Abstract: A propfan turbo-engine has two shrouded propfan rotors arranged upstream of a gas turbine which are driven by a contra-rotating working turbine. In addition to a favorable flow onto the blades, a low weight of the engine can be achieved.

Abstract: An unducted turbofan engine comprises first and second fan blades journaled for rotation from a folded position substantially parallel to the axis of rotation of the engine to a radially orientated propulsion condition. A releasable shroud normally retains the fan blades in the folded condition and releases the fan blades in a controlled sequence.

Abstract: A power takeoff for an unducted fan gas turbine engine having first and second counterrotating coaxial rotors coupled respectively to first and second propellers. The rotors and propellers are oriented for rotation about a longitudinal axis of the engine. A gear is coupled to each of the rotors for rotation therewith and arranged to provide rotational motion about an axis transverse to the engine axis. A shaft is coupled to the gear for rotation about the transverse axis. Each of the propellers includes a plurality of propeller blades, each of the blades is rotatable about a corresponding blade axis, and a control is coupled to the blades for varying the pitch thereof whereby power is selectively distributed between the propellers and the power takeoff. The power takeoff may include a propeller coupled to the shaft for developing thrust substantially transverse to the engine axis and/or a pump, compressor, or generator to supply fluids or electric power to other apparatus.

Abstract: An electric motor driven blade pitch varying system for the fan blades of an unducted fan type aircraft gas turbine engine utilizes permanent magnet alternating current motors located in the oil sump region of the engine. An alternator driven by the engine generates unregulated variable frequency, variable amplitude power which is rectified and placed on a DC bus. Controlled inverters convert the DC power on the bus to appropriate AC power for the motors. The system incorporates redundancy without significant weight penalty by providing alternators and motors dividing into two independent operating sections on common shafts. Separate electronic circuits are provided to supply power for each sectionalized motor or to rectify power from each alternator section. A common power bus may be used to couple the multiple motors and alternators. The common bus may alternatively receive power from tbe aircraft 400 Hz system or from on-board batteries.

Abstract: In a gas turbine engine including first and second differentially rotating members coaxial with each other, a low pressure region disposed about the first and second differentially rotating members, and an annular gas flowpath disposed within the first and second differentially rotating members defining a high pressure region, a method and apparatus for preventing fluid leakage between the first and second rotating members. An annular carrier is coupled to the first rotating members such that the annular carrier is coaxial with the first rotating member. The annular carrier is sandwiched between a first race and a second race with the first and second races coupled to the second rotating member. The second race is urged toward the first race such that leakage of a fluid from the high pressure region to the low pressure region is not substantially increased by frictional wear of any of the annular carrier, first race and second race.

Abstract: A blade attachment between a propfan blade and a propfan hub in a propfan propulsion system for a tube-launched expendable aircraft, the attachment including a hinger on a rotatable propfan hub on the aircraft, a stem of the propfan blade rotatably supported on the hinge, a pitch control arm rigidly attached to the propfan blade, and a pitch control link universally articulated at opposite ends to the pitch control arm and to the propfan hub. When the hinge is extended, the pitch control arm and pitch control link locate the propfan blade in a folded position generally flat against the fuselage of the aircraft for storage in and launch from a tube. After launch, the hinge rotates to a retracted position and the pitch control arm and pitch control link concurrently rotate the propfan blade to an unfolded position for propelling the aircraft forward when the propfan hub rotates.

Abstract: This invention relates to autogyros and to counter-rotating rotor helicopters. It further relates to compound autogyros and/or helicopters that employ a lifting surface or wing in forward flight. More specifically this invention provides an autogyro with counter-rotating rotors, circular planform wing integral with the rotors, and means for engaging power to the rotors for vertical ascent, descent and hovering.

Abstract: A pitch feathering system for a gas turbine driven aircraft propeller having multiple variable pitch blades utilizes a counter-weight linked to the blades. The weight is constrained to move, when effecting a pitch change, only in a radial plane and about an axis which rotates about the propeller axis. The system includes a linkage allowing the weight to move through a larger angle than the associated pitch change of the blade.

