Differential Or Independent Adjustment Patents (Class 416/130)
  • Patent number: 11111011
    Abstract: A rotor for an aircraft capable of hovering includes a stationary support structure and a rotative element which is rotatable about an axis with respect to the stationary support structure. The rotor has at least one blade, which is operatively connected with a rotative element. The rotor has a source of a magnetic field, which is either stationary or driven in rotation at a first rotational speed and an electric conductive element, which is operatively connected to the rotative element and can be driven in rotation at a second rotational speed different from first rotational speed. An electric conductive element is electromagnetically coupled so that an electromotive force is magnetically induced in electric conductive element itself Two rings extend radially inward from a tubular body of the rotor hub with the first ring connected to a plurality of thermally conductive rings of a flow deflector at an axial end of the rotor and the second ring supports the electric conductive element.
    Type: Grant
    Filed: December 29, 2017
    Date of Patent: September 7, 2021
    Assignee: LEONARDO S.P.A.
    Inventors: Luigi Bottasso, Antonio Zocchi, Massimo Brunetti, Luca Medici, James Wang, Giorgio Lucchi
  • Patent number: 11014658
    Abstract: A rotorcraft is provided which includes a rotor hub, a rotatable universal joint which tilts said rotor hub, and a plurality of servo drives which rotate the universal joint. The plurality of servo drives preferably includes four servomotors coupled together in a velocity summing arrangement to produce a single motion output.
    Type: Grant
    Filed: January 4, 2016
    Date of Patent: May 25, 2021
    Inventor: Delbert Tesar
  • Patent number: 10919625
    Abstract: Embodiments herein describe a reconfigurable UAV to allow for the deployment of a subsurface sensor. The UAV includes a rotor assembly that is slidably coupled to a landing base. The rotor assembly includes a plurality of rotors and a ring circumscribing the rotors. Upon landing, the rotor assembly rotates in a first direction with respect to the landing base, which reduces a spacing between the rotor assembly and the ground and drives a sensor coupled to the rotor assembly into the ground. To remove the sensor from the ground, the rotor assembly rotates in a second direction to increase the spacing between the rotor assembly and the ground. The ring and/or the landing base may include interlocking features such as helical threads that are utilized to translate a rotational motion of the rotor assembly into a linear translation of the rotor assembly along the length of the landing base.
    Type: Grant
    Filed: July 24, 2018
    Date of Patent: February 16, 2021
    Assignee: The Boeing Company
    Inventor: Erin Kathleen Anderson
  • Patent number: 10858092
    Abstract: A flying object according to the present invention has been developed to have a plurality of rotor blades or jet engines, and to reduce the risk of a crash even if any one of the rotor blades or jet engines is damaged. The flying object comprises: a flying fuselage; a plate-shaped protection member having a plurality of through-holes formed on the same circumference thereof; a driving means arranged in each of the through-holes; and a tilting means for tilting each of the driving means, or a rotating means for rotating the protection member around a shaft member, wherein the diameter of the protection member, the interval between the rotational axes of the rotor blades facing each other, the length of the shaft member, and the length of the flying fuselage have a predetermined ratio.
    Type: Grant
    Filed: October 28, 2016
    Date of Patent: December 8, 2020
    Inventor: Yang Woo Nam
  • Patent number: 9051050
    Abstract: A rotary-wing aircraft (100), comprising at least four rotors (110), which are disposed on girder elements (120a, 120b), wherein said rotors (110) and girder elements (120a, 120b) are disposed such that a free field of vision (S) is defined along a longitudinal axis (L) of said rotary-wing aircraft (100) at least between two terminal rotors.
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: June 9, 2015
    Assignee: Ascending Technology GmbH
    Inventors: Michael Achtelik, Jan Stumpf, Daniel Gurdan, Klaus-Michael Doth
  • Patent number: 8770935
    Abstract: A propeller arrangement has a first propeller assembly providing a row of first propellers, and a second propeller assembly, rearward of the first propeller assembly, providing a row of second propellers. The first and second propellers are radially extendable and retractable. The propeller arrangement further has a control system for controlling the extension and retraction of the first and second propellers. The control system is arranged such that when the propellers of one of the first and second propeller assemblies extend, the propellers of the other of the first and second assemblies retract.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: July 8, 2014
    Assignee: Rolls-Royce PLC
    Inventor: Alexander V. Lavrenko
  • Patent number: 8562283
    Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.
    Type: Grant
    Filed: October 29, 2012
    Date of Patent: October 22, 2013
    Assignee: Huntair, Inc.
