Abstract: An apparatus for generating a vortex in a collection vessel of a vacuum cleaner, using a blade assembly rotatably mountable in the collection vessel. By rotating the blade assembly, a vortex is generated inside the collection vessel, and enough suction is created to draw air through the entire system. The use of a blade assembly to generate the vortex may remove the need for an impeller external to the collection vessel, as the blade assembly may be capable of creating enough suction to draw air into the collection vessel. This may allow the vacuum cleaner to operate with lower noise.

Abstract: A gas turbine engine including a fan, a core including at least one rotatable shaft, and a gearbox mechanically coupling at least one rotatable shaft of the core to the fan is provided. The gas turbine engine also includes a coupling system for mounting the gearbox within the gas turbine engine. The coupling system includes a flexible coupling connected to at least one of a fan frame or a core frame, as well as a torque frame connected to the flexible coupling and the gearbox. Moreover, a deflection limiter is provided, loosely attaching the flexible coupling to the gearbox to provide a predetermined axial range of motion, radial range of motion, and circumferential range of motion between the gearbox and the frame to which the flexible coupling is attached.

Abstract: An actuation assembly for a variable pitch fan for a gas turbine engine is provided. The actuation assembly generally includes a plurality of fan blades, a scheduling ring, and a plurality of linkage arms. The plurality of fan blades are rotatably coupled to a disk and extend radially therefrom. The scheduling ring is rotatable relative to the disk and has a plurality of slots. Each of the plurality of linkage arms are operatively coupled to one of the plurality of fan blades and to one of the plurality of slots. Each of the plurality of fan blades rotate according to a blade pitch schedule defined by the slot to which it is operatively coupled, and at least two of the plurality of slots define different blade pitch schedules.

Abstract: There is described an assembly having a plurality of screws, a propeller and a related method for adjusting the fluid dynamic pitch of the blades of the propeller. The propeller has at least one blade pivoted rotatably to a cylindrical propeller casing, a hub coupled to an engine and mounted coaxially inside the propeller casing, a kinematic mechanism coupled to the hub and/or to the propeller casing, and to the blade for adjusting the fluid dynamic pitch of the propeller. The hub is rotatable with respect to the cylindrical propeller casing, or vice versa, for at least one non-zero angular interval (?) of operation of the kinematic mechanism for adjusting the fluid dynamic pitch and is also integral with a contact surface movable between disengagement from and engagement with, direct or indirect, at least one relative abutment integral with the cylindrical propeller casing which defines a limit stop of the angular interval (?).

Abstract: A rotating fan with a transmission mechanism and a blade deployment mechanism. In an energized state, an electromagnetic coil generates a magnetic force that causes a clutch plate to be in contact with a contact surface, thereby engaging a planetary gear system. In a de-energized state, the clutch plate is not in contact with the contact surface, thereby disengaging the planetary gear system. In a deployed configuration, a drive link activated by the planetary gear system rotates a blade link to cause a fan blade to pivot. The result is that the fan blade tip is farther from the motor shaft than the fan blade root. In a retracted configuration, the drive link rotates the blade link to cause the fan blade to pivot and retract. The result is that the fan blade tip is equidistant from the motor shaft as the fan blade root.

Abstract: An engine arrangement has a gear assembly that drives a first propeller assembly. The gear assembly is driven by a power drive shaft that joins to the gear assembly at a first side. The engine arrangement has a static conduit that extends along a longitudinal internal cavity of the power drive shaft. The conduit penetrates the gear assembly such that a portion of the conduit projects from an opposing second side of the gear assembly. The engine arrangement has one or more first fluid supply lines routed along the static conduit between a hydraulic pressure power source and the first hydraulic actuator. A first hydraulic rotating coupling is mounted to the projecting portion of the static conduit. The first fluid supply lines fluidly communicate with the first hydraulic actuator via the first rotating coupling.

Abstract: A device including a pair of counter rotating propellers with variable pitch which may be modified by an actuator located in a central cavity of the shafts. A system for transporting energy to the actuator includes a conduit passing into a static case in proximity to an epicycloidal gear train, and then control conduits leading to the actuator and crossing the planet carrier of an epicycloidal gear train. The junction is affected by a dynamic joint with a collector. This transport path avoids a high temperature turbine.

