Patent GB-760005-A (GB)
Title: Compound power plants including reciprocating engines and exhaust driven turbines
Inventor: BARLOW BENJAMIN WILLIAM
IPC: F02B37/10
Filed: 1953-01-12
Abstract: 760,005. Propelling aircraft ; variable pitch propellers. NAPIER & SON Ltd., D. Jan. 12, 1954 [Jan. 12, 1953], No. 945/53. Classes 4 and 114. [Also in Groups XXVI and XXVII] A power plant comprises an J.C. reciprocating engine exhausting to a turbine driving a supercharger, and two independently rotatable propellers, one at least of which is of variable pitch. One propeller is driven directly from one of the prime movers, and the other prime mover is connected to the input element of a differential mechanism the output elements of which are connected respectively to the other propeller and to the first primer mover and its associated propeller. In the plant of Fig. 1 contra-rotating propellers, both of which are of variable pitch are employed. The turbine-compressor shaft 11 carries a pinion 12 engaging an externally toothed ring 13 formed rigidly with a spider 14 carried by the propeller shaft 9. The shaft 15 of the C.I. engine carries a sun wheel 16 engaging planet wheels 17 carried by the spider and engaging also an internally toothed annulus 18 carried by the propeller shaft 10. The pitch of the propellers is automatically controlled through hydraulic means by constant speed governors 20, 25 driven respectively from shafts 11, 15. The setting of governor 20 is controlled by a balance lever 48 pivoted on an adjustable fulcrum 49 acted upon by a rod 43 subjected to the supercharging pressure and a rod 50 controlled primarily by the setting of a cam 51 acting through a spring 52. The cam is mounted on a shaft 53 having a manual control 54. The setting of governor 25 is controlled by a cam 64 on shaft 53. The fuel supply to the engine is controlled by a further cam 65 acting through a rod 68 and balance arm 70 on an arm 72 of an over-ride clutch the other arm 74 of which is coupled to a rod 75 controlling fuel pump mechanism 76. A turbine over-speed governor 79 supplies hydraulic fluid through pipe 81 to reduce or shut off the fuel supply if the turbine speed is excessive. If the supercharger pressure falls below that called for by the setting of cam 51, because the piston 36 cannot be moved to increase the turbine speed, pressure builds up in pipe 87 and depresses the piston 85 to reduce the fuel supply and rebalance the lever 48. In the arrangement shown in Fig. 2 the internally toothed annulus 18 secured to the propeller shaft 10 is driven by the turbine shaft 11 through gearing 12, 100. The hydraulic connections 23, 24, 30, 31 between the governors and the propellers are led to annular grooves in a part 101 rigid with the gear casing 99 and pressure fluid is transmitted through radial drilling 103 in the shaft 102 to concentric conduits formed by tubes 104... 107. The shaft 102 carrying the sun wheel 16 also carries a sun wheel 112 engaged by planet pinions 111 mounted on a radial flange 108 of the crank shaft 15. The pinions 111 mesh with an internally toothed reaction annulus 113 connected by a bolt 114 to a piston of a hydraulic cylinder coupled to a pressure indicator from the reading of which torque distribution between the elements of the gear can be determined. Further modifications of the gears are described, Figs. 3 and 4 (not shown). Specification 703,165 [Group XXVI] is referred to in the Provisional Specification.