Triple-Lip Bulkhead Seal for Battery Module Pressure Isolation

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Solution Overview

Problem

Existing bulkhead designs for electrical energy storage devices are difficult to manufacture, not easily accessible for repairs, and struggle with installation tolerances, while failing to provide reliable sealing and rapid response to sudden pressure increases and hot particle streams during thermal runaway.

Innovation Solution

A bulkhead seal with a fastening region, first and second sealing lips, and a middle sealing lip, designed to form intermediate spaces and respond to pressure changes, using silicone elastomers and intumescent coatings for enhanced sealing and tolerance compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bulkheads are connected to housing base and cover by welding, then sealing between modules is improved, but manufacturing complexity increases and repair accessibility deteriorates

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

Solution Approach 1:

The bulkhead seal is divided into multiple sealing lips (first sealing lip, second sealing lip, middle sealing lip) that can be independently positioned and function. This segmentation allows each lip to address specific sealing requirements while maintaining overall sealing reliability without requiring complex welding procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bulkhead seal acts as an intermediary component between the bulkhead and the housing, providing the sealing function without requiring direct welding between bulkhead and housing. This mediator approach simplifies manufacturing by using a separate sealing component that can be installed independently.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If bulkheads are welded to housing components, then structural strength is improved, but ease of repair deteriorates

Engineering Contradiction:
Improvestructural strengthVSAvoidrepair accessibility
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The seal is segmented into multiple lips that can independently maintain sealing function. If one sealing lip is damaged during thermal runaway, the other lips remain intact and continue to provide sealing, facilitating easier repair or replacement without compromising overall structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and second sealing lips are designed as sacrificial elements that may become brittle and fail during thermal runaway events. This deliberate design allows the middle sealing lip to remain functional and maintain sealing, enabling selective replacement of only the damaged outer lips rather than the entire bulkhead assembly.

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If sealing lips are designed to contact housing directly, then sealing effectiveness is improved, but tolerance compensation becomes more difficult

Engineering Contradiction:
Improvesealing effectivenessVSAvoidtolerance compensation
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The bulkhead seal is designed with specific geometric parameters including the arrangement of sealing lips at different positions and angles. The middle sealing lip is positioned between the first and second sealing lips, creating intermediate spaces that allow for parameter adjustments to accommodate manufacturing tolerances while maintaining effective sealing contact with the housing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sealing solution extends into the dimensional space by creating intermediate spaces between sealing lips and utilizing the vertical arrangement of multiple lips. This multi-dimensional approach provides tolerance compensation by distributing sealing contact across multiple planes and positions rather than relying on a single contact point.

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

4Speed

If bulkhead seal responds quickly to pressure increase, then safety is improved, but structural complexity increases

Engineering Contradiction:
Improveresponse speedVSAvoidseal structure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The bulkhead seal is designed with dynamic response characteristics where the multiple sealing lips can independently deform and respond to pressure changes. The intermediate spaces between lips allow for rapid pressure equalization and response without requiring complex active control systems, achieving fast response through passive elastic deformation.

Inventive Principle:
Principle #15Dynamics

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 bulkhead seal maintains sealing integrity even under thermal stress, protects against hot particle damage, and allows for easy installation and repair access, ensuring reliable separation of energy storage modules.

Implementation Method 1

The first sealing lip, the second sealing lip and the middle sealing lip are designed to contact the housing in the installed state

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

intumescent coatings for enhanced sealing and tolerance compensation

Methodology Applied
Scientific EffectIntumescent expansion: Intumescent Materials

Data Source

PatentEP4583256A1Bulkhead wall seal
Publication Date: 2025.07.09 CARL FREUDENBERG KG
  • EP4583256A1 patent drawingFigure 1
  • EP4583256A1 patent drawingFigure 2
  • EP4583256A1 patent drawingFigure 3

AI summary

Bulkhead seal (1) for sealing a first energy storage module (41) from a second energy storage module (42) in a common housing (50), wherein the first energy storage module and the second energy storage module are separated from one another by a bulkhead (30). The bulkhead seal comprises a fastening region (20) which is designed to be fastened to the bulkhead, a first sealing lip (11), a second sealing lip (12), and a middle sealing lip (13) which is arranged between the first sealing lip and the second sealing lip. Thus, a first intermediate space (14) is formed between the middle sealing lip and the first sealing lip. A second intermediate space (15) is formed between the second sealing lip and the middle sealing lip. The first sealing lip, the second sealing lip, and the middle sealing lip are designed to contact the housing.The first sealing lip is configured to seal the first energy storage module from the first intermediate space, and the second sealing lip is configured to seal the second energy storage module from the second intermediate space. The middle sealing lip is configured to seal the first intermediate space from the second intermediate space.