Valve Seal Assembly With Retaining Ring for Pressure-Adaptive Fixation

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Solution Overview

Problem

Existing sealing arrangements for fluid valves, particularly in butterfly and hinge valves, lack effective and cost-efficient methods to maintain the sealing element in place and ensure reliable fluid control between open and closed positions, especially under varying pressure differentials.

Innovation Solution

A sealing arrangement comprising a retaining ring with legs and a flexible sealing element, utilizing a press fit and spring force to secure the element in place, with a radial ridge and circumferential sealing lip, allowing for elastic expansion and pressure adaptation, and a recess to facilitate movement and reduce mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing element is secured using traditional fixing methods, then the sealing element can be held in place, but the method is complex and costly

Engineering Contradiction:
Improvesealing element fixationVSAvoidfixation mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The retaining ring is divided into multiple legs that can independently engage with the housing bore, allowing each leg to provide localized support and sealing contact. This segmentation enables reliable fixation while maintaining simplicity in the overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retaining ring incorporates elastic legs that can dynamically adapt to pressure differentials and assembly variations. The legs bend and flex to accommodate manufacturing tolerances and operational forces, providing reliable fixation without requiring complex adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

2Stability of the object's composition

If the sealing element is rigidly fixed, then position stability is achieved, but the element cannot adapt to pressure differentials

Engineering Contradiction:
Improvesealing element position stabilityVSAvoidpressure adaptation capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The elastic legs of the retaining ring provide dynamic adaptation to pressure differentials while maintaining positional stability. The legs can bend and flex in response to pressure changes, allowing the sealing element to adapt to varying operational conditions without compromising its secured position.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The retaining ring's elastic properties allow it to change its physical state in response to pressure differentials. The legs deform elastically under pressure, changing the retention force applied to the sealing element, thereby adapting to different pressure conditions while maintaining stable fixation.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the sealing element is made from standard materials, then manufacturing is simple, but friction properties and sealing effectiveness are insufficient

Engineering Contradiction:
Improvesealing element manufacturingVSAvoidsealing effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sealing element combines elastomeric material with a friction-modifying coating layer. This composite structure provides both the elasticity needed for sealing and the enhanced friction properties required for effective fixation and sealing under pressure, while remaining manufacturable through coating processes.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The friction-modifying coating is applied specifically to the outer peripheral surface of the sealing element where contact with the housing occurs. This local enhancement of friction properties improves sealing effectiveness and fixation reliability without requiring the entire element to be made from complex composite materials.

Inventive Principle:
Principle #3Local quality

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 provides a robust and cost-effective sealing mechanism that maintains the sealing element's position, enhances fluid flow control, and extends service life by adapting to pressure differentials, while ensuring reliable sealing and fluid flow management.

Implementation Method 1

the flexible sealing element can advantageously be held in place by, on the one hand, the (radially acting) compressive force generated by the interference fit between the first radial surface of the annular radial web and the counter-centering surface of the inner wall of the housing

Methodology Applied
Scientific EffectInterference fit: Friction

Implementation Method 2

by the spring force generated in the axial direction by the free ends of the legs of the retaining ring, which are supported under preload on the support section of the inner wall of the housing

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

allowing for elastic expansion and pressure adaptation

Methodology Applied
Scientific EffectElastic expansion: Elasticity

Data Source

PatentEP4426959B1Seal assembly
Publication Date: 2025.08.27 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP4426959B1 patent drawingFigure 1
  • EP4426959B1 patent drawingFigure 2~3
  • EP4426959B1 patent drawingFigure 4

AI summary

The invention relates to a seal assembly (100) for use in a fluid valve (10) which has a housing (20) and a flap (30) and which is designed to control a flow of fluid through a valve opening of the fluid valve (10) by adjusting the position of the flap (30) between a closed position and an open position. The seal assembly has a holding ring (110), which comprises a holding ring contact section (111) and a plurality of legs (112), and an annular flexible seal element (200), which has a circumferential radial web (201) and a first radial surface (202) that adjoins the radial web (201), is arranged on the upstream side when used as intended, and is designed to function as a centering surface in order to produce an interference fit together with a corresponding counter centering surface (23) of the inner wall (21) of the housing (20). A radial web (201) first lateral surface (203) which is arranged on the upstream side when used as intended is designed to rest against a contact surface (22) of the inner wall (21) of the housing (20), the holding ring contact section (111) has a holding ring contact surface which is designed to rest against a second radial web (201) lateral surface (204) which is arranged on the downstream side when used as intended, and free ends of at least one sub-quantity of the plurality of legs (112) are designed to be supported on a support section (24) of the inner wall of the housing (20) under pretension when used as intended, said support section extending substantially perpendicularly to the flow direction of the fluid.