    Inventor: Lawrence G. Hopkins
  • Patent number: 8556574
    Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: October 15, 2013
    Assignee: Huntair, Inc.
    Inventor: Lawrence G. Hopkins
  • Patent number: 8419348
    Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.
    Type: Grant
    Filed: April 5, 2011
    Date of Patent: April 16, 2013
    Assignee: Huntair, Inc.
    Inventor: Lawrence G. Hopkins
  • Patent number: 8287237
    Abstract: A pitch control system for blades on a rotor of an aircraft has a gimballing rotor hub (31) and a plurality of step-over arms (61) connected to the hub and capable of pivoting relative to the hub about a pivot axis. Each of a plurality of pitch links (55) connects one of the step-over arms (61) to a flight control system for pivoting the connected step-over arm (61) about the pivot axis and relative to the hub in response to inputs from the control system. Each of a plurality of step-over links (69) connects one of the step-over arms (61) to one of the blades for rotating the associated blade about the pitch axis in response to pivoting of the associated step-over arm.
    Type: Grant
    Filed: December 8, 2006
    Date of Patent: October 16, 2012
    Assignee: Textron Innovations Inc.
    Inventors: Frank B. Stamps, Richard E. Rauber, David A. Popelka, Patrick R. Tisdale, Thomas C. Campbell, Keith Stanney, James L. Braswell, Jr., Mark Wasikowski, Tom Donovan, Bryan Baskin, John J. Corrigan, III, Ryan Smith
  • Patent number: 8272833
    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.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: September 25, 2012
    Assignee: SNECMA
    Inventor: Francois Gallet
  • Patent number: 8251639
    Abstract: A gas turbine includes at least one multi-stage compressor unit 2, with the compressor unit 2 including several, independent compressor modules 3-5, which, independently of each other, are rotatably borne on a drive shaft 1 and are each engageable with the drive shaft 1 by at least one clutch unit 9-11.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: August 28, 2012
    Assignee: Rolls-Royce Deutchland Ltd Co KG
    Inventor: Metin Talan
  • Patent number: 8113776
    Abstract: A method of operating variable pitch fans in series to cool an operating computer system. The method comprises running a first variable pitch fan with blades positioned at an operational pitch to induce airflow through the computer system and through a second variable pitch fan disposed in series with the first fan, and, simultaneously, not running the second variable pitch fan with blades positioned for minimal impedance to the airflow. In response to detecting a failure condition of the first fan, the method includes running the second fan with blades positioned at an operational pitch to induce airflow through the computer system and through the first fan, and, simultaneously, not running the first fan with blades positioned for minimal impedance to the airflow. Preferably, the method includes locking the rotor of a fan that is not running, and locking the blades of the non-running fan in a minimal impedance position.
    Type: Grant
    Filed: April 10, 2008
    Date of Patent: February 14, 2012
    Assignee: International Business Machines Corporation
    Inventors: Michael Sean June, Michael Sven Miller, Paul Andrew Wormsbecher
  • Patent number: 7914252
    Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.
    Type: Grant
    Filed: March 24, 2008
    Date of Patent: March 29, 2011
    Assignee: Huntair, Inc.
    Inventor: Lawrence G. Hopkins
  • Publication number: 20110061579
    Abstract: A dynamic or aerodynamic fin comprising at least two parallel arranged fin sections. At least one fin section comprises a rotational axis for installing the fin section by a rotation shaft. An end stop is provided for stopping the rotational movement of the fin section to define an extreme position. In the extreme position the fin sections provide a substantially cambered shape to the fin. The dynamic fin is improved in that it comprises a pair of coupling elements. A first fin section is coupled to a second adjacent fin section by a pair of a first and second coupling elements. The first coupling element is complementary to the second coupling element. The first coupling element is part of, preferably integral, with the first fin section and the second coupling element is part of, preferably integral, with the second fin section.