Abstract: A marine drive (1) for a boat (3) includes a construction wherein a propeller supporting bearing device (29, 40) is disposed in a recess (28, 39) inside the propeller hub (23, 22). A bearing carrier (24, 37) is concentrically associated with a propeller shaft (20, 18). The carrier is provided with a rearwardly extending nose portion (27, 38) which is telescoped within the forwardly facing recess in an adjacent rearward propeller hub. The propeller shaft is journalled in the bearing device which is disposed between the carrier and the shaft and within the recess. In one aspect of the invention, the carrier is prevented from rotating about the shaft axis (17). In another aspect, a sealing device (26) is disposed between the propeller shaft and the rear end portion (8a) of an adjacent supporting gear case (8). In the embodiment disclosed, dual propellers and dual bearing carriers are utilized, with bearing carrier noses disposed in recesses in both propeller hubs.

Abstract: In one form of the invention, a counterrotating pair of aircraft propellers produces noise in the form of a frequency-modulated carrier wave. The frequency modulation allows a designer to manipulate the energy spectrum of the noise in order to, for example, place much of the acoustic energy into inaudible frequency ranges.

Abstract: A lightweight counterrotatable propeller system driven by a rotatable shaft is disclosed. The system includes first and second counterrotatable propellers, each propeller including a plurality of blades mounted on first and second hubs, respectively. Each blade is attached to the hub by means of a ball screw which converts centrifugal force on each of the rotating propeller blades into a pitch changing force. Gearing means for operatively connecting the shaft with each propeller are located between the propellers with a carrying member for one of the propellers forming an outer wall which radially bounds the gearing means. Additionally, non-rotating actuating means for changing propeller pitch are operatively connected to the blades of each of said first and second propellers through first and second thrust bearings, respectively.

Abstract: A marine drive unit (1) includes a lower torpedo housing (9). At least one propeller shaft (21) is mounted in the housing for rotation about a drive axis (17). The propeller shaft is driven by a driving gear (16) suitably connected to a marine engine (4) and mounted on the drive axis. A first forward thrust bearing (41) is disposed between the driving gear and the housing. In addition, a second forward thrust bearing (42) is disposed adjacent the forward end of the propeller shaft. A pre-loading device, in the present embodiment a washer-like Belleville spring (43) of a desired capacity, is disposed to provide an adjustable rearwardly biasing force on the second thrust bearing.

Abstract: A screw propeller (10) for boats includes two counter-rotating screws (12, 16) coaxial with an annular nozzle (20). The aft screw (16) has a smaller diameter than the forward screw (12) and the nozzle (20) has an annular duct (B) situated upstream of the rear screw (16) and arranged to discharge the exhaust gases from the engine.

Abstract: The disclosure describes a device for carrying and lifting loads and moving ame by aerodynamic lifting, rotary-wing aerial propulsion, having two coaxial rotors of same diameters rotating at the same speed and in reversed direction through a double crown wheel system which is driven by oppositely disposed rollers. The device includes a crown wheel operatively connected to two rotors which are driven by two rollers, one of which being driven by one or two motors mounted on the body. The internal crown wheel has a hub enabling external blades to be mounted in superimposed relationship.

Abstract: A power turbine (12) comprises alternate annular arrays of contra-rotatable turbine blades. Two arrays of turbine blades (30) and (47) have annular arrays of aerofoil propulsion blades (17,18) respectively attached thereto. Alternate arrays of turbine blades are attached to a primary drum member (55) in such a manner that below normal operating temperatures, limited relative radial movement is permitted between them. However when the normal operating temperature is reached, the relative radial movement is inhibited in such a manner that the rigidity of the power turbine (12) enhanced.

Abstract: A turboprop propulsion system where there is a core engine driving a power turbine that is connected through a planetary drive transmission to first and second counterrotating propellers. One of the propellers is connected to the ring gear, while the other propeller is connected to the planetary carrier, the sun gear being driven from the power turbine. The apparatus is provided with a substantially continuous gaseous flow path from the inlet to the exhaust nozzle of the engine, with the planetary drive transmission being spaced radially from the flow path. In some embodiments, the planetary transmission is positioned radially inwardly of the flow path, while in other embodiments, it is positioned radially outwardly of the flow path. The propellers can be in either the pusher configuration or the tractor configuration.

Abstract: An improved gas turbine engine is disclosed. The engine includes counterrotating first and second turbine rotors without an intervening nozzle. Disclosed also are means for obtaining pitch relative outlet velocity greater than pitch absolute inlet velocity for at least one of the rotors. In one embodiment, the reaction of at least one of the rotors is greater than a reference reaction effecting peak efficiency of the one turbine. Advantages include improved overall engine efficiency and decrease in weight, reduced cooling flow and complexity of the engine.

