Disc Brake Airflow Restriction for Low Aerodynamic Sound

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Solution Overview

Problem

Existing disc brake devices for railway vehicles face challenges in controlling the clearance between aerodynamic-sound reduction members and the brake disc, which affects cooling performance and production complexity.

Innovation Solution

A disc brake device with a separate airflow-rate restriction member, comprising a base plate and a protruding portion, is used to restrict airflow rate between the rotary member and the brake disc, facilitating control of clearance and simplifying production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a connecting portion is formed integrally with the brake disc to reduce aerodynamic sound, then aerodynamic sound is reduced, but the brake disc rigidity becomes non-uniform causing warpage

Engineering Contradiction:

Improveaerodynamic soundVSAvoidbrake disc uniformity

Core Design Contradiction:

Object-generated harmful factorsVSStability of the object's composition

Solution Approach 1:

The brake disc is divided into a disc body and a separate aerodynamic-sound reduction member. This segmentation allows the aerodynamic sound reduction function to be achieved without integrating the connecting portion into the disc body, thereby maintaining uniform rigidity and preventing warpage while still reducing aerodynamic sound through the separate member's structure.

Inventive Principle:

Principle #1Segmentation

2Object-generated harmful factors

If the connecting portion is integrated with the brake disc, then aerodynamic sound is reduced, but design freedom and manufacturing yield decrease

Engineering Contradiction:

Improveaerodynamic soundVSAvoidmanufacturing yield

Core Design Contradiction:

Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

By separating the aerodynamic-sound reduction member from the disc body, the patent enables independent manufacturing of each component. This segmentation allows the disc body to be produced using conventional high-yield methods without the complexity of forming integrated connecting portions, while the separate member can be manufactured and attached independently, thereby improving overall manufacturing yield and design freedom.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If the aerodynamic-sound reduction member is separate from the brake disc, then manufacturing flexibility is improved, but clearance control becomes more difficult

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidclearance control

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The aerodynamic-sound reduction member is designed to utilize the natural radial movement of the brake disc during operation. As the disc expands and contracts radially due to thermal and mechanical loads, the clearance between the aerodynamic-sound reduction member and the disc body automatically adjusts, eliminating the need for precise fixed clearance control while maintaining effective aerodynamic sound reduction throughout operating conditions.

Inventive Principle:

Principle #25Self-service

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 effectively reduces aerodynamic sound while maintaining good cooling performance of the brake disc, and simplifies the production process by eliminating the need for precise dimensional control of the clearance.

Implementation Method 1

an airflow-rate restriction member 30 for restricting an airflow rate between the rotary member 10 and the brake disc 20

Methodology Applied

Scientific EffectAirflow restriction:

Implementation Method 2

When the brake disc rotates with the wheel, the ventilation passage allows air to pass therethrough from an inner circumferential side to an outer circumferential side of the brake disc. The air flowing through the ventilation passage cools the brake disc.

Methodology Applied

Scientific EffectConvection cooling: Convection

Implementation Method 3

Friction between the brake lining and the brake disc decelerates the railway vehicle

Methodology Applied

Scientific EffectFriction heating: Friction

Implementation Method 4

by blocking a part of the ventilation passage by a protruding portion to impede flow of the air in the ventilation passage, it is possible to reduce aerodynamic sound generated while the railway vehicle is travelling

Methodology Applied

Scientific EffectAerodynamic sound reduction:

Data Source

PatentUS20250035172A1Disc brake device

Publication Date: 2025.01.30 NIPPON STEEL CORPORATION

AI summary

A disc brake device includes a rotary member, a brake disc, and an airflow-rate restriction member. The brake disc includes a disc body and a plurality of fins. The airflow-rate restriction member includes a base plate and a protruding portion. The base plate is sandwiched between the rotary member and the fins. The protruding portion is arranged inward in the radial direction of the disc body with respect to the fins. The protruding portion protrudes from the base plate toward a disc body side. The protruding portion extends in the circumferential direction of the disc body.