Offset Axis Door Assembly Reducing Wind Resistance
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Solution Overview
Problem
Conventional hinge-mounted door assemblies for payload bays are complex, prone to deformation, increase wind resistance, reduce aircraft stability, and obstruct access due to their design, which requires multiple hinges to support the door's weight and extent, leading to inefficiencies in aircraft operations.
Innovation Solution
A door assembly with a panel section that rotates about an axis offset from its plane, allowing the door to open to at least 90 degrees while minimizing its extension outside the payload bay, using a reinforcement member and actuation system that reduces the surface area exposed to airflow and enhances structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If hinge-mounted doors are used to allow full opening access, then access through the opening is maximized, but the door extends far from the structure reducing ground clearance and increasing wind resistance
Solution Approach 1:
The door rotates about an axis that is offset from the plane of the opening, transitioning from conventional edge-hinge rotation to a dimensionally different rotation path. This allows the door to open to at least 90 degrees while the panel section remains largely within the payload bay envelope, minimizing extension outside the structure and reducing wind resistance during flight.
2Strength
If multiple hinges are used to support door weight and forces, then door structural integrity is maintained, but device complexity increases and hinge deformation may occur
Solution Approach 1:
The invention extracts the hinge mechanism from the door assembly entirely, replacing it with a rotation axis formed by engagement features on the structure that directly receive engagement features on the door. This eliminates the need for separate hinge components, reducing device complexity while maintaining the rotational function and structural integrity through the simplified direct engagement system.
3Ease of operation
If the door opens fully to allow maximum access, then operational access is improved, but ground clearance is reduced and aircraft stability is negatively impacted
Solution Approach 1:
By changing the rotation dimension to an axis offset from the opening plane, the door achieves full operational access (at least 90 degrees rotation) while the panel section sweeps through a path that keeps it largely within the payload bay volume. This minimizes the door's projection outside the aircraft envelope, maintaining ground clearance and reducing adverse impacts on aircraft lateral stability.
4Ease of operation
If conventional hinges are used at the edge of the door, then door rotation is achieved, but several hinges are required supporting door weight leading to deformation or fatigue
Solution Approach 1:
The hinge component is completely removed from the system. Instead, the door incorporates engagement features that directly engage with corresponding features on the structure, forming a rotation axis without requiring separate hinge elements. This eliminates the reliability issues of hinge deformation and fatigue while maintaining smooth door rotation operation.
Solution Approach 2:
The functions previously separated into distinct hinge components are merged directly into the door structure and supporting structure through complementary engagement features. The door's engagement features and the structure's engagement features work together as an integrated rotation system, eliminating the need for separate hinge components and improving reliability.
Data Source
AI summary
A door assembly for a payload bay (10) having an opening (12), the door assembly comprising at least one door (20, 220). The at least one door comprises: a panel section (22, 222) having a first end (24, 224) and a second end (26, 226); and a first mounting member (30, 230) arranged orthogonally to the panel section at the first end and having a first engagement feature (31, 231) having a rotational axis (18, 218) about which the panel section is arranged to rotate. The engagement feature is arranged to engage with a first fixing member (16, 216) on one side of the payload bay to rotatably couple the panel section to the payload bay. The at least one door is arranged to translate between a closed configuration, in which the panel section is arranged in the same plane as the opening, and an open configuration, in which the panel section is arranged at at least 90 degrees to the plane of the opening, by rotating about the rotational axis. The panel section is arranged parallel to and offset from the rotational axis, such that an inner surface of the panel section faces the rotational axis.