Abstract: The system comprises a linear-displacement fluidic actuator (22) coaxial with the propeller, and a transmission device (23) connecting the actuator to the blades that are to be controlled. Advantageously, the transmission device (23) comprises at least two radial arms (36) arranged symmetrically with respect to the actuator and connected, on the inside, to a translationally mobile part of the actuator and, on the outside, to a translationally movable rotary transmission ring (25) which is connected to the pivot pins (11) of the blades (6) by intermediate connecting mechanisms (26) that convert the translational movement of the rotary ring brought about by the actuator into a rotation of the blades of the propeller.

Abstract: The invention relates to a turbocharger (1) having variable turbine geometry (VTG) having a turbine housing (2) with a supply duct (9) for exhaust gases; having a turbine rotor (4) which is rotatably mounted in the turbine housing (2); and having a guide grate (18) which surrounds the turbine rotor (4) radially at the outside, which guide grate (18) has a blade mounting ring (6) which has a plurality of guide blades (7) which in each case have a blade shaft (8) mounted in the blade mounting ring (6), which guide grate (18) has an adjusting ring (5) which is operatively connected to the guide blades (7) by means of associated blade levers (20) which are fastened to the blade shafts (8) at one of their ends, wherein each blade lever (20) has, at the other end, a lever head (23) which can be placed in engagement with an associated engagement recess (24) of the adjusting ring (5), and which guide grate (18) has a stop (25) at least for setting the minimum throughflow through the nozzle cross sections which are fo

Abstract: A turboprop having at least one propeller formed by a set of variable pitch blades. Each blade is swivel-mounted on a rotary support and carries a gearwheel meshing with an actuator annulus rotating on the rotary support and coupled to a control annulus via an epicyclic mechanism.

Abstract: The invention relates to a rotational device that is to be used in a fluid in order to generate power from the moving stream of a fluid or to convert energy into a motion of a fluid. Said rotational device comprises main rotating means which is fixedly connected to a central rotary shaft of the rotational device, one or several rotational surfaces which are mounted on the main rotating means so as to be rotatable about rotational surface rotary shafts spaced away from the rotary shaft such that the main rotating means are able to perform a rotational motion about the central rotary shaft by means of at least one rotational surface, the rotational surface rotary shafts extending parallel to the rotary shaft of the main body. A device is provided which adjusts an angle of the rotational surface relative to the direction of flow of the fluid in such way that the buoyancy principle is maintained on the rotational surface.

Abstract: A wind turbine and a drivetrain for a generator is provided. The drivetrain includes a hub configured to provide an input rotational speed, and a planetary gearbox in communication with the hub. The planetary gearbox includes a stationary or rotatable carrier and a plurality of planet gears. The planetary gearbox is configured to convert the input rotational speed to an output rotational speed, and includes at least one sun gear. The hub can be rigidly connected to the rotatable ring gear.

Abstract: A gas turbine engine is disclosed that includes a spool having a compressor section. An inlet case is arranged axially upstream from the compressor section. A gearbox is secured to the inlet case. The gearbox couples the spool and a fan. A sealing assembly is arranged between the inlet case and the gearbox to provide a sealed bearing compartment. The inlet case, gearbox and seal assembly provide a module. A fastening element removably secures the module to the spool. The gas turbine engine can be serviced by disconnecting the fastening element from the engine core. The gearbox and inlet case can be removed as a module from the engine core without disassembling the gearbox.

Abstract: The lifetime of plural shock absorbing resilient inserts of an adjustable pitch propeller with feathering blades may be increased. According to an embodiment, stops are implemented between metal surfaces that may be reached only in the event of shocks of great violence and following a certain elastic deformation of the shock absorbing inserts, which remain partially compressed. At the bottom of each circular cavity housing a respective annular insert of elastomer of the flange of a first cylindrical sleeve directly keyed on the drive shaft of the propeller a hole coaxial and of greater diameter than the diameter of a central hole of the annular insert and of the relative engaging pin is formed. Pins projecting from the face of the terminal flange of a second circular sleeve extend through the coaxially formed holes at the bottom of the respective circular cavities of the flange of the first sleeve.

