Abstract: A fan assembly (10) includes first and second housing sections (70, 72) which, when mated by a first set of fasteners, define a plurality of circumferentially spaced openings (162) that lead to an internal housing chamber (82). The fan assembly (10) also includes a plurality of blade units (140), each of which includes an integral support stem (142) having a journal portion (148) rotatably mounted within a respective one of the openings (162), an enlarged flange portion (144) and a radial post portion (138) rotatably supported by a hub member (106) within the internal chamber (82). Each blade unit (140) preferably has a thrust bearing (156), bushing sleeve (158) and fan blade (152) integrated with the support stem (142), with the fan blade (152) being preferably molded to the support stem (142) following positioning of the thrust bearing (156) and bushing sleeve (158) to form an integral component.

Abstract: A system for controlling propeller blade pitch is disclosed. The system comprises a transfer tube, wherein the transfer tube defines an element of the rotatable portion and wherein the transfer tube is non-translating relative the rotatable and non-rotatable portions. A transfer bearing for providing hydraulic fluid to and interfacing with the transfer tube is also used, wherein the transfer bearing is located on the non-rotatable portion. The system further includes a pitch change actuator and a mechanism form for actuating the pitch change actuator, wherein the mechanism is fluidically connected to and translatable relative to the transfer tube. A device for measuring blade angle of the propeller blade is also provided, wherein the device is separate and distinct from the transfer tube.

Abstract: An engine plant for aircraft comprising a multicylinder internal combustion engine (1) whose crankshaft drives an adjustable pitch propeller (5), mechanisms for adjusting the engine speed and a common power stick (4) that controls the operation of the engine and of the adjustment mechanisms, characterized in that said engine is a compression ignition engine (1) that cooperates with an electronic control system (3) controlling the quantity of the fuel injected.

Abstract: A variable-pitch marine propeller system has a propeller unit for mounting on a drive shaft, and a power unit including a stationary annular hydraulic cylinder for operating the propeller unit, a hydraulic remote control unit being fluid-coupled to the power unit. An annular piston of the hydraulic cylinder is coupled to a ring-shaped actuator yoke by a roller thrust bearing, the actuator yoke axially displacing a mating yoke of the propeller unit with which the actuator yoke is allowed to rotate. The piston operates in a sealed environment for the exclusion of water from the separately sealed surfaces of the cylinder itself. In one configuration, the propeller unit is replaceable without disturbing the sealed environment of the annular piston. The control unit includes a hydraulic control cylinder that is operated by a rotatably mounted barrel that engages a threaded piston rod. Alternatively, the control cylinder is actuated by a lever having biasing springs and an adjustable brake.

Abstract: A system for controlling functions of a propeller having a plurality of blades is disclosed. The system comprises an electronic control for controlling the functions of the propeller. A plurality of backup devices are provided for backing up the electronic control upon the occurrence of conditions. These conditions include at least one of testing, manual override, and a malfunction in the electronic control causing at least one of the functions to endanger safety. The system further includes a bypass device for bypassing the electronic control and for invoking at least one of the plurality of backup devices to acquire control over at least one of the functions. The bypass devices include a mechanism for determining the occurrence of at least one of the conditions and for actuating electronic control override.

Abstract: The hydraulic propeller system of the present invention has a central hub including a stationary portion and a rotatable portion. A plurality of propeller blades are connected with the rotatable portion, wherein each of the plurality of propeller blades has an adjustable pitch and a counterweight biasing the blades in a first pitch direction. An actuating mechanism is used for adjusting the pitch of each of the plurality of propeller blades. And a valve for locking the propeller blades at a last commanded pitch is further provided. At least the valve and the actuating mechanism are located on and rotatable with the rotatable portion.

