US3459267A - Bladed rotors - Google Patents

Bladed rotors Download PDF

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Publication number
US3459267A
US3459267A US630251A US3459267DA US3459267A US 3459267 A US3459267 A US 3459267A US 630251 A US630251 A US 630251A US 3459267D A US3459267D A US 3459267DA US 3459267 A US3459267 A US 3459267A
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United States
Prior art keywords
pitch
valve
motor
control
piston
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US630251A
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English (en)
Inventor
John Alfred Chilman
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Dowty Rotol Ltd
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Dowty Rotol Ltd
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H3/00—Propeller-blade pitch changing
    • B63H3/06—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical
    • B63H3/08—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid
    • B63H3/081—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid actuated by control element coaxial with the propeller shaft
    • B63H3/082—Propeller-blade pitch changing characterised by use of non-mechanical actuating means, e.g. electrical fluid actuated by control element coaxial with the propeller shaft the control element being axially reciprocatable
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C11/00—Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
    • B64C11/30—Blade pitch-changing mechanisms
    • B64C11/38—Blade pitch-changing mechanisms fluid, e.g. hydraulic
    • B64C11/40—Blade pitch-changing mechanisms fluid, e.g. hydraulic automatic

Definitions

  • a bladed rotor having adjustable blading, adjustment of which is effected by the operation of a fluid pressure motor, includes a control valve adjustable for appropriate control of the motor.
  • a further valve is operative, upon the occurrence of a predetermined but inadvertent amount of drift of the motor and thus of the blading, to lock the motor hydraulically.
  • the blading is conveniently of variable pitch, and the further valve may be disposed hydraulically in series with the control valve and arranged to close in the event of said inadvertent drift of the motor and blading.
  • This invention relates to bladed rotors having adjustable blading, such as blading of variable pitch, variable camber or variable twist type, it being intended that the term rotor should include propellers, wind motors, fans and the like.
  • a bladed rotor having adjustable blading adjustment of which is efiected by the operation of a fluid pressure motor, includes first valve means adjustable for appropriate control of the motor and further valve means operative, upon the occurrence of a predetermined but inadvertent amount of drift of the motor and thus of the blading, to lock the motor hydraulically to prevent further drift.
  • the further valve means are so arranged in series circuit with the first valve means as to be capable of preventing flow of pressure fluid to, and/or exhaust of pressure fluid from, the motor.
  • the first valve means may operate to prevent flow of pressure fluid to, and exhaust of pressure fluid from, a Working chamber on one side of the piston.
  • the said first and further valve means may be arranged within a hub of the bladed rotor coaxially of the rotation axis of the rotor.
  • the first valve means may form part of a closed-loop follow-up servo mechanism, and be arranged within a motor piston in such manner that relative axial displacement of the first valve means and the piston initiates movement of the piston in one direction or the other according to the direction of the relative axial displacement, with such movement following-up the movement of the first valve means and effectively returning the latter to a condition of equilibrium when the selected or governed condition is reached by the motor. If, during operation of the bladed rotor and following displacement of the first valve means, the piston fails to follow-up the movement of those valve means, due to some mechanical failure or pressure loss, a predetermined amount of drift of the piston is tolerated but any movement beyond 3,459,267 Patented Aug. 5, 1969 ice this predetermined amount causes said further valve means to close and thereby lock the motor piston against further drift.
  • the movable element of the further valve means may be of poppet type with a stem which extends axially through the movable element of the first valve means for connection externally of the latter to the control means, the spring box being arranged within the movable element of the first valve means which is slidable within the motor piston.
  • the poppet element in this arrangement preferably closes against a seat formed in or on the piston itself and through which the pressure liquid has to flow to one side of the motor piston.
  • the stem of the poppet element may be connected to an element of the control linkage with which it is aligned and which passes axially through the hub.
  • the invention is of particularly advantageous application to a variable pitch rotor mounted at the forward end of an aircraft power plant, for example a propeller, a wind motor (such as a ram air turbine) or a by-pass fan of a gas turbine engine.
  • a further suitable application is to fans used in gas-cushion vehicles or the like.
  • the invention is in no way limited as to the form of the blade adjusting means, and although the blades are preferably of variable pitch they may alternatively be of variable camber or variable twist type. Blades of variable camber type each have a fixed leading portion with an adjustable trailing portion pivoted thereon.
  • the first valve means may form part of a speed-responsive governor arranged to control the rotor speed automatically in dependence upon the datum setting of a speeder spring of the governor.
  • the governor may be arranged with its axis coincident with the axis of rotation of of the propeller, in which case the governor fly-weights rotate about this axis, or the governor may be arranged externally of the hub as may the valve means themselves.
  • a pump supplying liquid under pressure for operation of the motor may also be mounted in the hub, and also so mounted as to be driven by rotation of the rotor.
