Brake Disc Bell and Band Preload to Eliminate Rattle

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Solution Overview

Problem

Existing disc brake solutions experience rattling noises due to impacts between the braking band and the disc bell, and they do not effectively minimize axial and circumferential clearances, which also limits the compactness and space accommodation around the disc's rotation axis.

Innovation Solution

A disc brake design incorporating a braking band with radial teeth and a bell with axial teeth, where elastic elements are used to preload the band and bell in both axial and circumferential directions, minimizing clearances and impacts, and allowing for a compact axial design while maintaining mechanical strength and accommodating space for wheel hub components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If radial teeth of the braking band are coupled with axial teeth of the bell, then the connection structure is simple and production costs are low, but axial impacts and rattling noises occur between the braking band and bell

Engineering Contradiction:
Improveconnection structure simplicityVSAvoidaxial impacts and rattling noises
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an elastic element as an intermediary component between the braking band and bell. This elastic element absorbs axial impacts and eliminates rattling noises while maintaining the simple toothed connection structure. The elastic element acts as a mediator that resolves the harmful interactions between the rigid toothed components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastic element is pre-installed between the braking band and bell to provide beforehand cushioning against axial impacts. This preliminary cushioning measure prevents the occurrence of rattling noises and impact damages before they can occur during brake operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Ease of operation

If clearance is guaranteed in axial direction between braking band and bell, then the braking band can slide axially to orient coplanar to pads during braking, but axial impacts occur between braking band and bell

Engineering Contradiction:
Improveaxial sliding capabilityVSAvoidaxial impacts
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The elastic element serves as an intermediary that allows axial sliding motion while preventing harmful impacts. It provides the necessary compliance to enable the braking band to orient coplanar to pads during braking without generating impact forces against the bell.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of moving object

If compact axial design is implemented, then axial dimensions are reduced, but space for wheel hub components may be limited

Engineering Contradiction:
Improveaxial dimensionVSAvoidspace for wheel hub components
Core Design Contradiction:
Length of moving objectVSVolume of moving object

Solution Approach 1:

The patent resolves this contradiction by optimizing the spatial arrangement of components in different dimensions. The elastic element is positioned to utilize circumferential and radial spaces, allowing compact axial design while preserving necessary volume for wheel hub components through three-dimensional space optimization.

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

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 significantly reduces rattling noises, minimizes clearances between the braking band and bell, and allows for a more compact axial design without compromising mechanical strength, while providing space for wheel hub components and efficient heat dissipation during braking.

Implementation Method 1

a plurality of elastic elements (11), suitable to elastically preload the braking band (2) with respect to said bell (6)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3732382B1Brake disc for a disc brake and method
Publication Date: 2021.10.20 FRENI BREMBO SPA
  • EP3732382B1 patent drawingFigure 1~2
  • EP3732382B1 patent drawingFigure 3~4
  • EP3732382B1 patent drawingFigure 4bis~5

AI summary

A disc (1) for disc brake comprising a braking band (2); a bell (6), suitable to form a connection with the wheel hub of a vehicle associable with the disc (1); a plurality of elastic elements (11), suitable to elastically bias said braking band (2), a plurality of radial teeth (7) housed in a plurality of bell seats (10), so that said internal bell surface (16) is locally aligned with a radially internal edge surface (17) of each radial tooth (7); each elastic element (11) of said plurality of elastic elements (11) is removably connected to at least one axial tooth (9) of said bell; each elastic element (11) of said plurality of elastic elements (11 ) embraces at least one portion of a first axial tooth side (18), of a second axial tooth side (19) and of a at least one circumferential tooth side (20) of at least one radial tooth (7) of the braking band (2), elastically preloading said at least one radial tooth (7) with respect to said bell (6).