Note: Descriptions are shown in the official language in which they were submitted.
1~'7~
AIR JET RE~CTION CONTRAROTATING ROTOR GYRODYNE
WITH TllRtJST P~EVERSERS AND
SPECIFIC ROTOR AIR SUPPLY CONTROLS
This invention relates to a twin jet gyrodyne
supported by air j~t reac-tion contrarotating rigid
rotors, powere~ wi.th turbofan by~ass engines and havinc~
drop tip -~ings.
An objective in the design of aircraft has
been to provide an aircraft capable of vertical takeoff
and landing, having high speed in horizontal flight and
being of simple construction and easy to operate.
Prior art aircraft have not been able to
accomplish the objective stated above and the present
invention is not able to achieve the objective
completely but provides a closer approach to it than
prior aircraft.
An aiFpla~e can fly horiæontally at high
speed, but instat~d of ~eing able to take off
vertically, requires considerable horizontal run in
order for the relative wind, i.e. flow of air past the
wings, to enable the wings to develop sufficient lift
to sustain the weiyht of the airplane. In order to
enable airplane wings to develop sufficient lift at
lower speeds, forward wing slots, trailing edg-e wing
flaps and other wing modifications have been utilized,
but airplanes with such high-lift devices still require
a substantial horizontal run in order to take off.
Autogiros can take off with a much shorter
run than short takeoff and landing (STOL) airplanes,
and some autogiros can even make ~ump takeoffs, but
cannot continue tc rise vertically for any substantial
distance since their rotors autorotate, that is, are
revolved reactively by the relative wind. The speed of
~1 "
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the autogiro in hori~ontal ~light is limited as
compared to the speed of an airplane by rotor blade
stall. Also, a rotor installation, whether in an
autogiro or a helicopter, is structurally and
mechanically more complicated than the fixed wing of an
airp]ane.
The giroplane type of autogiro is capable of
higher forward spee~ than an autogiro having a rotor
the blade pitch of which can be changed only
collectively, by providing cyclic pitch control for the
rotor blades so that the pitch of a blade when it is
advancin~ is less than when it is retreating.
A helicopter is capable of vertical takeoff
and landing and can hover because its rotor is powered,
but its maximum hori~ontal speed is even less than that
of an autogiro and it is more complicated mechanically
because its rotor is powered instead of being
autorotating. Driving of some helicopter rotors has
been simplified somewhat by powering them with reaction
gas jets instead of mechanical gear drives, such as
disclosed in the following U.S. patents:
Papin et al. 1,133,660;
Stalker 2,443,936;
Stalker 2,617,487;
~oblhoff 2,81 8,223;
Mathews 2,831,543.
In order to enable the maximum horizontal speed of
helicopters to be increased somewhat, contrarotating
rotors have been used, dxiven by gearing, such as shown
in Figure 4 of the Maillard et al U.S. patent
2,644,533. Air turbines were used to rotate
contrarotating rotors in Ramme U.S. patent 3~417,~25.
~ 3~3~
Attempts have been made to combine the
high-sp~ed capability of airplanes and the vertical
takeoff and landing capability of helicopters by
convertip]an~S Whicil have been provide~ with some type
of ~echanical conversion to chan~e the thrust direction
from vertical to hori~ontal, such as an airscrew that
can be altered mechanically to rotate either in a
horizontal plane to serve as a rotor, or in a vertical
plane to serve as a propeller. In some instances, the
rotor blades have been locked to serve as fixed wings.
In other instances, ducted fans have been mounted
turnably on the ends of fixed wings to direct thrust
alternatively upward and forward. In still other
instances, propellers have been mounted on wings to
produce thrust chordwise of the wings and the win~s
have been turnable relative to the airplane fuselage
about spanwise axes. The principal difficulty with
such convertiplanes is problems produced in making the
transition from vertical flight to horizontal flight.
A further proposal to accomplish the
objective stated above is the gyrodyne or compound
helicopter. A gyrodyne is defined in the National
Aeronautics and Seace Administration Aeronautical
Dictionary, 1959, as follows:
A rotating-wing aircraft whose rotor or
rotors provide lift only, the system
customarily being powered for take-off,
hovering, landing, and for forward flight
throughout part of its speed range, but
usually autorotating at the hiyher flight
speeds, forward propulsion being provided by
a propeller or jet.
The gyrodyne is manufactured in a number of
different varieties: with or without wings in
adclition to its rotor; with different
mechanical arrangements for lif-t
e~ualization over the rotor; with or without
separate power plants for the rotor and
forward-propulsion system; etc.
The NASA Aeronautical Dictionary states that the term
I'compound helicopter" is a synonym for gyrodyne but is
used rarely.
