GB832656A - An improved aircraft propulsion unit - Google Patents

Abstract

832,656. Gas turbine plant. GENERAL MOTORS CORPORATION. Feb. 5, 1958, No. 39815/58. Divided out of 832,655. Class 110 (3). [Also in Group XXXIII] An aircraft propulsion unit comprises two engines connected to a common propeller, a common starter for simultaneously starting both engines, and a torque responsive starter clutch between each engine and the starter to release each engine from the starter as the engine becomes operative. In the Figure, the drive shafts 14, 15 of gas turbine engines 10, 11 are connected through one-way clutches 20, 21 to pinions 16, 17 meshing with a bull gear 18 on the shaft 19 of a variable pitch propeller 13. The shaft 31 of the starter 32 has a gear 30 meshing with gears 33, 34 connected respectively to shafts 14, 15 through gear 35 and oneway clutch 37, and gear 36 and one-way clutch 38. A propeller brake 40 is connected to gear 18 through gear 41, and is operable by shaft 31 through a coupling 39. On starting, rotation of shaft 31 releases the propeller brake 40, and drives shafts 14, 15. As each engine starts and delivers torque through its shaft, the associated clutch 37 or 38 becomes disengaged automatically. A preferred form of clutch is described. Reversed torque driving of a failed engine by the propeller is prevented by one-way clutches 20, 21. The propeller brake, initially released by the starter 32, is thereafter held off by the pressure of the engine oil system. Thus on failure or shut down of the power plant, the brake is applied. A preferred form of brake is described. Specification 832,657 is referred to.