GB670309A - Improvements in or relating to a starter device for high speed internal combustion engines - Google Patents

Abstract

670,309. Turning-gear. GARRETT CORPORATION. Nov. 25, 1949 [June 25, 1949] No. 30246/49. Class 7(v) In a starter device for high-speed internal combustion engines having a shaft 121, Fig. 1, and comprising a housing 22 adapted to be detachably connected to the engine 15, a drive shaft 100 rotatably supported in the housing 22 and adapted to be operatively connected to the engine shaft 121, a turbine in the housing 22 having an air driven wheel 55, and transmission means, such as sun and planetary gearing 53, 79 and 81, friction rings 88 and 97, driving element 40 and pawl and ratchet coupling 112, interconnecting the wheel 55 and the drive shaft 100, the transmission is adapted to partially or completely interrupt the transmission of power to the.drive shaft 100 in response to the occurence of an overload condition. Compressed air enters a scroll 68 and flows through tangential nozzles having nozzle openings 66 formed by inclined blades or partitions 67 to impinge upon the blades of the turbine wheel 55, the air then discharging axially through a passage 70 in which .is a screen 71. Rotation of turbine shaft 52 which has the sun gear 53 secured thereto is transmitted to the compound planetary gear 79 and 81, the part 81 meshing with gear 53 and part 79 meshing with a ring gear 85 that is engaged on opposite side faces by the friction rings 88 and 97, the former being secured to the casing and the latter to a ring 91 which is joined. by pins 94 to another ring 92, a spring 98 surrounding each pin and serving to load the friction rings. The ring gear 85 is held stationary so that the planetary gears 79, .81 travel round the gear 85 to rotate the driving element 40 at a speed slower than that of the turbine. Upon a predetermined load being exceeded the gear 85 overcomes the frictional resistance of the rings 88 and 97 and revolves whilst the planetary gears merely rotate on their own axes. The driving element 40 is coupled by a cross pin 45 to a driving member 46 which is in turn connected by the pawl and ratchet coupling 112 to the splined driving shaft 100 that engages the engine to be started. When the engine reaches operating speed sufficient torque and centrifugal force are imposed upon the spring-loaded coupling pawls 111 to cause them to pivot out of engagement with the ratchet and disconnect the drive to the engine, whereupon the starter is stopped. The starter may be permanently fixed to the engine or removed therefrom as soon as the engine has started. The compressed air is supplied by an auxiliary unit 20, Fig. 8, comprising a compressor 126, part of the output from which is led through pipes 135 past valves 140, 141, which control the air flow to either one or both of the starters 17 and 18, attached to engines 15 and 16, respectively. Part of the air may be diverted for other services whilst the remainder is directed through auxiliary combustion chambers 128 to enter the scroll of turbine 125 which drives the compressor.