Floating Disc Brake Rotor Attachment Using an Expander Ring

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Solution Overview

Problem

Integrated one-piece rotor and hat assemblies face thermal distortion and stress issues due to constrained thermal expansion, leading to vibration, cracking, and reduced performance, while conventional fastener-based designs suffer from bending and fatigue stresses, causing premature wear and maintenance challenges.

Innovation Solution

A floating disc brake assembly using an expander ring with a radial wave, fitted within grooves of both the rotor and hat, applies radial pressure to secure the rotor to the hat, minimizing bending stresses and ensuring uniform torque transfer, and is made of spring steel for enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If an integrated one-piece rotor and hat assembly is used, then the structure is simplified and no fasteners are required, but thermal distortion and stress lead to vibration, cracking, and reduced performance

Engineering Contradiction:
Improvestructure complexityVSAvoidbrake performance reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The brake assembly is divided into separate rotor and hat components that can float relative to each other, allowing thermal expansion without stress while maintaining structural simplicity. The rotor is detached from the hat, enabling independent thermal movement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rotor is designed to float dynamically on the hat rather than being rigidly fixed, allowing it to move axially and radially in response to thermal expansion. This dynamic adjustment prevents thermal stress and distortion while maintaining braking performance.

Inventive Principle:
Principle #15Dynamics

2Strength

If conventional fastener-based designs are used, then the rotor is securely attached to the hat, but bending and fatigue stresses cause premature wear and maintenance challenges

Engineering Contradiction:
Improveattachment strengthVSAvoidmaintenance interval
Core Design Contradiction:
StrengthVSDuration of action of stationary object

Solution Approach 1:

Fasteners are completely removed from the design. The rotor attaches to the hat through floating contact surfaces without bolts, nuts, or other fastening elements, eliminating the source of bending and fatigue stresses that lead to premature failure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The attachment mechanism transitions from rigid mechanical fastening to elastic floating contact, changing the physical state of the connection from fixed to compliant. This allows the assembly to accommodate thermal expansion while maintaining secure attachment.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the rotor is constrained at the hat, then the assembly structure is stable, but thermal expansion is limited causing thermal coning and high thermal stress

Engineering Contradiction:
Improveassembly stabilityVSAvoidthermal stress
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The rotor is designed to float dynamically on the hat rather than being rigidly fixed, allowing it to move axially and radially in response to thermal expansion. This dynamic adjustment prevents thermal stress and distortion while maintaining braking performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The floating design explicitly accommodates thermal expansion by allowing the rotor to move independently from the hat. The rotor can expand radially and axially without constraint, preventing thermal coning and high thermal stress while maintaining assembly stability through gravitational and contact forces.

Inventive Principle:
Principle #37Thermal expansion

4Temperature

If a floating rotor design is used, then thermal expansion is accommodated, but lateral separation and twisting can occur reducing reliability

Engineering Contradiction:
Improvethermal expansion accommodationVSAvoidattachment reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The attachment geometry is designed with features that constrain movement in lateral and rotational dimensions while permitting thermal expansion in the axial dimension. This dimensional differentiation allows thermal movement without compromising attachment reliability.

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

Solution Approach 2:

The attachment mechanism transitions from rigid mechanical fastening to elastic floating contact, changing the physical state of the connection from fixed to compliant. This allows the assembly to accommodate thermal expansion while maintaining secure attachment.

Inventive Principle:
Principle #35Parameter changes

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 reduces thermal stress and fatigue, increasing the life and reliability of the brake assembly by preventing lateral separation and twisting, thus minimizing maintenance costs and improving braking performance.

Implementation Method 1

The expander ring is made of spring steel for enhanced durability

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3563073B1Floating rotor disc brake with marcel expander ring attachment
Publication Date: 2021.03.17 PERFORMANCE FRICTION CORP
  • EP3563073B1 patent drawingFigure 1
  • EP3563073B1 patent drawingFigure 2A
  • EP3563073B1 patent drawingFigure 2B

AI summary

A floating disc brake assembly, and method of assembly, comprising a disc brake rotor (100) comprising an outer friction ring, an inner circumferential flange having a plurality of rotor tabs (106) spaced about the flange and a circumferential groove about the inner circumferential flange, a hat (130) comprising a cylindrical axial body, an outer circumference, a rotor mounting flange (134) extending radially about the outer circumference and having a plurality of rotor mounting tabs (136) spaced about the rotor mounting flange and forming slots (137) interspersed therebetween structured and arranged for receiving the rotor tabs, and a circumferential groove about the outer circumference of the axial body, structured and arranged to align with the circumferential groove of the disc brake rotor, and at least one expander ring (120) structured and arranged to fit within the circumferential grooves of both the rotor and the hat.