1498

Item 1498

DESIGN: Single-Bladed All Electric Rotor- Rotor Hub - Hub #0, 2, 3, 5, & 6

Proposed Means of Achieving the Objective:

0/ ~ Patent ~ 6619585 Helicopter single-blade rotor, September 16, 2003 ~ The present invention relates to a single-blade main rotor for helicopters designed so that the component of the blade lift normal to the rotational axis of the rotor is compensated by the inertial force obtained through the self-adjustment

It must be noted that, although not obvious, in the following sketches and pictures, the mast is stationary and the head rotates about the mast.

2/ ~

Give the blade a NEGATIVE precone. This should result in the Centrifugal force of the counterweight reducing faster than that of the blade during teetering.

"I was just reading on a model plane forum, how on one bladed props the counterweight is given a negative coning angle and some lead/lag angle. I dismissed this clue, but now I understand why this might be useful to equalize moments." ~ Al Hammer

3/ ~
PROBLEM: See the end of this section.

The sketch shows a rotor head with 2 links (actually 2 pair of links).
The sketch shows that the links are of different lengths. It also show that the horizontal distance between the pivot points in the hub equal the horizontal distance between the pivot points in the blade-counterweight.

PROBLEM: The movement of the links will move the pinion in respect to the crown.

Could consider double universal joint and telescoping shaft.

Or because the angular and linear movement is so small consider some style of flexible coupling. The Rexnord Omega?

5/ ~

A combination of the above two methods 3 and 4.

6/ ~

The advantage of this method is that the 1P horizontal motion and the 2/P vertical motions in method 4/ should be significantly reduced.

This arraignment is identical to method 4/ except there is a knuckle joint in the mast at the location where the blade's pitch axis intersects the mast's axis. The mast does not rotate and it is desired that the disk only tilt forward and aft, since dissimilar collectives provides roll. Therefore this joint can be a knuckle joint instead of a universal joint.

The teetering action is provided for by the knuckle joint. It should be noted that this motion does not require that the centroid of the whole rotor be moved off the centerline of the mast. In fact the rotor does not know that it is tilted. The linkage design in method 4/ has put the mean precone onto the disk. Therefore, it is only a change in the thrust that will pull the rotor's mass of the centerline of its rotation. Unlike method 4/, the teetering does not pull the rotor's mass of the centerline of its rotation.

Another advantage of this over method 4/ is that the linear and the angular changes between the motor and the hub will be significantly reduced. Perhaps reduced to the point where an omega flexible coupling might do.

Notes:

In all cases the above methods the masses of the blade and CW move toward the right as the blade flaps and the Pull increases to the left.

Hopefully, the blade flapping will provide damping. Perhaps, the assistance of a mechanical damper (tighten the four pivots) might help.

Components: (The following will go on separate pages, just as the final crown and pinion gears etc. are.)

Planetary Gears:

Highest strength to weight.

All of the power train rotates in the same direction ~ re. The utilization of gyroscopic precession.

Bearings:

The motor will require heavier thrust bearing for the armature.

The planetary gears may require special bearings that will handle more thrust.

Shear Pin:

An overrunning clutch cannot be incorporated since the motor provides the flight control. The drive train and motor should not create much resistance to autorotation. Perhaps a shear pin could be incorporated, which will brake if the motor or the planetary gears (or the crown and pinion?) lock.

Hub Spring:

The high rigidity of the rotor should make the inclusion of a hub spring acceptable. To not generate a vibration during normal flight the hub springs should only come into effect when the blade flap is excessive. The hub spring should allow the gap between the rotors on a coaxial configuration to be reduced slightly.

Housing:

See: Cast Housings

Notes:

If there is a choice, put;

'Draggy' items on blade side
'Weighty' items on motor side.

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Initially displayed: January 9, 2006 ~ Posted on PPRuNe; January 11, 2006; on Rotary Wing Forum; January 9, 2006~ Last Revised: February 7, 2006

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.