  • a liquid reservoir may also be disposed in the hub and be formed by the hub structure, centrifugal force urging the liquid radially outwardly against the inner wall of the hub to constitute an annular reservoir.
  • a bladed rotor in accordance with the invention may be so constructed as to include other means both for locking blade pitch and for restricting the range of the movement of the motor and thus the range of adjustment of the blading.
  • FIGURE 1 is an axial sectional view of the propeller
  • FIGURES 2 to 7 are diagrammatic views illustrating the operation of the valve means which control the blade pitch of the propeller.
  • the propeller has three variable pitch blades such as 1 separately mounted in a hub 2 by means of respective blade retention bearing assemblies such as 3.
  • blade retention bearing assemblies such as 3.
  • the root end of only one blade 1 is illustrated.
  • a fluid pressure motor operative to vary the blade pitch comprises a cylinder 4 bolted to and projecting forwardly of the hub 2, and within which a piston assembly 5 is axially slidable.
  • This assembly comprises an outer portion 6 forming the piston proper and slidable directly within the cylinder 4, front and rear working chambers A and B of the motor respectively being formed within the cylinder on opposite sides of the portion 6, and an inner tubular portion 7 slidable within a hollow cylindrical spigot 8 which is supported at the rear side of the hub 2 and projects forwardly through the latter.
  • An intermediate tubular portion 9 of the assembly 5 projects rearwardly into the hub 2, and this portion 9 is formed internally with straight teeth 10 which cooperate with complementary teeth 12 on the outer surface of the spigot 8 to prevent rotation of the piston assembly 5 relatively to the hub 2.
  • the intermediate portion 9 On its outer surface the intermediate portion 9 is provided with helical teeth 13 which engage helical tooth spaces in the hollow boss 14 of a bevel gear 15 mounted centrally within the hub 2.
  • the control port 37 communicates with the passageway 36 through a passage 39 and past a ported spring abutment plate 40 which surrounds the stem 25 and is engaged by a spring 41 which urges the control valve element 21 in the righthand direction as shown in FIGURE 1, i.e. to a coarse-pitch control position corresponding to increasing blade pitch.
  • the lock valve element 24 is capable of axial movement relatively to the control valve element 21 against the action of the spring box means 23, and these means urge the valve element 24 to a limit position in which a circlip 42 on the stem 25 engages an abutment shoulder 43 formed within the valve element 21.
  • the control port 37 is constantly in communication, internally of the control valve 20 and through a radial bore 44 in the valve element 21, with a passageway 45 in the stem 25.
  • This passageway leads to one end of the balancing chamber 34, the other end of which is permanently in communication with the pressure passageways 28 and in fact forms part of the pressure supply conduit to the valve 20.
  • the differential area of the piston 41 is so chosen that at all times the valve elements and operation linkage are pressure balanced.
  • FIG- URE 2 illustrates a position of the control valve element 20 corresponding to a pitch-fining operation, the control port 46 being connected to the pressure port 27, and the control port 37 connected to exhaust, i.e. back to drain, via the exhaust port 30'. This results in pitch adjusting movement of the piston assembly 5 which follows-up the previous control movement of the valve element 20.
  • FIGURE 3 illustrates a coarse-pitch position of the control valve element 21 corresponding to a pitch changing operation with the blades 1 moving in the direction of increasing pitch.
  • the pressure and exhaust connections are interchanged as compared with FIGURE 2, the port 46 being connected to the pressure port 27 and the port 46 connected to exhaust through the port 32.
  • the piston assembly 5 follows-up movement of the valve element 21 until equilibrium conditions are again restored corresponding to the selected pitch position.
  • FIGURES 4 to 7 illustrate the manner in which the mechanism is safeguarded against pitch drift in the event of several diiferent forms of control failure.
  • the effect of loss of oil supply pressure is illustrated in FIGURE 4, which shows that any drift of the piston assembly 5 in the decreasing pitch or pitch-fining direction is limited by closure of the lock valve element 24 which seals the passageway 36.
  • the liquid in the working chamber A at the forward end of the cylinder 4 is trapped, as previously described, to retain the pitch adjustment. Any further slight movement, the rate of which is dependent on any leakage past the lock valve element 24 which may occur, tends to shut the lock valve even more to reduce still further any leakage drift which may occur.
  • a bladed rotor having adjustable blading, adjustment of which is effected by the operation of a fluid pressure motor, and including first valve means adjustable for appropriate control of the motor and including a valve element movement of which controls both directions of adjustment of the blading, and further valve means which are normally open so as to have no effect on blade adjustment but which close, upon the occurrence of a predetermined but inadvertent amount of drift of the motor and thus of the blading, to lock the motor hydraulically to prevent further drift.
  • a bladed rotor according to claim 1 wherein said first valve means is spring loaded in a direction corresponding to blade adjustment in the direction opposite to that in which drift renders the further valve means operative.
  • a bladed rotor having adjustable blading and a hub structure within which is disposed a hydraulic motor for adjustment of the blading, a follow-up servo valve which is moved by a control linkage for control of the motor in both operative directions thereof and a lock valve which operates to lock the motor hydraulically, both valves being mechanically linked in such manner that in the event of failure of hydraulic pressure or seizure of either valve the lock valve becomes operative if the motor, and hence the blading, inadvertently drifts a small predetermined amount from the control position.