Abstract: The invention relates to a wind turbine rotor comprising at least one blade and at least on pitch mechanism comprising a ring shaped motor for controlling the blade. The wind turbine rotor is characterized in that, the ring shaped motor controls the blade through gearing means of a planetary type. The invention further relates to a rotation controlling mechanism comprising, at least one ring shaped motor for controlling the rotation of at least one first part in relation to at least one second part. The rotation controlling mechanism is characterized in that, the ring shaped motor controls the relative rotation through gearing means of a planetary type. Even further the invention relates to a method for controlling at least one blade of a wind turbine rotor.

Abstract: In a contra rotating propeller engine propeller blade assemblies are provided which rotate in opposite directions as a result of association with an epicyclic gear assembly acting as a differential gearbox. A carrier is provided to drive one propeller blade assembly. Actuators are provided to cause pitch angle adjustment of the respective propeller blades of the assemblies. These actuators, are secured upon a stationary structure and act through actuator rods and appropriate mechanisms to cause such angular pitch adjustment. Rotational de-couplers are provided to rotationally isolate the actuators while an actuator rod part acts across the assemblies and a rotational de-coupler to de-couple contra rotation between the assemblies while still allowing axial displacement for adjustment of the other propeller blade assembly.

Abstract: A fan motor assembly with integrated redundant availability is recited. The fan motor assembly can include a fan motor subassembly with a first fan motor and a second fan motor, and a fan motor selector mechanism coupled to the fan motor subassembly, so that the fan motor selector mechanism selectively couples the first fan motor or second fan motor to a fan. The fan motor assembly can also include a control unit coupled to the fan motor selector mechanism, wherein the control unit is configured to control the fan motor selector mechanism such that either of the first fan motor and second fan motor is selectively engaged to the fan.

Abstract: A turbomachine stator flap including a structural beam which is formed integrally with a structural core for a vane, and fastening portions, and a composite envelope surrounding the structural core and forming at least the aerodynamic profile of the vane.

Abstract: A mechanism (16) for controlling independently the pitch of a plurality of blades (15A, 15B, 15C) of a wind turbine (10) includes: a hub (11) rotatable about an axis (x-x) relative to a nacelle (12); a plurality of blades mounted on the hub for rotation therewith about the hub axis, each blade having a shaft (21) and being mounted on the hub for rotation about its axis of elongation; a plurality of motors (34) mounted on the nacelle, each motor having an output shaft (35) and being associated with a respective one of the blades; and a coupling mechanism (37) operatively interposed between each motor and its associated blade for selectively rotating such blade about its axis to vary the pitch of the associated blade relative to the hub axis. The pitch of each blade may be controlled independently of the pitch of the others.

Abstract: An actuator for varying the pitch of a plurality of propeller blades mounted on a propeller blade hub comprising an electric motor driving a drive gear, a reduction gear set driven by the drive gear and driving an externally threaded drive spool, an internally threaded pitch ring including a tangential slot, a pin received within the tangential slot and disposed on a blade hub to which the propeller blade is secured. Rotary movement of the drive gear, the reduction gear set, and the drive spool results in translational movement of the pitch ring. Translational movement of the pitch ring causes movement of the pin within the tangential slot, resulting in rotation of the propeller blade.

Abstract: The invention relates to an adjustment device for variable-pitch propellers or turbo-engines. A drivable rotor is mounted on a hollow flange of a shaft that is connected to the variable-pitch propeller. The rotor is rotatably mounted on the hollow flange, and its inside diameter has a formation which interacts with intermediate wheels and gears mounted in the hollow flange.

Abstract: A multiple vane, variable pitch, fluid active or reactive device to move or be moved by a fluid including first and second wheels each rotatable about its axis and the axes disposed in selected parallel offset relation. Aperatures provided in the first wheel receive rotatable vane shafts. A vane is provided on each shaft and a distal end of each shaft extends through the aperture. Follower members are connected to the distal ends of the shaft and extend generally parallel to the chord line of the vanes to control the pitch angle of the vanes. The second wheel is inset a selected distance from the first wheel and provides cams that extend outwardly from the second wheel to engage the follower members of the first wheel. A drive member is provided so that a rotational force applied to either wheel is transferred by a gear drive to the other wheel.

