Railway Brake Disk Venting for Cooling With Lower Aerodynamic Sound
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Solution Overview
Problem
Existing brake disk designs for railway vehicles face challenges in maintaining cooling performance during high-speed braking while minimizing aerodynamic sound, as reducing airflow rate to reduce noise also decreases cooling efficiency.
Innovation Solution
A brake disk unit with a control member that includes a plate-shaped support portion and projecting portions between adjacent fins, which controls airflow rate and increases air flow velocity along the brake disk surface, enhancing cooling performance while reducing aerodynamic sound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the cross-sectional area of ventilation passages is reduced to limit airflow rate, then aerodynamic sound is reduced, but cooling performance of the brake disk decreases
Solution Approach 1:
The invention applies local quality by providing connecting portions only at specific locations where fins are adjacent in the circumferential direction, rather than uniformly across all fins. This localized approach reduces aerodynamic sound at noise-generating areas while preserving cooling airflow paths in other regions, thus resolving the contradiction between noise reduction and cooling performance.
Solution Approach 2:
The brake disk is segmented into multiple fins with connecting portions strategically placed between adjacent fins. This segmentation creates multiple small ventilation passages that collectively maintain cooling efficiency while each individual passage limits airflow rate to reduce aerodynamic sound generation.
2Object-generated harmful factors
If airflow rate in ventilation passage is limited, then aerodynamic sound is reduced, but flow velocity of air along brake disk surface decreases
Solution Approach 1:
The invention transitions from a two-dimensional view of airflow (through the ventilation passage cross-section) to a three-dimensional understanding by positioning connecting portions at specific radial and circumferential locations. This dimensional approach allows the airflow to be constrained in the circumferential direction (reducing sound) while maintaining velocity in the radial direction (preserving cooling).
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 secures the cooling performance of the brake disk during braking while reducing aerodynamic sound generated during high-speed travel, by controlling airflow and increasing heat transfer efficiency.
Implementation Method 1
The control member controls an airflow rate between the fins that are adjacent
Implementation Method 2
When the brake disk rotates with the wheel, the ventilation passage allows air to pass from the inner circumferential side toward the outer circumferential side of the brake disk to thereby cool the brake disk
Implementation Method 3
the ventilation passage allows air to pass from the inner circumferential side toward the outer circumferential side of the brake disk to thereby cool the brake disk
Implementation Method 4
Friction between the brake lining and the brake disk applies a braking force to the brake disk and the wheel
Data Source
AI summary
A brake disk unit includes a rotating member, a brake disk, and a control member. The brake disk includes a disk main body, fins, and convex portions and/or concave portions. The control member includes a support portion and a projecting portion. At least a part of the projecting portion is arranged between fins that are adjacent in the circumferential direction of the brake disk. A gap is formed between the projecting portion and the brake disk. On the surface of the brake disk, the convex portions and/or the concave portions are provided further on the outer side in the radial direction of the brake disk than a minimum opening portion of the gap.