GB2359533A

GB2359533A - Modular airframe and rotor unit for rotorcraft

Info

Publication number: GB2359533A
Application number: GB0006737A
Authority: GB
Inventors: Michael W Piasecki
Original assignee: Dragonfly Pictures Inc
Current assignee: Dragonfly Pictures Inc
Priority date: 2000-02-25
Filing date: 2000-03-21
Publication date: 2001-08-29
Also published as: CA2301350A1; AU2246400A; AU784766B2; GB0006737D0

Abstract

The unit comprises an airframe to which are detachably secured, by quick disconnect fastenings 22, an engine 30, and a transmission 12, transmitting drive to a rotor assembly 11. The airframe supports a drive shaft 34, which may be detachably connected at one end to the engine 30 by a flexible coupling, while the other end may be connected to an input shaft 21, of the transmission 12, by means of a pulley and belt drive arrangement 39, gearing or other power transfer arrangements. The unit may be detachably connected to a framework supporting a counter torque rotor (fig. 2), drive to the counter torque rotor being transmitted via a clutch assembly. Alternatively, two units may be coupled to produce a twin rotor craft (figure 3). Various forms of quick disconnect connector are disclosed (figs. 4-10). The craft may be an unmanned vehicle.

Description

2359533 UNIVERSAL VTOL POWER AND ROTOR SYSTEM MODULE n () 2 5 This

application is related to and claims priority from U.S. Patent Application Serial No. 091045,991 filed March 23, 1998 which is incorporated herein by reference.

BACKGROUND

This invention broadly relates to aerial vehicles having vertical takeoffllanding (VTOL) capability, of which helicopters are a common type, and of which the described VTOL aircraft has a particularly useful capability as an unmanned aerial vehicle.(UAV), sometimes referred to as a "drone" aircraft.

More particularly, the invention is a common universal power drive and lifting rotor system module from which various types of single and multiple rotor VTOL aircraft can be produced. The simplicity and versatility of the power drive and lifting rotor system module of the invention is such that it has a particular adaptation to providing VTOL UAV aircraft of several types that are highly suitable to carrying out military and commercial surveillance missions.

There is a particular need for a portable, remotely controlled VTOL UAV platform carrying visual and sensing recording devices for performing a variety of military and commercial missions including transmitting or re cording visual and other ground data information that is not readily available or possible by other means. The capability of recently developed, simple and lightweight devices for recordin and transmitting a wide variety of visual and other data 9 c) is such that their usefulness can be greatly expanded by mounting them on a tp portable and remotely controlled VTOL UAV aircraft platform. Typical missions for such VTOL UAV units would be aerial intelligence gathering and reconnaissance, commercial cinematography, news coverage, aerial mapping, law enforcement and anti-terrorism augmentation, border patrol, disaster. assessment, environmental assessment, utility inspection and maintenance, etc.

1:" 1 2-5 SUMMARY OF THE INVENTION

The invention provides a universal power drive and lifting rotor system unit or module suitable for powering a variety of types of VTOL aircraft including both single and multiple rotor type VTOL aircraft, and both single rotor convention and compound helicopters.

The invention further provides a system capable of rapid assembly and disassembly into small modules for man portable transport and/or rapid maintenance without the use of hand tools.

The invention incorporates WOL power producing and lifting rotor systems and their interconnections on and within a component support airframe. The component support airframe is configured for the detachable attachment of an engine and VTOL augmentation framework. The lifting rotor assembly and transmission are mounted on the component support airframe and receive power from a power train comprising a main drive shaft detachably coupled to the engine and extending within the component support airframe. The main drive shaft and transmission are adapted for detachable connection to a drive shaft of a rotor torque compensating means mounted on any one of the VTOL conversion auxiliary frameworks affixed to the module component support airframe. Thus, a variety of types of VTOL aircraft can be powered by attaching the versatile power drive and rotor system module to an auxiliary framework on which is mounted the particular type of rotor torque compensating system utilized on the specific type of VTOL aircraft being produced.

-, i) BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side elevation of one embodiment of the invention.

Figure 2 is a side elevation of a second embodiment of the invention.

Figure 3 is a side elevation of a third embodiment of the invention.

Figure 4 is an illustration of an embodiment of a quick disconnect fastener for use with the invention.

Figure 5 is an illustration of another embodiment of a quick disconnect fastener for use with the invention.