Abstract: The present invention relates to a ram air turbine which is preferably used in conjunction with a refueling pod on an aircraft for purposes of operating a fuel pump and/or reeling mechanism for paying in and paying out a fuel line. The turbine generally comprises a rotatable housing having a main turbine output shaft disposed therein and rigidly connect thereto. A plurality of variable pitch turbine blades extend outwardly from and are cooperatively engaged to the housing such that rotation of the turbine blades causes simultaneous rotation of the housing and output shaft. Means are provided within the housing for establishing a preset reference rotational speed for the output shaft. Additionally, a control means cooperatively engaged between the turbine blades and the reference means is provided for adjusting the pitch of the turbine blades in response to a difference in the rotational speed of the output shaft and the preset reference rotational speed.

Abstract: A system for changing pitch in aircraft propfans is disclosed, in which a motor, located at a stationary position, changes pitch of the blades by of a gear train. Three features of the system are that a feather brake can override the motor and drive the blades toward feather; a unison brake can prevent pitch from undergoing excursions toward fine pitch when propeller speed exceeds a limit; and the motor is non-rotating in the absence of pitch change. A pair of such systems can be used in a counterrotating propfan system, in order to independently change pitch of the propfans.

Abstract: A gas turbine engine for aircraft propulsion includes a variable pitch fan, pitch change of which is effected by providing a small D.C. excitation current to a selected one of two non-rotating field coils dependent upon the direction of pitch change desired. The field coils each form the static part of respective polyphase A.C. alternators, and the rotating armatures of the alternators connect to respective separate stator windings of a compound polyphase A.C. reversible induction motor rotating with the fan. An armature of the motor is relatively rotatable and couples with the fan blades to pivotally vary their pitch angle. An A.C. current is available from the non-excited alternator field coil, and may be rectified and controlled for use as the D.C. excitation current. Thus, all energy requirements of the pitch change apparatus may be extracted from the rotor of the fan engine.

Abstract: The invention concerns a pitch change mechanism for an aircraft propeller in which a common ring gear (51) changes pitch of all propeller blades on a given rotor simultaneously. Motion of the ring gear (51) is induced by a planet (40)-and-carrier (101) system driven by a pinion (110). Acceleration of the pinion causes a change toward flat pitch. Deceleration of the pinion causes change toward feathered pitch. If the motor driving the pinion fails, a large deceleration occurs, driving the blades to a safe, feathered position.

Abstract: The invention concerns pitch-change mechanisms, of the planetary gear type, for use in aircraft propellers. Planet gears engage three ring gears at different gear ratios, thereby causing relative rotation of the ring gears to occur when the planet gears rotate. A linkage between the ring gears and the propeller blades converts the relative rotation into a change in pitch. A sun gear drives the planet gears. A planet carrier prevents excessive skew of the planets from occurring if one of the ring gears should break, and thereby release its load on the planet gear.

Abstract: The invention concerns aircraft propellers of the variable pitch type. Each propeller blade is carried by a trunnion which is rotatably mounted to a common ring. Each trunnion contains a reduction gear set which is driven by a radial shaft. The reduction gear sets multiply the torque applied by the shafts, thus allowing shafts of reduced diameter to be used. The reduced diameter is important when the shafts must pass through a turbine flowpath, and thus be concealed within turbine blades. The reduced diameter shafts can be easily concealed within turbine blades without redesigning and compromising blade aerodynamics.

Abstract: The invention relates to pitch-change systems for aircraft propfans of the counterrotating type. The pitch of each propfan stage is independently adjustable. Further, in the case where one of the propfan stages acts as a rotating obstacle for a mechanism which causes pitch change of the other stage, a system is provided which transfers the pitch-change torque through this obstacle-stage without being affected by the speed of the obstacle-stage.

Abstract: The invention relates to pitch-change systems in aircraft propellers. The invention includes redundant planetary gear systems, each of which can independently change pitch if the other fails. The invention also includes a system for reducing displacement of the planets, which can occur during a failure.

