Brake Pad Sliding Geometry for Complete Disc Retraction

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Solution Overview

Problem

Disc brake pads often fail to fully retract after brake release, leading to residual contact with the brake disc, which causes drag, reduces fuel efficiency, and increases wear on both the brake pad and disc.

Innovation Solution

A brake pad design featuring a sliding portion that extends downwards, utilizing gravitational force and vibrations to move away from the brake disc upon brake release, eliminating the need for additional retracting mechanisms and reducing friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the brake pad is designed with a sliding portion extending downwards towards the opposite surface, then the brake pad can fully retract after brake release by utilizing gravitational force and vibrations, but the friction between the sliding portion and the carrier increases during normal operation

Engineering Contradiction:
Improveretraction completenessVSAvoidfriction force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The sliding portion is designed with a downward extension that creates a gravitational component to assist retraction. The geometry is specifically configured so that during normal braking operation, the sliding surfaces remain in stable contact, but during retraction, gravity acts on the extended portion to promote separation from the brake disc.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The sliding portion extends in a downward direction towards the opposite surface, adding a vertical dimension to the sliding interface. This dimensional extension creates a lever arm that allows gravitational force to act on the brake pad, generating a retracting moment that helps overcome friction and ensures complete retraction.

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

2Reliability

If additional retracting mechanisms are added to ensure full retraction of the brake pad, then drag is reduced, but the device complexity increases

Engineering Contradiction:
Improveretraction completenessVSAvoidretracting mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The brake pad design incorporates a self-retracting feature through the downwardly extending sliding portion. The geometry of the sliding interface, combined with gravitational force and vibrations, enables the brake pad to automatically retract itself without requiring external actuators, springs, or other active retracting mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the retraction function from separate mechanical mechanisms and integrates it into the fundamental geometry of the sliding portion itself. By redesigning the sliding interface to extend downward, the retraction capability is built into the basic structure rather than being added as a separate system.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of energy

If the sliding portion extends downwards to utilize gravity for retraction, then fuel efficiency is enhanced by reducing drag, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvefuel efficiencyVSAvoidsliding portion geometry precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The design optimizes the geometry parameters of the sliding portion, including the extension length, angle, and surface finish, to achieve the desired retraction performance. By carefully selecting these parameters, the design ensures that gravitational force effectively promotes retraction while maintaining compatibility with standard manufacturing tolerances.

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 design effectively reduces drag, enhances fuel efficiency, and minimizes wear by ensuring complete retraction of the brake pad without extra mechanisms, leveraging gravitational and vibrational forces.

Implementation Method 1

the brake pad will due to gravitation and vibrations move away from the brake disc, when the driver has released the brake pedal

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 2

Vehicle vibrations further add to urge the brake pad to move in the retracting direction when no brake force is applied by the driver

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP3953600B1A brake pad for a vehicle, a brake arrangement, a brake system and a vehicle
Publication Date: 2023.02.15 VOLVO TRUCK CORP
  • EP3953600B1 patent drawingFigure 1
  • EP3953600B1 patent drawingFigure 2a~2c
  • EP3953600B1 patent drawingFigure 3

AI summary

The invention relates to a brake pad for a vehicle, adapted to be connected to a carrier around a rotatable brake disc which rotates around a geometrical centre axis, the brake pad comprising an upper side, a lower side, a friction surface extending downwardly from the upper side to the lower side and being adapted to be pressed against a brake disc, an opposite surface extending downwardly from the upper side to the lower side and being adapted to be faced away from the brake disc, wherein the lower side comprises at least one sliding portion configured to slide against a mating sliding portion of a carrier, wherein the at least one sliding portion extends downwards towards the opposite surface.