Abstract: The invention relates to intakes for turbopropeller gas turbine engines of the tractor type. A tractor turbopropeller gas turbine engine comprises a gas generator, an upstream propeller and a downstream propeller. The propellers are positioned upstream of the gas generator, and the propellers are driven via shaft means and gear means. An intake means supplies air to the gas generator, the intake means comprises an intake opening and an intake duct. The intake opening is positioned axially between the propellers, and a portion of the intake duct extends axially through the downstream propeller. This arrangement reduces the length of the shaft and the turbopropeller gas turbine engine, and reduces the weight accordingly. The intake opening is arranged to provide improved protection against ingestion of large foreign objects, such as birds, into the intake duct and gas generator.

Abstract: A marine drive unit (1) includes a lower gear case (8) forming a torpedo housing (9). A pair of coaxial propeller shafts (21, 25) are rotatably mounted in the housing and carry a pair of propellers (10, 11) thereon. The propeller shafts are driven by a pair of opposed driving gears (16, 24) suitably connected through a generally vertical main drive shaft (14) to a marine engine (4) and mounted on the horizontal drive axis (17). A pair of thrust bearings (44, 45) adapted to carry forward thrust loads are respectively disposed adjacent the facing portions of the opposed driving gears, with the pair being separated by a spacer (46) tightly confined therebetween. The spacer is locked against rotation but is freely floatable in an axial direction, and transfers the forward thrust load from one bearing to the other, so that the load is ultimately transferred from the outer propeller shaft (25) to the inner central shaft (21).

Abstract: This disclosure relates to a marine propulsion system including a double propeller. To obtain a forward thrust, the two propellers are driven in opposite directions while producing forward propulsion forces. To obtain a rearward thrust, only one propeller is driven in the direction to produce a rearward force. The two propellers are attached to coaxial inner and outer horizontal shafts. A single vertical shaft is coupled by bevel gears to the shafts, and movable clutches couple the driving force to the horizontal shafts.

Abstract: A spider differential assembly (7) of a marine drive is constructed so that the spider (16) and its associated spider pinion gears (20) can float in all directions, except about the common central axis (5) of the propeller drive shafts (4, 8). More particularly, a spider is provided with a central hub opening (18) through which the main drive shaft passes. A plurality of radially extending spindles (19) carry the spider gears and extend outwardly where they terminate in an enclosure (30, 31) arranged to prevent circumferential spider movement about the common drive shaft axis, but which permits free spider floating.

Abstract: A gas turbine engine comprising a core gas generator engine for generating combustion gases, an additional power turbine, an additional fan section, and a booster compressor is disclosed. The power turbine includes first and second counterrotatable turbine blade rows effective for rotating first and second drive shafts, respectively. The fan section includes a first fan blade row connected to the first drive shaft and a second fan blade row connected to the second drive shaft. The booster compressor includes a first compressor blade row connected to the first drive shaft and a second compressor blade row connected to the second drive shaft.

Abstract: Aircraft with rotary wings, characterized in that it comprises a nacelle (1) surrounding the user who seats on a seat (9) slidingly arranged in the medial plane of said nacelle, substantially in the normal displacement direction of flight of the aircraft, two parallel crowns (40-41) carried by the nacelle and imparted with identical rotational motions but in inverted directions about a common axis, extending substantially at the center of the nacelle, perpendicularly to the plane of said crowns, each of the crowns supporting at least one pair of blades (48-49, 50-51) or wings diametrically opposite and arranged in the prolongation of each other, drive means (19-37) for driving the crowns about the nacelle and means (66-67) for changing in each pair of blades the pitch thereof in an equal but opposite way for each of them.

Abstract: A stern tube bearing system of contra-rotating propeller includes an inner shaft having a rear propeller and an outer shaft having a front propeller, both shafts being rotated in opposite directions. A shaft center portion of the inner shaft is made hollow, a plurality of oil supply holes are bores radially in the inner shaft so as to pass therethrough perpendicularly to the outer peripheral surface thereof, and a plurality of rows of these oil supply holes are arranged in the longitudinal direction of the inner shaft, whereby seizing of the bearing owing to offset contact at its rear end caused by the propeller being overhung can be prevented.

Abstract: An integrated control system for coaxial counterrotating aircraft propulsors driven by a common gas turbine engine. The system establishes an engine pressure ratio by control of fuel flow and uses the established pressure ratio to set propulsor speed. Propulsor speed is set by adjustment of blade pitch.

