Stepped Sealing Lip Design for Flange Airtightness

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Solution Overview

Problem

Existing control valve flange connections face challenges in maintaining an airtight seal due to manufacturing tolerances, which can lead to leaks and malfunction, especially when dealing with fine unevenness like scratches on the flange surfaces.

Innovation Solution

A control valve seal with a stepped sealing lip design, featuring a basic sealing lip for large-area unevenness compensation and a filigree second sealing lip for fine unevenness, allowing for more cost-effective flange manufacturing and improved sealing efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single sealing lip is used to compensate for flange unevenness, then large-area unevenness can be sealed, but fine unevenness like scratches cannot be effectively sealed

Engineering Contradiction:
Improveflange surface qualityVSAvoidsealing effectiveness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The sealing lip is divided into two distinct segments: a first sealing lip with a larger cross-sectional area for compensating large-area unevenness, and a second sealing lip with a smaller, filigree cross-sectional area for sealing fine unevenness like scratches. This segmentation allows each lip to specialize in different types of surface defects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the sealing structure are given different properties: the first sealing lip has a larger cross-sectional area and is positioned to handle coarse surface variations, while the second sealing lip has a finer structure and is positioned to address micro-scale defects. This local differentiation of sealing capabilities ensures comprehensive coverage of all unevenness types.

Inventive Principle:
Principle #3Local quality

2Reliability

If the seal is made filigree to compensate for fine unevenness, then sealing of scratches improves, but the ability to compensate for large-area unevenness is reduced

Engineering Contradiction:
Improvesealing of fine unevennessVSAvoidcompensation for large-area unevenness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing function is segmented between two lips with different geometries. The first sealing lip provides the structural bulk needed for large-area compensation, while the second sealing lip extends filigree structures into the unevenness for fine defect sealing. This segmentation resolves the contradiction by assigning different scales of sealing to different segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second sealing lip is positioned on top of the first sealing lip, with the filigree structures of the second lip extending into the unevenness while the first lip provides the foundational sealing for larger variations. This nested arrangement allows both fine and coarse sealing capabilities to coexist in a hierarchical structure.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If high surface pressure is applied to seal the flange connection, then sealing effectiveness improves, but manufacturing tolerances must still be very tight

Engineering Contradiction:
ImproveairtightnessVSAvoidflange tolerance requirements
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing mechanism changes from relying solely on high contact pressure between flat surfaces to utilizing the geometric interlocking of stepped sealing lips with the unevenness profile. This parameter change in the sealing mechanism allows for reduced flange tolerance requirements while maintaining airtightness.

Inventive Principle:
Principle #35Parameter changes

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 stepped sealing lip design enhances the airtightness of the flange connection, reducing tolerance requirements on the flanges and improving the sealing effect, while maintaining a stable installation process.

Implementation Method 1

a first sealing lip formed on the sealing body with a pressure surface running circumferentially around the compressed air channel for airtight pressing against one of the flanges

Methodology Applied
Scientific EffectPressure surface: Pressure Increase

Implementation Method 2

a second sealing lip formed on the pressing surface and partially covering the pressing surface

Methodology Applied
Scientific EffectSealing lip geometry:

Implementation Method 3

The stepped sealing lip design enhances the airtightness of the flange connection, reducing tolerance requirements on the flanges and improving the sealing effect

Methodology Applied
Scientific EffectStepped sealing geometry:

Data Source

PatentEP2753518B1Control valve seal and control valves with this control valve seal
Publication Date: 2020.12.02 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP2753518B1 patent drawingFigure 1
  • EP2753518B1 patent drawingFigure 2
  • EP2753518B1 patent drawingFigure 3

AI summary

The invention relates to a method for braking a rail vehicle (2) having at least two wheels (8), comprising a central control device (12) for specifying a common control variable (14) for both wheels (8) and a decentralized control device (10) for each wheel (8) in order to control the wheels (8) individually on the basis of an individual control variable (32) that is dependent on the common control variable (14), said method comprising the steps: receiving the common control variable (14) from the central control device (12) in one of the decentralized control devices (10); determining (30) the individual control variable (32) on the basis of the common control variable (14); and braking (38) the wheel (8) associated with the decentralized control device (10) on the basis of the individual control variable (32).