Co-rotating Propellers Joined by Tip Connectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotor-craft with fewer propellers lack redundancy, making them unable to maintain controlled flight in case of motor failure or propeller damage, and existing propellers suffer from inefficiencies due to vortices, noise, and deflection.
Innovation Solution
A redundant aircraft propulsion system using multiple motors to drive a single shaft coupled to a propeller, with tip connectors joining adjacent propellers to form a closed structure, reducing vortices and noise, and providing structural rigidity to prevent deflection and enhance durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple propellers are used for propulsion, then redundancy is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple propellers into a single integrated closed structure where adjacent propellers are joined by tip connectors to form a continuous loop. This combining approach maintains the redundancy benefit of multiple propellers while reducing the complexity of having separate, independently controlled propulsion units. The merged structure allows the propellers to function as a unified aerodynamic element with shared structural support.
2Power
If propeller blades are made longer to increase thrust, then power is improved, but propeller blades are more susceptible to deflection and failure
Solution Approach 1:
The closed propeller structure incorporates curved tip connectors that join the propeller blades in a continuous loop configuration. This curved geometry optimizes the structural distribution of aerodynamic loads, reducing stress concentrations and preventing deflection. The curved design allows the structure to better withstand bending moments while maintaining the necessary blade length for adequate thrust generation.
Solution Approach 2:
The propeller system is segmented into multiple adjacent propellers joined by tip connectors, creating a modular closed structure. This segmentation allows each individual blade to be optimized for thrust while the interconnected structure provides collective structural support, distributing the mechanical stresses across the entire closed loop rather than concentrating them on single long blades.
3Productivity
If propeller rotational speed is increased to improve productivity, then speed is improved, but noise and vortex drag increase
Solution Approach 1:
The closed propeller structure converts the potentially harmful vortices generated at propeller tips into beneficial aerodynamic features. By joining the tips of adjacent propellers to form a closed loop, the structure eliminates the free-running tip vortices that cause drag and noise, transforming the tip region into a controlled aerodynamic element that contributes to thrust while reducing harmful vortex formation.
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
Multiple propeller blades (504, 506) may be joined by tip connectors (508) to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.