Abstract: A power turbine suitable for a gas turbine engine which a blade of one array of turbine blades has a fan propulsion blade attached to its radially outer extent. A drum member is further provided which carries at least one further annular array of turbine blades and is coaxially interposed between the arrays of turbine blades and fan propulsion blades to rotate with the same in operation. Aperatures are defined through the drum member to accommodate the attachment structure provided between the turbine blade and the fan propulsion blades such that relative radial movement is permitted between the turbine blade and the drum.

Abstract: A fan jet engine assembly comprising a hoop fan surrounding a turbojet (19) is disclosed. The hoop fan includes a pair of rotatable hubs (27, 29) that encircle the turbojet. A stage of fan blades (31, 33) is attached to each hub (27, 29) and radiates outwardly therefrom. The tips of the blades (31, 33) of at least one of the stages attached to a loop (23/25 or 61) that encircles the tips of the blades (31, 33) of both stages. Due to the attachment of the hoop (23/25 or 61) to the blades (31, 33), the hoop rotates as the hubs (27, 29) are rotated by the turbojet (19). The pitch of the blades of at least one of the stages is adjustable.

Abstract: The invention relates to a rotor system, particularly a boat propeller system, which consists of a main propeller and a turbo unit in the form of a fore-propeller and a turbine mechanically coupled thereto, the turbo unit being freely rotatably journalled.

Abstract: An improved arrangement of a turbofan engine comprises a core engine, an upstream fan, a downstream fan and a booster compressor. The upstream fan and downstream fan are both positioned upstream of the core engine, and are arranged to be driven in opposite directions by a gear assembly. The gear assembly is positioned axially between the upstream fan and downstream fan. The booster compressor is positioned upstream of the upstream fan and downstream fan, and comprises a first rotor carrying blades and a second rotor carrying blades. The first rotor is driven with the upstream fan and the second rotor is driven by the turbine of the core engine in opposite direction to the first rotor.

Abstract: The invention relates to a boat propeller unit with double, counter-rotating propellers. The forward propeller is designed to function without cavitation, while the after-propeller is optimally cavitating by being made cupped and with a blade width of between 60% and 75% of the blade width of the forward propeller.

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 propeller module for an aero gas turbine engine comprising two contra-rotating propellers has a reduction gear train positioned axially between the propellers. Pitch change mechanism are provided to change the pitch of the blades of both propellers independently of the differential speed of the propellers. The pitch change mechanisms comprise two sets of hydraulic motors one set of which is mounted on a carrier member of the gear train within the planet gears, the other set is mounted on the hub of the second propeller. Pitch selector valves control the supply of hydraulic fluid to the hydraulic motors, and the pitch selector valves are operated by a pitch change power unit. The pitch selector valves are positioned coaxially of the propellers and a transfer tube extends coaxially between the pitch selector valves to transfer hydraulic fluid therebetween independently of differential speed of the propellers.

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: A propeller module for a gas turbine engine comprising two contra-rotating propellers has a reduction gear positioned axially between the propellers. Pitch change mechanisms are provided to change the pitch of the blades of both propellers independent of the differential speed of the propellers.

Abstract: A propeller module for an aero gas turbine engine comprises two contra-rotating propellers driven by a reduction gearbox positioned axially between the propellers.Pitch change mechanisms operated by a pitch change power unit are provided to change the pitch of the propeller blades. The pitch change power unit is positioned in the hub of the second multi-bladed propeller and is remote from the first multi-bladed propeller. The first and second pitch change mechanisms are mounted on the reduction gearbox. The first pitch change mechanism comprises first pitch change gears which are rotatably mounted on a carrier of the reduction gearbox by spindles which extend axially through planet gears of the gearbox. The second pitch change mechanism comprises second pitch change gears rotatably mounted on the carrier.

Abstract: A marine contra-rotating propeller apparatus for propelling a ship by contra-rotating propellers is characterized by the provision of an inner shaft having one end directly coupled to an output shaft of a main diesel engine and the other end to which an outside propeller is mounted and an outer shaft having one end coupled to the inner shaft through a reversing transmission mechanism and an elastic coupling and the other end to which an inside propeller is mounted.

Abstract: In an aircraft propulsion system including a gas turbine engine driving a pair of counter rotating bladed members through a planetary gear set, a brake for simultaneously retarding rotation of both bladed members after engine shut-down includes a pair of concentric transfer shafts each rotatably connected to separate elements of the planetary gear set, a pair of friction plates supported on respective ones of the transfer shafts for rotation therewith, a plurality of non-rotatable reaction members between the friction plates, and a single actuator selectively operable to compress the stack of friction plates and reaction members to simultaneously retard rotation of both transfer shafts and thereby simultaneously retard rotation of and eventually simultaneously stop both of the counter rotating bladed members.

