Floating Disc Brake Pad Clip and Return Spring Assembly

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Solution Overview

Problem

Existing floating disc brake systems face issues with friction between brake pads and the rotor during non-braking, leading to increased drag, wear, and elevated assembly costs due to complex and separate handling of pad clips and return springs.

Innovation Solution

A floating disc brake design where the pad clip and return spring are integrated as a subassembly, allowing for simultaneous mounting and utilizing a coil spring with a central axis oriented in the rotational direction to efficiently transfer elastic force, reducing wear and assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a return spring is provided between the inner and outer pads to separate friction surfaces from rotor side surfaces upon braking release, then drag torque and lining wear are reduced, but the assembling operation becomes troublesome and assembling cost increases

Engineering Contradiction:
Improvedrag torqueVSAvoidassembling operation
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The return spring and pad clip are integrated into a single assembly unit. The return spring is mounted between the inner and outer pads, while the pad clip is fixed to the support with positioning protrusions that engage with positioning recesses on the pads. This merging allows the return spring to be pre-positioned and secured during a single assembling operation, eliminating the need for separate mounting steps and reducing assembling complexity while maintaining the drag reduction function.

Inventive Principle:
Principle #5Merging (Combining)

2Force

If the return spring is engaged to the outer peripheral edges of the pads, then the elastic urging force is applied to separate pads from rotor, but the pads become apt to be inclined toward the rotor at inner diameter sides and friction occurs

Engineering Contradiction:
Improveelastic urging forceVSAvoidfriction between lining and rotor
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The return spring is repositioned to engage with the inner peripheral edges of the pads rather than outer peripheral edges. This local change in engagement position modifies the force application point, creating a more balanced elastic urging force distribution that prevents the pads from inclining toward the rotor at inner diameter sides, thereby eliminating the harmful friction while maintaining effective separation force.

Inventive Principle:
Principle #3Local quality

3Device complexity

If the same magnitude of elastic urging force is applied to both inner and outer pads, then simplicity is maintained, but unequal wear occurs with outer pad wearing more due to friction resistance

Engineering Contradiction:
Improvespring configurationVSAvoidwear uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The return spring configuration is made asymmetric by applying different magnitudes of elastic urging force to the inner and outer pads. The outer pad receives a larger elastic urging force to counteract the additional friction resistance it experiences during movement. This asymmetric force distribution compensates for the unequal mechanical conditions of the two pads, ensuring uniform wear patterns while maintaining overall system simplicity.

Inventive Principle:
Principle #4Asymmetry

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 integration simplifies the assembly process, reduces assembly costs, and effectively separates brake pads from the rotor during non-braking, minimizing wear and maintaining consistent braking performance.

Implementation Method 1

a return spring which presses the pad toward a direction getting away from the rotor

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a coil section provided between the returning section and the engaging section, and having a central axis substantially oriented in a rotational direction of the rotor

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP2557330B1Floating disc brake, method of assembling same, and assemblies consisting of pad clips and return springs
Publication Date: 2019.10.16 AKEBONO BRAKE IND CO LTD
  • EP2557330B1 patent drawingFigure 1
  • EP2557330B1 patent drawingFigure 2
  • EP2557330B1 patent drawingFigure 3

AI summary

Disclosed is a structure such that when pad clips (15g) are to be mounted, it is possible to handle return springs (16e) and the pad clips (15g) as integral articles (subassemblies), thereby facilitating mounting work. Constraining sections (24, 24) are provided at both axial ends of each of the pad clips (15g). Furthermore, the return springs (16e) are composed of inner spring elements (26g) and outer spring elements (26h). These two types of spring elements (26g, 26h) are helical torsion springs provided with helical sections (27c). Abutting sections (59, 59) are provided on the spring elements (26g, 26h), respectively. The abutting sections (59, 59) are pressed against the inner surfaces of the constraining sections (24, 24) by elastic restoring forces. Moreover, the central axes of the coil sections (27c) are substantially oriented in the rotational direction of the rotor.