Electrotor

	ELECTROTORS
	ELECTROTORS

Electrically Driven Principal Assemblies, where a hub-motor is an integral part of the rotorhead.

Primarily for bilateral and coaxial rotorcraft.

Electrotor - Simplex;

A simple arrangement, for development purposes, with teetering rotors.

Electrotor - MicroLite;

A simple arrangement, for development purposes, with 'Absolutely' Rigid Rotors.

.... Electrotor - SloMo;

A very rigid rotor assembly that incorporates a slow speed electric motor in its hub. The 1:1 ratio eliminates the need for a reducer and other moving components.

Electrotor - Plus;

Incorporates a 2-blade teetering rotor where there is enhanced flight control due to hub springs combining with the gyroscopic precession of a very high-speed hub-motor.

Electrotor - BladeMotor;

Each blade has its own motor that sets pitch and contributes to rotor rotation.

Single-Bladed All Electric Rotor:

A rotor with just one blade.

Objectives:

A very, very light personal VTOL.

Electrically powered.

Extremely reliable.

Extremely easy to pilot.

Extremely safe.

Low component count.

Low maintenance.

Low cost.

Means of Progressively Attempting to Achieve the Above Objectives:

Gimbaled rotorhead and weight-shift cyclic control.

Greater precone angle than the conventional. To give greater speed stability in light of the parasitic drag of the pilot.

Slow speed electric motor; thereby eliminating the requirement for a mechanical speed reduction device.

Low inertial rotor blades; for ease of controllability and quick rotor rpm change.

Two-position collective pitch control by, torque/pitch coupling, lag/pitch coupling, or by piezoelectric pitch control.

Increasing the diameter of the two rotors w/o significantly increasing the pilot's physical effort.

Experimentation with Coaxial, Intermeshing, Interleaving and Side-by-side configurations.

Auto-collective, by torque/pitch coupling, or by piezoelectric pitch control.

Multiple independent power and control circuits, for power transmission reliability; by multi-phase.

Assured power at landing and takeoff; by having short-term power storage, such as ultra-capacitors.

Elimination of autorotation. See; Rotary Wing thread; The Demise of Autorotation

Further increasing the rotor diameters, perhaps with Aerodynamically Active Blade Twist, or by electric flight control.

Electrical braking of rotors after landing; (perhaps).

Electrical regeneration during descent from high elevations; (perhaps).

Enhanced tip clearance for Intermeshing configuration (perhaps). To give greater speed stability in light of the parasitic drag of the pilot.

Questions to be Answered:

Which is the best configuration for; flying, plus transportation and storage.
How best to implement the roll assist mechanism (for Side-by-side and perhaps interleaving configurations.)
Design and construction of optimal blade, (Optimal may differ for different configurations).
Torque-Pitch coupling (2-position and actively variable position)
Active tip control.
How large can the blade span become before it is too difficult to pilot.
Consider 3-blade rotors with slow speed and wide chord. To reduce required power, reduce pulsation, and distribute the moments more equitably around the rotor's bearing and motor's circumference.

Projects:

The SloMo.

The basic MicroLite craft.

To develop and test larger rotor blades; with torque-pitch coupling (for collective) and then active tip control (for cyclic control assist).

To migrate the electrics up to larger advanced VTOL craft. (perhaps the AeroVantage and/or the UniCopter)

Increasing Safety through Deconstruction
Starting small, then grow ~

Backpack helicopters are cute, they are funny and they are dangerous.

The following is a serious look at the Backpack helicopter from an unusual perspective.

The backpack helicopter that incorporates; a coaxial configuration, short span blades, collective by rotor rpm, and cyclic by weight shifting, is probably the most economical helicopter that can be built and the easiest helicopter to fly.

However, critics are rightly concerned that it will be a very unsafe craft due to; the lack of speed stability in forward flight, the inability to autorotate, and the risk of stumbling during a stand-up landing.

