Refrigerator Door Pressure Valve Assembly to Prevent Icing

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Solution Overview

Problem

Conventional pressure equalization valves in refrigeration appliances tend to ice up, leading to operational failures, require significant installation effort, and are not easily replaceable or repairable, while also allowing continuous air and heat exchange.

Innovation Solution

A valve assembly with an inlet and outlet on different sides of a seal, featuring a recess for easy installation and a second seal for air-tight anchoring, utilizing a membrane that seals via surface contact rather than edge contact, and a sealing ring for secure positioning, which reduces the risk of leakage and icing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional pressure equalization valve is installed by embedding it in insulation material, then the valve can be securely positioned, but the installation effort increases significantly and the valve becomes difficult to replace or repair

Engineering Contradiction:
Improvesecure positioning of valveVSAvoidinstallation effort
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The pressure equalization valve is divided into separate modular components: a valve body, a sealing element, and a positioning structure. This segmentation allows the valve to be installed as a complete unit without embedding in insulation material, reducing installation effort while maintaining secure positioning through the positioning structure that engages with the housing wall.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The valve assembly is pre-assembled with the sealing element and positioning structure attached before installation. This preliminary preparation ensures proper sealing and positioning without requiring complex on-site installation procedures or embedding in insulation material, thereby reducing installation effort while maintaining reliability.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a conventional pressure equalization valve is embedded in insulation material, then the valve is securely anchored, but the valve cannot be easily replaced or repaired when defective

Engineering Contradiction:
Improvesecure anchoring of valveVSAvoidreplaceability of valve
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The valve is designed as a modular assembly with distinct components that can be independently replaced. The valve body, sealing element, and positioning structure are separate, allowing the entire valve assembly to be removed and replaced as a unit without damaging the insulation material or housing, thereby enabling easy repair while maintaining secure anchoring during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positioning structure incorporates movable or adjustable elements that allow the valve to be securely anchored during operation but easily removed when needed for replacement. This dynamic design enables the valve to transition between a secured state during operation and a removable state for maintenance, resolving the contradiction between secure anchoring and replaceability.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a passage is created through the seal for pressure equalization, then negative pressure is prevented, but continuous air exchange and heat transfer occur between the interior and environment

Engineering Contradiction:
Improveprevention of negative pressureVSAvoidheat and moisture exchange
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The pressure equalization valve incorporates a movable closing body (membrane or valve element) that dynamically opens only when negative pressure differential exists across the seal. When pressures are balanced, the closing body automatically seals the passage, preventing continuous air exchange and heat transfer. This dynamic operation allows the system to maintain pressure equalization functionality while minimizing energy losses during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The valve mechanism incorporates a feedback system where the pressure differential itself controls the valve position. When negative pressure develops, the pressure difference automatically opens the valve to equalize pressures. When pressures are balanced, the valve closes automatically. This pressure-driven feedback control ensures the passage remains closed during normal operation, preventing continuous heat and moisture exchange while maintaining pressure equalization when needed.

Inventive Principle:
Principle #23Feedback

4Device complexity

If a membrane seals against the walls of the passage in a conventional lip valve, then the valve can be simple in structure, but the sealing effect is poor and dimensional accuracy requirements are high

Engineering Contradiction:
Improvesimplicity of valve structureVSAvoidsealing effect
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The sealing surface of the closing body is designed with a curved or spherical geometry that matches a corresponding curved sealing surface on the valve seat. This curved contact provides a larger sealing area and more forgiving dimensional tolerances compared to edge sealing, improving the sealing effect while maintaining simple valve structure. The curved surfaces naturally conform to each other, enhancing sealing reliability without requiring high dimensional accuracy.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The sealing mechanism transitions from edge contact (one-dimensional line contact) to surface contact (two-dimensional area contact). The closing body contacts the valve seat over a substantial surface area rather than along a narrow edge, providing more robust sealing with lower dimensional accuracy requirements. This dimensional change from line to area contact improves sealing reliability while keeping the valve structure simple.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Facilitates easy installation and replacement, minimizes the risk of leakage and icing, and maintains air-tight sealing while allowing pressure equalization without continuous air exchange, ensuring efficient operation and reduced maintenance effort.

Implementation Method 1

a closing body lying on it is acted upon by its own weight in the closed position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an overpressure prevailing in the inlet chamber lifts the closing body from the intermediate wall, so that the valve assembly becomes permeable

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 3

the second seal can also be used for frictionally engaged, releasable anchoring of the valve assembly in the recess

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2283286B1Refrigeration device comprising a pressure compensation valve
Publication Date: 2011.09.07 BSH HAUSGERATE GMBH
  • EP2283286B1 patent drawingFigure 1~3
  • EP2283286B1 patent drawingFigure 4~5

AI summary

The invention relates to a refrigeration device which comprises a carcass (2) and a door (1) which surround a cooled interior space and which have wall surfaces (3; 7) that face each other and that define a gap filled with a seal (10). A recess (11) bridging the seal (10) is formed into at least one of the wall surfaces (7). A valve assembly (12) having an inlet (16) and an outlet (17) is inserted into the recess (11) on different sides of the seal (10).