Abstract: A propeller unit, each blade (1) being fixed to a blade foot (2) rendered integral with a hub (3) rotating around an axis but mobile with respect to the hub on translation in the direction of the axis and rotating around a second axis orthogonal to the first axis, this foot (2) being moreover rendered integral with an arch (5) in translation but free with respect to the arch on rotation; a pitch modifier is linked to the arch to translate the arch along the spin axis of the hub (3); the hub (3) and each blade foot (2) have members (8, 23) for activating the feet in rotation provoking from translation of the arch (5) the rotation of the blade feet around an axis mobile on translation in the same direction and orthogonal to the blade feet.

Abstract: The invention relates to a turbo-engine with a hydraulic device for adjusting the blades of a variable-pitch propeller. A hydraulic pump for hydraulically adjusting the blades of the variable-pitch propeller is disposed within a chamber through which passes the shaft of the turbo-engine. This chamber is filled with an incompressible fluid, for example an oil receiver for lubricating bearings.

Abstract: A hydraulic adjustment device for variable-pitch propellers of turbo-engines comprise a shaft for driving the variable-pitch propeller. A plurality of transmission elements for feeding and draining, as well as for guiding a hydraulic fluid is disposed in the shaft. A rotation passage for the hydraulic fluid is disposed in a chamber, which surrounds the shaft. The chamber is disposed adjacent to the variable-pitch propeller and is in fluid communication with a transport medium. The hydraulic fluid is harmonious to the transport medium.

Abstract: The pitch change mechanism for a variable pitch propeller blade or Advanced Ducted Propulsor (ADP) interconnecting the pitch change actuator and the propeller blades of the type that includes a trunnion attached to the root of the propeller blade, the connecting mechanism includes in one embodiment a translating ball screw nut interconnecting the trunnion through a yoke and a cooperating sliding pin and arm connector. In another embodiment where a hydraulic piston is included in the pitch change actuator the cylindrical housing supports a plurality of circumferentially spaced pins that are in sliding relationship with a rod attached to the trunnion. The trunnions in both embodiments are extended to make the interconnections. Means are provided to prevent the blades from binding up during pitch change movements. This invention eliminates the heretofore utilized sliding anti-rotation spline and the multiple linkage connectors.

Abstract: A marine drive has a propeller rotatable about a drive axis and having a plurality of blades themselves pivotable about respective blade axes projecting generally radially from the drive axis and each movable between a low-pitch end position extending generally parallel to a plane perpendicular to the drive axis and a high-pitch end position extending at a large acute angle to the plane. An engine rotates the propeller about the drive axis at a variable drive speed in a forward rotation direction. The blade axes are so positioned relative to the respective blades that on forward rotation of the propeller the blades are urged into one of their end positions. A single-acting hydraulic actuator connected to the blades has a compartment pressurizable to displace the blades into the other of the end positions.

Abstract: The pitch of either a fan or propeller driven by a gas turbine engine is changed by utilizing a pair of impulse turbines interfacing between the stationary and rotating portion of the fan or propeller and utilizing a servo control responding to a desired pitch input signal for actuating the normally inactive impulse turbines during fixed pitch to drive the impulse turbine which in turn is operatively connected through a pitch change actuator to change the pitch in accordance with the input signal.

Abstract: A control for a hydraulic propeller pitch actuator includes a low power pilot valve responsive to digital electronic input signals to control movement of a hydraulic servomotor driving a higher power servovalve. Negative feedback motion is delivered from the servomotor to both the pilot valve and the servovalve.

Abstract: An inboard servo for a controllable pitch propeller of the force rod type comprises a feedback device comprising a feedback ring located externally of the propeller drive shaft, affixed to the force rod for rotation and axial translation therewith and having a planar surface perpendicular to the propeller drive shaft axis, and a distance-measuring device for substantially continuously detecting the position of the ring, and therefore the position of the force rod. The distance-measuring device directs a high frequency pulsed signal onto the ring surface from a fixed position spaced apart therefrom, detects the signal as it is reflected by the ring surface from a fixed position spaced apart therefrom, and processes the directed and reflected signals to produce a signal indicative of the position of the ring surface based on the time difference between the pulses directed onto the ring surface and the pulses reflected from the ring surface.