The conventional solution to overcome these shortcomings would be to upgrade the wish-list by adding; landing gear, then longer blades, then a collective, then a teetering hinge, and finally a bigger engine and transmission to lift this heavier craft. By this point the craft is much more expensive to build and somewhat more difficult to fly. In addition, all these upgrades add their own reliability concerns.

As an alternative, consider the possibility of taking a VERY DIFFERENT APPROACH. An approach that might be called 'deconstruction'.

Consider the possibility of producing a safer backpack helicopter by reducing its complexities and thereby increasing its reliability:

Replacing the dozens of wearing engine and transmission parts with a brushless electric motor whose only wearing parts are it's two bearings.
Divide the controller's power circuit, the motor's coils, and the battery packs into two or more totally independent circuits.
Incorporate redundancy and polling into the control circuitry.
The rotor blades are extremely rigid and there are no hinges.
Give the blades (propellers) a 2-position pitch (initially).
Locate the batteries below the torso of the pilot.
Discharging the weighty primary batteries in a worst case scenario.
Provide the pilot with undeniable knowledge of low battery power, plus a controlled reduction in the available power to the motor.

__________________

Elaboration on the above numbered points.

2. Should a power circuit fail, the motor will still operate, but at reduced power.[/SIZE]

3. In addition, this simple craft requires very few pilot actuated controls. [/SIZE]

4. To give speed stability during forward flight.[/SIZE]

5. A torque-pitch capability so that the rotor can provide thrust and accommodate autorotation. Disk loading would only be 3-1/5 lb/ft. on a 10 ft dia. [/SIZE]

6. The lower location of the batteries will assist with weight shifting and reduce the weight of the motor-rotor assembly[/SIZE]

7. A lowering or dropping of the batteries will significantly lighten the remaining weight and significantly assist with a controlled landing. Dropped batteries could have their own small parachute incorporated into the battery pack unit.[/SIZE]

8. An ultra-capacitor might be incorporated to provide power during the landing if the battery pack unit has been released. [/SIZE]

The 'objective' being; absolute reliability, assured power for touchdown, and easy piloting.

Related Pages - This Site:

Is Sikorsky Attempting to Inhibit Others from Developing Electric Rotorcraft?

Patent Application US 20090140095 ~ ELECTRIC POWERED ROTARY-WING AIRCRAFT

This Patent Application makes claims on features such as;

The rotor system and the electric motor mounted on the same axis of rotation.
The electric motor mounted at least partially within the rotor hub.
The use of a slow speed (such as axial-flux - pancake) motor to eliminate the need for a gearbox.

All of the above features were previously incorporated in one or more of the above Electrotors.

Also, the primary Electrotor inventions above were; published on the Internet and posted to four different forums, even the Domain name [Electrotor.com] was acquired, before all of the US 20090140095 dates. ~ The Provisional Patent Application was filed on Nov. 30,2007. The Patent Application was filed on January 23, 2008. The Patent Application was published on on June 4, 2009.

In addition, all of the claims in the patent application are commonly known attributes that any rotorcraft and/or electrical savvy person would know.

The above Electrotor motor driven rotorcraft concepts (un-patented inventions) are in the public domain for the use of any and all who wish to participate in the research and development of electrically driven rotorcraft?

For additional information see;

PPRuNe Forum ~ Is Sikorsky Attempting to Inhibit Others from Developing Electric Rotorcraft?

Rotary Wing Forum ~ Is Sikorsky Attempting to Inhibit Others from Developing Electric Rotorcraft?

Eng-Tips Forum ~ Patenting of publicly known ideas and concepts.

RC Groups Forum ~ Is Sikorsky Attempting to Inhibit Others from Developing Electric Rotorcraft?

File of rough notes 'Patent Application 20090140095.html' in Helicopter/Web Page/Working Data

OTHER SECTIONS:

Aerodynamics	Intermeshing Information	Miscellaneous
Flight Dynamics	Helicopters - Outside	Regulations
Mechanics	Helicopters - Inside	Composites
Electrics	Rotor Concepts:	CNC Workstation

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Last Revised: April 22, 2010