Fuel Cell Housing Assembly With Floating Retention for Stack Expansion

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Solution Overview

Problem

Existing fuel cell housings face challenges in securely retaining the fuel cell stack without tilting or slipping, particularly during expansion, and existing solutions are either costly or require complete replacement of the housing when the stack is replaced.

Innovation Solution

A housing assembly with a stack cover featuring a floating bearing and a holding bolt system, where the bolt extends through a through-opening and is supported by a blind hole in the stack cover, allowing for expansion compensation and secure retention, with the option of replacing only the housing cover and retaining component when the stack is replaced.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a holding bolt is used to secure the fuel cell stack in the housing volume, then the stack is prevented from slipping and tilting, but the stack cannot accommodate expansion during operation

Engineering Contradiction:
Improveretention stabilityVSAvoidexpansion accommodation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by designing the holding bolt with a floating bearing that allows longitudinal movement. The holding bolt can move along its axis within the blind hole of the stack cover, enabling dynamic adjustment to accommodate thermal expansion of the fuel cell stack while maintaining secure retention. This transforms a static fastening system into a dynamic one that adapts to operational changes.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the fuel cell stack is securely fastened in the housing, then positioning precision is improved, but replacement of the stack requires complete replacement of the housing

Engineering Contradiction:
Improvepositioning precisionVSAvoidcomponent replaceability
Core Design Contradiction:
Manufacturing precisionVSEase of repair

Solution Approach 1:

The patent applies segmentation by dividing the housing into modular components: the main housing body, the stack cover, and the holding bolt assembly. The holding component with the floating bearing is integrated into the stack cover, which can be separately removed and replaced. This allows the fuel cell stack to be replaced by only swapping the stack cover and holding component, rather than replacing the entire housing, thus improving ease of repair while maintaining precise positioning.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If a fixed bearing structure is used for the holding bolt, then manufacturing simplicity is improved, but the structure cannot compensate for stack expansion

Engineering Contradiction:
Improvestructural simplicityVSAvoidexpansion compensation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by creating a floating bearing structure where the holding bolt is not rigidly fixed but can move longitudinally within the blind hole. The bearing surface in the stack cover provides support while allowing movement, creating a simple yet effective dynamic structure that compensates for expansion without complex mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies this principle by designing the stack cover with an integrated holding component as a replaceable unit. Rather than making the entire housing complex and expensive to accommodate expansion, the simple holding structure is made replaceable, allowing cost-effective replacement of only the necessary components when needed.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 cost-effective, secure, and space-efficient retention of the fuel cell stack, preventing slipping and tilting, while allowing for easy replacement of components, thus minimizing waste and reducing operational costs.

Implementation Method 1

The floating bearing movement is enabled, particularly in the longitudinal direction of the retaining pin, to compensate for expansion of the fuel cell stack during fuel cell operation

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4226443B1Housing assembly for a fuel cell, stack cover and fuel cell
Publication Date: 2025.08.20 ROBERT BOSCH GMBH
  • EP4226443B1 patent drawingFigure 1~2
  • EP4226443B1 patent drawingFigure 3~4

AI summary

The present invention relates to a housing assembly (10) for a fuel cell (30), comprising: - a stack housing (20) for a fuel cell stack (11), which stack housing has a stack cover (40); - a fuel cell housing (12), which has a housing volume (26) for receiving the stack housing (20), a housing outer face (14), a housing inner face (15), a bearing surface (16) on the housing outer face (14), and a through-opening (17) from the housing outer face (14) to the housing inner face (15); and - a retaining component (18), which has a mating bearing surface (19) for supporting the retaining component (18) on the bearing surface (16) and a retaining pin (13) for retaining the stack housing (20) in a predefined position in the housing volume (26); wherein the retaining pin (13) extends through the through-opening (17) from the housing outer face (14) outside of the housing volume (26) to the housing inner face (15) and beyond the housing inner face (15) into the housing volume (26), and wherein the stack cover (40) has a floating bearing (41) with a blind hole (42) for supporting the retaining pin (13). The invention also relates to a stack cover (40) for a housing assembly (10) according to the invention and to a fuel cell (30) having a housing assembly (10) according to the invention.