Direct Orientation Vector Rotor for Helicopter Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotary wing aircraft, particularly helicopters, face instability and reduced flight speed due to lift dissymmetry caused by uneven airflow over the rotor disk, leading to potential stalls and limited directional flight capabilities.
Innovation Solution
The Direct Orientation Vector Rotor (DOVER) system allows for a more direct angling of the rotor disk into the relative wind through an articulated rigid mast assembly and ball-face spline-tooth gear coupling, enabling translational motion and azimuthal rotation, which reduces retreating blade stall and allows for shorter blades and faster rotor speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotor disk is angled directly into the relative wind to increase airflow and decrease lift dissymmetry, then lift distribution improves and stall risk decreases, but the fuselage must be positioned in a nose-down attitude which increases induced drag
Solution Approach 1:
The invention separates the rotor disk orientation control from the fuselage attitude control. The rotor disk can be independently angled into the relative wind while the fuselage maintains a level flight attitude, resolving the contradiction between improving lift distribution and minimizing induced drag
Solution Approach 2:
The rotor disk orientation is made dynamically adjustable during flight, allowing it to be angled into the relative wind when needed for improved lift distribution, while the fuselage attitude remains independent and can maintain optimal aerodynamic configuration
2Ease of operation
If cyclic pitch control mechanisms are used to control rotor blade pitch, then directional flight control is achieved, but the mechanism complexity and rotor configuration weight increase
Solution Approach 1:
The invention extracts and eliminates the complex cyclic pitch control mechanisms from the rotor system. Directional flight control is achieved through alternative means that do not require blade pitch cycling, thereby reducing mechanism complexity and rotor configuration weight
Solution Approach 2:
Instead of controlling blade pitch to achieve directional flight control, the invention inverts the approach by controlling rotor disk orientation or other parameters to achieve the same flight control objectives without the complex pitch control mechanism
3Force
If longer rotor blades are used to increase lift, then total lift increases, but retreating blade stall is amplified at higher air speeds limiting flight speed
Solution Approach 1:
The rotor disk is pre-oriented into the relative wind to create more uniform airflow distribution across all blades throughout the rotation cycle. This preliminary anti-action prevents the development of severe dissymmetry of lift that leads to retreating blade stall, allowing longer blades to be used without limiting flight speed
Solution Approach 2:
The invention changes the operational parameters by orienting the rotor disk at an angle to the relative wind rather than keeping it parallel. This parameter change transforms the airflow pattern over the rotor disk, eliminating the conditions that cause retreating blade stall and enabling higher flight speeds with longer blades
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances vehicle speed, maneuverability, and stability, enabling the DOVER to combine the utility of helicopter rotors with the speed and reliability of fixed-wing or tilt-rotor aircraft, potentially leading to supersonic capabilities and improved safety during slope and obstacle-laden landings.
Implementation Method 1
ball-face spline-tooth gear coupling
Implementation Method 2
ball-face spline-tooth gear coupling
Implementation Method 3
conveyed gyroscopic rotation
Implementation Method 4
vertical lift component produced by the rotating blades
Implementation Method 5
inclination mechanism configured to incline the rotor
Implementation Method 6
azimuthal rotation mechanism configured to provide torque from the mechanism for mobile torque application to the rotor
Data Source
Figure 1
Figure 2
Figure 3A~4
AI summary
A direct orientation vector rotor (DOVER) for use on rotary wing aircraft includes a gear set for multidirectional rotor orientation based on the spherical coordinate system; an inclination mechanism, wherein the rotor is moved from the 0° horizontal position to an inclined position; a rotational turret, wherein the rotor is moved along the azimuth and wherein the inclination mechanism is housed; and a motion- adapted gear lubrication housing.