Prior gyrodynes or compound helicopters
include: the Lockheed AH-56 mentioned in the
McGraw-Hill Encyclopedia of Science and Technoloqy
Third Edition, 1971, Volume 6, page 435, column 1,
bottom; and page 441, column 1, top, and shown in
Figure 8 (e) on page 440; and also shown in Volume 3,
page 504, Figure 4; and mentioned on page 506, column
1, top; and
the McDonald XV~1 mentioned and shown in the
McGraw-Hill ncyclopedia of Science and Technoloqy,
Third Edition, 1971, Volume 3, page 504, column 2, top,
Fig~lre 3; and mentioned in Volume 3 on page 506, column
1, top.
Both of these gyrodynes have small fixed
wings and single rotors.
It is the principal object of the present
invention to provide a gyrodyne construction which is
more efficien-t in producing vertical lift than single
rotor helicopters, is less complicated than helicopters
having contrarotating rotors that are rotated
mechanically and which will have a higher forward speed
than single rotor autogiros, helicopters or previous
gyrodyn~s.
A furthex obj ec-t is to provide a simpler and
more efficient -type of rotor ins-tallation.
It is also an object to simplify the
propulsion of contrarotAtin~ rotors by utili.zing air
jet reaction propulsion instead of mechanical drive
mechanism~
A further object is to proportion the supply
of air between the rotors rotating contrarGtationally
to equalize the llft forces produced by the two rotors,
or to unbalance such forces in a predetermined manner,
as may be preferred~
Another object is to be able to control the
utilization of bypass air supplied by twin turbofan
engines in variable proportions to rotate
contrarotating rotors reactively or to supplement
exhaust gas jets from the engines by producing a
rearwardly discharged air jet to increase horizontal
flight propulsion force and to provide propulsion for
taxiing with the rotors stationary~
An additional object is to provide drop tip
wings the tip portions of which can be swur.g downward
to reduce the effect of such tip portions in blanketing
downdraft from the rotors and which tip portions
further serve as outriggers for laterally stabilizing
the gyrodyne if it is floating on water.
Another object is to interconnect the
contrarotating rotors mechanically so as to coordinate
their rotations not only so that the rotors will rotate
at the same speed, but so that the positions in which
blades of the upper and lower rotors are in
regi.stration as they cross each other during rotation
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can be controlled with respect to the fixed wing and
fuselage of the cJyrodyne.
Some o:E the fore~oing objects can be
accomplisile~ by providing in a gyrodyne the lmprovement
com~risirl~ the combination of a fixed ~/ing, a hollow
mast mourlted centrally of the gyrodyne, concentric
contraxotating rotors carried by said hollow mast, twin
turbofan engines carried by the gyrodyne at opposite
sides of said hollow mast and discharging exhaust yas
to effect jet thrust for ~he gyrodyne, duct means
connecting said turbofan engines and said hollow mast
for supplying bypass air from said turbofan engines to
the interior of said hollow mast, air discharge means
carried by the b].ades of said contrarotating rotors for
discharging transversely thereof air received from said
hollow mast to effect reaction rotation of said rotors,
two tai.l pipes extendinc~ rearward from said turbofan
engines, respectively, and disposed in substantially
spaced parallel relationship for discharging exhaust
gas from said turbofan enyines and forming an
outrigger, rudder control devices mounted in the
slipstream from each of said tail pipes and rudder
control means for swinging said rudder control devices
for said two tail pipes simultaneously.
Others of such ob]ects can be accomplished by
providing in a gyrodyne the improvement comprising the
combination of a fixed wing, a hollow mast mounted
centrally of the gyrodyne, concentric contrarotating
rotors carried by said hollow mast, twin turbofan
engines carried by the gyrodyne at opposite sides of
said hollow mast and discharging exhaust gas to effect
jet thrust for the gyrodyne, duct means connecting said
turbofan engines and sai~ hollow mast for supplying
bypass air from said turbofan en~ines to the interior
of said hollow mast/ air discharge means carried by the
blades of said contrarotating rotors for discharging
transversely -thereor air rece:ived rrom sai~ hollow mast
to effect reaction rotation of said rotors, two tail
pipes extendiny rearward from said turbofan engines,
respectively, and disposed in substantially spaced
parallel relationship for discharging exhaust gas from
said turbofan engines and forming an outrigyer, rudder
control devices mounted in the slipstream from each of
said tail pipes, rudder control means for swinging said
rudder control devices for said two tail pipes
simultaneously, a longitudinally extending air duct
located between said tail pipes for discharging an air
~et therefrom, and control means for supplying at least
a portion of the bypass air from said turbofan engines
to said longitudinally extending air duct.
