Brake Disc Flange Facing Angle for Frictional Closure

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Solution Overview

Problem

Brake discs for commercial vehicles face insufficient frictional closure during high braking moments, leading to relative movements between the disc and wheel hub due to compressive strains, which result in wear and tear, particularly in the radially interior area of the disc flange, where reinforcement is limited by structural space constraints.

Innovation Solution

The flange facing of the brake disc is designed to enclose an acute angle with the axis of rotation, shifting compressive strains from the radially interior to the exterior area, creating a wedge-like gap that concentrates strain in the exterior area when braced, thus reducing tearing risk and enhancing frictional closure efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the flange facing is configured planar (perpendicular to axis of rotation), then the frictional closure is achieved, but compressive strains concentrate in the radially interior area causing wear and tear

Engineering Contradiction:

Improvefrictional closureVSAvoidtear resistance in radially interior area

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The flange facing is given a conical configuration with a specific angle (0.5° to 3°) relative to the plane perpendicular to the axis of rotation. This geometric modification redistributes the compressive strains from the radially interior area to the radially exterior area, reducing wear and tear in the critical interior region while maintaining adequate frictional closure through the overall conical surface contact.

Inventive Principle:

Principle #3Local quality

2Strength

If reinforcement is added to the radially interior area to reduce tearing, then tear resistance improves, but weight and construction space increase

Engineering Contradiction:

Improvetear resistance in radially interior areaVSAvoidbrake disc weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

Instead of reinforcing the radially interior area to resist tearing, the invention converts the harmful compressive strains into a beneficial distribution pattern by using a conical flange facing. The geometry redirects the strains to the radially exterior area where they can be better accommodated, eliminating the need for additional material and weight while maintaining structural integrity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If high tightening moments are applied to improve frictional closure, then the frictional closure is enhanced, but compressive strains increase causing more wear in the radially interior area

Engineering Contradiction:

Improvefrictional closureVSAvoidwear and tear in radially interior area

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The flange facing angle is optimized to a specific range (0.5° to 3°) to achieve the best compromise between frictional closure and strain distribution. This parameter optimization allows adequate tightening moments to be applied for reliable frictional closure while the conical geometry simultaneously redistributes the resulting compressive strains away from the vulnerable radially interior area.

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 configuration reduces the risk of tearing and enhances the effective radius for brake moment transfer, preventing relative movement between the brake disc and wheel hub, while maintaining minimal weight and construction space.

Implementation Method 1

Extreme compressive strains are generated, due to the high requirements that are demanded of the brake disc, particularly in the transitional area between the disc flange and the disc pot

Methodology Applied

Scientific EffectCompressive strain: Compression

Implementation Method 2

a frictional closure is achieved between the two flange facings by the aforementioned axially disposed screwed connection, such that any moments occurring during the braking operation are essentially transferred to the wheel hub via the frictional closure in the contact zones

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9297432B2Brake disc for a land vehicle, and land vehicle, in particular with a brake disc of this type

Publication Date: 2016.03.29 ZF CV SYST EURO BV

AI summary

The invention relates to a brake disc for a land vehicle, particularly a commercial vehicle, having an axis of rotation, a friction ring, a disc pot and a disc flange for flange-mounting the same to the wheel hub of a vehicle, wherein the disc flange includes a flange facing.According to the invention, it is provided that the flange facing encloses an acute angle with a normal of the axis of rotation in the longitudinal sectional plane that contains the axis of rotation, when the flange facing is in the non-flange-mounted state thereof.