Figure 6 is an illustration of another embodiment of a quick disconnect fastener for use with the invention.

Figure 7 is an illustrationof another embodiment of a quick disconnect fastener for use with the invention.

Figure 8 is an illustration of another embodiment of a quick disconnect fastener for use with the invention.

Figure 9 is an illustration of another embodiment of a quick disconnect fastener for use with the invention.

Figure 10 is a side elevation of one embodiment of a coupling for use with the invention.

DETAILED DESCRIPTION OF THE INVENTION

The module 10 utilized to power various types of VTOL aircraft. subsequently described is illustrated in Figure 1, in which a lifting rotor assembly 11 and transmission 12 are mounted onto a component support airframe 13 on which the components of the module are supported.

Components of module 10 are preferably connected using quick disconnect fasteners 22. Fasteners 22 preferably provide a self aligning interface for the components of module 10 and allow quick connection and removal without use of hand tools.

Is j 1 The rotor assembly 11 is preferably of a conventional nature with rotor blades 14, 15 supported thereon. Rotor assembly 11 may also be multibladed, may be bearingl ess, or may employ a hollow main rotor shaft or other apparatus commonly known or used in the art. The main rotor interface of rotor assembly 11 is preferably easily adaptable to accommodate a variety of rotor head designs (including fully articulated, bearingless, teetering, off-set teetering, and co-axial designs) capable of providing variable rigidity in flapping and movement. This flexible design has a direct impact on the suitability of rotary wing aircraft to perform successful launch and retrieval in heaving, pitching, and rolling conditions on a boat landing or when landing on ground inclines. The pitch of the rotor blades 14, 15 is preferably controlled by a linkage arrangement of a swash plate assembly 19 actuated by servo motors 20 and of which the details will not be described as being well known in the art. Rotor assembly 11 is also preferably configured for quick disconnection and connection at point 16 using quick disconnect fasteners.

The rotor transmission 12 is preferably driven by a power input shaft 21 which preferably extends from the transmission 12. The power input shaft 21 is preferably adapted for detachable connection to the main power drive shaft 34 and for receivine an external rotatable shaft (not shown). The component supporting airframe 13 of the module on which the lifting rotor assembly 11. and transmission 12 and other components of the module are supported is preferably a cylindrical composite airframe structure which provides fuel storage as well as allows for increased space for payloads. This provides an innovative solution to the traditional design compromise over the location of the fuel tank vis-a-vis other supporting structures by actually making the fuel tank the airframe. Engine 30 is preferably mounted on airframe 13 using quick 0 -) Z, 4 disconnect fasteners 22.

The support airframe 13 is preferably provided with bolt holes (not shown) and other facilities for attaching augmentation auxiliary framework using quick disconnect fasteners 22. The rotor assembly 11 and transmission 12 are preferably supported by a base plate 33 fastened to the lower side of the transmission housing 23 and to the component support airframe 13 using quick disconnect fasteners 22. The component support aidrame 13 preferably provides space in which various control and operational components required for operation of a VTOL may be stowed and for which the consumption of fuel does not adversely affect the balance of the aircraft during operation.

A main power drive shaft.34 extending longitudinally of the component support airframe 13 is preferably supported for rotation in the airframe structure. One end of the drive shaft 34 is preferably detachably connected to the engine 30 by a flexible coupling (not shown) that de-links axially.

A preferred powering unit mounted on the component support airframe 13 is a two-stroke air cooled engine with twin opposed cylinders. A more preferable powering unit is a diesel engine, but other engines suitable for C.

mounting on the front end of the airframe 13 could be utilized. Preference for a two-stroke engine is discussed below with respect to module 10 being used to power a dual rotor configured VTOL aircraft. Auxiliary power for the module 10 may be provided using one or more generators (not shown). It is preferred. that a combination starter/generator is used to provide both auxiliary power and starter capability. Use of a combination starter/generator also provides benefits in terms of reduced weight.

Rotational power of the main drive shaft 34 is preferably transferred to the transmission power input shaft 21 by means of a pulley and belt drive arrangement 39. The pulley-belt drive arrangement 39 is one preferred C 1; embodiment as being light and effective. Gear trains and other well known power transfer apparatus may be utilized for power transmission. The main drive shaft 34 is also preferably adapted for detachable connection to an external rotatable shaft of a VTOL augmentation auxiliary framework. This can be accomplished using a splined coupling (not shown) to allow for quick connection and disconnection to the transmission power input shaft 21 or other external rotatable shafts. A centrifugal clutch (not shown) may be incorporated with the main drive shaft 34 for selectively connecting and disconnecting the main drive shaft 34 from the transmission power input shaft 2 1.