Others of such objects can be accomplished by
providing a gyrodyne comprising a fixed wing;
contrarotating rotors mounted on the gyrodyne; twin
bypass gas turbine turbofan engines carried by the
gyrodyne, mounted on opposite sides of its center line
and discharging exhaust gas; duct means connectiny the
engines and the rotors for supplying bypass air from
the engines to the rotors; air discharge means carried
by the blades of the contrarotating rotors for
discharging transversely thereof air received from the
engines, and tail pipes extending rearwardly from the
engines and disposed in substantially spaced parallel
relationship for discharying exhaust gas from the
engines; the improvement comprising the rotors be.ing
3~1L
carried coaxially by a hollow mast which is mounted
centrally on -the gyrodyrle; the en~ines being mounted on
opposite sides of said hollow mast; the cluct means
connect the turbofarl engines ancl said hollow mast for
sup~lyincJ bypass air from the turbofan engines to the
rotors through the interior of said hollow mast; air
discharye means for dischargincj from the rotors air
received Erom said hollow mast to effect reaction
rotation of the rotors in opuosite directions;
horizontal stabi~izer means connecting the rearward end
portions of the tail pipes for forming an outrigger;
and vertical control surfaces mounted on said
horizontal stabiliæer means in alignment with the
discharge ends of the tail pipes for controlling the
direction of the yyrodyne, said vertical control
surfaces being bifurcated and their bifurcations being
spreadable to divert exhaust gas emitted Eorm the tail
pipes laterally and forward to constitute thrust-
reversiny means.
Others of such objeets can be accomplished by
providing in a gyrodyne, the improvement comprising a
hollow mast, contrarotating rotors carried by said
mast, turbofan engine means earried by the gyrodyne,
air diseharge means carried by the blades of said
contrarotating rotors for discharging transversely
thereof air received from said hollow mast to effect
reaction rotation of said rotors, duct means conneeting
said turb~fan engine means and said hollow mast for
receiving bypass air from said turbofan engine means
and conveying it to said hollow mast for flow
therethrough to the rotor blades, and control means for
varyincJ the distribution of the air flowing through
7A
B
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said hollow mast from said turbofan engine means to
supply to ~11 of the blades of one of said rotors
substantially all the supply of air from said tur~ofan
engine means to said hollow mast.
Others of such obJects can be accomplished by
providinc~ in a gyrodyne, the improvemen-t comprising a
rotor in which each rotor bl.ade is mounted to turn
about a spanwise axis to alter its pitch, and
counter~eight means carried by the tip portion of each
rotor blade and projecting forward beyond the major
yortion of the leading edge of the rotor blade for
substantially balancing the rotor blade statically
about such spanwise axis.
Others of such objects can be accomplished by
providing a gyrodyne comprising a fixed wing, a hollow
mast mounted centrally of the gyrodyne, contrarotating
rotors carried by said hollow mast, twin turbofan
engines mounted at oppos.ite sides of said hollow mast,
tail pipes extending rearward from said turbofan
engines and disposed in substantially spaced parallel
relationship for discharging exhaust gas from said
turbofan engines and forming an outrigger, duct means
connecting said turbofan engines and said hollow mast
for receiving bypass air from said turbofan engines,
brake means effective to retard the rotative speed of
both of said rotors, means for proportioning the flow
of air from said duct means through said hollow mast to
said rotors, horizontal stabilizer means connecting the
rearward end portions of said tail pipes, and vertical
control surfaces mounted on said horizontal stabilizer
means in alignment with the discharge ends of said tail
pipes for controlling the direction of the gyrodyne,
. ,
7 B
said vertical control surfaces being bifurcated and
their bifurcati.ons being spreadable to divert exhaust
gas emitted :Erom said tail pipes laterally and forward
to constitut:e thrust-reversin~ means.
In drawings which illustrate the preferred
embodiment of the invention,
Figure 1 is a plan of the gyrodyne, Figures 2
is a front elevation of the gyrodyne and Figure 3 is a
side elevation of the c;yrodyne,
7C
B
Figure 4 is a top perspective of the gyrodyne
with the rotors omitted,
F:igure 5 i~ a top perspective of the tip
portion of a rotor bla~e with parts broken away,
Figllre 6 is a side elevation of the central
portions of the upper and lower rotors with parts of
the roto.r mast and parts of the rotor hubs broken away,
Figure 7 is a to2 perspective of the upper
portion of the rotor mast and the central portion of
the upper rotor showing parts o~ the rotor hub and it~
mounting in exploded relationship,
Figure 8 is a top perspective of the
central portion of the lower rotor and adjacent
portions of the rotor mast,
Figure 9 is a side elevation of the central
portion of the lower rotor and adjacent portions of the
rotor mast, showing control mechanism for the rotor
blades, with parts broken away,
Figure 10 is a horizontal section taken on
20 line 10--10 of Figure 9,
Figure 11 is a detail perspective showing
control mechanism for the lower rotor blades, parts
being broken away,
Figure 12 is a side elevation of the central
portions of the rotors and the rotor mast showing rotor
interconnecting gear train mechanism for mechanically
synchronizing rotation of the rotors, Figure 13 is a
plan showing such mechanism, and Figure 14 is a detail
perspective of a portion of such mechanism,
Figure 15 is a somewhat diagrammatic plan of
the engine installation, parts being bxoken away, and
Figure 16 is a somewhat diagrammatic side elevation of
--8--
such install~tion with parts broken away.