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  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Mechanically-Actuated Valves (AREA)
  • Wind Motors (AREA)
  • Hydraulic Motors (AREA)
US630251A 1966-04-12 1967-04-12 Bladed rotors Expired - Lifetime US3459267A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB06007/66A GB1185041A (en) 1966-04-12 1966-04-12 Adjustable Bladed Rotors

Publications (1)

Publication Number Publication Date
US3459267A true US3459267A (en) 1969-08-05

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ID=10069507

Family Applications (1)

Application Number Title Priority Date Filing Date
US630251A Expired - Lifetime US3459267A (en) 1966-04-12 1967-04-12 Bladed rotors

Country Status (6)

Country Link
US (1) US3459267A (fr)
JP (1) JPS4540496B1 (fr)
CH (1) CH458084A (fr)
DE (1) DE1506629B1 (fr)
GB (1) GB1185041A (fr)
SE (1) SE320890B (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3603698A (en) * 1969-11-19 1971-09-07 Nordisk Ventilator Axial flow fan wheel
US3690788A (en) * 1970-02-16 1972-09-12 James M Pedersen Controllable pitch propeller
US3746466A (en) * 1971-06-25 1973-07-17 Dieselmotorenwerk Veb Adjusting and locking device
US3819296A (en) * 1972-03-06 1974-06-25 Mitsubishi Heavy Ind Ltd Control for hydraulic machine having adjustable blades
US3918837A (en) * 1973-02-17 1975-11-11 Dowty Rotol Ltd Bladed rotors
US4028004A (en) * 1974-07-03 1977-06-07 Lips B.V. Feathering controllable pitch propeller
US4921403A (en) * 1988-01-15 1990-05-01 Dowty Rotol Limited Propeller blade assembly
FR2683789A1 (fr) * 1991-10-25 1993-05-21 United Technologies Corp Interrupteur de limite inferieure du pas, a commande hydraulique, pour un dispositif de variation du pas d'une helice.
US5263898A (en) * 1988-12-14 1993-11-23 General Electric Company Propeller blade retention system
US5478203A (en) * 1994-04-28 1995-12-26 Rolls-Royce Plc Blade pitch change mechanism
CN107933890A (zh) * 2017-11-08 2018-04-20 镇江市丹徒区顺发船舶螺旋桨有限公司 一种后期维护的螺旋桨

