Segmented Rivetless Brake Wear Liner to Reduce Warping

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Solution Overview

Problem

Current aircraft brake systems face issues with torque transfer problems, warping, and increased part count and manufacturing costs due to the use of single-piece wear liners and fasteners in friction disk assemblies.

Innovation Solution

The implementation of segmented wear liners with tenon and mortise dovetail shapes that couple to the friction disk core without fasteners, reducing waste and part count, and allowing for easier replacement and manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single-piece wear liner is used, then manufacturing is simplified, but warping occurs and material waste increases

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidwarping resistance
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The wear liner is divided into multiple segments (typically 3-6 segments) that can be manufactured separately and then assembled around the friction disk core. This segmentation prevents warping by allowing each segment to be manufactured from smaller, more manageable pieces that are less prone to thermal and mechanical distortion, while still forming a complete circular liner when assembled.

Inventive Principle:
Principle #1Segmentation

2Reliability

If rivets are used to fasten wear liners to the core, then the liner is securely attached, but part count and manufacturing cost increase

Engineering Contradiction:
Improveattachment securityVSAvoidpart count
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The attachment features (tenons and mortises) are integrated directly into the wear liner segments and core structure, eliminating the need for separate rivets or fasteners. The tenons are built-in protrusions on the liner segments that fit into corresponding mortises (recesses) in the core, creating a unified structure where the attachment mechanism is part of the components themselves rather than separate fastening elements.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a flange is used to attach the liner to the core, then attachment is achieved, but torque transfer problems occur when the liner is worn

Engineering Contradiction:
Improveattachment reliabilityVSAvoidtorque transfer efficiency
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The attachment mechanism transitions from a radial/flange-based attachment (attaching at the outer edge) to an axial/interlocking attachment (tenons extending axially into mortises). This dimensional change allows the liner to be securely attached through the thickness of the core, providing superior torque transfer by distributing forces across the axial interface rather than relying on radial flange contact that degrades with wear.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Ease of manufacture

If the entire disk is formed and the center is removed, then a wear liner is created, but manufacturing waste increases

Engineering Contradiction:
Improvemanufacturing processVSAvoidmaterial waste
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

Instead of forming a complete disk and removing the center (which wastes the removed material), the wear liner is manufactured as segmented components that are shaped and sized precisely for their final position. Each segment is manufactured independently with minimal material removal, and the segments are assembled to form the complete liner, significantly reducing material waste compared to the subtractive manufacturing of a single-piece liner.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3712457B1Segmented rivetless wear liner with structural carbon or ceramic core
Publication Date: 2021.11.17 GOODRICH CORP
  • EP3712457B1 patent drawingFigure 1
  • EP3712457B1 patent drawingFigure 2A
  • EP3712457B1 patent drawingFigure 2B

AI summary

A friction disk includes a friction disk core having an inner diameter edge, an outer diameter edge, and a first surface (106) with multiple mortises (120) extending radially across the first surface, each of the multiple mortises having a different dimension at the inner diameter edge than at the outer diameter edge. The friction disk further includes a first wear liner (150) having two wear liner segments each including a wear surface and a non-wear surface having a tenon with a complimentary shape to each of the multiple mortises, the tenon being configured to be received by a corresponding mortise of the multiple mortises to couple the wear liner segments to the friction disk core to form an annular liner.