While the principles involved in the gyrodyne
of the present invention are adapted for use in larger
aircraftl and to some e~tent for use in smaller
aircraft, they are especially applicable to an ~i~craft
Of medium size such as would carry 20 to 40 passengers.
In Figures 2 and 3 of the drawings, the fuselage 1 is
shown as having a capacity for 24 passengers. Although
the gyrodyne would have advantages over a helicopter or
an autogiro without having a fixed ~ing, it is
preferred that the gyrodyne have a fixed wing 2. Also,
it is preferred that that wing be a high wing so as to
provide a spanwise central platform structure for
attaching the tubular rotor mast 3 in a position
substantially coinciding fore and aft with the center
of pressure of the wing and substantially coinciding
with the center of gravity of the aircraft. Rota~ively
mounted on the rotor mast are an upper rotor having
four blades 4 and a lower rotor having four blades 5 in
contrarotational relationship.
As shown in Figures 2 and 3, the spanwise
central platform of the high wing 2 also serves as a
mounting base for twin turbofan engines 6 that are
spaced laterally a distance slightly greater than the
width of the fuselage 1 and at least partially forward
of rotor mast 3, as shown in Figure 2. The exhaust gas
from the turbofan engines is dischargecl rearwardly
through tail pipes 7 shown best in Figures 1, 4, 15 and
16 which also serve as outriggers. The bypass air from
the turbofans is channeled into centrally-directed
pipes 8 and conveyed either through the hollow of rotor
mast 3 to the rotor blades 4 and 5 to provide reaction
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propulsior1 for the ro~ors, or through the branch
rearwardly-convergin~ conduits 9 which ioin to supply
compressed air to the rearwardly-extending
alr-discharge conduit 10, located centrally between
tail pipes 7, which serves as a ~urther outrigger.
~ lthough the aircraft is capable of vertical
takeoff and landing~ it is desirable to provide a
light, wheeled, preferably tricycle, undercarriage
including transversely spaced rear wheels 11 and a pair
of steerable center forward wheels 12 to sllpport the
aircra~t for taxiing over the ground, It is preferred~
however, that the aircraft be of the amphibian type,
which is a furthex reason for the wing 2 to be a high
wing so as to provlde maximum clearance from waves and
spray. Such wing includes fiYed root or inboard
sections `l3 at opposite sides of a center section or
platform to which are joined tip or outboard sections
14. Such inboard and outboard sections cooperatively
form a stub wing which preferably has a swept back
leading edge. The inboard end of each outboard wing
section of each wing is joined to the adjacent outboard
end of the corresponding inboard wing section by a
chordwise-extending hinge 15 to form a drop wing tip.
The span of the tip section is such that a float 16
carried by its tip will be disposed slightly higher
than the bottom of the fuselage 1 when the wing tip
section is swung downward so as to form a flotation
outrigger. The drop wing tip can be swung between its
raised horizontal position and its lower drop position
by a hydraulic jack 17 connected between the inboard
wing section 13 and the outboard wing section 14 and
bridging across hinge 15.
- 1 0 -
~ ~t~ 3~
The rearward portions of the outrigger tail
pipes 7 and the air jet discharge duc-t 10 are connected
by horizontal stabilizers 18, as shown in Figures 1 and
4. Vertical fins 19 are mounted on the outboarcl ends
of the stabili~ers. I'he tip sections of the outboard
win~ sections 14 may be provided with ailerons or
flaperons 20 to assist rolling and directional con-trol
durin~ forward flight and, if desired, to augment the
lift of the wing 2.
The blades 4 of the upper rotor and the
blades 5 of the lower rotor may be identical, and
in-terchangeable if the blades are of symmetrical cross
section. The cross section of the blade 4 shown in
Figure 5, however, is not of symmetrical cross
section. The spanwise axis about which the blade can
turn to alter its pitch is located forward of the
spanwise center of gravity of the blade, preferably
substantially coincident with the center of pressure of
the blade. In order to balance the blade statically
about such axis and to provide additional mass for
increasing the momentum of the blade in auto-rotation
mode, a counterbalancing weight 21 can be located
forwardly of the senera] leading edge of the blade,
preferably at the blade tip as shown best in Figure 5.
Spanwise stiffening of the blade is provided
by a spanwise-extending spar 22 which divides the
hollow of the blade into air passages 23 forward and
rearward of it for flow o~ air from the rotor mast 3
outward through the blade even to its tip. Air may be
discharged from the rear passage through
rearwardly-directed boundary layer control slots 24
through the upper surface of the blade which may extend
~ 3~31
throughout substantially the entire span of the rotor
blade, to increase lift and postpone stall of the
blade. Such slots may be located approximately 60
percent of the chord aft of the leading edge of the
blade. In addition to the rotor-rotating reaction
produced by dischar~e of air through the boundary layer
control slots, air can be discharged through apertures
or nozzles 25 located at the blade tip and directed
rearwardly. Such apertures or nozzles may be circular,
oval, square or rectangular as may be preferred~
The root of each rotor blade 4 and 5 is
formed as a hollow, cylindrical stub shaft 26 joined to
the blade proper by a flaring adapter 27. The blade
root stub shaft is received between the spider halves
of a split hub 28 having radial hollow arms 29 that
embrace the upper and lower sides of each blade root
stub shaft. Such hollow spider arms have
axially-spac~ed circumferential grooves 30 receiving
combined radial-and-thrust bearings 31 encircling the
blade root stub shafts to withstand the pull produced
on the blade by the centrifugal force resulting from
the rotor rotation while enabling the blade to turn
about its axis for adjustment of the blade pitch.