    Type: Application
    Filed: March 10, 2010
    Publication date: March 17, 2011
    Inventor: Klaas Boudewijn VAN GELDER
  • Patent number: 7780412
    Abstract: Methods and apparatus for continuing wind turbine operation when normal wind turbine motor control is unavailable due to overheating of one or more wind turbine control motors. Technical effects of the present invention include providing an effective control strategy continuing operation during over-heating of a wind turbine control motor, such as a pitch control motor and a yaw control motor.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: August 24, 2010
    Assignee: General Electric Company
    Inventors: Xiaoyun Zang, Dong Wang, Meng Gao
  • Patent number: 7585153
    Abstract: An upper rotor control system is contained within an upper rotor shaft and upper hub assembly of a contra-rotating rigid rotor system. A collective servo assembly includes a hydraulic actuator that provides collective pitch to all blades through axial extension/retraction of the control rod relative the upper rotor shaft for collective pitch control of the rotor blades. The collective servo assembly includes a spherical bearing for attachment of the control rod to aircraft structure. An X-Y positioner assembly includes a bearing arrangement which allows the shaft to rotate, while the X-Y positioner assembly remains non-rotational therein. The X-Y positioner assembly includes a multitude of hydraulic actuators, orthogonally positioned, to tilt the control rod about the spherical bearing off the axis of rotation of the upper rotor shaft for cyclic pitch control of the rotor blades.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: September 8, 2009
    Assignee: Sikorsky Aircraft Corporation
    Inventors: David N. Schmaling, Pedro L. Cabrera
  • Patent number: 7264199
    Abstract: A rotor system (12) for a helicopter (10) includes a rotating shaft (82). A gimbaled hub assembly (56) is coupled to the rotating shaft (82). Rotating blades (24) and non-rotating blades (33) are coupled to the gimbaled hub assembly (56). The non-rotating blades (33) provide lift for the helicopter (10) in forward flight unloading the rotating blades. The rotating and non-rotating blades (24, 33) provide equal and opposite rolling moments for lift offset operation.
    Type: Grant
    Filed: October 18, 2005
    Date of Patent: September 4, 2007
    Assignee: The Boeing Company
    Inventor: Thomas A. Zientek
  • Patent number: 7077629
    Abstract: A multi-fan assembly whose revolution speed can be controlled by a member fan designed with a reverse rotating structure, which includes a housing in which is provided a rotatable member; a positive-rotation member fan is equipped with a positive-rotation motor, the positive-rotation motor serves to rotate blade holders and fan blades mounted on the blade holders, the positive-rotation member fan is fixed to the rotatable member via a holding arm; a reverse-rotation member fan is equipped with a reverse-rotation motor, the reverse-rotation motor serves to rotate blade holders and fan blades mounted on the blade holders, the reverse-rotation motor's rotating direction is opposite to that of the positive-rotation motor, the reverse-rotation member fan is fixed to the rotatable member via a holding arm.
    Type: Grant
    Filed: August 9, 2004
    Date of Patent: July 18, 2006
    Inventor: Chia-Teh Chen
  • Patent number: 7052242
    Abstract: A multi-fan assembly includes: a down rod assembly having a first end for fixing to a ceiling wall and having a second end provided with a canopy, a rotary assembly being fixed to a lower end of the down rod assembly and covered by the canopy. At both sides of the rotary assembly is provided with a fixed arm for connecting with a member fan respectively, a pair of vertical oscillating means are disposed between the fixed arm and the member fan, and a speed control device is mounted on the rotary assembly and then covered by the canopy of the down rod assembly.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: May 30, 2006
    Inventor: Chia-Teh Chen
  • Patent number: 6082967
    Abstract: A constant-speed twin spool turboprop unit including a twin spool gas generator having a low-pressure spool and a high-pressure spool each including a compressor and a turbine which drives the compressor, is described in which at least one propeller of the unit is driven by at least the high-pressure spool of the gas generator.
    Type: Grant
    Filed: March 25, 1998
    Date of Patent: July 4, 2000
    Assignee: Societe Nationale d'Etude et de Construction de Moteurs d'Aviation "Snecma"
    Inventor: Jean Maurice Loisy
  • Patent number: 6053700
    Abstract: A turbine 400 has a central duct 410 which accelerates fluid passing through it and a blade configuration which retards the flow of fluid near the tips of the turbine. This structure results in a vortex having a higher fluid pressure behind the tips of the turbine blades 408 and a lower fluid pressure behind the duct. In the present invention, this vortex is enhanced by (1) an increased acceleration of the fluid passing through the duct 410 and a deceleration of the fluid passing through the blades 408; and/or (2) by a fluid redirection device 850 for directing the fluid passing through the duct towards the outer diameter of the turbine.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: April 25, 2000
    Assignee: Fosdick High-Tek Wind Turbines, Inc.
    Inventor: George A. Fosdick
  • Patent number: 5860788
    Abstract: A fan assembly includes a circular first array of first fan blades; a first primary ring member supportively connecting inner extremities of the first blades about a fan axis, respective end extremities of at least a majority of the first blades defining inside and outside diameters of the array, the first blades being oriented for producing a primary axial fluid flow between the inside and outside diameters in response to rotation of the first ring member, the first ring member extending between the inside and outside diameters. A second primary ring member connects outer extremities of the first blades, the first blades in combination with the first ring member defining a generally circular opening about the fan axis.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: January 19, 1999
    Assignee: Shell Electric Mfg. (Holdings) Co. Ltd.
