04 Coaxial Counter Rotation Compound Bi-Props Rotor

A Variable Pitch Anti Torque Coaxial Counter Rotation Compound Bi-Props Rotor

A Reinvent of Aircraft Propeller After A Century Of Its Birth

Patent Pending # 60,807,487 By Inventor Romeo Linn

In the industries of light airplanes, spot light planes, ultra-light planes, gyro-planes, power parachutes, trike ( power hang gliders ), as well as airship etc., a single engine driving a single propeller is a standard configuration, and main stream configuration. To have pilots operate these small private aircrafts safely, FAA set the single engine private pilot license, and single engine spot pilot license for these categories of private aircrafts.

Single engine single propeller rear push configuration in the

Ultra-light industry

Single engine rear pushing single prop gyro-craft

Single engine push prop powered parachute Single rear push prop trike

Rear push prop powered parachute Rear push prop trike ( powered hang glider)

Light & Ultra Light Aircrafts Industry

Front pulling single prop light aircrafts

Single engine light aircrafts, gyro-crafts, spot ultra-light plane makers and builders have being long expecting and waiting decades for some short of efficient, torque-less, compact coaxial counter propellers to eliminate the torque problem.

Rear pushing single prop micro light seaplane

Drawbacks and disturbing of the torque of common single propeller:

Pilots have to do busy trimming, to offset the torque of single propeller aircrafts after they just take off, in order to keep they aircrafts flying straight.
Pilots have to keep the prop quasi constant speed RPM ( QCS) during flight to avoid busy frequently trimming the aircraft ailerons and rudder.
Air breaking is done by banking the aircraft sharply near to stall angle.

Rear pushing single prop high speed light aircrafts

Other problems of common fixed pitch single propeller system.

Heavy vibration and loud noise;
Poor aerodynamic efficiency ;
Poor Thrust / RPM xRotor square area ratio interpreted as --- Thrust / per square inch & per rotation

Low Thrust / per Horse Power conversion ratio;
High fuel consumption;
Poor flight maneuvering.

Single engine single prop front pulling seaplane

Some imperfection anti-torque solutions in the industry You will commonly find :

A. Utilizing large dimension gear box having uneven gears driving structure. Result to low torque, good for specific low torque small engines and power ultra light only. A European made COAX-P counter coaxial gear is one of examples. That is only for fixed pitch simply counter rotation propellers.

B. Utilizing 2 engines to power the 2 coaxial counter rotation propellers separately. Hiller Museum ’s historical Flying Platform is an example. Dual engines are high cost, excessive mass, complex on synchronizing operation between the 2 engines

C. Utilizing Gyro sensing electronic servos or actuators control trimming to offset torque automatically. This technique is commonly utilized to power and to control UAV. It’s a torque alleviating solution, not perfect solution.

A Variable Pitch and Variable RPM Anti Torque Coaxial Counter Rotation Compound Bi-Props Rotor

A century technology breakthrough finally come up, after totally a century period since the invention of aircraft propeller. This short named -- Counter Bi-Prop Rotor features not only anti-torque, but also variable pitch on both rotor blades and yet both sides to make forward thrust and backward reversed thrust. Reversed thrust can perform air breaking.

Besides, the bi-rotors prop system features variable RPM to enhance efficiency, fuel consumption, and flight maneuvering. Its bi-rotors structure took reference from bi-planes aircraft wings having high lift and shorter wingspan. Thus, it performs extremely high density thrust while at mild RPM, yet very low vibration, quiet, streamline smooth, ultra efficient.

The Counter Bi-Prop Rotor is driven by a magic on axis symmetrical compact gear box. This unique gear box utilizes dual redundant gears driving structure that can handle extremely high torque.

The bi-rotors prop has multi stage pitch control plates and multiple push rods, to control the dual head rotor blades variable pitching at double sides, thus to produce forward and backward thrust. The pitching principle is pretty similar the helicopter tail rotor control system.

Significance of the Innovation

1. Anti torque, no need rolling trim tab control mechanical system on aircrafts;
2. Variable pitch make easy to accelerate, Reversible negative pitch make possible to decelerate;
3. Feel free to accelerate and to decelerate your aircraft without trimming operation, better 3D flight maneuver ;
4. Torque-less makes variable RPM speed possible, better flight maneuvering control,;
5. Reversible pitch can produce negative thrust for air break without banking the aircraft near to stall angle;
6. Utilizing 2 layers bi prop-rotors structural like biplane to increase thrust density and improve aerodynamic efficiency;
7. Higher density thrust per square inch than same diameter 4 blades common propeller at same RPM,; 8.
8. Lower RPM to get more and smoother thrust and better aerodynamic efficiency than Quasi Constant RPM propellers;    9. Low RPM benefits to low drag, low vibration, quiet. remove blasting shockwave sound. lower fuel consumption,
10. The anti torque Bi-Rotor prop make possible to configure VTOL aircrafts floating in air precisely;
11. Can configure either front pull or rear push to meet variety single engine light aircrafts and rotor-crafts applications.
12. Higher density thrust per square inch than same diameter common 4 blades propeller at same RPM,
13. More thrust, lower fuel consumption and increase payload.                                                                                            14. No more need pilots busy steering to keep straight flight, pilots have never feel so easy to fly.