Col]ars 32 secured to the stub shafts 26 provide
abutments preventing such shafts from being pulled
spanwise out of bearings 31~
The meeting sides of the arms 29 of the
spider hub halves have edge flanges that match when the
split hub halves are assembled~ Such flanges have
holes ln them located so that they will be aligned when
the hub halves are assembled to receive bolts which
clamp the hub halves in assembled relationship.
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When the hub and blades of each rotor have
been assembled, the rotors are mounted on the mast.
Each hub has upper and lower annular end bearing seats
33 engageable, respectively, with antifriction thrust
bearings 34 above and below each rotor. Such thrus-t
bearings are held against movement axially of -the mast
by the weight of the rotor acting downward and by the
lift that it produces acting upward. Downward movement
of the upper rotor and movement of the lower rotor in
both directions are prevented by anchor rings 35 of
angle cross section encircling the mast close beneath
the lower thrust bearing 34 of the upper rotor and
alongside both bearings of the lower rotor. Such
collars are secured to the mast by radial screws 36
extending through holes in the ring and the mast spaced
circumferentially about the ring, the holes in one or
the other part being tapped~ Upward movement of the
upper thrust bearing 34 is prevented by a thrust nut 37
screwed onto the upper end of the rotor mast instead of
an upper anchor ring 35. Such thrust nut can be
retained in place by radial screws 38 extending through
it into the mast 3.
The upper end of the rotor mast 3 is closed
by an end plate 39 having an annular shoulder providing
a reduced portion which iS inserted into the upper end
of the mast and an upper circumferential flange
abutting the end of the mast. Such end plate is
retained on the mast and the entire mast is
strengthened by a tension or tie tube 40 extending
axially throughout the entire length of the mast. The
upper end of such tube passes through a central
aper-ture 41 in the end plate 3'~ and is retained in
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place by a nut 42. The lower end of such tension tube
extends through the platform on which the turbofan
engines 6 are mounted and which serves both as the top
of the central portion of the fuselage 1 and the
structure tyin~ together the root portions of the wings
.
Rings 43 are mounted respectively on the
bottom of the top rotor hub and on the top of the
bottom rotor hub which carry braking rings 44
engageable by the plungers of hydraulically operated or
~lectrically-operated spot brakes 45 shown best in
Figures 6, 8 and 9. Such brakes enable the speed of
the rotors to be re~uced controllably when they are in
the autorotation mode and enable the rotors to be held
against rotation when the aircraft is being taxied on
the ground or on water.
In addition, the ring 43 has an auxiliary
sensor ring 46 having in it circumferentially-spaced
holes. The mast carries a sensor 47 having a head
disposed adjacent to the auxiliary ring 46, providing
a stationary magnetic sensing device the magnetic field
of which is altered as each hole passes the head. The
speed with which the rotor is turning is directly
related tG such magnetic field alterations that are
converted by appropriate circuitry into an indication
of the rotational speed of each rotor.
Air to drive the rotors reactively is
supplied from the turbofan engines 6 to one or both of
the rotors through the hollow mast 3O Air can flow
from the rnast into the hollow roots of the blades in
the lower rotor through circumferentially spaced
apertures 48L in -the wall of the mas-t, which
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preferably are ln the Eorm of circumferential slo-ts.
Air is diverted rom the mast through such slots by a
deflector rinc3 491, projectinq inwarcl Erom the inner
wall of the mast above such slots~ The inner edge of
such lower rotor cleflector ring is spaced radially from
the tie tube 40 sufficiently to provide an annular
passa~e between such deflector rin~ and the tie tube
through which air can flow to the upper rotor. If it
is desired to restrict or block completely the flow of
air throu(lh SUCh passaye to the upper rotor, an annular
inflatable choke ring 50 mounted on the tube 40 can be
inflated into the space between the deflector ring 49L
and a constriction 51 above the deflector ring. To the
extent that such passage is restricted, a greater
proportion of air entering the mast will be supplied to
the lower rotor than to the upper rotor.
A~ternatively, the flow of air into the lower
rotor through apertures 48L can be restricted or
blocked completely by inflating an inflatable choke
ring 52 mounted on the underside of the deflector riny
49L and distensible into enga~ement with the inner wall
of the apertured mast and into engage~ent with a
constriction 53 located below the deflector ring 49L.
