Composite Disc Rotor Coupling Units for Weight Reduction

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Solution Overview

Problem

Conventional composite disc rotors for high-performance vehicles have a high number of parts, leading to increased costs and durability issues due to high forces applied during braking, with existing solutions using materials with poor yield and additional weight contributing to reduced ride quality and stability.

Innovation Solution

A composite disc rotor design with a reduced number of parts, utilizing a disc main body made of lightweight materials like ceramic or carbon composites and a coupling bracket of light alloys, featuring coupling units with bobbins, clips, and washers that allow for torque transmission and thermal expansion absorption, while minimizing material stress through elastic support and ventilation slots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the disc rotor is made with sufficient strength and rigidity to withstand high braking forces, then the braking performance is improved, but the weight increases

Engineering Contradiction:
Improvebraking strengthVSAvoiddisc rotor weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The disc rotor is divided into two separate components: a disc main body made of lightweight material (ceramic composite, carbon composite, or cast iron) and a coupling bracket made of light alloy. These segments are connected through coupling units, allowing each part to be optimized for its specific function while reducing overall weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite construction by combining different materials: the disc main body uses materials with high strength-to-weight ratio (ceramic composite, carbon composite, or cast iron), while the coupling bracket uses light alloys. This composite approach achieves sufficient braking strength while minimizing weight.

Inventive Principle:
Principle #40Composite materials

2Power

If multiple coupling units are used to connect the disc main body and coupling bracket, then torque transmission is improved, but the number of parts increases and cost increases

Engineering Contradiction:
Improvetorque transmissionVSAvoidnumber of parts
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The coupling unit integrates multiple functions into a single component structure that combines the bobbin, clip, and washer into one unit. This merging reduces the total number of parts while maintaining the ability to transmit torque and absorb thermal expansion differences between the disc main body and coupling bracket.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coupling unit is designed as a multi-functional component that simultaneously transmits torque, absorbs thermal expansion differences, and provides elastic support. This universal design eliminates the need for separate components for each function, reducing part count and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If the disc main body and coupling bracket are strongly coupled and fixed, then structural stability is improved, but excessive force is applied to coupling units during braking

Engineering Contradiction:
Improvestructural stabilityVSAvoidforce on coupling units
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The coupling unit incorporates elastic elements (clips) that allow for dynamic movement and absorption of forces. This elastic connection enables the structure to adapt to thermal expansion and contraction while preventing excessive force from being transmitted to the coupling units during braking operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastic clip in the coupling unit acts as a pre-designed cushioning element that absorbs and dampens shock loads and thermal expansion forces before they can damage the coupling units. This beforehand cushioning protects the structural integrity while maintaining stability.

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

4Power

If a plate spring with poor material yield is used for coupling, then torque transmission is achieved, but the manufacturing cost increases

Engineering Contradiction:
Improvetorque transmissionVSAvoidmanufacturing cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The coupling unit uses a clip made of spring steel that is relatively inexpensive to manufacture compared to plate springs with poor material yield. This clip design achieves the necessary torque transmission and elastic support functions at a lower manufacturing cost, making it economically viable.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 secures sufficient durability and reliability while reducing manufacturing costs by minimizing part count, preventing excessive force application during braking, and maintaining necessary strength and rigidity, thus enhancing ride quality and stability.

Implementation Method 1

both the disc main body and the coupling bracket are relatively displaced while elastically deforming the spring parts of the clips provided in the respective coupling units

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a difference of amounts of thermal expansion and contraction based on temperature changes can be absorbed

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2604883B1Composite disc rotor
Publication Date: 2019.11.13 AKEBONO BRAKE IND CO LTD
  • EP2604883B1 patent drawingFigure 1
  • EP2604883B1 patent drawingFigure 2
  • EP2604883B1 patent drawingFigure 3~4

AI summary

A composite disc rotor (1) includes a disc main body (2), a coupling bracket (3) and coupling units (4). Each of the coupling units includes a bobbin (16), a clip (17) and a coupling bolt (18). A head part (20) of the bobbin includes a torque receiving portion (22) inserted into a notch (15) formed at the coupling bracket and a projection (23a) projecting in a circumferential direction from an end of the torque receiving portion. A pipe part (21) of the bobbin extends from the head part and is fitted in a coupling through hole (9) of the disc main body. The clip includes a connecting portion (29) between the torque receiving portion and the notch and a pressing portion (30b) extending from the connecting portion between the head part and the coupling bracket. The coupling bolt is inserted into each of through hole of the bobbin to fix the coupling bracket to the coupling unit.