Abstract: A blade pitch control system for a rotary wing aircraft which incorporates a mast and rotor which is pivotally adapted for movement of the mast between a generally horizontal stored position and a vertical position for operation in a helicopter mode. The pitch control system incorporates a motion amplification mechanism such as a star gear arrangement connected to the pitch horn to amplify control motions which are transmitted to the pitch horns through a push-pull control tube generally parallel to the folding axis of the rotor blade. In another embodiment, the push-pull tube inputs parallel to the mast axis. A locking mechanism retains the blades so pitch changes cannot be made during a predetermined portion of the blade coning cycle.

Abstract: A variable pitch arrangement to enable reverse pitch settings of fan blades to be achieved without the leading and trailing edges of adjacent fan blades abutting each other comprises two sets of fan blades and two sets of actuators. The two sets of fan blades are rotatably mounted on the fan rotor, and arranged circumferentially on the fan rotor. The blades in the first set of fan blades are arranged alternately circumferentially with the blades in the second set of fan blades. There are equal numbers of blades in each set of fan blades. The two sets of actuators act independently of each other on the two sets of fan blades such that the pitch of the blades in the first set and the pitch of the blades in the second set are varied in a phased relation to prevent fouling of the blades. Initially one set of blades varies pitch quickly while the other set of blades varies pitch slowly, and then the first set of blades varies pitch slowly while the other set of blades varies pitch quickly.

Abstract: A self-locking pitch change actuator is configured to fit within an annular hub (34). A ring gear (40) is driven circumferentially by a tangentially oriented ballscrew (42) and traveler (44). The ballscrew (42) is driven by a hydraulic motor (50) controlled responsive to an electric pitch change motor (74). A pitchlock (62) is positioned by the collective actions of the ballscrew (42) and pitch change motor (74), with any movement relative to a preselected null position driving the hydraulic motor beta control valve (60) into an operative position.

Abstract: An improved no-back mechanism for propeller pitch control comprises a brake which resists motion of a first member and a uni-directional coupling between the first member and a drive connecting a pitch control prime mover to an adjustable pitch propeller. The coupling permits limited movement of the drive with respect to the first member during back driving as in dither cycling of the blade while coupling the drive and first member for braking the back driving after the limited movement. As a result, dither cycling can occur during normal operation without release or slipping of the brake, thereby effecting a substantial wear reduction of brake plates of the brake.

Abstract: A pitch controller (10) for controlling the pitch of a plurality of blades (11) of a fan powered by a turbine propulsion engine, with a pitch adjusting device (16) having an input (18) for controlling the pitch of the blades. An input drive shaft (15) provides rotary power from the free turbine to the first input of a transmission (14). The transmission also has a second input (25) controlling the input to the pitch adjusting device, a first output (18) which is the input to the pitch adjusting device and a second output (21) which is applied to a rotary power device (20). Input power from the free turbine is provided to the rotary power device by the transmission which in response to a pitch control signal (28) causes the second input to rotate at a speed different from the first input thereby changing the pitch of the blades in proportion to the pitch control signal.

Abstract: An adjusting device for adjustable rotor vanes of a machine rotor including a first gear wheel (34) on a machine shaft (2) and a second gear wheel (44) on an adjusting shaft (4), whereby a relative rotation between the machine shaft and the adjusting shaft can be initiated through a transmission (38) by either of two braking devices (12, 22). The adjusting device of the invention makes it possible to adjust the rotor vanes with a simple construction and with a good degree of efficiency while simultaneously providing good accessibility for assembly and service. A further brake (40, 41) is provided between the transmission (38) and the machine shaft (2) or the adjusting shaft (4) to maintain synchronous rotation of the adjusting shaft (4) with the machine shaft (2) during normal operation, i.e., so long as no adjustment of the rotor vanes (64) is to take place.

Abstract: A mechanical pitch lock includes a pitch lock screw (60) that simultaneously rotates within an actuator (42) while the actuator moves to change the pitch of a propeller blade (16). While rotating simultaneously with the motion of the pitch actuator, the pitch lock screw maintains a longitudinal position allowing the actuator to move. If the pitch lock screw does not rotate simultaneously with the actuator, the pitch lock screw moves longitudinally with the actuator until it abuts a projection 66 thereby preventing further movement by the actuator.