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4348155A (en) * 1980-03-17 1982-09-07 United Technologies Corporation Wind turbine blade pitch control system
US4523891A (en) * 1983-06-15 1985-06-18 United Technologies Corporation Propeller pitch change actuation system
DE102004017323A1 (de) * 2004-04-06 2005-11-03 Repower Systems Ag Windenergieanlage

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2781856A (en) * 1952-06-06 1957-02-19 Rotol Ltd Control system for variable pitch screw propellers
US3080928A (en) * 1955-05-16 1963-03-12 Dowty Rotol Ltd Hydraulically operated variable pitch propellers
US3219121A (en) * 1962-08-03 1965-11-23 John W Barden Controllable pitch propeller hydraulic locking device
US3240275A (en) * 1963-12-03 1966-03-15 Curtiss Wright Corp Hydraulically operable pitch aircraft propeller
US3242992A (en) * 1964-09-25 1966-03-29 United Aircraft Corp Feedback system
US3261406A (en) * 1963-05-16 1966-07-19 United Aircraft Corp Attitude control system for an aeronautical propeller

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1050202B (fr) * 1959-02-05
GB927718A (en) * 1958-12-04 1963-06-06 Dowty Rotol Ltd Improvements in or relating to variable pitch propellers and propeller fans

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2781856A (en) * 1952-06-06 1957-02-19 Rotol Ltd Control system for variable pitch screw propellers
US3080928A (en) * 1955-05-16 1963-03-12 Dowty Rotol Ltd Hydraulically operated variable pitch propellers
US3219121A (en) * 1962-08-03 1965-11-23 John W Barden Controllable pitch propeller hydraulic locking device
US3261406A (en) * 1963-05-16 1966-07-19 United Aircraft Corp Attitude control system for an aeronautical propeller
US3240275A (en) * 1963-12-03 1966-03-15 Curtiss Wright Corp Hydraulically operable pitch aircraft propeller
US3242992A (en) * 1964-09-25 1966-03-29 United Aircraft Corp Feedback system

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3603698A (en) * 1969-11-19 1971-09-07 Nordisk Ventilator Axial flow fan wheel
US3690788A (en) * 1970-02-16 1972-09-12 James M Pedersen Controllable pitch propeller
US3746466A (en) * 1971-06-25 1973-07-17 Dieselmotorenwerk Veb Adjusting and locking device
US3819296A (en) * 1972-03-06 1974-06-25 Mitsubishi Heavy Ind Ltd Control for hydraulic machine having adjustable blades
US3918837A (en) * 1973-02-17 1975-11-11 Dowty Rotol Ltd Bladed rotors
US4028004A (en) * 1974-07-03 1977-06-07 Lips B.V. Feathering controllable pitch propeller
US4921403A (en) * 1988-01-15 1990-05-01 Dowty Rotol Limited Propeller blade assembly
US5263898A (en) * 1988-12-14 1993-11-23 General Electric Company Propeller blade retention system
FR2683789A1 (fr) * 1991-10-25 1993-05-21 United Technologies Corp Interrupteur de limite inferieure du pas, a commande hydraulique, pour un dispositif de variation du pas d'une helice.
US5478203A (en) * 1994-04-28 1995-12-26 Rolls-Royce Plc Blade pitch change mechanism
CN107933890A (zh) * 2017-11-08 2018-04-20 镇江市丹徒区顺发船舶螺旋桨有限公司 一种后期维护的螺旋桨

Also Published As

Publication number Publication date
GB1185041A (en) 1970-03-18
JPS4540496B1 (fr) 1970-12-19
CH458084A (fr) 1968-06-15
SE320890B (fr) 1970-02-16
DE1506629B1 (de) 1970-02-26

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