    Inventor: Bradford T. Sorensen
  • Patent number: 5601257
    Abstract: The yaw control in an air vehicle having counter rotating rotors is provided by selectively and controllably applying a frictional drag or braking force to drive gears for the two rotors. Each of the drive gears includes a friction surface. Friction pads are located adjacent to and are releasably engagable with the friction surfaces of the drive gears. The friction pads are supported by a control mechanism for selectively moving each of the friction pads into engagement with the respective drive gear to provide a frictional drag on the drive gear and to a disengaged position spaced from the respective drive gear. The frictional forces created by engagement of the friction pads with the drive gear friction surfaces cause net torques on the air vehicle frame to rotate the air vehicle in the desired directions. Normally, the torque developed the counter rotating rotors is canceled, maintaining the air vehicle in the desired yaw orientation.
    Type: Grant
    Filed: August 11, 1994
    Date of Patent: February 11, 1997
    Assignee: Benchmark Corporation
    Inventor: H. Smith McKann
  • Patent number: 5242265
    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.
    Type: Grant
    Filed: July 23, 1990
    Date of Patent: September 7, 1993
    Assignee: General Electric Company
    Inventors: Petr Hora, Thomas C. Hermans, David E. Bulman, Edwin K. Miller, Thomas G. Wakeman, David L. Joyce
  • Patent number: 5154580
    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.
    Type: Grant
    Filed: July 23, 1990
    Date of Patent: October 13, 1992
    Assignee: General Electric Company
    Inventor: Petr Hora
  • Patent number: 5152668
    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.
    Type: Grant
    Filed: July 23, 1990
    Date of Patent: October 6, 1992
    Assignee: General Electric Company
    Inventors: David E. Bulman, Petr Hora, Thomas C. Hermans
  • Patent number: 4936746
    Abstract: A propeller system has a pair of hub assemblies driven in counter-rotation, each hub assembly having a mechanical pitch change actuator, each actuator being provided with a pitch lock that rotates simultaneously with the motion of the actuator to allow the actuator to set propeller blade pitch, but locks the propeller blade positionally when not rotating simultaneously with the actuator, and a differential for transmitting a pitch change signal across a rotating gap between the two hub assemblies and for providing power to a means for providing the pitch change signals. A pair of motors provide the rotative signal to set the pitch of the blades in each hub assembly. One of the pair of motors drives the actuator towards high pitch and the other motor drives the actuator towards low pitch. A synchronizer coordinates the signals of the first and second motors so that a pitch lock moves simultaneously with the actuator.
    Type: Grant
    Filed: October 18, 1988
    Date of Patent: June 26, 1990
    Assignee: United Technologies Corporation
    Inventors: Millard G. Mayo, Edward H. Kusiak, Philip E. Barnes, Paul A. Carvalho
  • Patent number: 4842484
    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.
    Type: Grant
    Filed: August 28, 1985
    Date of Patent: June 27, 1989
    Assignee: General Electric Company
    Inventor: Kenneth O. Johnson
  • Patent number: 4772181
    Abstract: A counterrotatable bladed rotor assembly drivable by a rotatable shaft comprises a leading propeller, a trailing propeller, and a gearbox located axially between the two propellers and enclosed by a non-rotatable casing having an end for attachment to a support structure. The gearbox has a first output shaft to the leading propeller and a second output shaft to the trailing propeller. A first fluid-pressure operable actuator is provided to vary the pitch of the blades of the leading propeller, and a second fluid-pressure operable actuator is provided to vary the pitch of the blades of the trailing propeller. In addition passageways are provided to connect the first and second actuators to a source of fluid under pressure. The casing rotatably supports the second output shaft at a position between the gearbox and the leading propeller and rotatably supports the first output shaft at a position between the gearbox and the trailing propeller.
    Type: Grant
    Filed: September 23, 1986
    Date of Patent: September 20, 1988
    Assignee: Dowty Rotol Limited
    Inventor: Michael Poucher
  • Patent number: 4767270
    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.
