1493

Item 1493

OTHER: Helicopter - Inside - Single-Bladed All Electric Rotor - Complete Rotorcraft

Features:

Two single-bladed all electric rotors.

Potential Configurations.

Side-by-side.

Coaxial ~ This could be the preferred choice for a prototype craft.

Single

Gyrocopter

Side-by-Side Application:

Rotors:

Side-by-side Configuration: Could be coaxial, but the efficiency will be lower. Cannot be intermeshing or interleaving because the rotor rpm's are independent of each other. ~ See: 1515.html

A Side-by-side configuration with a pair of single-bladed rotors located at the tips of the wings with dihedrals is mentioned in 'Open Airscrew VTOL Concepts', the 'Rotafix' on page 191.

Direction of rotation: Inside forward (breaststroke).

Drawing:

Drawing of a Complete Craft:

Rotor radius is now 10 feet.

Most of the above components that are not part of the 'Principal Assembly' are taken from the SynchroLite.

Efficiency:

Configuration: The side-by-side configuration gives the best power-to-lift ratio of all rotorcraft configurations.

Number of Blades: The fewer blades the better power-to-lift ratio, therefore the single blade may give the best efficiency.

Frame:

Much of the tubing could be carbon, if there is a need to keep the weight down. The tubing would be produced on the filament winder that is currently being built.

There could be a tail boom and a nose boom and cables from the two booms hold the rotor side arms and place.

There could be cables to a central mast and to the undercarriage, if necessary.

Thoughts:

Lateral Static stability: Have the two disks tipped inward slightly.

Portability:

The supporting arms for the principal assembly (blade, hub, power train & motor) swing back and inward to the sides of the fuselage. The two blades swing forward and inward. This gives a very collapsed configuration for storage and ground transportation.

The tail feathers could be detachable.

The skids are detachable so that the rear of the craft can be lowered to the ground..

Final collapsed size will be approximately 2-1/2' wide by 12' long by 4' high.

Categories:

Ultralight:

Meeting the 254# empty weight limitation should not be a problem.

Experimental:

If the principal assembly (blade, hub, power train & motor) is factory produced, then homebuilders can purchase and build all the rest.

Sport Plane/Pilot:

With the use of a factory built and maintained principal assembly, no collective and basic cyclic control, this rotorcraft may exceed the gyrocopter in flight safety and user allowable maintenance. Since the gyrocopter is excepted into Sport Plane/Pilot then there is no reason why this craft cannot be accepted in the future.

Unmanned Air Vehicle (UAV):

Best loiter time of any rotorcraft configuration; except for the fact that it is electrical. The battery weigh is the negative. Would solar cells help a little?
A UAV craft provides a safe way to develop and test the craft.
Absolutely quiet.
The UAV has no need for a central fuselage. There would be a pod below both rotor hubs. In these two pods would be located the batteries and payloads.
The craft could have a pair of electrical linear actuators that are used to swing the arms in a out from the fuselage. This. In conjunction with aligning the blades allows the UAV to remotely park in a collapsed configuration and then 'spread its wings' for flight.
For special long range or long loiter flights, cheap one-charge electrical storage devices (batteries etc.) could be progressively dropped when there energy has been consumed. This will reduce the total weight and extend the duration of the flight.

Concerns Related to Complete Craft:

Aeroelastic Stability and Vibration:

See; Forces, Moments & Vibration

Coaxial Applications:

The universal joint of the lower rotor will have a large diameter. The will allow for a larger hole in the X-piece of the universal. Through this hole will pass the static mast, which is common to both rotors.

The efficiency will be lower than that of the side-by-side configuration. Consider increasing the span of the blades by one or two feet.

The very high frequency at which the power of the motor can be changed should allow for Higher Harmonic Control. This should reduce the rotor -rotor (blade - blade) induced vibration. The pulse widths on the motor may be varied at 25,000 per second therefor if the RRPM is 560 there are 7.4 pulses per degree of rotor azimuth. Of course, inertia will significantly reduce this rate of HHC.

On the coaxial, the crossing azimuth of the blades will be constantly changing, due to the variable RRPM.

See; OTHER: Helicopter - Inside - Single-Bladed All Electric Rotor - Coaxial Cyclical RRPM

Gyrocopter Applications:

Electric Motor / Counterweight: Consider using the electric motor / counterweight as;

A prerotor for takeoffs.
A takeoff assist for shorter ground roll.
A full-time rotor assist during flight.
A landing assist for shorter ground roll

Implimentation: There could be a small generator attached to the engine. There might be a clutch between the generator and the engine for disengagment.

Capacitor: Consider adding a large (lightweight) and streamlined capacitor. The capacitor is charged while the engine is being warmed up. Once the motor has done its function as a prerotor the generator is decoupled from the engine. The engine applies all its power toward forward thrust and the capacitor provide 5 to 15 seconds of rotor rpm assist. This combining of engine power and capacitor power during take off will further reduce the ground roll. The capacitor might also be used in flight to help maintain rotor rpm and elevation when the propeller thrust (engine) is throttled back for short periods of time.

Detriment: The motorized rotor will impart a small counter-torque on the fuselage.

Last Revised: August 30, 2009

The above utility invention is openly and publicly disclosed on the Internet to negate an entity from patenting it, to the exclusion of all others whom may wish to use it. ~ Reference patent law 35 U.S.C. 102 A person shall be entitled to a patent unless - (a) the invention was known ... by others in this country, ..., before the invention thereof by the applicant for patent.