By controlled inflation of the choke ring 50 and the
choke riny 52, all of the air supplied from the
turbofan engines to the mast 3 can be delivered to the
upper rotor, or all of such air can be delivered to the
lower rotor, or the flow of air to the two rotors can
be e~ualized or proportioned in any way desired. From
-the interior of the mast 3, air passing the
constriction 51 flows into the hollow root stub shafts
26 of the upper rotor blades 4 throuyh apertures 48U in
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the upper portion of the mast wall. The flow of air
from the hollow mast through such apertures can be
deflected smoothly by a downward]y concave annular
deflector ring 4~U bridging the gap between the inner
wall of the mast and the outer wall of the central tube
40.
A collective pitch control thrust rod 54
extends through and is reciprocable lengthwise within
tie tube 40. The upper end of this rod e~tends through
an aperture in the center of a pitch control spider 55.
Encir~ling such central aperture are upper and lower
depressions 56 having central recesses of a size to
receive snugly in them upper and lower antifriction
bearings 57 disposed at opposite sides of a dividing
web between such recesses. The lower bearing rests on
a stop collar 58 pinned to the upper end of thrust rod
54 and the bearings and spider 55 are clamped between
such stop collar and a nut 59 screwed onto the threaded
upper end of collective pitch control rod 54.
Each arm 60 of the spider 55 is connected to
radially-projecting lugs 61 on the root end of the
corresponding blade by a link 62. Each pair of lugs 61
projects forward from a blade root in the direction of
rotor rotation and receives the lower end of the link
62 between the lugs of such pair which is pivotally
connected to such lugs. By shifting the collective
pitch control rod upward, the spider 55 will be raised
to pull links 62 and lugs 61 upward and turn the rotor
blades for increasing their pitch.
The mechanism described above is capable of
adjusting the pitch Gf the upper rotor blades 4 only
collectively. It is preferrecl for the pitch-adjusting
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mechanism for the blades 5 of the lower rotor to be
capable of controlling the blade pitch both collectively
and cyclicly. Such pi-tch control is effected by the
pitch control spider 63 shown in Figures 9 and 10,
which is similar to the spic~er 55 described above in
having radial arms 60 connected by links 62 to lugs 61
projecting laterally from the hub portions of the
individua] ro-tor blades.
Instead of the spider 63 being shiftable only
lengthwise of the rotor mast 3 to alter the pitch of
the blades 5 collectively, such spider must be tiltable
relative to the mast universally and must be capable of
maintaining any given tilted position as to direction
and degree during rotation of the rotor relative to the
mast~ To enable the spider yoke 63 to be shifted
vertically along rotor mast 3 and to be tilted relative
to the mast in any longitudinally adjusted position,
the pitch control mechanism is mounted on a collar 6
that is slidable up and down the mast. The central
portion 65 of such collar is spherically convex and is
complemental to a spherically concave inner surface of
an outer ring 66 encircling the collar. The ring 66 is
rotatively isolated from the ring 67 connecting the
arms 60 on the spider 63 by an antifriction
radial-and-thrust bearing 68 so that the spider 63 can
rotate relative to the ring 66 in all tilted and
elevationally adjusted positions of the ring.
Elevational adjustmen-t of collar 6~ along the
rotor mast 3 is effected by a control lever including a
yoke portion 69 embraclng the mast and an actuating arm
69' projecting outward from a fulcrum pivot 70. Such
fu]crum pivot is supported on a bracket 71 attached to
~ (3(~3~
the slde of ti~e mast 3. The actuating arm can be swung
up and down by a thrust rod 72 connected to the yoke
arm by a pivot 73. The yo~e portlon 69 of the lever is
connected to the collar 64 by a link 74 which is
attached to the link by a pivot 75 and to the collar by
a pivot 76. Reciprocation of rod 72 will swing the
contro] lever 69, 69' to slide the collar 64 up or down
the mast 3 for changing the pitch of the lower rotor
blades 5 collectively corresponding to -the extent of
elevational change of collar 64 alony the mast 3.
In order to be able to tilt the ring 66
relative to the spherical surface 65 with the pitch
control collar 64 in various elevationally-adjusted
positions of such collar, such tilting of the ring 66
is effected by appropriate adjustment of four small
hydraulic jacks 77 mounted on pivots 78 supported
from the downwardly extending skirt 79 of collar 64.
One pair of such jacks is located in the longitudinal
plane of the aircraft and another pair of such jacks is
located in a transverse plane of the aircraft. The
jacks are supplied with hydraulic liquid through hoses
80.
If it is desired to tilt the ring 66 fore and
aft, hydraulic liquid will be supplied to one of the
fore-and-aft jacks and a corresponding amount of
hydraulic liquid will be drained from the other jack.
Similarly, if it is desired to tilt ring 66 about a
fore-and~aft axis, hydraulic liquid is supplied to one
of the lateral jacks in appropriate amount and a
corresponding amount of hydraulic liquid is drained
from the other lateral jack.
