GB1451069A - Fans suitable for gas turbine ducted-fan engines - Google Patents

Abstract

1451069 Gas turbine ducted fan engines DOWTY ROTOL Ltd 14 Feb 1974 [17 Feb 1973] 7887/73 Headings F1C and F1J The invention relates to a ducted fan assembly or module which may be secured to the front of a main gas turbine engine to convert the engine to a ducted fan type engine. The fan assembly shown 'comprises a non-rotative sub-assembly comprising a frame member 11, stator vanes 17 and a fan duct casing 16, the sub-assembly being adapted to be secured at the forward end C of a gas turbine engine B. A fan rotor shaft 36 is rotatably mounted in bearings 14, 15 within the frame member 11, the shaft being driven from the engine shaft by means of a splined shaft 37. The fan rotor assembly is mounted on the shaft 36 and comprises a hub portion on which are mounted fan rotor blades 13 each blade being mounted for angular movement. Mounted within the hub portion for rotation therewith are a fluid reservoir 18, one or more gear pumps 19 which take their suction from the reservoir and discharge to an actuator 20 of the vane type comprising two relatively angularly movable parts 21, 22; the part 21 is formed with a bevel gear 23 and the part 22 with a bevel gear 24, the two bevel gears engaging bevel pinions 26 one of which is mounted at the root portion of each rotor blade 13. Thus as the parts 21, 22 of the actuator are moved, the pitch of the rotor blades is adjusted. The hub portion also includes a control valve assembly V comprising a position control valve and a condition control valve each of which is controlled by linkage such as 44, 43, 42, 41, 45 connected through tube members to the valve assembly. The valve assembly controls flow of fluid from the gear pumps to the actuator so as to adjust the fan rotor blades for such positions as fine pitch, coarse pitch, feathering, and negative pitch for thrust reverse operation. The gear pumps are driven through gearing which includes a gear pinion formed on a tubular member which is secured to stationary structure. A flow of air enters the spinner assembly through inlet 30 and passage 31 to flow across the wall of the annular fluid reservoir 18 whereby the fluid is cooled; the air-flow is acted on by impeller blades 32 and finally discharges through outlet 33.