Twin Contra-Rotating Propellers for Flight Control
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Solution Overview
Problem
Existing flying platforms with contra-rotating vertical axis propellers lack commercial practicality and control efficiency, making them impractical for real-world use.
Innovation Solution
A flying machine with twin contra-rotating vertical axis propellers, featuring adjustable pitch blades, a collective pitch mechanism, and handlebar controls for yaw and lift management, along with a tail rotor for enhanced control and stability, is designed to address airflow differences and torque reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single propeller is used to generate lift, then the structure is simple, but the control and stability are insufficient
Solution Approach 1:
The single propeller is divided into two separate propellers (first and second propellers) that rotate in opposite directions. This segmentation allows independent control of each propeller's pitch and speed, providing better control and stability while maintaining a relatively simple overall structure.
Solution Approach 2:
Each propeller is equipped with its own pitch adjustment mechanism and motor, allowing local optimization of performance. The first and second propellers can have different pitch angles and rotational speeds tailored to their specific positions and airflow conditions.
2Adaptability or versatility
If propeller pitch is fixed, then the structure is simple, but the adaptability to different airflow conditions is poor
Solution Approach 1:
The propeller pitch is made variable through pitch adjustment mechanisms that allow the pitch angle to be changed during operation. This enables the propellers to adapt to varying airflow conditions, load requirements, and flight phases dynamically.
Solution Approach 2:
The pitch parameter of the propeller blades can be changed to optimize performance under different conditions. The pitch adjustment mechanisms allow modification of the pitch angle parameter to match varying operational requirements.
3Ease of operation
If twin propellers rotate in the same direction, then the structure is simple, but torque reaction causes poor directional control
Solution Approach 1:
The first and second propellers rotate in opposite directions (contra-rotation) rather than the same direction. This inversion of the rotation direction cancels out the torque reactions that would otherwise cause unwanted yawing and rolling, providing natural balancing and improved directional control.
4Ease of operation
If the seat and handlebars are positioned at the periphery of the propellers, then the leverage for control is maximized, but the user is exposed to harmful airflow and debris
Solution Approach 1:
A protective screen or shield is introduced as an intermediary element between the user (seat and handlebars) and the propellers. This screen blocks harmful airflow and debris from reaching the user while still allowing the user to control the propellers effectively through the handlebars.
Solution Approach 2:
The user positioning is moved from a horizontal arrangement at the periphery to a vertical arrangement above the propellers. This dimensional change allows the user to be protected from airflow while maintaining control leverage through the handlebars.
5Power
If the propellers are large in size, then the lift generation capability is improved, but the machine becomes more vulnerable to debris and has poorer maneuverability
Solution Approach 1:
The harmful exposure to debris is extracted or eliminated by positioning the user above the propellers and using protective screens. This allows the propellers to maintain their size for lift generation while the user remains protected from debris.
Solution Approach 2:
The user positioning is moved to a vertical arrangement above the propellers rather than at the periphery. This dimensional change allows large propellers to generate sufficient lift while the user is protected from debris by the protective screen and elevated position.
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
The solution provides improved control and stability, enabling efficient lift generation and directional maneuverability, overcoming the impracticalities of previous designs by allowing for precise control of lift and yaw through adjustable pitch mechanisms and handlebar operations.
Implementation Method 1
a propeller to generate lift to raise the platform from the ground
Implementation Method 2
the blades of which are arranged to generate lift on rotation of the propellers by the motor
Implementation Method 3
the handlebars are operative to vary a characteristic of the contra-rotating propellers to induce a torque reaction to cause the machine to yaw
Data Source
AI summary
A flying machine comprises a chassis on the underside of which is mounted two vertical axis contra-rotating propellers, which share a common rotational axis. The propellers are driven by two motors through a common drive mechanism, the motors being mounted on the chassis above the propellers and being longitudinally spaced apart along the chassis. Handlebars are movably mounted on the chassis between a seat and a nose piece. A user of the machine thus sits substantially centrally on top of the propellers with their legs straddling the motors and drive mechanism, the riding position thus being closely similar to that of a motorbike. Various collective and cyclic blade pitch control mechanisms are also disclosed. The handlebars and seat in some embodiments are replaced by a load carrying region.