Abstract: A low pitch alarm assembly 70 comprises a capped sleeve 72 disposed about the distal end 55 of the rotating and translating fluid delivery tube 50 so as to define a chamber 75 receiving the end 55 of the fluid delivery tube for axial translation therein, a fluid supply conduit 80, a pressure drop orifice 82 disposed in the fluid supply conduit 80, and a pressure switch 90 opening to the supply conduit downstream of the pressure drop orifice. The sleeve 72 has relatively large flow area outlet holes 74 opening through the capped end 76 of the sleeve 72 to a low pressure and a relatively small flow area inlet opening 73 through the sleeve side wall 78 connected to the fluid supply conduit 80. The pressure switch 90 generates an alarm signal whenever the end 55 of the fluid delivery tube 50 passes out of registration with inlet opening 73.

Abstract: A pitch change actuation system is disclosed for adjusting the pitch of a variable pitch propeller blades (120) operatively connected for pitch change to a pitch change actuator piston (140). A pitch change control system (10) is operatively connected to the pitch change actuator piston (140) for selectively pressuring the pitch change actuator piston to effectuate a desired change in the pitch of the propeller blades (120). The pitch change control system (10) comprises a primary electrohydraulic valve (30), a protection valve (60), an electronic controller (20) and a protection solenoid (50). During normal operation, the primary electrohydraulic valve (30) is modulated under control of the electronic controller (20) to effect pitch change.

Abstract: A pitch change actuation system for changing the pitch of the blades (16) of a prop-fan propulsor (10) comprises a translating pitch change actuator (30) and a flexible feather latch member (50) including a feather stop (56) and a feather latch (58), the feather latch member (50) being selectively releasable so as to permit the pitch change actuator (30) to drive the blades (16) through feather to a desired reverse pitch setting. Pitchlock lugs (96) and (98) operatively engage a pitchlock screw lug (97) on a pitchlock screw (80) to provide pitchlock screw stops at full reverse pitch and feather, respectively, with the pitchlock lug (98) being selectively displaceable so as to permit the pitchlock screw (80) to rotate when the pitch change actuator (30) is translated to drive the blades (16) through feather to reverse pitch.

Abstract: A pitch change actuation system is disclosed for adjusting the pitch of a variable pitch propeller blade (20) rotatably mounted to a hub (10) of the propeller. The pitch change actuator comprises a blade actuation piston (30) operatively connected to the propeller blade (20), a pitchlock piston (50) having a longitudinally directed annular shaft (56) extending therefrom about the shaft (34) of the blade actuation piston (30), pitchlock assembly (130, 140, 150) operatively interconnected between the pitchlock piston (50) and the blade actuation piston (30) for restraining inadvertent blade pitch reduction, bias spring (60) for exerting a preload force against the pitchlock piston (50), and fluid supply conduit (70) operatively interconnected in fluid communication between control valve (100) and the pitch change actuator.

Abstract: An improved RAM air turbine (30) for the generation of emergency power on an airplane is disclosed. The RAM air turbine has an operational range in which reduced power is produced by a power controller (40) at speeds at which stalling of the RAM air turbine would occur under the control of a governor (16) which adjusts the pitch of the blades (12) of the turbine in combination with a pressure regulator (150) controlling the output of pressurized hydraulic fluid from a variable displacement hydraulic pump (19).

Abstract: A fan assembly has variable pitch blades adjustable from outside the assembly while the fan is operating so as to alter the volume and direction of the induced airflow. The fan blades have an airfoil configuration such that air is moved by the fan in either direction with equal inefficiency. The airfoil configuration of the blades is neutral and the blades are straight. The fan assembly is lubricated by a pick-up non-rotatably mounted in a reservoir formed by the pulley hub and blade hub. The pick-up feeds lubrication directly to the bearing assemblies on which the spider and pulley hub are mounted.The neutral airfoil shape of the blade extends along the blade, and the blade has a blunt leading edge and a tapered trailing edge.

