Aircraft Propeller Locking Pin Mechanism to Prevent Windmilling
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Solution Overview
Problem
Current aircraft propeller locking mechanisms are prone to wear due to friction and require complex folding and locking systems, which can be inefficient and prone to failure during flight.
Innovation Solution
A propeller locking mechanism that includes a mounting ring with a locking extension, a solenoid mount with a solenoid and lever, and a locking pin that is pivotally coupled to the lever, allowing for precise locking and unlocking of the propeller without the need for electrical power to maintain the locked position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring loaded link is used in the locking mechanism, then the locking mechanism can provide automatic locking, but the device complexity increases
Solution Approach 1:
The patent extracts the complex spring-loaded link mechanism from the locking system and replaces it with a simple solenoid-actuated locking pin. The solenoid mount with lever provides the necessary actuation without requiring complex spring-loaded components, thereby reducing device complexity while maintaining locking reliability through the solenoid's direct actuation capability
Solution Approach 2:
The patent replaces the mechanical spring-loaded link system with an electromechanical solenoid actuation system. The solenoid converts electrical energy to mechanical motion to pivot the lever and move the locking pin, eliminating the need for complex mechanical spring-loaded links while achieving the same locking function with simpler components
2Reliability
If folding and locking systems are used, then the propeller can be secured during forward motion, but the device complexity and potential for failure increase
Solution Approach 1:
The patent removes the complex folding and locking systems from the propeller assembly and replaces them with a simple locking pin that engages with an aperture in the mounting ring. This extraction of unnecessary components reduces device complexity while maintaining propeller security through the direct locking action of the pin-aperture engagement
Solution Approach 2:
Instead of using complex folding mechanisms to secure the propeller, the patent inverts the approach by using a simple pin that directly engages with an aperture in the mounting ring. The locking action is achieved through the pin's insertion into the aperture rather than through folding and interlocking mechanisms, thereby simplifying the system while maintaining security
3Reliability
If a locking mechanism with multiple components is used, then the propeller can be securely locked, but friction and wear increase
Solution Approach 1:
The patent extracts unnecessary intermediate components from the locking mechanism, reducing the number of contact surfaces where friction and wear can occur. The direct solenoid-lever-pin connection minimizes the number of moving parts and contact points, thereby reducing friction and wear while maintaining locking security
Solution Approach 2:
The patent replaces complex mechanical linkages with a solenoid-actuated system that uses electromagnetic force to move the locking pin. This substitution reduces the number of mechanical contact surfaces, thereby minimizing friction and wear while maintaining the same locking security function
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 mechanism effectively locks the propeller in place, preventing windmilling and reducing drag, while withstanding lateral forces during flight and allowing for safe and efficient unlocking via propeller torque without damaging components.
Implementation Method 1
The solenoid mount includes a solenoid and a lever operatively coupled to the solenoid, such that the solenoid is configured to pivot the lever within the solenoid mount
Implementation Method 2
A spring is attached to the first arm of the lever and configured to bias the locking pin into the aperture
Implementation Method 3
A magnet is configured to interact with and hold the solenoid pin in a first position or a second position
Data Source
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AI summary
A propeller locking mechanism (100) for an aircraft includes a mounting ring having a locking extension with an aperture. A solenoid (112) is configured with a solenoid pin (113) which interacts with a first arm (110A) of a lever (110). The lever includes a pivotable second arm (110B) configured with a spring (108) and locking pin (106). The second arm is able to pivot and insert the locking pin into the aperture (118) of the locking extension on the mounting ring. The spring biases the locking pin in the locked orientation. Upon sufficient motor torque, the spring force is overcome allowing the locking pin to be removed from the aperture and the mounting ring to be unlocked.