| 摘要 |
1484948 Gas turbine ducted fan engines ROLLS-ROYCE (1971) Ltd 4 Sept 1975 [7 Sept 1974] 39181/74 Headings F1C and F1J The invention relates to a gas turbine ducted fan engine having a variable pitch fan which is driven through a reduction gear, the pitch of the fan blades being adjustable by means of a motor which rotates with the fan about the axis thereof. In the engine shown the fan comprises blades 12 mounted on a fan rotor 28, 29 which is secured to the shaft 23, the shaft 23 being driven by a main shaft 22 through epicyclic reduction gearing 25; a sun gear 24 formed on the shaft 22 engages planet pinions 25 mounted on a planet carrier 26 secured to the shaft 23, the planet pinions engaging an internal ring gear 27 secured to stator structure. The fan blade actuator motor is indicated at 30 and is of the radial vane type operated by high-pressure fluid; the motor drives bevel gears 32 one mounted on each fan blade, the outer casing of the motor being connected to the shaft 23 so that the motor rotates with the fan. The inner casing of the motor is connected to an auxiliary shaft 34. When the motor is actuated the inner and outer casings rotate relative one to the other so that the auxiliary shaft 34 rotates relative to the shaft 23 and this is utilized to provide an indication of the degree of pitch change. The shaft 23 is connected through the planet carrier 26 to a sleeve 35 mounted for rotation in bearings 48, 49 and carrying a ring gear 36 at its free end. An intermediate pinion 37 engages with the ring gear 36, the pinion 37 engaging also a gear 39. The inward end of the auxiliary shaft 34 carries a gear 43 which drives a shaft 46 through pinion 44, the shaft 46 passing between the planet pinions 25. The shaft 46 carries at its other end a gear 45 which engages a ring gear 47 supported on the bearings 48, 49. A gear 50 engages with the gear 47 and is mounted on a shaft 38 whereby a gear 50A is driven, the gear 50A engaging a pinion 41. A gear 40 freely mounted on shaft 38 engages the gear 39, also the pinion 41. The pinion 41 is mounted on a swinging link 42 freely mounted on the shaft 38, the link carrying a bevel pinion 51 which engages a bevel pinion 52 mounted on a shaft 53 which drives an indicator. Thus movement of the blade actuator motor causes relative rotation between the gears 50A and 40 and so movement of the gear 41 and thus of the link 42, the movement being shown on the indicator. |