Abstract: A variable-speed propeller in a ship drive has the hydraulic valves feeding the working chambers of the hydraulic drive for the variable-speed propeller formed as electromagnetic valves controlled by timing relays which can be switched by a rocker switch or push-button switches to adjust the propeller pitch by an angular increment controlled by the "on" time of the relays. The engine speed is detected and, when the engine speed exceeds the maximum speed of the engine, the relay associated with increased pitch is triggered to obtain an increment of engine-speed reduction, thereby preventing the system from inadvertently having the blade pitch reduced when the engine is at maximum speed.

Abstract: A pitch control system has a main electronic control, a mechanical back-up control and a switching system for transferring pitch control from the electronic to the mechanical control in the event of electronic control failure. The switching system utilizes a switch for comparing the output of the electronic and mechanical control systems, the switch choosing the mechanical system if a failure occurs in the electronic control system. By utilizing the switching system, a failure of the electronic control does not permit the blades to go to feather. In certain failure modes, an enable valve or an enable solenoid locks out the switch, to ensure mechanical pitch change control.

Abstract: A pitch control system has a main electronic control, a mechanical back-up control and a switching system for transferring pitch control from the electronic to the mechanical control in the event of electronic control failure. The switching system utilizes a switch for comparing the output of the electronic and mechanical control systems, the switch choosing the mechanical system if a failure occurs in the electronic control system. In certain failure modes, an enable solenoid simultaneously locks out the switch, to ensure mechanical pitch change control, and resets the mechanical back-up control to provide a lower degree of pitch control than conventional back-up controllers.

Abstract: A fan assembly has variable pitch blades adjustable from outside the assembly while the fan is operating so as to alter the volume and direction of the induced airflow. The fan blades have an airfoil configuration such that air is moved by a fan in either direction with equal efficiency. The fan assembly includes a non-rotating secondary shaft axially moveable in a main shaft. The secondary shaft has a spider interconnected with the crank arms of the blade arms by a snugly fitted universal joint assembly. The airfoil configuration of the blades is neutral and the blades are straight. The fan assembly is lubricated by a pick-up non-rotatably mounted in a reservoir formed by the pulley hub and blade hub. The pick-up feeds lubrication directly to the bearing assemblies on which the spider and pulley hub are mounted.

Abstract: A controllable pitch propeller, particularly for a boat drive, has a driven rotating hub and adjustable propeller blades positioned thereon. An adjustment device is provided, having an adjustment ring that can move axially and which has adjustment bars attached to it for adjustment of the propeller blades. At least one continuous waste gas channel is positioned in the hub. In order to relieve the hub of external adjustment forces, the adjustment ring is constructed as a cylinder piston which is movably axially positioned in a cylinder chamber of the hub, and which can be acted upon hydraulically on both sides.

Abstract: A controllable and variable pitch propeller assembly. This assembly includes a main drive shaft mounted for rotation, and a propeller hub connected to the drive shaft for rotation with the drive shaft. Power cylinders are formed integrally in a unitary cylinder member affixed to a watercraft, or to the drive housing thereof. These power cylinders have actuator rods movable with respect to the watercraft in a direction substantially parallel to the drive shaft. A plurality of propeller blades are mounted to the hub for rotation therewith. Each blade is rotatable about a respective hub radial, and each of the blades has at its inner end a respective thrust collar. A ring assembly is provided, connected between the actuator means and the respective thrust collars at one side of each of the propeller blades, the ring assembly causes the propeller blades to rotate about their respective hub radials, thereby changing the pitch of the propeller blades.

Abstract: An oil distribution box for a marine controllable pitch propeller of the type having a main hydraulic servo within a hub for controlling the pitch of propeller blades rotatably carried by the hub and including a directional valve actuated by a tubular valve rod extending through the propeller shaft from the oil distribution box comprises an outer stationary housing, a shaft received within the housing and coupled to the propeller shaft and an auxiliary servo chamber cylinder coupled to the shaft. A piston received in the servo chamber is coupled to the valve rod. Oil is supplied to the valve rod through an elongated annular supply chamber defined between the shaft and the valve rod by spaced-apart seals, a port in the valve rod opening to the supply chamber, a port in the shaft opening to the supply chamber and a journal clearance seal between the housing and shaft in register with the port in the shaft.

