GB745239A - Improvements relating to gas turbine engines - Google Patents

Abstract

745.239. Gas turbine plant. ROLLSROYCE. Ltd. June 3. 1954 [June 24, 1953], No. 17572/53. Class 110(3) In a gas turbine engine comprising independently rotatable low- and high-pressure rotor systems, each comprising a turbine driving a compressor, in which the low pressure compressor delivers at least in part to the high-pressure compressor, the low- and highpressure turbines are connected in series, and the low-pressure rotor system drives an aircraft propeller, and automaticallyengaging clutch means is provided to establish driving connection between the low- and high-pressure rotor systems ,when the ratio of the rotational speed of the former to that of the latter tends to exceed a predetermined value. The shaft 16 of the low-pressure turbine 20 is splined at 17 to the shaft 10 of the low-pressure compressor, the latter comprising rotors 11. 'A variable-pitch aircraft propeller 28 is driven from the shaft 10 through reduction gearing. The high-pressure turbine rotor 34 and the high-pressure compressor rotors 32 are mounted on a shaft 30. The shafts 10, 16 normally rotate independently of shaft 30 but become connected to it by a freewheel 40 of the roller-andramp type if they tend to rotate faster than the shaft 30, as during landing of the aircraft or other low power conditions step-up or reduction gearing may be interposed between the shaft 30 and the freewheel.