Abstract: A boat propeller drive with double, counter-rotating propellers is distinguished by the after propeller having one more blade than the fore propeller as well as a smaller diameter than the fore propeller.

Abstract: The invention relates to a rotor device, preferably a boat propeller device. The propeller shaft drives, via a planetary gear system, two propellers in the rotational direction of the shaft and one propeller counter to the rotational direction of the shaft. The propellers are dimensioned so that they absorb approximately equal torques.

Abstract: A combined counterrotation propeller and reduction gear in which the shaft for the forward propeller also carries the pinions of the reduction gear and the hollow shaft for the rearward propeller also carries the ring gear in mesh with the pinions. The bearings for the propeller shafts also support the elements of the reduction gear.

Abstract: A propeller assembly is usable in combination with a watercraft drive unit having a generally horizontal drive support tube fixed on the craft and a drive shaft projecting from the rear end of the support and rotatable about a drive axis. The drive assembly has a hub fixed on the shaft adjacent the support and having a front hub portion immediately behind the rear support end and a rear end spaced therefrom. A rear propeller is fixed to the rear portion of the hub so that it rotates therewith and with the shaft. A planet carrier defining a plurality of planet axes parallel to and spaced equiangularly about the drive axis is secured to the support so the planet axes are fixed relative to the support and drive axis. A sun gear fixed on the front portion of the hub within the planet axes meshes with respective planet gears rotatable on the carrier about the planet axes.

Abstract: A double propeller drive unit for boats having an inclined steering axis and a trim fin arrangement which is fixed to the cavitation plate of the drive unit, is disposed in the boundary region between the propellers, and is designed to balance torques acting on the drive unit.

Abstract: An aircraft propulsion means 20 comprises a multibladed, unshrouded, propeller fan 27 adapted in a cruise condition to operate at such high disc loadings that a substantial component of swirl is imparted to the slipstream in a given sense, and swirl reducing means (for example a multi-bladed stator 35) arranged with respect to the propeller fan to impart a considerable component of swirl in the opposite sense, whereby the total swirl imparted to the slipstream is nil or relatively low.

Abstract: The invention provides a helicopter of the type having two coaxial counterrotating rotors with a differential drive mechanism interposed between the power plant and the rotors. The power output of the power plant is coupled to the power input of the differential drive which has two power outputs, one of which is directly connected to the mounting hub of one of the rotors and the other one is connected to the mounting hub of the other rotor through a rotation inverting mechanism. Two embodiments are described and illustrated which differ only by the construction of the differential and the rotation inverting mechanisms.

Abstract: Pitch control linkage for the upper rotor of coaxial counterrotating rotors utilizes conventional swashplate, control rod and servomotor elements for changing blade pitch but without the conventional rotating and non-rotating scissors for reacting swashplate torque. This is accomplished by the use of rotating and non-rotating walking beams and combination torque reacting control rods between the walking beams and the rotatable and non-rotatable swashplate elements. Means are also disclosed for shimming the rotatable walking beams to achieve pre-track adjustment of the pitch of individual blades.

Abstract: A rotor arrangement for an aircraft comprising two coaxially counter-rotatable rotators, each rotor being journaled freely rotatable about an imaginary axis of rotation common to both rotors on or through a fuselage part or a support member, each fuselage part or support member being either rigidly connected to or journaled on the fuselage, each rotor together with the other respective rotor or with the component part of the support member or fuselage part supporting the first mentioned rotor constituting an integral part of an electromotor by forming the counteracting parts of the electromotor ("rotor" and "stator") which rotate relative to one another by securing a plurality of poles of the electromotor to the respective rotor and by arranging on the other counter-rotating rotor or on the component part of the support member or fuselage part supporting the first mentioned rotor the corresponding poles of the electromotor facing toward the poles of the respective rotor such that a reciprocal field effect exi

Abstract: A helicopter having a small diameter and fast rotating upper horizontally disposed conventional airplane propeller and a large diameter slower and counter-rotating large diameter bladed rotor equipped with variable pitch blades is provided and the bladed rotor is mounted in such a manner that its plane of rotation may be readily adjustably canted in all directions relative to the axis of rotation of the small diameter upper airplane-type propeller. Further, the blades of the rotor may be simultaneously adjusted in pitch and a single manually shiftable control is provided for selectively simultaneously or independently canting the plane of rotation of the rotor blades and varying the pitch of the rotor blades.