Railway Coupler Body Avoidance Area Reduces Stress Concentration

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Solution Overview

Problem

The coupler body in railway vehicles experiences premature failure due to stress concentration at the roots of the traction platforms near the lock chamber, leading to reduced service life and increased maintenance costs.

Innovation Solution

The coupler body design includes a traction surface divided into a contact area and an avoidance area, with the avoidance area located near the lock chamber and pin hole, creating a gap between the avoidance area and the coupler knuckle, thereby reducing stress and preventing premature failure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the traction platforms are designed to be close to the lock chamber for compact structure, then the coupler body achieves compact design, but stress concentration occurs at the roots of the traction platforms leading to premature failure

Engineering Contradiction:

Improvecoupler body volumeVSAvoidservice life of coupler body

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent extracts the problematic contact area from the traction platform by introducing an avoidance area that does not contact the coupler knuckle. This separation removes the stress concentration zone while maintaining the functional contact area, thereby preventing premature failure without increasing overall volume.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The traction surface is differentiated into distinct zones: a contact area for load bearing and an avoidance area near the lock chamber that avoids contact. This local differentiation allows the coupler body to maintain compact dimensions while preventing stress concentration at critical locations.

Inventive Principle:

Principle #3Local quality

2Strength

If the contact area between traction platforms is extended near the lock chamber, then load bearing capacity is improved, but stress concentration increases causing premature fracture

Engineering Contradiction:

Improveload bearing capacityVSAvoidstress concentration at traction platform roots

Core Design Contradiction:

StrengthVSStress or pressure

Solution Approach 1:

The traction surface is segmented into a contact area for load transmission and an avoidance area that prevents contact with the coupler knuckle. This segmentation allows the design to achieve adequate load bearing capacity through the contact area while eliminating stress concentration by preventing contact in the avoidance area near the lock chamber.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The avoidance area acts as an intermediary zone between the contact area and the lock chamber. It mediates the interaction by creating a gap that prevents direct contact between the traction platform and coupler knuckle, thereby reducing stress concentration while maintaining load bearing functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11560161B2Railway vehicle, coupler, and coupler body thereof

Publication Date: 2023.01.24 CRRC QIQIHAR ROLLING CO LTD

AI summary

A railway vehicle, a coupler, and a coupler body thereof. The coupler body comprises an upper traction platform, a lower traction platform, a lock chamber, and a pin hole. A traction surface of an upper traction platform and/or a lower traction platform is divided into a contact area and a yielding area along the direction approaching the lock chamber, an extension face of the end of the contact area close to the lock chamber is an M2 face, and the yielding area is positioned at the side of the M2 face close to the pin hole. The yielding area is positioned on the side of the contact area next to the lock chamber and there is a gap and no contact between the yielding area and a traction platform of a coupler knuckle.