Abstract: A modular, easily replaceable, pitch actuation system is removably secured within the hub of an aircraft. The modular system houses a driving system which provides a rotational output to set the pitch of propeller blades mounted to the hub, and a pitch changing system that controls the driving system. The driving system includes a high-speed, low-torque hydraulic motor that drives an harmonic drive to amplify the torque of the motor. The pitch changing system includes an actuator which positions a valve that controls the hydraulic motor, and a nulling gear which repositions the valve and acts as a pitch lock.

Abstract: An apparatus for varying the pitch of propulsor blades of a gas turbine engine by eccentrically driven gears. The gas turbine engine includes a rotating structure, an annular gas flowpath coaxial with the rotating structure, a plurality of rotor blades coupled to the rotating structure and extending into the gas flowpath such that a gas stream flowing through the flowpath causes the rotating structure to rotate with respect to the stationary member and a plurality of variable pitch propulsor blades coupled to and disposed radially outwardly of the rotating structure. The pitch of the blade is varied by a pinion gear coaxially coupled to one of the propulsor blades and an internal gear radially disposed about the pinion gear for driving the pinion gear. Annular displacement of the pinion gear causes angular displacement of the propulsor blade with respect to the rotating structure.

Abstract: An apparatus for varying the pitch of propulsor blades of a gas-turbine engine by eccentrically driven gears. A first gear is coaxially coupled to one of the propulsor blades whereby angular displacement of the first gear with respect to an engine center-line causes angular displacement of the propulsor blade. A second gear is rotatably coupled to the first gear with one of the first gear and second gear being a first internal gear and the other being a first mating gear. The first internal gear is eccentrically disposed with respect to the first mating gear and has more teeth than does the first mating gear. A third gear is rigidly coupled to the second gear. A fourth gear is rigidly coupled to a rotating structure of the engine and rotatably coupled to the third gear with one of the third gear and fourth gear being a second internal gear and the other being a second mating gear. The second internal gear is eccentrically disposed with respect to the second mating gear.

Abstract: A drag operated collective pitch control system is provided for gyroplane rotary wing aircraft. The system employs drag surfaces which are selectively engaged while the hub is rotating to actuate the system. Each blade mount is provided with a feathering pivot. Pinion gears control the pitch of each blade, and the pinions, mounted on the hub, are engaged by a pair of ring gears, also carried on the hub. To operate the system, either one or the other of the ring gears, to which the drag surfaces are coupled, is engaged by suitable drag means. The pitch of all the blades is thereby adjusted simultaneously.

Abstract: Overspeed conditions in a ram air turbine are eliminated through a novel blade pitching mechanism. The mechanism includes a rotatable shaft with a hub mounted thereon for rotation therewith. The hub rotatably mounts at least one blade and a hollow blade pitch control shaft extends generally concentrically about the rotatable shaft and is mounted for reciprocating movement in a path toward and away from the hub. A reciprocating to rotary motion converting mechanism interconnects the control shaft and the blade so that the pitch of the blade can be controlled by controlling the position of the control shaft in the path. A first motor is provided for incrementally moving the control shaft within the path and a second motor is provided for rapidly moving the control shaft within the path to a position therein corresponding to a feathered position of the blades.

Abstract: An apparatus for controlling pitch variations of the blades of a propeller. A first planetary gearset includes a sun gear, a ring gear and at least one planetary gear meshed with the sun and ring gears, the sun gear being statically grounded. A second planetary gearset is stacked in concentric juxtaposition with the first planetary gearset and includes a sun gear, a ring gear and at least one planetary gear meshed with the sun and ring gears. The planetary gears of the respective gear sets are coupled for conjoint orbiting about their respective sun gears. A main rotor drive input is coupled to the ring gear of the second planetary gearset. A blade actuator output is coupled to the ring gear of the first planetary gearset to be rotated thereby.

