U.S. patent number 3,700,189 [Application Number 05/051,923] was granted by the patent office on 1972-10-24 for vtol propulsion system.
This patent grant is currently assigned to General Electric Company. Invention is credited to Eugene L. Timperman.
United States Patent |
3,700,189 |
Timperman |
October 24, 1972 |
VTOL PROPULSION SYSTEM
Abstract
A propulsion system is described which comprises two tip-turbine
driven fan units pivotally mounted in a pod. For vertical
propulsion the units are respectively registered with vertically
aligned inlet and discharge ports in the pod. For forward
propulsion the units are swung into registration with a horizontal
passageway through the pod.
Inventors: |
Timperman; Eugene L.
(Cincinnati, OH) |
Assignee: |
General Electric Company
(N/A)
|
Family
ID: |
21974229 |
Appl.
No.: |
05/051,923 |
Filed: |
July 2, 1970 |
Current U.S.
Class: |
244/12.4;
244/23A |
Current CPC
Class: |
B64C
29/0025 (20130101) |
Current International
Class: |
B64C
29/00 (20060101); B64c 015/00 (); B64c
029/00 () |
Field of
Search: |
;244/12,23,52,56,53,12A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Farrell; Andrew H.
Claims
Having thus described the invention, what is claimed as novel and
desired to be secured by Letters Patent of the United States
is:
1. A propulsion system comprising:
a pod having a horizontal passageway therethrough with an air inlet
at one end, a nozzle at the other end, and first and second pairs
of vertically aligned inlet and discharge ports opening to and from
said horizontal passageway, said pairs of ports being spaced apart
intermediate the inlet and nozzle, the inlet ports being formed on
relatively large radii after the nature of a bellmouth, and the
inlet to said pod passageway being relatively sharp for efficient
entry of air at high speed forward propulsion,
first and second air pressurizing units, each having a duct through
which air flows as it is pressurized, and
means for selectively registering the ducts of the first and second
units respectively with the first and second pairs of ports for
vertical propulsion and registering the ducts of both units with
the horizontal passageway for forward propulsion.
2. A propulsion system as in claim 1 wherein:
the means for selectively registering said ducts includes means for
pivotally mounting said units on said pod and means for pivoting
said units on their pivots between vertical and horizontal
positions.
3. A propulsion system as in claim 2 further comprising:
vane means in the discharge port which are pivotally mounted about
axes perpendicular to the direction of forward thrust,
means for pivoting the vanes from a generally vertical position
when the pressurizing units are in a vertical position to an angled
position in transitioning from vertical propulsion to horizontal
propulsion;
means for pivoting one of said units to its horizontal position
during such transition while the other unit remains in a vertical
position blocking said horizontal passageway, and
means for aerodynamically bypassing the horizontal unit past the
vertical unit during such transition.
4. A propulsion system as in claim 3 wherein:
said one unit is the upstream pressurizing unit moved to a
horizontal position during transition, and
the bypassing means comprise passageways extending at a low angle
through said pod to its exterior intermediate said units, flap
means normally closing the bypass passageways and means for
swinging said flap means outwardly to provide said bypass
function.
5. A propulsion system as in claim 2 wherein each of said units
comprise a casing and
the means for pivotally mounting said units includes trunnion means
having axes disposed at the intersection of the axes of said pod
passageway and said ports, and
further including
means for sealing said unit ducts from said ports when they are
registered with said pod passageway and sealing said ducts from
said pod passageway when they are registered with said ports.
6. A propulsion system as in claim 5 wherein:
the pod, its passageway, the ducts and ports are circular in cross
section; and
the sealing means are spherical.
7. A propulsion system as in claim 2 wherein:
each of said units comprises a casing, a gas generator mounted
remotely therefrom, a fan rotor having a tip-turbine, means for
ducting hot gases from the gas generator to the tip-turbine and an
annular discharge from the tip-turbine for the hot gases,
and further including
passageway means in said pod with which the annular discharge of
the upstream unit is registered in the horizontal position of the
unit, thereby discharging the hot gases thereof to the exterior of
the pod, and
the annular discharge of the downstream unit is registered with the
pod passageway in the horizontal position of that unit.
