Brake Disc Hub Friction Ring Undercut Connection

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Solution Overview

Problem

Prior-art brake discs with a friction ring and hub produced as separate elements suffer from thermal expansion gaps due to differing expansion rates, leading to reduced load-bearing capacity and acoustic anomalies like rattling.

Innovation Solution

The brake disc design incorporates recesses in the friction ring with undercuts and corresponding projections on the hub, which engage to counteract radial expansion, creating a stabilizing force that opposes further expansion, eliminating the need for additional connecting elements and allowing a rotationally fixed connection without thermal joining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the friction ring and hub are produced as separate elements and connected via separate connecting elements, then the brake disc can be manufactured with modular components, but thermal expansion gaps form between the elements due to different expansion rates

Engineering Contradiction:

Improvemodular manufacturingVSAvoidthermal expansion gap

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The brake disc is divided into two separate elements: a friction ring and a hub, which are manufactured independently and then assembled together. This segmentation allows for optimized manufacturing of each component while maintaining modular production benefits.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent explicitly addresses thermal expansion by designing the connection to accommodate differential expansion between the friction ring and hub. The connecting elements and their engagement geometry are designed to maintain stable connection despite thermal dimension changes during brake operation.

Inventive Principle:

Principle #37Thermal expansion

2Ease of operation

If separate connecting elements are used to join the friction ring and hub, then the components can be assembled independently, but the load-bearing behavior of the connection deteriorates due to thermal expansion gaps

Engineering Contradiction:

Improveassembly independenceVSAvoidload-bearing capacity

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The connecting elements are designed with pre-established engagement geometries that are configured to maintain optimal load-bearing contact under thermal conditions. The connection geometry is predetermined to compensate for expected thermal expansion, ensuring stable load transfer from the friction ring to the hub during brake operation.

Inventive Principle:

Principle #10Preliminary action

3Stress or pressure

If the friction ring is allowed to expand freely radially outward, then thermal stress is reduced, but acoustic anomalies (rattling) occur due to the expansion gap

Engineering Contradiction:

Improvethermal stressVSAvoidacoustic anomalies

Core Design Contradiction:

Stress or pressureVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the connection parameters and engagement geometry to control the friction ring's radial movement. The connecting elements and their engagement features are designed with specific dimensional parameters that allow controlled thermal expansion while preventing excessive movement that would cause rattling or acoustic anomalies.

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

This design enhances the load-bearing capacity and acoustic performance by stabilizing the connection between the friction ring and hub, reducing thermal expansion gaps and eliminating the need for additional connecting elements, thus simplifying production and assembly.

Implementation Method 1

due to different expansions of the elements, i.e., the friction ring and hub, in particular due to a typically rather great expansion of the outwardly arranged friction ring, a thermal expansion gap forms between the elements, which enlarges with increasing heating

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10527116B2Brake disc comprising a friction ring and a hub produced as a separate element and arranged inside of the friction ring

Publication Date: 2020.01.07 VOLKSWAGEN AG

AI summary

A brake disc having a friction ring and a hub produced as a separate element and arranged inside the friction ring according. Recesses are configured in the friction ring on the inside to connect the hub to the friction ring and corresponding projections are formed on the hub, which projections engage in the recesses of the friction ring in order to be able to transfer torque from the friction ring to the hub. The recesses have an undercut at least partially in a radial direction, as viewed looking inward from the outside. The disc is simple and cost-effective to manufacture and has an acoustically advantageous operating performance, in particular in the case of thermal expansion.