Abstract: A helicopter blade position and control mechanism including a hollow rotor shaft for mounting a plurality of rotor blades with provision for pitch adjustment. A control shaft is disposed within the rotor shaft and is rotatable relative thereto and is associated with actuators for the blades such that the pitch of the blades is changed when the control shaft rotates relative to the rotor shaft. A planetary gear assembly interconnects the control shaft and a source of power fixed to the helicopter fuselage and is such that when an input to the planetary gear assembly is quiescent, the control shaft will rotate in the same direction and at the same rate as the rotor shaft to maintain a desired blade pitch. Conversely, when an input is placed on the planetary gear system, relative rotation between the control shaft and the rotor shaft will occur to provide the desired adjustment in blade pitch.

Abstract: A fluid-flow machine, particularly of the hydraulic propeller-pump type, comprises a central hub, a bearing support fixed to the hub for rotation therewith, a plurality of blades distributed symmetrically around the hub, each blade having a pivotable blade-root for adjusting the angle of attack of the blades. The blade-roots are mounted on the bearing support for rotation around the longitudinal axis of the hub. An adjusting device pivots the blades about the longitudinal axis of the blade-roots, the latter including, for each blade, a self-locking reduction gear and a drive shaft. The bearing support is formed with open-ended housings, each corresponding to one of the blade-roots. The drive shafts, the reduction-gears and the blade-roots are mounted, at least partially, within the housings aforesaid.

Abstract: A pitch-change apparatus for a ducted thrust fan having a plurality of variable pitch blades employs a camming ring mounted coaxially of the hub at an axially fixed station along the hub axis for rotation about the hub axis both with the blades and relative to the blades. The ring has a generally spherical outer periphery and a plurality of helical camming grooves extend in a generally spherical plane on the periphery. Each of the variable pitch blades is connected to a pitch-change horn having a cam follower mounted on its outer end, and the camming ring and the horns are so arranged about the hub axis that the plurality of followers on the horns engage respectively the plurality of helical camming grooves. Rotary drive means receives pitch-change commands from an appropriate controller and rotates the camming ring relative to the blades to cause blade pitch to be changed through the cooperative operation of the camming grooves on the ring and the cam followers on the pitch-change horns.

Abstract: In a variable pitch fan assembly having a plurality of fan blades mounted in a rotor for rotation about their longitudinal axes and a drive shaft for rotatively driving the rotor, the pitch varying mechanism has a planetary gear train connected to each fan blade to rotate the latter to change the pitch or angle of attack of the blades, actuator means for effecting bi-directional rotation of the planetary gear train and a no-back, bi-directional brake interposed between the actuator means and the planetary gear train to transmit pitch-changing rotation from the actuator means to the planetary gear train and lock the planetary gear train to the rotor and prevent transmission of blade torque loads to the actuator means during steady state operation when no blade pitch-change is being effected.

Abstract: A pitch-change apparatus for a ducted thrust fan having a plurality of variable pitch blades employs a rotatable ring bearing a plurality of camming members, and each of the plurality of blades is connected with a pitch-change horn engaged by one of the camming members. The ring and camming members rotate coaxially about a hub axis with the blades and rotate about the hub axis relative to the blades to collectively change blade pitch. The rotatable ring, the camming members and the pitch-change horns develop a variable mechanical advantage, and the pitch horns are connected with their respective blades so that the minimum mechanical advantage corresponds with the low-load, feathered pitch position of the blades and greater mechanical advantages correspond with the higher load, forward and reverse pitch positions of the blades.

Abstract: An improved actuating mechanism is provided for a gas turbine engine incorporating fan blades of the variable pitch variety, the actuator adapted to rotate the individual fan blades within apertures in an associated fan disc. The actuator includes means such as a pair of synchronizing ring gears, one on each side of the blade shanks, and adapted to engage pinions disposed thereon. Means are provided to impart rotation to the ring gears in opposite directions to effect rotation of the blade shanks in response to a predetermined input signal. In the event of system failure, a run-away actuator is prevented by an improved braking device which arrests the mechanism.

Abstract: A negative torque sensing and control system is disclosed which is useful with a differential geared or fixed shaft gas turbine engine of the type installed in general aviation aircraft. Negative torque is sensed in the gear train between the propeller and the aircraft engine whenever there is a powerplant failure. When the reverse torque exceeds a selected threshold, hydraulic valves are actuated which remove oil pressure from the pitch control mechanism of the propeller. Loss of oil pressure causes the propeller to assume the feathered position.