Quick Disconnect Propeller Coupling with Radial Key
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Solution Overview
Problem
Current rotary wing aircraft propeller replacement methods are time-consuming and cumbersome, especially in competitive events, and do not easily accommodate different propeller types without adding weight or increasing production costs.
Innovation Solution
A quick disconnect coupling system featuring a propeller hub with an axial keyway and a rotatable shaft with a radial key and actuator, allowing for simple and rapid propeller change by retracting and extending the radial key to engage and disengage the propeller from the motor, while maintaining compatibility with various propeller types and not adding weight to the aircraft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a threaded connector (nut and shaft) is used to secure the rotor blade to the motor, then the propeller is firmly secured to the motor, but the time required to replace the propeller increases significantly
Solution Approach 1:
The coupling system is divided into separate components: a motor coupling portion with a radial key that can be independently retracted, and a propeller coupling portion with an axial keyway. This segmentation allows the propeller to be quickly released by retracting the radial key without requiring removal of the entire threaded connector assembly, thus reducing replacement time while maintaining secure connection during operation.
Solution Approach 2:
The radial key is made movable between an extended position (for secure engagement with the axial keyway) and a retracted position (for quick release). This dynamic element allows the connection to transition from a static threaded fastener to a dynamic quick-disconnect mechanism, enabling firm securing during operation but rapid replacement when needed.
2Loss of time
If a quick disconnect mechanism is implemented, then the propeller replacement time is reduced, but the device complexity increases
Solution Approach 1:
The radial key is nested within the motor coupling portion, and the axial keyway is nested within the propeller hub bore. This nesting arrangement allows the quick disconnect functionality to be integrated within the existing coupling structure without requiring separate external mechanisms, thereby reducing overall device complexity while still achieving rapid propeller replacement.
Solution Approach 2:
The radial key is extracted as a separate movable element from the motor coupling portion, allowing it to be independently controlled for quick release. This extraction enables the quick disconnect function without requiring complete redesign of the coupling mechanism, maintaining simplicity while achieving reduced replacement time.
3Loss of time
If a radial key and actuator mechanism are added for quick disconnect, then the propeller can be quickly released, but the weight of the aircraft increases
Solution Approach 1:
The spring-loaded actuator automatically extends the radial key into the axial keyway to secure the propeller, eliminating the need for additional fasteners or complex locking mechanisms. This self-service feature achieves quick disconnect functionality with minimal added components, thereby limiting weight increase while enabling rapid propeller replacement.
Solution Approach 2:
The radial key, actuator, and spring are merged into a single integrated motor coupling portion assembly. This consolidation reduces the number of separate components that would otherwise need to be installed and secured, minimizing the overall weight addition while achieving the quick disconnect function.
4Ease of operation
If a radial key extending through the shaft is used, then the propeller can be quickly engaged and disengaged, but the manufacturing complexity and cost increase
Solution Approach 1:
The radial key is designed to work with a standard axial keyway configuration that can be applied to various propeller types. This universal design allows the same motor coupling portion to quickly engage different propellers without requiring custom-manufactured components for each propeller type, thereby easing operation while limiting manufacturing complexity and cost.
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
Enables quick and easy propeller replacement, accommodating different types without increasing aircraft weight or production costs, enhancing operational efficiency in competitive scenarios.
Implementation Method 1
A spring biases the actuator into a non-depressed position for extending the radial key to engage with the axial keyway of the propeller hub bore to couple the propeller to the motor
Data Source
AI summary
A coupling is disclosed for connecting a propeller to a motor in an aircraft such as a rotary wing aircraft and the like. The coupling comprises a propeller hub having an inner propeller hub bore defining an axial keyway. A rotatable shaft has an internal shaft bore connected for rotation with the motor. A radial key is slidably located in a radial aperture extending through the rotatable shaft. An actuator is slidably mounted within the internal shaft bore of the rotatable shaft. The radial key is received with the axial keyway for securing the propeller hub to the rotatable shaft. A depression of the actuator retracting the radial key relative to an outer surface of the rotatable shaft for permitting the propeller hub bore to be introduced onto the rotatable shaft.