The versatility of the above described module 10 for powering a variety of types of VTOL aircraft, particularly VTOL UAV aircraft (drone helicopters) is demonstrated in the following descriptive matter relating to the illustrations of Figures 2 and 3. Figure 2 illustrates the module of the invention powering a VTOL aircraft havina a tail mounted torque compensating rotor. Referring now to Figure 2, a main drive shaft clutch assembly extension 60 is detachably attached to the module component supporting airframe 13 by quick disconnect fasteners 22 or other attaching components. VTOL augmentation framework 45 is connected to clutch assembly extension 60 using quick disconnect fasteners 22. The augmentation framework 45 contains a torque compensating rotor (counter torque rotor) 49. A counter torque rotor drive shaft 50 is preferably supported for rotation within the augmentation framework 45 and is-- operatively connected to rotate the counter torque rotor 49. Counter torque rotor drive shaft 50 is preferably also detachably connected to the main power drive shaft 34. The counter torque rotor drive shaft 50 is preferably a floating thin-walled drive shaft. Augmentation framework 45 preferably comprises a tail boom section 45a detachably connected to a tail section 45b with quick disconnect fasteners 22.

An undercarriage 51 is preferably configured with a landing support 52 connected thereto using quick disconnect fasteners 22. The undercarriage 51. is attached to the module 13 using the quick disconnect fasteners 22. The undercarriage ill ustrated in Fig. 2 is one suitable for a VTOL UAV type aircraft. If the module 10 is of a size and power suitable for powering pilot controlled aircraft, the undercarriage structure and configuration would conform more closely to a conventional VTOL fuselage.

In a preferred embodiment of the invention an exhaust boom support structure is used to reduce the thermal heat signature and muffle the exhaust sound signature. The augmentation framework 45 (and 59 discussed below) structure provides valuable space aboard the aircraft which can reduce noise pollution in commercial environments and increase survivability and stealth in war or near war environments. Accordingly, the augmentation framework 45 is preferably used for exhaust baffling to reduce 6e sound signature.

A particularly useful VTOL configuration utilizing a pair of the modules 10 of the invention for powering a twin rotor VTOL aircraft is illustrated in Figure 3. By interconnecting a pair of modules 10 of the invention in a backto-back arrangement, the payload is considerably more than can be carried by a single module configuration, the lifting rotor torque generated by one module being counteracted by the other module. This configuration is also preferable when one engine fails to operate, for whatever reason, as the other engine can still apply power to both rotor systems permitting safe recovery of the aircraft. Referring to Figure 3, an augmentation framework 59 is configured for rapid detachable connection to the module component support airframe 13 via quick disconnect fasteners 22. A connecting drive shaft 61 is detachably connected to the transmission input shafts 21 of the respective modules 10. The tandem rotor configuration of the VTOL aircraft of Figure 3 requires the liftina rotors 1 0 S to -Is 1 ' j.

1 .... Y1 "). X) 11 of the respective back-to-back arranged modules 10 rotate in opposite directions. e.g., the engine 30 of the left side module 10 rotates clockwise as viewed from the. front side of the engine and the engine 30 of the right side module 10 rotates counterclockwise as viewed from the front side of the engine. Two-stroke engines are preferred since two- stroke engines have the characteristic of operating in either direction with no change to the timing or other operative components of the engine. A two-stroke engine operates in the saffle direction in which it is started. Hence, an operative configuration of the described tandem rotor VTOL aircraft of Figure 3 powered by a pair of modules of the invention connected back-to-back in the manner described is easily achieved by starting the respective engines of the pair of modules in opposite directions. Four-stroke engines may be utilized, but require a different timing adjustment of each of the respective engines and other modifications. It is preferred that engine timing is electromagnetically switched using a plurality of Hall effect sensors mounted on the rotating components of the engine, thereby eliminating the need for manual timing adjustments.

The embodiment shown in Figure 3 can be modified to include a third engine (not shown) mounted on or within augmentation framework 59 to provide additional payload capacity. The third engine is preferably connected to the augmentation framework 59 using quick disconnect fasteners.

