Background of the Invention

 Human beings have long dreamt of Vertical Take Off and Landing (VTOL) inexpensive air vehicles for door to door 3D transportation without the need of airports or airfields for take-off or landing. Want just like a car that can do door to door transportation. However, countless inventors, aircraft , rotorcraft designers have being working near a century, this dream has not been fulfilled, and remain for challenge.  When an ideal “ air car “ be birth ?

The existing air vehicles that near to the dream are tail rotor helicopters and gyroplanes. However, they have this or that restricted characters and many shortages that are difficult to overcome.  Let’s give an overview to existing tail rotor helicopters and gyroplanes.

DETAILED DESCRIPTION

Shortcoming of Tail Rotor Anti Torque Helicopters

A.      Tail rotor anti-torque helicopters need a small tail rotor to balance the torque generated by the main rotor system. However, the tail rotor does not produce lift , but dragging over 1/ 3 of engine power and consumes 1/ 3 extra fuel burned for anti torque that dose not contribute to lift nor forward flight.

B.     Bigger and heavier engine is required to power up a helicopter to offset the 1/ 3 power wasted. And larger fuel tank is needed. Both issues significantly drop the helicopter payload, and make the payload operation cost higher.

C.     Tail rotor helicopters use multiple large mass blade grips, blade holders and low aerodynamic efficiency radius length fixed airfoil rotor blades in its rotor assembly. That makes the helicopter burden excessive weight to take off and flight. It further lower efficiency, and takes much fuel consumption.  

D.     The tail rotor produces drag and blasting noise due to spinning at 2000-3000 high speed RPM, approximately X 7 times of the main rotor RPM. Such high RPM makes the blade tip spinning near the speed of sound, produces turbulence and lousy noise.

E.     Slow forward flight. comparing other type of aircrafts. During high-speed forward flight, the tail rotor produces a cylindrical airflow perpendicular to forward flight. The large dimensions of the tail rotor assembly and the perpendicular airflow generated by the tail rotor become significant barriers to high-speed forward flight, and not avoidable.

F.      No back up for mechanical fails or engine fail. The helicopter have to do emergency instant auto-rotation landing. What about salvage on  water surface ?  fire fighting on a burning mountain or sloping mountain ? fighting on enemy control area ? No auto-rotation landing is allowed.

G.    Therefore, the total efficiency of tail rotor helicopters are extremely poor. Thus, tail rotor helicopters are not good for interstates flight, not even mention coast to coast flight, efficiency and high fuel consumption.

H.     There is only one main rotor producing lift, therefore all the helicopter weight (and loads) single point suspends below this main rotor. From a physics point of view, a single point hook-up compared to a dual point hook-up is less stable, and more prone to swing and oscillate.

Therefore, upgrading the single lift rotor to dual lift counter rotation twin rotors will significantly enhance stability efficiency.

Shortcoming of Gyroplanes and Gyro-crafts

A typical gyroplane is powered by a pusher prop. The gyroplane rotor obtains head wind mill to make auto rotation. There is no swash-plate nor pitch control rods on its top rotor. The gyroplane rotorcrafts have some advantage features over common tail rotor helicopters: Efficient, simple, cost effective, less vibration, long cycle life, low fuel burn, less maintenance.  However,

·        Gyroplanes are  not VOTL type. They need short runway to take off and landing. They are STOL type ;

·        Gyroplanes are not able to hover nor levitating;

·        Gyroplanes carry little payload, usually only 1 or 2 seats;

·        Gyroplanes engine is too close to pilot, almost right behind the pilot seat. Thus, engine noise and vibration is significant, despite no pitch cyclic retrieving heavy striking vibration on its top rotor.

 Is there possible to combine the great features of both tail rotor helicopters and gyroplane together and eliminate their shortcomings ?  The novel Fail Safe Multi Rotors VTOL Compound Heli-Gyro Copter shorted naming as the Heli-Gyro Copter gives the answers.

 Basic on the twin top rotor type, the Heli-Gyro Copter has 2 different versions. Version 1 applies common 3 or 4 blades rotor system on its twin top rotors.     Version 2 applies novel anti deforming variable airfoil diameter rotary wings on its twin top rotors,  also named as the Diameter Rotary Wings Compound Heli-Linn Copter.

The Heli-Gyro Copter has following extraordinary performance over existing helicopters and gyroplanes :                          

A. Removed the low efficiency lousy noise tail rotor assembly and gain over 1/3 engine power to produce lift and forward flight, significantly enhance rotors thrust efficiency to produce lift, and convert more engine power to lift. Thus, the Heli-Gyro Copter can produces heavy duty lift more than its weight.

B. A fully articulate pusher prop-rotor is installed at straight back of its fuselage to produce direct and ultra efficient forward propulsion, much powerful than top rotor blades cyclic retrieving pitch forward propulsion. Therefore, the Heli-Gyro copter performs ultimate forward flight speed exceed any rotorcrafts while consuming less fuel.

C. Able to perform aero-brake without nose up tail down banking the fuselage by simply reverse the pusher Prop-rotor blades pitch to negative, and produce reversed velocity. Besides, easier to accelerate or decelerate forward flight.

D. Neutral swash-plate status at cruise flight, eliminates the top rotors cyclic retrieving strike vibration, and the impulse noise that is common happen in tail rotor helicopter.  Thus effort greatly extends the twin top rotors pitch control system and swash-plate life cycle.

SUMMARY OF THE INVENTION

The Compound Heli-Gyro Copter have twin 2 rotors on top. They rotate in counter direction, intermesh, and self contain anti-torque without the bother of tail rotor assembly which has too many drawbacks. Both top rotor produce lift simultaneously. They take less engine power than single main rotor helicopters while producing the same payload lift.  Due to the total aerodynamic efficiency, the twin rotors Heli-Gyro Copter can produce the payload lift more than its self weight which is very difficult to achieve in the helicopter industry, and even aviation industry. Besides, the fully articulate variable pitch pusher prop-rotor can produce forward or backward thrust, and perform forward flight acceleration or air brake deceleration. Its direct propulsion to forward flight is much efficient than twin top rotor forward vector propulsion. While twin top rotors and the pusher prop-rotor, 3 rotors working together, the combination aerodynamic propulsion exceeds any single top rotor anti-torque helicopters or single or dual propellers gyroplanes. Furthermore, the Heli-Gyro Copter can fly at multiple flight modes to enhance its  fuel saving flight, its 3D flight performance and to achieve fail safe non-stop flight in case of emergency happening.  The Heli-Gyro Copter can be scaled down to have a very compact rotor span due to its aerodynamic efficiency and payload allowance. Thus, it’s the most ideal future air vehicle, so called “Air Car” for private door to door 3D transportation.  For further reference and information, please check www.Linvents.com or www.HoverCopter.com .