Coaxial Three-Propeller Assembly for Wide-Regime Thrust Efficiency
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Solution Overview
Problem
Existing counter-rotating propeller propulsion systems are inefficient and thrust-limited outside their optimized flight regimes, and are complex, heavy, and costly to maintain.
Innovation Solution
A propulsion system with three propellers arranged on a common axis, where two propellers rotate in opposite directions and are driven by separate motors, allowing independent speed control, reducing complexity and weight while maintaining efficiency and thrust across a wide operating regime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If counter-rotating propellers are optimized for a particular flight regime, then efficiency and thrust are improved in that regime, but efficiency and thrust decrease when operating in non-optimized regimes
Solution Approach 1:
The patent implements variable pitch mechanisms on the propeller blades, allowing the pitch angle to be dynamically adjusted based on operating conditions. This enables the propellers to maintain optimal performance across a wide range of flight regimes by adapting blade angles to match varying speed and load requirements, resolving the contradiction between optimized performance in specific regimes and adaptability across multiple regimes
Solution Approach 2:
The system changes operational parameters by allowing independent RPM control of each propeller and adjusting blade pitch angles. By varying these parameters dynamically, the propulsion system can optimize thrust and efficiency for different flight conditions (takeoff, cruise, landing) without being restricted to a single optimized regime, thus expanding the operational envelope while maintaining high performance
2Productivity
If counter-rotating propellers are used to improve efficiency and thrust, then propulsion performance is improved, but system complexity, weight, and cost increase
Solution Approach 1:
The patent combines multiple propellers onto a single shared shaft assembly, merging what would traditionally be separate propulsion units. This integration reduces the number of independent motor mounts, support structures, and control systems needed, thereby lowering overall system complexity and weight while preserving the efficiency benefits of counter-rotating propellers
Solution Approach 2:
The shared shaft and motor assembly serves multiple functions: it drives both propellers, provides structural support for the entire propulsion unit, and enables coordinated control of both blades. This multi-functionality reduces the number of separate components needed, simplifying the overall system design and reducing weight while maintaining propulsion efficiency
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 system achieves increased efficiency and thrust with reduced weight and complexity by utilizing three propellers with varying diameters and independent motor control, enhancing performance beyond optimized flight regimes.
Implementation Method 1
Aircraft such as airplanes, helicopters, and unmanned air vehicles commonly use propulsion systems with propellers to provide thrust for the aircraft
Data Source
AI summary
A propulsion system (50) is disclosed. The propulsion system (50) includes a first propeller (52), a second propeller (54), and a third propeller (56). The first propeller (52), the second propeller (54), and the third propeller (56) are arranged to rotate about a common axis and the second propeller (54) is disposed between the first propeller (52) and the third propeller (56). The first and third propellers (52, 56) are configured to rotate about the common axis in a first direction (A) and the second propeller (54) is configured to rotate about the common axis in a second direction (B) opposite to the first direction (A). A first motor (60) may be coupled to the first and third propellers (52, 56) and a second motor (64) may be coupled to the second propeller (54). A first shaft (58) and second shaft (62) may be arranged along the common axis, wherein the first and third propellers (52, 56) are coupled to the first shaft (58) and the second propeller (54) is coupled to the second shaft (62).