Abstract: The pitch of a marine controllable pitch propeller is detected by a motion/DC current transducer in the propeller hub. Circuitry rotating with the propeller shaft converts an AC power signal to DC for energization of the transducer and converts a DC output signal from the transducer to AC. The AC power and output signals are transferred from the rotating circuit to a stationary circuit in the vessel hull by rotary transformers. There are no contacts between relatively moving parts of the transducer or rotary transformers, thus ensuring long life for the pitch detection system.

Abstract: Hydraulic fluid is input to a transfer tube of a variable pitch propeller system forward of a rotatable portion of a controller. A transfer bearing is provided about the drive shaft to transfer hydraulic fluid therethrough and between the drive shaft and the transfer tube to transfer hydraulic fluid from the drive shaft into the transfer tube, such transfer bearing allowing relative rotation between the housing and the drive shaft and between the drive shaft and the transfer tube. The transfer tube is slideably connected to the rotatable portion of the controller.

Abstract: A blade angle control device for an axial flow fan, the blades (7) of which are adjustable between two extreme positions during operation, comprises a control ring (9) coaxial with the hub (1) of the fan impeller and connected, through links (15), with control arms of each blade. In an initial position, where the blades are in one extreme position, the control ring (9) abuts on one face of the hub (1) which is located in a radial plane of the impeller. A pneumatically operated piston device (11,12,14) connected to the control ring (9) and located radially within the ring may shift the ring axially from the initial position towards a position in which the blades are in their other extreme position. A plurality of precompressed springs are located in tubes (18) extending through bores in the hub radially outside the piston device. Each spring surrounds a pin (19) connected to the control ring and biases the ring towards its initial position.

Abstract: In an impeller for use in an axial flow fan and having blades (5) which are adjustable during operation of the fan, each blade (5) is, through a blade shaft (7) connected to a hub (1) designed as a compact unit.The blade shaft (7) and an axial thrust bearing device (9) on which the blade (5) is journalled in such a manner that it can, through a control mechanism, be pivoted about its axis for controlling the blade angle, are retained axially in a bearing housing (8) screwed into a threaded bore (18) in the periphery of the hub (1).For adjusting the radial distance between the periphery of the hub (1) and the blade tip the thrust bearing device (9) is held against a closed end of the bearing housing (8) by a spring (43) and a nut (14) screwed onto a threaded portion (15) of the blade shaft (7) and lockable in an arbitrary position by a lock screw (16).

Abstract: A bladed rotor assembly and a control means therefor, which comprises a bladed rotor, a fluid-pressure-operable actuator for effecting a change of blade pitch, a first valve member connect to, and movable with the actuator and a second valve member co-operable with the first valve member, both valve mebmers having fluid passageways therein for supplying fluid to the actuator, and override means being provided to control the position of the second valve member relative to the first valve member, wherein safety means are provided to cause, in the event of failure of the over-ride means, the actuator to effect increased blade pitch.

Abstract: An actuating system for a controllable pitch propeller comprises a hydraulic servomotor arranged in the propeller hub and being connected mechanically to the propeller blades. Pressure medium is delivered to the servomotor, under the control of a control valve, from a pressure-medium source, which is connected to a stationary pressure-medium chamber which embraces a rotatable shaft connected to the propeller and which is sealed against the outer surface of the shaft and communicates, via a radial pressure-medium channel in the shaft, with an axial pressure-medium channel located in the shaft and extending to the hydraulic servomotor. The system further comprises an additional stationary pressure-medium chamber which embraces the shaft and seals against the outer surface thereof and which, via an additional radial pressure-medium channel in the shaft communicates with the axial pressure-medium channel in the shaft.

