Aircraft Pressure Relief Valve Bias Setting Without Shim Iteration

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Solution Overview

Problem

Manufacture of conventional aircraft pressure relief valves is costly and time-consuming due to an iterative process involving coining and shim selection to ensure proper functionality, leading to potential alignment errors and increased manufacturing time.

Innovation Solution

The pressure relief valve design includes a conical valve seat and a threaded end stop element, allowing for improved sealing engagement and adjustable biasing force without iterative processes, reducing manufacturing complexity and time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional ball and spring assembly with iterative coining and shim selection process is used, then proper seating and functionality can be achieved, but manufacturing cost and time increase significantly

Engineering Contradiction:
Improveproper seating and functionalityVSAvoidmanufacturing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The conical valve seat is pre-formed during housing manufacturing rather than requiring post-manufacturing coining. The biasing element is pre-assembled with the ball carrier in a predetermined position, eliminating the need for iterative shim selection and adjustment during assembly. These preliminary actions ensure proper seating and biasing force are achieved without time-consuming iterative processes.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If iterative coining and shim selection process is used, then proper valve functionality can be ensured, but manufacturing complexity increases

Engineering Contradiction:
Improvevalve functionalityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The conical valve seat geometry is incorporated into the housing design and manufactured in advance, eliminating the need for iterative coining processes. The biasing element is pre-positioned with the ball carrier assembly, removing the complexity of iterative shim selection. These preliminary design and manufacturing actions simplify the overall manufacturing process while ensuring proper valve functionality.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If conventional flat valve seat design is used, then manufacturing is simpler, but sealing engagement and reliability are compromised

Engineering Contradiction:
Improvevalve seat manufacturingVSAvoidsealing engagement
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The valve seat is designed with a conical geometry featuring a curved surface that complements the spherical shape of the valve ball. This curved conical surface provides optimal contact area and sealing engagement between the ball and seat, improving reliability. The conical shape is manufactured as an integrated feature of the housing, maintaining ease of manufacture while achieving superior sealing compared to flat valve seats.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 improved design enhances manufacturing efficiency and reliability by eliminating the need for iterative processes and iterative processes, while ensuring precise setting of the biasing force and sealing engagement.

Implementation Method 1

a biasing element arranged within the inner cavity and configured to bias the ball carrier toward the inlet end wall

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a valve ball arranged within the inner cavity and configured to sealingly engage with the valve seat to seal the inlet opening

Methodology Applied
Scientific EffectMechanical Force: Force

Implementation Method 3

an end stop element configured to threadedly engage with an interior surface of the valve housing, and a locking nut configured to threadedly engage with an end of the end stop element and secure the end stop element to the valve housing

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Data Source

PatentEP4660497A1Aircraft pressure relief valves
Publication Date: 2025.12.10 HAMILTON SUNDSTRAND CORP
  • EP4660497A1 patent drawingFigure 1A~1B
  • EP4660497A1 patent drawingFigure 2A~2B
  • EP4660497A1 patent drawingFigure 3A~3B

AI summary

Pressure relief valves include a valve housing (206, 300) having an inlet end wall (310) and an inner cavity defined within the valve housing (206, 300). An inlet opening (208, 308, 408) defining a valve seat is formed within the inlet end wall (310). A valve ball (202, 422) is configured to sealingly engage with the valve seat to seal the inlet opening (208, 308, 408). A ball carrier (214, 424) is arranged to retain the valve ball (202, 422) between the ball carrier (214, 424) and the inlet end wall (310). A biasing element (204) is configured to bias the ball carrier (214, 424) toward the inlet end wall (310). An end stop element is configured to threadedly engage with an interior surface of the valve housing (206, 300) and the biasing element (204) is biased against a stop surface of the end stop element. A locking nut is configured to threadedly engage with an end of the end stop element and secure the end stop element to the valve housing (206, 300).