When the blades of the rotors cross during
~'7~
contrarotation of the rotors~ the lower rotor blades
will blanket to some extent the downwash fro~ the upper
rotor blades, decreasing the efficiency of the upper
rotor. Also, when the blades of both rotors cross
above the fusei.age 1 and the fixed wing 2, s~lch
fuselage and fi.xed wing also blanket the downwash from
the blades of both rotors. Consequently, it may be
desirable for the blades of the upper and lower rotors
to cross when they are in fore-and-aft position over
the fuselage and in transverse position over the wing.
In order to assure such crossing relationship, it would
be necessary to interconnect the upper and lower rotors
mechanically both to ensure -their relative crossing at
consistent positions during their rotation and to
establish two such positions as being fore and aft over
the fuselage and transversely over the wing. Mechanism
for coordinating such rotation of the rotor blades 4
and 5 is shown in Figures 12, 13 and 14.
An internal ring gear 81 mounted on the lower
side of the upper rotor hub and an internal ring gear
82 mounted on the upper side of the lower rotor hub are
interconnected by gearing which will ensure coordinated
equal and opposite rotation of the rotors. Such
interconnecting gearing includes lower upright shafts
83 extending through a lower support 84 carried by and
projecting outward from the mast 3 and upright upper
shafts 85 extending through an upper support 86 carried
by and projecting outward from the mast. The lower end
of each lower sha:Et 83 has a gear 87 meshed with the
internal ring gear 82 of the lower rotor and the upper
end of each shaft 85 has a gear 88 meshed with the ring
gear 81 of the upper rotor. The upper end portion of
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1~'7~ ?~.
each lower shaft 83 carries a gear 89 meshing with a
gear 90 carried by the lower end portion o~ an adj acent
upper shaft 85. Prefer~bly severa] paired shafts 83
and 85 are arranged around the mas-t, three sets of such
shafts being shown in Figure 13~ Gears 89 and 90
cooperate to assure ~hat the shafts 83 and 85 will
rotate in opposite directions to coordinate equal
rotation of the rotors in opposite directions.
It should be emphasized that the gearing
interconnecting the upper and lower rotor hubs is not
powered but is simply idler gearing. The propulsive
force effectiny rotation of each of the rotors is
provided by reaction jets as described above. On
occasion a small amount of power may be transmitted
from either rotor to the other through the connecting
gearing in order to synchronize their rotation, but in
normal operation it is not intended that any
appreciable amount of power be transmitted from one
rotor to the other through such gearing.
Principally, Figures 4, 15 and 16 illustrate
the air distribution and control system. Flow of
bypass air from the turbofan engines 6 through the
conduits 8 either to the mast 3 or to the branches 9
of thrust air discharge duct 10 is controlled by
valves 91 that can be swung between positions closing
the passages from ducts 8 to ducts 9, so that all of
the bypass air will flow to the mast 3, and positions
in which such valves extend across the ducts 8 so as
to scoop all of the bypass air flowing into them from
the engines into the branch ducts 9.
An aerodynamic control surface device 92
swingable about an upright axis is mounted at the
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~'7i~
discharge end of the air outlet duct 10. Similar
control surface devices 93 swingable about upright axes
are mounted at the discharge ends of tail pipes 7.
Preferably, such upright control surface devices 92 and
93 are interconnected for joint swinging about their
pivots.
Each of such control surface devices
preferably includes two vanes that normally would be
folded and disposed substantially in a longitudinal
plane. The control devices can be swung to either side
of such longitudinal plane, as indicated in broken
lines in Figure 15, to serve as rudders for controlling
yaw of the aircraft when it is flying at considerable
forward speed. The control surfaces are more effective
for such yaw control because they are mounted in the
slipstreams of the air discharge duct 10 and the
turbine exhaust tail pipes 7.
Each of the yaw control devices 92 and 93
preferably includes two vanes that can be swung away
from each other to deflect gas discharged from the
pipes transversely of the aircraft for balancing engine
thrust so that no propulsive force is applied to the
aircraft, or the vanes can be separated sufficiently
far to deflect the gas flowing from such ducts forward
to serve as thrust reversers either for slowing forward
movement of the aircraft or for actually effecting
rearward movement of the aircraft.
The lift force afforded by rotation of the
rotors can be supplemented when desired by downwardly
directed exhaust gas thrust from the engines ~. Short,
upright ducts 94 may extend from the tail pipes 7
downward through the wing 2 at locations preferably
-21-
directly athwartships of the rotor mast 3. Valves 95
in the tail pipes can swinq between positions closin~
the upper ends of ducts 94 so that all of the exhaust
gas will be discharged rearwardly through the tail
pipes 7 and upwardly swung positions blocking flow of
exhaust gas through the tail pipes 7 rearwardly of the
upright ducts 94 and acting to scoop the exhaust gas
downward through such vertical jet thrust ducts 94~
Control air jets can be provided in addition
to control surfaces for trimming or controlling the
attitude of the aircraft fuselage particularly at low
speeds~ Air under pressure for such control jets can
be supplied from a distribution valve 96 to which air
is supplied under pressure by being bled from the
compressor sections of the turbofan engines 6 into
supply pipes ~7. From the distribution valve 96/ air
may be supplied through a forwardly extending conduit
98 to a nose control jet 99 ejecting air downward to
increase the pitch of the aircraft by reaction.