Abstract: A rotor stage disposed within an annular fluid flowpath in a turbomachine is disclosed. The rotor stage includes outer and inner rings and a plurality of first and second airfoils. The outer and inner rings define flowpath surfaces for said flowpath. The first and second airfoils extend between the rings for transferring energy between the fluid and the rotor stage. At least one of the first airfoils surrounds means for transmitting energy across the flowpath.

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: A rotary joint having a non rotary housing surrounding a rotating shaft and being sealed by a mechanical seal. Monitoring impulses are transmitted by hydraulic fluid which is transported between the housing and the shaft by means of a distribution socket. The socket is arranged so that a number of column seals are formed between the shaft and the socket. The apparatus is supported by two prestressed, reversed roller bearings.

Abstract: An impulse activated and controlled variable pitch propeller whereby the complete high pressure hydraulic system is incorporated in propeller hub assembly, including two identical type reciprocating hydraulic pumps which operate and control the propeller blade pitch settings by low force linear mechanical impulses transmitted from a remote stationary source through a pronged lever with input arm pivoting two anti-friction radial bearings attached to the pronged output ends for transmitting two equally balanced radial bearing contact forces in parallel on a rotating slidable flanged sleeve mounted on a propeller shaft adapter between the engine and the propeller, whereby said linear mechanical impulses are transmitted only during pitch change to actuate said pumps with the propeller otherwise free of any external mechanical contact during rotation.

Abstract: In an axial blower, a plurality of blades are disposed around a hub and each blade is supported on a respective strut which is rotatable in a pair of radially separated bearings. An axially displaceable disk in the hub is connected with the blades for rotating them. The drive shaft for the rotor is hollow and delivers oil to the disk which in turn delivers it to the rotation levers of the struts. The oil moves successively to the bearings radially outward of the disk and accumulated oil is collected by a scoop at the radially outer bearing. The collected oil is delivered to a collection chamber and is recirculated by a pump back to the hollow shaft. An additional cooling circuit may be provided.

Abstract: A propeller hub supports a plurality of adjustable pitch propeller blades which are rotated by a hydraulic cylinder and control system between a feather position and a reverse position through low and high pitch positions. The reverse pitch position is precisely set by axially adjusting a tubular sleeve threadably connected to the hydraulic cylinder and having an inner end surface forming a stop for the piston within the cylinder. The feather position is precisely set by axially adjusting lock nuts mounted on a threaded end portion of the piston rod projecting forwardly beyond the forward end of the sleeve. The hub also encloses feedback control rods which carry externally adjustable nuts providing for pilot control of the blade pitch into the reverse position.

Abstract: A low profile, externally controlled, variable pitch fan blade hub assembly is disclosed which is especially useful in high humidity environments such as are encountered in the fan induced, hot air discharge section of an industrial water cooling tower. The hub housing has central hub means including a member which is telescoped over the drive shaft therefor to limit the overall height of the assembly. The hub member is biased axially of the hub by a series of peripherally located springs contained within the housing. A fluid such as air may be introduced into the housing under pressure to shift the hub unit in a direction against the spring bias thereon. The housing has a plurality of radially extending bores each of which rotatably receives a respective fan blade axle provided with an elongated arm on the innermost end thereof within the housing positioned such that a cam follower on each arm is received in a cam track forming a part of the hub unit.

Abstract: An axial flow fan impeller having a number of blades, which are rotatably journalled in a wheel rim (3), each with its blade root (4) which is connected with an adjusting device (10) for the blades. The wheel rim comprises as a supporting member for the blades an annular body of revolution (6) with bores (5) for the blade shafts and a cut-out for taking up a thrust bearing (7). The body of revolution is connected with the body plate (18) and the front plate (21) of the impeller through tubular connecting pieces (19, 20), which are symmetrical relative to the body of revolution and are elastically deformable by loading forces acting in the radial plane of the wheel, but have a relatively great rigidity against forces acting in the axial direction. The impeller may thus be fabricated by welding, without the occurrence of dynamic loads exceeding the allowable values for the welding joints (25, 26).