    Type: Grant
    Filed: April 16, 1986
    Date of Patent: August 30, 1988
    Assignee: The Boeing Company
    Inventor: Gerhard E. Seidel
  • Patent number: 4621978
    Abstract: An improved counterrotating power turbine is disclosed. The power turbine includes a support having an annular axial cross-section and forward and aft portions. The forward portion of the support has a diameter greater than the diameter of the aft portion. Also included are a first rotor and a second rotor. The first rotor is supported on the first portion of the support by first bearing means and extends to the aft portion forming a first interface therewith. The second rotor is supported on the first rotor by second bearing means and extends to the aft portion of the support forming a second interface therewith. In this manner, it is possible to have low diameter slip rings at the first and second interfaces while maintaining relative high diameters for the rotor bearing means.
    Type: Grant
    Filed: December 3, 1984
    Date of Patent: November 11, 1986
    Assignee: General Electric Company
    Inventor: Alan R. Stuart
  • Patent number: 4483658
    Abstract: The action of upstream and downstream foil sets rotating on a common shaft within a fluid is enhanced by fixing certain interrelations of the foils such as the axial distance between the foils, the radial index between foils and pitch of one foil relative to the other so that the foil stages are fixedly mounted with the foils of each stage being symmetrically and equidistantly spaced from one another and from the foils of the next adjacent foil stage so that the interacting uniform adjacent foil pressures and the upstream foil wake beneficially interacts optimally with at least one of the surfaces or boundary layers of the foils of the next adjacent downstream foil stage.
    Type: Grant
    Filed: March 5, 1982
    Date of Patent: November 20, 1984
    Inventor: Elliott M. Levine
  • Patent number: 4367063
    Abstract: A directional and yaw control mechanism for coaxial helicopters, comprising a three coaxial ring system interconnected through a cam and link assembly for transmitting control signals from a steering station to change the rotor blade pitch either collectively to provide lift or independently in opposing directions to control yaw. Cyclic pitch control is also similarly provided.
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: January 4, 1983
    Inventor: Juan C. Herruzo
  • Patent number: 4347997
    Abstract: A helicopter including a power absorber arranged to selectively absorb power from a sustaining rotor system during deceleration. In an illustrated embodiment for a helicopter having a single sustaining rotor, the power absorber comprises a tail rotor assembly having two tail rotors located one on each side of a tail cone, and a control operative to adjust the pitch setting of the tail rotors to provide lateral thrust forces in opposed directions with a net lateral thrust force in one direction in order to maintain a desired heading during deceleration.
    Type: Grant
    Filed: March 24, 1980
    Date of Patent: September 7, 1982
    Assignee: Westland Aircraft Limited
    Inventors: Geoffrey M. Byham, Ronald V. Smith
  • Patent number: 4170437
    Abstract: Yaw control device for helicopters with contra-rotating rotors which controls the anti-torque action of the rotors on the helicopter fuselage by means of a variable speed reduction ratio drive transmission comprising a differential traction drive. At one setting of the yaw controls the rotor torques are balanced by means of the differential in which the input shaft drives a planet carrier and the output shafts are driven by traction discs.The yaw control is accomplished by means of tilting the axes of rotation of the planets thus changing the effective radia of driving the discs which upsets the rotor torques equilibrium. In a stabilized flight of the helicopter the rotations of the planets on their carrier is practically nil, hence the power loss due to the use of the traction drive is small.
    Type: Grant
    Filed: February 23, 1976
    Date of Patent: October 9, 1979
    Inventor: Kazimierz Korsak
  • Patent number: 4123018
    Abstract: The invention relates to improvements to helicopters with coaxial rotors, of convertible type in particular, consisting of at least two contra rotative rotors carrying blades for lifting and propelling, the fuselage having an axis parallel to the axes of the rotors and wherein each rotor consists of a nave carrying arms radially arranged, the arms carrying a coating with a propeller blade section, movable in incidence through whirling on to said arms. The naves are axially displaced along and rotatably supported about a shaft coaxial with the fuselage axis and comprising a structural support member of the fuselage.
    Type: Grant
    Filed: May 16, 1977
    Date of Patent: October 31, 1978
    Inventor: Rene C. A. Tassin de Montaigu
  • Patent number: 4008979
    Abstract: A control for a helicopter having dual, coaxial, counterrotating rigid rotors which varies the cyclic control phase angle of each rotor in flight as a function of vehicle forward speed to thereby control the coupling of lateral cyclic pitch with longitudinal cyclic pitch so as to introduce differential cyclic pitch inputs which automatically produce aerodynamic moments in each rotor to minimize maneuver generated gyroscopic precession moments, which also produce optimum lateral lift vector displacement for all flight speeds.
    Type: Grant
    Filed: November 13, 1975
    Date of Patent: February 22, 1977
    Assignee: United Technologies Corporation
    Inventors: Dean Earl Cooper, Robert Fuller Klingloff