8. A propulsion system as in claim 7 wherein:
the pod, its passageways, the ducts and the ports are circular in
cross section,
the inlet ports are formed on a relatively large radii after the
nature of the bellmouth,
the inlet to said pod passageway is relatively sharp for efficient
entry of air at high speed forward propulsion,
the means for pivotally mounting said units includes trunnion means
having axes disposed at the intersection of the axes of the pod
passageway and said ports, and
further including
spherical means for sealing said unit ducts from said ports when
they are registered from said pod passageway and sealing said ducts
from said pod passageway when they are registered with said
ports,
covers for said ports which conform to the outer surface of said
pod,
means for pivoting inlet port covers to open positions when the
units are in their vertical positions, means for pivoting the
discharge port covers about axes perpendicular to the direction of
forward thrust when the units are in their vertical positions,
means for pivoting the discharge port covers in a rearward position
toward a closed position so that they function as vectoring flaps
in transitioning between vertical and horizontal propulsion,
means for pivoting the upstream unit to a horizontal position
during such transition while the other unit remains in a vertical
position blocking said pod passageway,
bypass passageways extending at a low angle through said pod to its
exterior intermediate said units to direct the fan discharge from
the upstream unit to the exterior of the pod during transition,
flap means normally closing the bypass passageways and
means for swinging said flap means outwardly to provide said bypass
function.
Description
The present invention relates to propulsion systems and more
particularly to an improved system providing vertical take-off or
landing capability for aircraft.
While many proposals have been made to provide vertical propulsion
for fixed wing aircraft, none had any substantial measure of
commercial success. This may be attributed to various shortcomings.
Where separate powerplants are employed for vertical and forward
propulsion, expense and weight have been prime problems. When
vectorable nozzle have been considered, complexity has been a
deterrent factor. Where powerplants have been swiveled relative to
the aircraft, compromises between the differing aerodynamic
requirements for vertical and forward propulsion have made the
overall system uneconomical.
In this last regard, it will be noted that forward propulsion is
more efficient where a relatively high pressure rise is imparted to
the motive fluid stream. For vertical propulsion, a high mass flow
in the motive fluid stream is more important than its pressure rise
or pressure ratio. Other compromises are also found in the inlet
and nozzle areas where the different modes of operation dictate
differing configurations.
Accordingly, one object of the invention is to provide an improved
propulsion system having a relatively high mass flow for vertical
propulsion and a high pressure rise for forward propulsion of
winged aircraft.
Another object of the invention is to additionally provide inlets
and nozzles which are specifically suited for the differing
requirements of vertical and forward propulsion.
These ends are broadly attained by a propulsion system comprising
two or more air pressurizing units which pressurize separate air
streams for vertical propulsion and a single air stream for forward
propulsion.
More specifically, these air pressurizing units are mounted in a
pod having a horizontal passageway with a thin edged inlet at one
end and a discharge nozzle at its other end. The units have ducts
which are registered with vertically aligned inlet and discharge
ports in the vertical mode. In the forward mode, these ducts are
registered with the horizontal passageway of the pod. The inlet
ports may be rounded for efficient vertical propulsion.
Preferably the air pressurizing units comprise fans having
tip-turbines driven from remote gas generators. Special features
are provided for handling the hot gas discharge from the units and
also for transitioning between vertical and forward propulsion.
The above and other related objects and features of the invention
will be apparent from a reading of the following description of the
disclosure found in the accompanying drawings and the novelty
thereof pointed out in the appended claims.
In the drawings:
FIG. 1 is a fragmentary perspective view of an aircraft
incorporating a propulsion system embodying the present invention
and illustrating it in a vertical flight mode;
FIG. 2 is a section, on an enlarged scale, taken on line II--II in
FIG. 1;
FIG. 3 is a section, on a further enlarged scale, taken on line
III--III in FIG. 2;
FIG. 4 is a perspective view similar to FIG. 1 illustrating the
propulsion system in its forward mode;
FIG. 5 is a section taken on line V--V in FIG. 4;
FIG. 6 is a section, on an enlarged scale, taken on line VI--VI in
FIG. 5;
FIGS. 7 and 8 are sections similar to FIGS. 2 and 5 illustrating
transition between vertical and horizontal propulsion modes;
and
FIG. 9 is a section, on a further enlarged scale, taken generally
on line IX--IX in FIG. 8.
FIG. 1 illustrates an aircraft 10 which is conventional to the
extent that it comprises a fuselage 12 having wings 14 projecting
from its opposite sides. Mounted on each of the wings 14 is a
propulsion unit comprising a pod 16 mounted beneath the wing.
Mounted within each pod are fan propulsion units 18 and 20 which
are driven by a pair of gas generators 22 mounted at the forward
end of the pod 16.
Each of the units 18 and 20 comprises a central frame structure 24
which is supported on a casing 26. The casing 26 has a central duct
28 and an outer spherical surface 30 which is received by a
corresponding surface formed in the pod 16. Trunnions 32 mount the
casings for pivotal movement on the pod 16. Actuators 34 are
provided to rotate the units 18 and 20 as will later be
described.
The units 18 and 20 each further comprise a rotor 36 having fan
blades 38 projecting therefrom and outlet guide vanes 40 also
supported from the casing 26. The hot gas stream from one of the
gas generators 22 is discharged into a longitudinal passageway 42
(FIGS. 3 and 6) and passes through the trunnion 32 to a scroll 44
formed in the casing 26. Scroll 44 directs the hot gas stream to
turbine blades 46 secured to the outer ends of the fan blades 38.
