1031

Item 1031

OTHER: Helicopter - Inside - Principal Assembly - ELECTROTOR-SloMo (Backpack , Ultralight)

Should this not be a page on a complete craft???

Objective:

To develop and build; the lightest, simplest, easiest to fly and reliable, manned electric helicopter possible.

It is to incorporate; short span blades, collective by rotor rpm w/ torque-pitch assist, and cyclic by weight shifting. It must be the easiest helicopter to fly and eventually the most economical helicopter that can be build.

For installation in twin-rotor helicopter configurations; such as Coaxial, Intermeshing, Interleaving, Side-by-side and perhaps Tandem.

The current intention is to develop it for a Backpack helicopter. Then eventually after motor and rotor refinements put it on the SynchroLite's Fuselage. (for a weight increase of +/- 35 lbs)

For now see this thread on the Rotary Wing Forum for additional information.

Drawing or Sketch:

Radial Flux Motor:

_________________

Axial Flux Motor:
This drawing is old. The axial flux motor may not be used.

Bill of Material 1031 ~ Principal Assembly ~ only rough draft so far.

Considerations on Diameter of Kaydon Reali-Slim Bearings:

Based on the Predator 37.

Power:

The Predator has a 4" OD by 3.327" depth.
Its maximum power is 19 hp. A conservative power might be 19/3 = 6.33 hp.
If a power of 36 hp is required for a light Electrotor craft then the requirement is 18 hp per rotor.
This crudely implies that the diameter of an 18 hp motor will be 4" x (18hp / 6.33hp) = 11.37" dia.
This means that a 12" OD motor, particularly if the depth of 3.327" in increased.

Rotational Speed:

The Predator has a maximum rotational speed of slightly over 6,000-RPM.
Rotors with 10.5-ft diameters will have an rotational speed of 1,000-RPM to give a tip speed of 550-fps.
This implies that the diameter of the motor should be 4" * 6,000-RPM / 1,000-RPM = 24" dia.
An increase in the number of phases c/w an increase of the depth of 3.327 should reduce the diameter to below 24"

Consider using a pair of 18" OD motors with a thickness 4.5"

This means that the Kaydon bearing number will be xx180xxx or xx200xxx for imperial, or model number BB40040 for metric 'X' bearing.

Description of Operation:

Future Refinements for Consideration:

An idea for increasing the disk area without increasing the weight-shifting control forces on the pilot. OTHER ~ Flight Dynamics - Rotor Hub - Aerodynamically Active Blade Twist (AABT). The following may need revision or elimination; Electrotor-SloMo - Rotorhub - Torque-Pitch-RRPM

An idea for giving variable pitch change based upon the power to the rotor. OTHER: Miscellaneous - Thoughtless Ideas - Torque/Pitch Collective Rotor Hub
SynchroLite Fuselage after the efficiency has been improved.

More Notes:

See notes on Side-by-side, as well. These notes are for the teetering rotor.

This configuration has a wider overall width than synchropter narrow, but the direction of thrust is vertical and the effective disk area is larger.
This configuration is not the best for large moments and forces, but since the rotors are teetering they will generated the smallest moments.

Experimental, but to comply with United States - FAA ~ Ultralight (part 103)

The large diameter of the motor may offer the advantage of acting rotor beanie, thereby restricting the root vortices and/or using them to cool the motor.

Autorotation: The only purpose of autorotation is that of allowing the craft to safely descend until a conventional powered vertical landing can be made by the pilot under reserve power.

Concerns:

2-rev vibration due to the 2-blade 'absolutely' rigid rotors.

Unmanned Arial Vehicle (UAV):

Unmanned Arial Vehicle (UAV). The induced velocity distribution throughout the total disk area should be quite good, particularly during forward flight. This is because 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 engine(s) power trains and payloads. There is no need for active blade twist. The ABC and ARR should improve the induced velocity distribution.

Thoughts:

Consider increasing the RRPM; so as to have a cooler motor. Forget the 550-fps noise because this might not exist at slow forward speeds (look into blade slap) and perhaps reduce the disk size slightly. 707 RRPM and 8 ft Radius gives 592 ft/min it also fits with the CSIRO motor x 1.5.

Note that the 1.5 motor might have more power than required but the weight less batteries will be below 254 and the stronger motors will allow for bigger batteries (= longer flight time)

Consider changing the RRPM for collective. If the cutout is large enough consider a fixed tip pitch of 2% and have a large taper and make the root have the pitch changes. A negative root pitch may provide for autorotation.

Consider the inclusion of capacitors for use during overpowering during takeoff, maneuvers and landing flare.

The following section is now obsolete since the current objective is to initially produce a Backpack motor-rotor assembly that will be common for all twin-rotor configurations. ~ September 18, 2009

Drawing of Proposed Principal Assemblies:

For Side-by-Side Rotors:

Axial flux electric motor directly connected to, and tipping with, the rotorhub.

For Intermeshing Rotors:

~ or ~

For Interleaving Rotors:

For Coaxial Rotors: See; 0812.html

Configurations:

An Interleaving, Side-by-side, Intermeshing, Coaxial or even Tandem configuration, to improve the lift/power ratio.

Each one will have its own advantages and idiosyncrasies. A primary consideration may be Figure of Merit due to today's limited electrical storage capability.

Fuselage:

Perhaps ~ Use components of SynchroLite's fuselage, or one developed by others, to create a helicopter that is; homebuilt or prebuilt, transportable, and FAA Ultralight (max. 254 lb. dry weight).

Initially displayed: July 23, 2006 ~ Last Revised: February 20, 2010

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.