As previously indicated, the space provided on and around the module. component support airframe 13 is available for installation of components involving operative control of the module lifting rotor assembly 11 and operative control of VTOL augmentation framework mounted flight control units. The present invention is adapted to powerincy VT01---UAV aircraft. The described VT01---embodiments of Figures 2 and 3 are of this unmanned type preferably include equipment which establishes remote control of the aircraft from the ground. An example of such equipment is disclosed in U.S. Patent 3,096,046 which is incorporated herein by reference.

Figures 4.and 5 illustrate two embodiments of the quick disconnect fasteners 22 which can be used to connect landing support 52 to undercarriage 5 1. Figure 6 shows an embodiment of quick disconnect fastener 22 which can be used to connect augmentation framework 45 to main drive shaft clutch assembly extension 60. Figure 7 shows an embodiment of the quick disconnect fastener 22 which can be used to connect transmission 12 to component support air frame 13. Figures 8 and 9 show an embodiment of quick disconnect fastener 22 which can be used to connect tail boom section 45a to main drive shaft clutch assembly extension 60. Figure 10 shows an embodiment of a coupling which may be used to'connect main drive shaft 34 to transmission power input shaft 21 or counter torque rotor drive shaft 50.

It should be understood that the foregoing disclosure involves preferred embodiments of the invention and that numerous modifications or alterations therein may be made without departing from the spirit and scope of the

C> invention as set forth in the appendant claims.

i 1 ()

Claims

What is claimed is:

1 A universal power drive and lifting rotor system module for single and multiple rotor type VTOL aircraft comprising: a component support airframe having a plurality of quick disconnect fasteners for detachably connecting components thereto, a main drive shaft supported for rotation within said component support airframe, said main drive shaft being adapted for detachable connection to an engine, a lifting rotor assembly and transmission mounted on said component support airframe, said lifting rotor assembly and said transmission being fastened to said component support airframe using said quick disconnect fasteners, said rotor transmission having a power input shaft adapted for detachable connection to said main drive shaft for transferring power between said main drive shaft and said power input shaft.

2. The module of claim 1 wherein said main drive shaft further comprises a coupling for axially delinking said main drive shaft and said engine.

3. The module of either of claims 1 or 2 further comprising power 0 transfer apparatus having a main drive shaft pulley and a power input shaft 0 pulley, said pulleys being interconnected by a belt.

4. The module of claim 1 wherein said liftine, rotor assembly is C) configured for detachable connection to said rotor transmission.

5. The module of claim 1, wherein said component support airframe comprises a composite structure for providing fuel storage.

6. The module of claim 5, wherein said component support airframe further provides payload capacity on and around said support airframe.

7. A VTOL aircraft comprising: the module of any one of claims 1, 2, 4, 5 or 6, a main drive shaft clutch extension detachably connected to said component support airframe using quick disconnect fasteners. a first augmentation framework having a counter torque rotor, said first augmentation framework being detachably connected to said main drive shaft clutch extension using quick disconnect fasteners, a counter torque rotor drive shaft within said first augmentation framework adapted for detachable connection to said main drive shaft and said counter torque rotor.

8. The VTOL aircraft of claim 7, wherein said first augmentation framework is adapted for use as exhaust baffling to provide reduced sound signature for said aircraft.

9. The VTOL aircraft of claim 7, further comprising an undercarriae,e detachably connected to said component support airframe.

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10. A VTOL dual rotor aircraft comprising: a pair of the modules of any one of claims 1, 2, 4, 5 or 6, a second atiamentation framework detachably attached to said 0 eoitpcment support airtrame each of said pair of modulea, a connecting drive shaft detachably connected to and extending between said power input shafts of said pair of modules.

11. The VTOL dual rotor aircraft of eWn 10, wherein saM second augmentation framework is adapted for removably mounting an engine thereto.

12. The VTOL aircraft of claim 10, wherein said second augmentation framework is ted for use as exhaust baffling to provide reduced suund signature for said aircraft.

13. The module of claini 1, furffier comprising a starterlsencrator devicc providing auxiliary power and starting capability.

14. The YTOL aircraft of claim 10, furdier comprising a plurality of engInes having electromagnetically switched engine timing using a plurality of HaR effect semors inounted on one or more rotating components of said engines.