Floating Rotor Disc Brake Retention Ring Fastener

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Solution Overview

Problem

Existing floating disc brake assemblies face issues with bending and fatigue stresses due to non-uniform torque transfer and thermal expansion, leading to potential cracking and increased maintenance costs, as well as damage to the rotor and hub components.

Innovation Solution

A floating disc brake assembly design featuring a disc brake rotor with radial tabs and a hub having uniformly spaced rotor mounting tabs and slots, secured by a retention ring that minimizes moment arm and bending stresses, allowing for in-plane torque transfer and accommodating thermal expansion without apertures or through holes, using a retention ring that is radially yieldable for secure attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional fastener assemblies (bolts/studs with nuts) are used to connect rotor to hub, then the rotor can be securely attached, but bending stresses and fatigue are induced due to moment arm created by axial displacement, leading to cracking and breaking

Engineering Contradiction:
Improveconnection strengthVSAvoidresistance to cracking and breaking
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent removes the conventional fastener assembly (bolts, studs, nuts) and replaces it with a retention ring that engages with slots in the hub and tabs on the rotor. This extraction eliminates the moment arm problem caused by axial displacement of fasteners, thereby preventing bending stresses and fatigue that lead to cracking and breaking while maintaining secure attachment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The retention ring acts as an intermediary component between the rotor and hub. It features slots that receive hub protrusions and engages with rotor tabs, creating a connection mechanism that minimizes moment arm and bending stresses. The retention ring distributes forces uniformly across multiple engagement points, preventing localized stress concentrations that cause cracking.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the rotor is rigidly connected to the hub, then structural stability is improved, but thermal expansion is constrained causing thermal coning, thermal gradient, and thermal stress leading to thermal cracking

Engineering Contradiction:
Improvestructural stabilityVSAvoidresistance to thermal cracking
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent creates a dynamic connection between the rotor and hub using the retention ring with slots and protrusions. This allows the rotor to float and move slightly relative to the hub, accommodating thermal expansion in the radial direction while maintaining structural stability. The slots provide clearance that enables thermal growth without constraint, preventing thermal coning and thermal stress.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The retention ring design changes the connection parameters from rigid fixed positions to floating positions with controlled clearance. The slots in the retention ring and corresponding protrusions on the hub create a connection that maintains structural integrity while allowing thermal expansion movements, thereby preventing thermal cracking.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If a floating rotor design with clearance is used, then thermal expansion is accommodated, but non-uniform torque transfer through perforated flange causes high stresses at individual apertures, leading to cracking or breakage

Engineering Contradiction:
Improvethermal expansion accommodationVSAvoidstress at apertures
Core Design Contradiction:
TemperatureVSStress or pressure

Solution Approach 1:

The patent segments the connection interface into multiple discrete slots and corresponding protrusions around the circumference. This segmentation distributes the torque transfer across multiple engagement points rather than concentrating it at individual apertures. The slots in the retention ring and protrusions on the hub create multiple load paths, reducing stress at any single location and preventing cracking or breakage.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If integrated one-piece rotor and hub assembly is used, then no fasteners are required eliminating wear and fatigue problems, but the assembly is constrained at the hub causing thermal distortion and requiring complete replacement when damaged

Engineering Contradiction:
Improveelimination of fastenersVSAvoidreplacement cost and time
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The patent segments the brake assembly into separable rotor and hub components connected by the retention ring. This allows the rotor to be detached and replaced independently from the hub, eliminating the need for complete assembly replacement when the rotor is damaged. The slot-and-retention ring connection provides a simple mechanical interface that enables easy separation and reassembly.

Inventive Principle:
Principle #1Segmentation

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 design enhances the life and reliability of the brake assembly by reducing bending and fatigue stresses, ensuring uniform torque distribution, and allowing the rotor to float relative to the hub, thereby minimizing thermal distortion and maintenance costs.

Implementation Method 1

allowing for in-plane torque transfer and accommodating thermal expansion without apertures or through holes

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3350467B1Floating rotor disc/hub with rentention ring fastener
Publication Date: 2019.11.06 PERFORMANCE FRICTION CORP
  • EP3350467B1 patent drawingFigure 1
  • EP3350467B1 patent drawingFigure 2
  • EP3350467B1 patent drawingFigure 3

AI summary

A floating disc brake assembly having a disc brake rotor (120) secured to a hub (110) with a retention ring (130) structured and arranged to fit within retention ring flanges (118) of a plurality of rotor mounting tabs (112) extending from the hub. A method of uniformly transferring braking forces from a rotor of a brake assembly about a hub of the brake assembly and a kit of parts are also provided.