1620

Item 1620

DESIGN: AeroVantage - Transition Mechanism - Proposed Methods - Linear Actuator

Initially do for 1/2-scale along with PropRotor etc?

Pros & Cons:

Pros:

Cons:

The arms may create an excessive amount of drag during cruise. They might contribute to swirl reduction.

Drawing:

Notes:

Mechanical:

Ball screws, rack & pinion, hydraulic cylinders or linear actuators move the forward and aft proprotors in a longitudinal direction between their hover and their cruise positions.
The ball screws, rack & pinion, and hydraulic cylinders might be mechanically or hydraulically interlocked so that they are moved in unison by one motor. See below.
The arms that fold upward and downward should be given an aerodynamic profile. They might reduce the swirl of the forward stream tube slightly, although they are not in the propeller's high velocity region. They may also reduce aerodynamically induced vibration.
Locks may be required at both end of travel for safety.
The 90º rotation of the proprotors results from the movement of the arms.
There will be a pair of arms. One on each side of the motor.
The arms are what gives rigidity to the assembly.

Transmission of Power to Transition Mechanisms:

Consider a lateral-traversing shaft between the port and starboard transition mechanisms, which is located in the wings.
At the end of each end of the shaft is a worm gear.
Each worm drives a wheel and the wheels turn a ball-nut or sliding-nut.
The nut rotates about a ball-screw or threaded shaft and this rotation moves the forward PropRotorMotor longitudinally.
The nut drives a second nut in the opposite rotation by a set of sput gears.
These spur gears will have a ratio of other than 1:1.
The second nut will move the aft PropRotorMotor longitudinally.
PropRotor Assist:

A differential thrust between the for and aft PropRotor would assist with the extension and retraction of the mechanisms. However, when the PropRotors are close to their hover positions they will impart a pitch to the craft. In addition, the slow forward velocity of the craft at this time will not allow the elevators to compensate for the pitching moment.

Calculations: Rough for now

Fore:

Aft:

Diameter of PropRotor:

100"

Movement of Extension:

50"

For information on some of this see; MAKE: Workbench - X-axis - Assembly

Initially displayed: February 19, 2008 ~ Last Revised: May 24, 2008

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.

	Fore:	Aft:
Diameter of PropRotor:	100"
Movement of Extension:	50"