Disc Rotor Inner Extension Cutouts for Heat and Corrosion Control

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Solution Overview

Problem

Disc brake devices face issues with excessive heat generation leading to temperature rise and potential warpage, as well as corrosion due to water collection in recesses formed by the disc rotor and wheel hub, which can cause vibration and performance degradation.

Innovation Solution

A disc brake device with a ring-shaped disc rotor featuring an inner extension and cutouts in the radial direction to increase heat capacity while preventing water collection through evenly spaced cutouts around the central axis, ensuring effective drainage and reducing corrosion risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the inner extension is added to increase heat capacity, then the temperature rise is suppressed, but water collects in the recess causing corrosion

Engineering Contradiction:
Improvetemperature rise of disc rotorVSAvoidwater collection and corrosion
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The inner extension is divided into multiple segments by forming cutouts between adjacent fastening portions. This segmentation prevents continuous water accumulation by creating drainage pathways while maintaining sufficient heat capacity through the remaining extension structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Water collection is prevented by extracting the harmful water from the recess space through cutouts. The cutouts serve as extraction pathways that allow water to drain out while the inner extension remains to provide heat capacity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If the volume of disc rotor is increased to improve heat capacity, then the heat resistance is improved, but the device complexity increases

Engineering Contradiction:
Improveheat resistance of disc rotorVSAvoidstructural complexity of disc rotor
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The inner extension is segmented into multiple portions by cutouts between fastening portions. This segmentation maintains the overall volume and heat capacity while simplifying the structure by creating drainage pathways, avoiding the need for separate drainage components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner extension serves multiple functions: it increases heat capacity by extending toward the central axis, provides structural support for fastening portions, and prevents water accumulation through integrated cutouts. This multi-functionality reduces the need for additional components.

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

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 solution enhances the heat capacity of the disc rotor, reducing temperature rise and minimizing corrosion-related judder, thereby improving brake performance and reliability.

Implementation Method 1

A plurality of cutouts, which are recessed outward in a radial direction of the wheel, are formed in the inner extension... water that has collected in the recess is discharged through the cutouts

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

When the brake caliper presses the brake pad against the disc rotor, friction is generated between the brake pad and the disc rotor. The frictional resistance brakes the rotation of the disc rotor.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4414580A1Disc brake device and straddled vehicle
Publication Date: 2024.08.14 YAMAHA MOTOR CO LTD
  • EP4414580A1 patent drawingFigure 1
  • EP4414580A1 patent drawingFigure 2~3
  • EP4414580A1 patent drawingFigure 4

AI summary

There is disclosed a disc brake device (7) wherein a disc rotor (20) has a large heat capacity and judder due to corrosion is less likely to occur; the disc rotor (20) of a disc brake device including: a contact portion (21) to be in contact with a cylindrical portion (11) of a wheel hub (10); and an inner extension (22) that is located closer to a central axis (5C) than the contact portion (21), is facing a ring-shaped portion (12) of the wheel hub (10), and is spaced apart from the ring-shaped portion (12); a plurality of cutouts (23), which are recessed outward in a radial direction, are formed in the inner extension (22).