Alternatively, air under pressure can be supplied from
the distribution valve 96 rearwardly through duct 100
for discharge through the tail control jet 101 to
reduce the pitch of the aircraft. Alternatively, or in
addition, air under pressure can be supplied from the
distribution valve 96 to one or the other of the
conduits 102 extending from it through the wings 2 to
wing tip jets 103 projectable downward. Such wing tip
jets are mounted close to the tips of the wing drop tip
sections 14 and consequently the air supply conduits
102 must cross the hinge 15 between the inboard wing
sections 13 and the outboard wing sections 14. At the
locati.on of such hinge crossing, the conduits 102 may
~7~1[3~
include a flexible coupli1lg 104 in the nature of
corrugated tublng which will enable the inboard and
outboard sections of the condLIit 102 to be swung
relat.ive to each other without interrupting their
communication.
The flight capability of the gyrodyne of the
present i.nvention is very versatile. For takeoff,
maximum llft can be accomplished by adjusting the
blades of both the upper rotor and the lower rotor to
high-pitch condition and by setting the tail-pipe
valves 95 so as to defleet all of the exhaust gas
discharge from the engines 6 downward through the
upright ducts 94. The amount of lift and downward jet
force can then be varied by simply altering the speed
of the engines. If desired, the pitch of the rotor
blades can be increased rather suddenly after the
rotors have been brought up to substantial rotational
speed so as to provide a sudden inereaSe in lift to
effect a jump takeoff.
When the aircraft has become airborne,
horizontal or climbing flight ean be aeeomplished by
swin~ing valves 95 downward to close the upright thrust
ducts 94 so that the exhaust gas from the engine will
be projected rearwardly through the tail pipes 7.
For eontrolling the rate of elimb of the
aircraft, the collective pitch of the upper rotor
blades 4 and the lower rotor blades 5 can be adjusted
as desired by the use of more or less conventional
pilot's controls~ To alter the attitude of the
alreraft, the pilot ean adjust the eyclie control of
the lower rotor blades 5 and may supplement such
control by utilization of approprlate control ~ets
-23-
selected from the nose control jet 91, the tail
control jet 10l and -the wing tip control jets 103.
As the forward speed of the aircraft
increases, choke ring 50 and/or choke ring 52 shown in
Figure 6 can be inflated to reduce or block flow of air
to the rotor blades, and valves 91 in ducts 8 can be
swung to deflect engine bypass air from such ducts into
branch ducts 9 so as to effect discharge of air from
longitudinal duct 10 to supplement the thrust of the
engine exhaust jets discharged from tail pipes 7. By
such operation, one or both of the rotors can be
converted to autorotation mode which will enable the
horizontal speed of the aircraft to be increased.
During operation of the aircraft in the high
horizontal speed range, yaw control can be accomplished
by swinging the rudder devices 92 and 93 with their
vanes folded and roll control can be effected by the
flaperons 20. For pitch control either elevators could
be provided on the horizontal stabilizers 18, or the
nose control jet 99 and the tail control jet 101 could
be utilized to effect such pitch control, or the cyclic
pitch control mechanism for the blades 5 of the lower
rotor could be utilized.
It may be desirable for the blades 5 of the
lower rotor to be somewhat shorter than the blades 4 of
the upper rotor so as to equalize substantially the
lift between the upper and lower rotors, taking into
consideration the action of the lower rotor blades 5
blanketing the downwash from the upper blades 4 to a
greater or lesser extent as they cross during their
contrarotation operation. Especially if the upper and
lower rotors are not interconnected by gearing, as
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~L~'J ~7~
shown in Figures 12, 13 and 14, to ensure equal and
opposite rotation of the rotors, it will be desirable
for the pilot to be able to determine the rotative
speed of each rotor by indicating mechanism responsive
to the sensors 47 cooperating with the apertured rings
46. The relative speed of rotation of the two rotors
can then be controlled by regulating the relative flow
of air to them by appropriately inflating the air flow
control ring 50 con-trolling flow of air to the upper
rotor and/or inflating the control ring 52 controlling
f low of air to the lower rotor~
When the gyrodyne is on water or land, both
the rotor air choke ring 50~ and the rotor air choke
ring 5~ should be inflated to block flow of air to both
rotors and brakes 45 should be extended into engagement
with the brake rings 44 to hold the rotors stationary.
The discharge of exhaust gas through the tail pipes and
the discharge of air through the longitudinal air duct
10 can then propel the aircraft forward and the rudder
devices 92 and 93 can be swung appropriately to steer
the aircraft, to stop it and to reverse its movement,
if desired, simply by control.ling the speed of engines
6.
