Aircraft Brake Heat Shield Retention for Lower Mass Assembly
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Solution Overview
Problem
Existing thermal screens for aircraft braking systems require additional mass and complexity for fixation, increase the cost and warm-up of the torsion tube, and necessitate tool-assisted assembly, which complicates maintenance and prolongs mounting time.
Innovation Solution
A thermal screen with a coaxial tubular body and elastically deformable support legs that axially immobilize within the torsion tube, allowing tool-free assembly, reducing mass and cost, and limiting thermal conduction by only partly covering the inner surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If heat shields are fixed to the torque tube using screws and connecting pieces, then the heat shield can effectively protect the hub from thermal radiation, but the mass and complexity of the torque tube increase
Solution Approach 1:
The heat shield and retaining tabs are merged into a single integral component. The retaining tabs are directly formed as part of the heat shield body, eliminating the need for separate connecting pieces and screws. This integration reduces the number of parts and simplifies the overall structure while maintaining the protective function against thermal radiation.
Solution Approach 2:
The retaining tabs are designed to be elastically deformable, allowing them to self-adjust and self-lock into the torque tube without external tools or additional fastening components. The elastic deformation enables the tabs to engage with the torque tube's internal features, providing self-retention and simplifying the assembly process.
2Reliability
If heat shields are fixed with screws and connecting pieces, then the heat shield can be securely attached, but assembly time and preparation time increase significantly
Solution Approach 1:
The elastically deformable retaining tabs enable tool-free installation. The tabs naturally deform during insertion and automatically lock into position within the torque tube, eliminating the need for screws, connecting pieces, or specialized assembly tools. This self-assembling mechanism significantly reduces assembly time and preparation time while maintaining secure attachment.
Solution Approach 2:
The traditional mechanical fastening system (screws, connecting pieces, tools) is replaced by an elastic deformation mechanism. The retaining tabs use elasticity to achieve secure attachment without requiring threaded fasteners or external tightening tools, streamlining the assembly process.
3Object-affected harmful factors
If heat shields extend over the entire length of the torque tube, then complete coverage is achieved, but the heating of the torque tube increases
Solution Approach 1:
The heat shield is designed with selective coverage, extending only from the wheel web to a specific position along the torque tube rather than covering the entire length. This local coverage approach protects the hub area from thermal radiation while leaving other portions of the torque tube exposed, thereby reducing overall heat accumulation in the torque tube structure.
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 solution effectively protects the hub from thermal radiation while simplifying assembly and maintenance, reducing the overall mass and cost of the braking system while minimizing torsion tube heating during braking.
Implementation Method 1
a plurality of elastically deformable holding tabs secured to the tubular body, each of the holding tabs and an inner surface of the torsion tube comprising complementary reliefs to cooperate together so as to axially immobilize the heat shield inside the torsion tube
Implementation Method 2
a heat shield intended to extend opposite an outer surface of the hub facing the stack of discs to protect said hub from thermal radiation generated by the stack of discs
Implementation Method 3
the tubular body comprises stampings in the form of spherical caps facing the inner surface of the torque tube to form point contacts with said inner surface of the tube. These stampings ensure the mechanical strength of the heat shield while limiting thermal conduction between the main body and the torque tube.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Device (1) for braking a wheel (2) of an aircraft the hub (5a, 5b) of which is mounted so as to rotate about an axle (6), comprising a stack (11) of discs threaded on a torque tube (12) which is attached to the axle and equipped internally with a heat shield (20) extending opposite an outer surface (5.1) of the hub facing the stack of discs so as to protect the hub from heat radiation generated by the stack of discs. The heat shield comprises a tubular body (21) which is coaxial with the torque tube, and a plurality of retaining tabs (22) which are resiliently deformable and secured to the tubular body, each of the retaining tabs and an inner surface (12.1) of the torque tube comprising additional raised portions intended to engage with one another so as to axially immobilise the heat shield inside the torque tube. Wheel, landing gear and aircraft provided with such a braking device.