Aircraft Cowl Pivot Joint Assembly Without Bore Radial Loading
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Solution Overview
Problem
Existing pivoting-connection devices for aircraft cowls require access to both sides of the clevis for assembly and can introduce radial loadings on the bore of one branch, leading to stress on components.
Innovation Solution
A pivoting-connection device with a guide ring and immobilizing system that allows assembly from one side, featuring a tubular body with a flange and continuation that expands radially, and a blocking system using a screw thread and nut to immobilize the guide ring, preventing radial loading and stress on components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a traditional pivoting-connection device with cylindrical pin and split pin is used, then the connection between clevis and arm is achieved, but access to both sides of the clevis is required for assembly which reduces assembly efficiency
Solution Approach 1:
The connection device is segmented into modular components: a guide ring that fits into the clevis bore, a cylindrical pin that passes through the guide ring, and a blocking system with screw thread and nut. This segmentation allows the guide ring to be pre-installed in the clevis bore from one side, and the cylindrical pin to be inserted from the same side, eliminating the need for access to both sides of the clevis during assembly.
Solution Approach 2:
The cylindrical pin is inserted through the guide ring, which is already positioned in the clevis bore. The blocking system components (screw thread and nut) are nested within the guide ring structure. This nesting arrangement allows all components to be assembled from one side of the clevis, improving assembly accessibility while maintaining the required connection functionality.
2Ease of operation
If a connecting system with expanding tubular body is used to allow one-sided assembly, then assembly accessibility is improved, but radial loadings are introduced on the bore of one branch which increases stress on components
Solution Approach 1:
The guide ring acts as an intermediary component between the cylindrical pin and the clevis bore. It provides a smooth guiding surface for pin insertion while distributing loads evenly. The blocking system with screw thread and nut serves as an intermediary locking mechanism that secures the pin without requiring radial expansion of the clevis bore, thereby avoiding additional stress concentrations.
Solution Approach 2:
The blocking system uses threaded engagement to convert rotational motion into linear clamping force, providing a controlled and distributed locking mechanism. This alternative to radial expansion changes the parameter of force application from radial to axial, avoiding the harmful radial loadings on the clevis bore while maintaining secure connection.
3Reliability
If both sides of the clevis must be accessible for assembly, then proper immobilization of the cylindrical pin can be achieved, but the device complexity and assembly time increase
Solution Approach 1:
The blocking system merges the immobilization function and the assembly function into a single integrated mechanism. The screw thread and nut combination provides both the locking action and the assembly procedure, allowing the cylindrical pin to be immobilized reliably while assembling from one side only. This reduces assembly procedure complexity without compromising immobilization reliability.
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 assembly from one side of the clevis without radial loading on the bore, ensuring the device is stress-free in the blocked state, improving assembly efficiency and component durability.
Implementation Method 1
the continuation having at least one slot that allows the continuation to expand radially in an elastic manner
Data Source
AI summary
A pivoting-connection device connecting at least two components and comprising a clevis having first and second branches, an arm positioned between the first and second branches of the clevis, a cylindrical pin connecting the clevis and the arm, at least one guide ring which has a flange configured to bear against an interior face of the first branch, an immobilizing system configured to occupy a free state and a blocked state in which the cylindrical pin and the guide ring are immobilized with respect to one another in the longitudinal direction, in both senses of that direction, and a blocking system configured to occupy an unfitted state and a blocked state in which the blocking system is in contact with the exterior face of the first branch.