Actuator Bushing Integral Seal Deflection

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Solution Overview

Problem

Existing actuator bushings with separate O-ring seals are ineffective in cold environments due to reduced flexibility and prone to material degradation in high temperatures, leading to poor sealing performance.

Innovation Solution

Integration of a flexible ring-shaped structure within the bushing, which can be deflected by pressurized fluid or biasing elements to form a seal against the stem, eliminating the need for separate seals and enhancing sealing efficiency with a tapered edge contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate O-ring seal is used in the bushing, then the sealing function is provided, but the seal becomes ineffective in cold environments due to reduced flexibility and prone to material degradation in high temperatures

Engineering Contradiction:
Improvesealing performanceVSAvoidtemperature adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent merges the seal into the bushing structure itself, creating an integral seal that is formed as part of the bushing body. This eliminates the need for separate O-ring seals and their associated temperature sensitivity issues, providing reliable sealing across varying temperature conditions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the physical parameters of the sealing structure by forming an integral seal with specific geometric features (such as tapered edges) that allow it to maintain flexibility and sealing effectiveness across a wide temperature range, unlike conventional O-rings that become rigid in cold environments.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a separate O-ring seal is used, then sealing is provided, but the design complexity and part count increase

Engineering Contradiction:
Improvesealing functionVSAvoidpart complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The seal is merged with the bushing to form a single integral component, eliminating the need for separate seal parts and reducing overall design complexity while maintaining effective sealing functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bushing is designed to perform multiple functions simultaneously: it provides structural support, guides the stem, and incorporates an integral seal. This multi-functionality reduces the number of separate components needed in the system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If a flexible ring structure is deflected by pressurized fluid, then sealing efficiency is enhanced, but the structure must withstand varying pressure conditions

Engineering Contradiction:
Improvesealing efficiencyVSAvoidpressure resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The integral seal is designed with dynamic characteristics that allow it to deflect and conform to the stem surface under varying pressure conditions. The flexible ring structure can adjust its position and shape in response to pressure changes while maintaining sealing effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The bushing incorporates a localized flexible ring structure with specific geometric features (such as tapered edges) that concentrate sealing force at critical contact points, enhancing sealing efficiency while distributing pressure loads appropriately across the structure.

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 bushing provides a reliable and flexible seal with reduced friction and increased durability across varying temperatures, simplifying design and reducing part complexity and costs.

Implementation Method 1

The groove is to receive a force to deflect the flexible member toward the stem

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

The flexible ring-shaped structure may be tapered so that an inner surface of the flexible ring-shaped structure makes edge contact against the outer surface of the stem

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3008353B1Actuator bushings having integral seals
Publication Date: 2019.08.07 FISHER CONTROLS INT LLC
  • EP3008353B1 patent drawingFigure 1
  • EP3008353B1 patent drawingFigure 2
  • EP3008353B1 patent drawingFigure 3

AI summary

Actuator bushings having integral seals are described herein. An example apparatus includes a bushing (300, 400) having a central bore (302) to receive a stem and an annular groove (310, 404) at an end of the bushing. The annular groove surrounds the bore to define a flexible ring (312, 406) to form a seal against the stem.