The rotor 36 is thus rotated so that the fan blades 38 pressurize
air entering through the passageway 28 and discharge the
pressurized air through the outlet guide vanes 40 to provide a
propulsive force. The hot gas stream, after being discharged from
the turbine blades 46, is directed through outlet guide vanes 48
and then a concentric outlet passageway 50.
The left fan unit 20 is similarly powered by the discharge of the
other gas generator 22 which is directed through a longitudinal
passageway 52 to the hollow trunnion of that unit. The construction
of the units may be identical and like reference characters are
employed to identify like components. It will also be pointed out
that the tip-turbine driven fans are well known per se so that
further description of these air pressurization devices is not
required.
In the vertical mode of propulsion, the units 18 and 20 are
positioned with their axes vertically disposed and with their ducts
28, respectively, in registration with inlet ports 54 in the top of
the pod 16 and also in registration with discharge ports 56 in the
bottom of the pod 16. Cover 58 for the inlet ports 54 is opened in
the vertical flight mode by actuators 55 through a mechanical
connection 57. Covers 60 for the discharge ports 56 are swung to
open positions for the vertical mode by actuators 59 through a
mechanical connection 61. It will also be seen that struts 63
support the covers 60.
Referencing next FIGS. 4 - 7, it will be seen that the pod 16 has a
central passageway 62 with which the ducts 28 of the units 18 and
20 may be brought into registration by being rotated through a
90.degree. angle of travel. The pressurized air is then discharged
from a nozzle 64 formed at the discharge end of the passageway 62.
In the forward mode, air pressurized by the fan blades 38 of the
unit 18 enters the second unit 20 and is further pressurized. This
further pressurized air, along with the hot stream from the outlet
50 of the second unit 20, is discharged from the nozzle 64 to
provide the forward propulsive force. The hot stream discharge of
the unit 18, through the concentric passageway 50, is directed
through a passageway 66 in the pod 16 so that it is angled
outwardly along the outer downstream surface of the pod 16.
Passageway 66 extends circumferentially around the pod a limited
angular distance to prevent discharge of hot gases toward the wing
14.
FIGS. 7 - 9 illustrate transition of the propulsion system from
vertical to horizontal operation. The first step is to
progressively swing the lower covers 60, which function as vanes or
flaps, rearwardly so that a horizontal forward thrust component is
produced as illustrated in FIG. 7. Next, the fan unit 18 is pivoted
to a horizontal position as illustrated in FIG. 8. The pressurized
air from this unit then bypasses the unit 20 by being discharged
through passageways 68 formed on the sides of the pod 16. In
forward propulsion, flaps 72 are respectively aligned with the
flowpath of the pod and the outer surface of the pod. During
transition, these flaps are swung open about their upstream pivot
points by actuators 74 through a mechanical linkage 76 which is
diagrammatically illustrated. Aerodynamic forces could, in some
cases, obviate the need of actuators to swing the flaps 70, 72. The
passageways 68 function as nozzles so that the air discharged
therefrom contributes to the forward thrust of the system.
After the aircraft has gained sufficient forward speed for the
wings 14 to provide necessary lift, fan 20 is rapidly rotated into
its horizontal posture and then the covers 58 and 60 for the fan
unit 20 are closed as are the flaps 70, 72, returning the
propulsion system to the position illustrated in FIGS. 4 - 6.
It will be apparent that the described propulsion system provides a
high mass flow with a relatively low pressure ratio during vertical
propulsion and a higher pressure ratio and lower mass flow for
efficient forward propulsion. Further, the inlet and discharge
ports 54 and 56 for vertical propulsion are independent of the
inlet and nozzle for forward propulsion. This enables the use of
bellmouth inlets for better vertical performance and a sharp edge,
high speed inlet for better forward performance. Likewise, the
discharge ports or nozzles 56 can have the proper area for vertical
propulsion while the nozzle 64 has the proper area for forward
propulsion. Also, by conforming the covers 58 and 60 to the
cylindrical shape of the pod, more efficient forward propulsion is
obtained.
While a preferred embodiment has been disclosed, variations thereof
within the broader aspects of the invention will occur to those
skilled in the art. For example, the fan or air pressurizing units
could have self-contained gas generators, as for example, after the
nature of a turbofan engine, or in certain aspects a turbojet
engine. Dependent on the aircraft configuration, there could be one
or a number of propulsion systems and the pod could have other than
a cylindrical shape. The pod could contain any number of propulsion
units similarly arranged.
In transitioning, the rear fan unit could be in a horizontal
position while the forward unit is in a vertical position. In this
case, the forward unit would be aerodynamically bypassed by opening
passageways in the pod to introduce air to the second unit.
* * * * *