Aircraft Brake Assembly Ground Reaction Wheel Torque Transfer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Aircraft landing gear components face significant stress and strain due to the torque generated during braking, leading to increased weight, complexity, and reduced lifespan, as existing brake systems require reinforcement through bolts, rods, and flanges to manage braking forces.

Innovation Solution

The introduction of a ground reaction wheel that transfers braking forces to the ground, eliminating the need for reinforcement components like bolts and flanges, and allowing for a lighter, simpler landing gear design by decoupling the rotation of the brake sub-assembly from the landing gear leg.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If brake pads push against disc brakes creating frictional force to slow down the aircraft, then braking function is achieved, but substantial stress and strain are imposed on landing gear components

Engineering Contradiction:
Improvebraking forceVSAvoidlanding gear component strength
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

A reaction wheel is introduced as an intermediary component between the brake assembly and the landing gear. The reaction wheel absorbs the reactive torque generated during braking by rotating in the opposite direction, thereby mediating the force transmission and preventing direct stress on the landing gear structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The brake assembly is divided into separate functional components: the brake pads and disc brakes remain attached to the wheel, while the reaction wheel is separately mounted on the landing gear leg. This segmentation allows the braking function to be isolated from the structural load-bearing components.

Inventive Principle:
Principle #1Segmentation

2Strength

If landing gear are reinforced to withstand significant braking torque, then component strength is improved, but weight and complexity increase

Engineering Contradiction:
Improvelanding gear component strengthVSAvoidlanding gear weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The reaction wheel serves as a mediator that protects the landing gear structure from braking forces. By introducing this intermediate rotating mass, the structure can be significantly reduced in size and weight while still withstanding the operational loads.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the dynamic parameters of the landing gear by allowing controlled rotation of the reaction wheel during braking. This dynamic response enables the structure to withstand high transient forces without requiring proportional increases in static structural strength.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If brake assembly is fixed to landing gear using bolts or flanges to prevent rotation, then rotational stability is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvebrake assembly rotational stabilityVSAvoidlanding gear structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The reaction wheel is mounted to rotate freely on the landing gear leg rather than being rigidly fixed. This dynamic mounting allows the reaction wheel to absorb braking torque through rotation, eliminating the need for complex rigid fixation mechanisms while maintaining operational stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of preventing rotation through rigid fixation, the system inverts the approach by allowing controlled rotation of the reaction wheel to achieve rotational stability. The reaction wheel's rotation counteracts the braking torque, providing stability without mechanical constraints.

Inventive Principle:
Principle #13The other way round (Inversion)

4Force

If reinforcement components like bolts and rods are used to manage braking forces, then braking force management is improved, but ease of maintenance deteriorates

Engineering Contradiction:
Improvebraking force managementVSAvoidbrake assembly maintenance
Core Design Contradiction:
ForceVSEase of repair

Solution Approach 1:

The brake assembly is segmented into independently mounted components. The reaction wheel is separately attached to the landing gear leg with minimal fasteners, allowing it to be easily removed and replaced without affecting the brake pads or disc brakes. This modular segmentation significantly improves maintenance accessibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reaction wheel acts as a removable intermediary component between the brake assembly and the landing gear structure. Its simple mounting arrangement with few fasteners allows for quick removal and replacement during maintenance, unlike integrated reinforcement components that would require extensive disassembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration reduces the weight and complexity of the landing gear, simplifies manufacturing, and enhances maintenance by eliminating the need for additional fixings, while effectively managing braking forces without compromising safety or durability.

Implementation Method 1

the ground reaction wheel is arranged to transfer the braking force from the second sub-assembly to the ground

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2852527B1Aircraft brake assembly
Publication Date: 2017.05.24 MESSIER DOWTY
  • EP2852527B1 patent drawingFigure 1
  • EP2852527B1 patent drawingFigure 2
  • EP2852527B1 patent drawingFigure 3

AI summary

An aircraft brake assembly comprising a support leg (3), a main wheel (4) rotatably mounted on the support leg (3), a brake (2) comprising a first sub-assembly fixed to the main wheel (4) and a second subassembly (6) moveably mounted on the support leg (3) and a ground reaction wheel (8) coupled to the second sub-assembly (6), wherein on application of the brake (2), the first sub-assembly engages with the second sub-assembly (6) to exert a braking force on the second sub-assembly (6); and wherein the ground reaction wheel (8) is arranged to transfer the braking force from the second sub-assembly (6) to the ground.