GB515457A - Improved means for driving the propelling systems of aircraft - Google Patents

Abstract

515,457. Elastic-fluid turbines; turbo-compressers; controlling aircraft; regulating free-piston compressers. PESCARA, R. P. June 2, 1938, Nos. 16603 and 16604. Convention dates, June 2, 1937, and May 19, 1938. [Classes 110 (i) and 110 (iii)] [Also in Groups XXVII, XXVIII and XXXIII] Aircraft propelling-plantincludes a freepiston compresser feeding a turbine which drives the airscrew, the ratio of compression being regulated, preferably automatically, in depend-. ence upon the altitude of the aircraft; a constant ratio between the flying speed and the speed of revolution of the airscrew is thus maintained. The regulation may additionally depend upon the speed of rotation of the main turbine and the temperature of the motive gases. The two compressors may be mounted in the wings, or combined in one unit G, Fig. 3, and supply a turbine 3 driving the airscrew 2, the exhaust from turbine 3 passing to an auxiliary turbine 18 coupled on the shaft of a turbo-compresser 17 feeding the unit G. The parts 3, 17, 18 are enclosed in a fairing 19. Turbine 18 may be supplied directly from unit G and the inlet may have a valve coupled to a barometric box, Fig. 4 (not shown). The turbo-compresser 17 may be regulated by a slide-valve 26, Fig. 6, connecting the unit inlet 21 with one or other of the stages of the compresser by passages 251 ... 25<4>, valve 26 being controlled by a barometric box 27 with return spring 28. In a similar way a number of low pressure stages of turbine 3 may be short-circuited, or the degree of admission reduced. Turbo-compresser 17 may be coupled direct to turbine 3, Fig. 5, and additional fuel may be injected under pressure either into turbine 3 between two of its stages, into cylinder 4, or into conduit 15 between cylinder 4 and turbine 3, or into turbine 3 and either cylinder 4 or conduit 15. This injection may be effected by a pump 30 driven from a compressed-air source 101 and controlled by a barometric box 32. In a further modification, Fig. 7, pump 30 is also controlled through levers 31, 38, a thermostatic device 34 mounted in a conduit 35 receiving the motor gases acting on lever 31 and a speed governor 37 coupled to turbine 3 acting on lever 38 whilst the barometric box 32 acts on both levers. 'The timing of the injection may be varied at the same time as the amount.