Abstract: Axial flow fan blade roots (1) are rotatably journalled to blade shafts (4) by bayonet plug and socket couplings. The socket recesses (30, 31) provide an axial play for the plug cam portions (28, 29). Screws (34, 35) extending through the blade root (1) have shoulders (43) abutting spring members arranged between the root and the shaft to thus bias the blade outwardly and establish frictional engagement between the bayonet coupling cam portions and recesses.

Abstract: In hydrostatic pumps, motors and transmissions; faces, which slide and seal along adjacent faces, commonly have recesses for hydrostatic lubrication or for control of flow through ports.The invention provides additional arrangements on such faces for the provision of additional functions, for example, for the control of hydrodynamic flow into spaces between faces, the control of an additional control flow through the faces and the sealing therof or it provides recesses or seal inserts of specific locations or configurations for the improvement of the efficiency of the faces or for assurance of additional actions by the faces.

Abstract: On an intermediate shaft connected to a propeller shaft there are supported a stationary housing and a distributor or separator ring structure limiting two annular passages in the housing which can be selectively impinged with pressurized oil. The annular passages are connected to two oppositely effective working spaces of a servo motor of the adjustable pitch propeller by control passages extending through the intermediate shaft and the propeller shaft. The separator or distributor ring structure comprises axial sections, each of which is formed of one part in circumferential direction and is fixedly connected in axial direction to an axial section thereof associated with the same annular passage by web or bridging members bendable in radial direction. Each axial section is sealingly guided in a cylindrical bore of the housing by a respective sealing ledge protruding from the outer circumferential face thereof.

Abstract: The adjustable propeller has an adjusting mechanism for adjusting the pitch of the individual propeller blades. The adjusting mechanism comprises an actuator and a correction mechanism for each propeller blade for cyclically adjusting the pitch angle of a related propeller blade under the control of a control device.

Abstract: A pitch control system (10) for a variable pitch propeller effects engine governor (330), control of blade pitch under normal operating conditions and automatically effects direct (beta) control of blade pitch by the power lever (305) throughout a predetermined range of power lever settings. The system is hydromechanical and comprises a pitch actuator (40) and a pair of control valves (120 and 210), a first of the valves (120) applying a metered fluid pressure from a governor controlled pilot valve to the actuator and blocking that signal and replacing it with a supply fluid pressure at the point of transition from governor to beta control. The second control valve (210) effects a controlled draining of the actuator and connection thereof with the power lever (305).

Abstract: A propeller pitch change actuation system comprises an input actuator (230) driving a ball screw (200). Operation of the ball screw rotates a torque tube (140) about the longitudinal axis thereof to drive a screw 145 and control valve 120 which controls the pressurization of pitch change actuator (87). Actuator (87) is supplied with hydraulic fluid through the interior of the torque tube.

Abstract: A rotatable bladed device for vehicles, such as especially a helicopter rotor, which has its blade pitch controlled by a setup which includes a swash plate setup controlled by a set of hydraulic actuators and the particular swash plate setup position and attitude in turn controls the blade pitch by a plurality of rods pivoted together at one end at one particular point movable longitudinally of the rotor axis, one of which rods has its other end pivoted at a point on the pitch arm by which it controls pitch and another of which rods is also pivoted at a point fixed by the rotational position at any particular time of the rotor hub.

Abstract: The assembly includes a propeller shaft, a hollow hub closed at one end and secured at its other end to said shaft, a space being formed within said hub, said hub carrying blades which are rotatably driven by said shaft and hub and are changeable in pitch, a crosshead supported within said space for axially reciprocatable movement and coupled to said blades so as to change the pitch of said blades as said crosshead reciprocates, said crosshead having an end part adjacent said shaft and said end part forming a piston that is slidable on the inner surface of said hub, said piston defining on one side thereof a first chamber formed by said piston, said hub and said output end of said shaft, and defining a second chamber on its opposite side, formed by said piston and said hub, each of said chambers being adapted to be supplied individually with hydraulic fluid. The blades are rotatably connected to the hub, and the connection includes two spaced seals.