc 42 is prevented by sealing rings 76, 78 mounted in eccentric grooves in the faces to co-operate with the adjacent stationary structure. The disc 42 is hollow and is supplied with coolant in the form of lubricating oil through shaft 44, the oil leaving the disc through holes 80 to flow into an annular chamber 82 before returning to a sump. Alternatively, the coolant can be air bled from the compressor 14. The fuel for combustion chambers 37 is supplied to injectors in a predetermined sequence by a fuel pump 38 driven by one of the shafts 46, the latter also driving a rotary spark distributor for the ignition plugs. The timing sequence is arranged for the four combustion chambers 37 to fire one after the other or, alternatively, two at a time in opposite pairs. The power turbine and compressor shafts 86, 16 respectively may be connected by a clutch during engine braking. In modifications, each valve disc 42 may be replaced by a pair of poppet valves, and the axial flow turbine 104 replaced by a radial flow turbine.