GB987032A - Wind motors - Google Patents

Abstract

987,032. Wind motors. DOWTY ROTOL Ltd. Feb. 25, 1964 [March 18, 1963], No. 10606/63. Heading F1T. A wind motor mounted on a retractable support on a vehicle includes means to retard the rotor prior to retraction operable in conjunction with positioning means to stop the rotor in a predetermined position so that the wind motor presents its overall smallest crosssectional area to an opening in the wall of the vehicle for retraction of the wind motor through the opening. A wind motor 11 mounted on an aircraft to drive an emergency hydraulic pump 28 comprises a two-bladed rotor 12 mounted on a retractable leg 15 controlled by a jack 19. When the aircraft main hydraulic pumps 33 are operating normally leg 15 is held in a retracted position within the aircraft by a locking peg 63 engaging recess 16a in the leg pivot 16 under the action of hydraulic pressure fed to the right-hand side 54 of a servo-piston 57. The same pressure fed to the right-hand side 52 of servo-piston 50 holds the end portion 77 of a locking rod 41 in engagement with recess 78 in plate 76 attached to the rotor 11 so as to lock the blades 13 in a position parallel with leg 15. Hydraulic pressure on the right-hand side 70 of jack piston 66 holds the operating rod 21 in the retracted position against the action of spring 19a. Upon failure of main pumps 33 pressure in lines 38, 53, 64 falls and locking peg 63 is released by spring 58 acting on servo-piston 57. Simultaneously leg 15 is lowered under the action of spring 19a in jack 19. When the fully lowered position is reached peg 49, under the action of spring 51, engages recess 16b to lock the leg and simultaneously locking rod 41 is released from recess 78 to allow the rotor 11 to rotate and drive emergency pump 28 through gearbox 27. A governor 29 controls the pitch of the rotor blades 13 to maintain the rotor speed constant. When hydraulic pressure from the main pump is restored in lines 38, 53 servo-piston 57 moves to the left and overrides governor 29 in such a manner that the blades 13 are moved beyond their feathered position into the reverse pitch range. The rotor 11 therefore slows down and then reverses, at which point locking rod 41 re-engages in recess 78 to lock the rotor with the blades 13 parallel to leg 15. An hydraulic accumulator 30 ensures that pitch reversal occurs. Leg 15 then retracts into the aircraft under the action of main pump hydraulic pressure.