Cooling machine, reefer container

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Solution Overview

Problem

Existing cooling machines for reefer containers face issues with dirt accumulation around fastening means and joints between the back-plate and fan grille, leading to potential bacterial growth and increased cleaning complexity, as well as higher weight and risk of damage to cargo due to sharp edges and materials.

Innovation Solution

An integrated fan grille is formed directly into a one-piece back-plate made from materials like fiberglass or plastic, with a mesh structure that can vary in density and orientation to minimize edges and joints, reducing weight and facilitating easier cleaning while preventing accidental contact with fan blades.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate stainless steel grille is mounted on the back-plate using fasteners, then the fan opening is protected and adequate strength is achieved, but dirt accumulates around fastening means and joints leading to bacterial growth and increased cleaning complexity

Engineering Contradiction:
Improveprotection of fan openingVSAvoidcleaning ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The grille is merged with the back-plate to form an integrated one-piece structure, eliminating separate fastening means and joints where dirt could accumulate. This integration removes the cleaning complexity associated with multiple components while maintaining the protective function of the fan opening.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The back-plate is designed with integrated grille structures that segment the surface into functional zones (grille areas and smooth back-plate areas) within a single piece, allowing different regions to serve different purposes while avoiding the need for separate components and fasteners.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a separate stainless steel grille is mounted on the back-plate, then the fan opening is protected, but the overall weight of the back-plate increases

Engineering Contradiction:
Improveprotection of fan openingVSAvoidback-plate weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The back-plate is made from composite materials such as fiberglass or fiber-reinforced plastic that provide adequate strength and protection while being lighter than traditional stainless steel constructions. The integrated design allows these composite materials to be used effectively without requiring additional fastening hardware.

Inventive Principle:
Principle #40Composite materials

3Reliability

If a separate stainless steel grille is mounted on the back-plate, then the fan opening is protected, but the risk of damage to cargo increases due to sharp edges and fasteners

Engineering Contradiction:
Improveprotection of fan openingVSAvoiddamage risk to cargo
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By merging the grille with the back-plate into a single integrated structure, all separate fasteners, joints, and potential sharp edges are eliminated. The seamless integration removes protruding elements that could damage cargo while maintaining the protective function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The back-plate and integrated grille are designed with smooth, curved surfaces that eliminate sharp edges and corners. The continuous molded structure provides rounded transitions that reduce the risk of cargo damage while maintaining structural integrity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Reliability

If a separate stainless steel grille is mounted on the back-plate, then the fan opening is protected, but the number of machining processes and manufacturing complexity increases

Engineering Contradiction:
Improveprotection of fan openingVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The grille and back-plate are merged into a single integrated component that can be manufactured in one molding or forming process. This eliminates the need for separate machining, assembly, and fastening operations, significantly simplifying manufacturing while maintaining protective functionality.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3558850B1Cooling machine, reefer container
Publication Date: 2022.06.29 MAERSK CONTAINER IND
  • EP3558850B1 patent drawingFigure 1
  • EP3558850B1 patent drawingFigure 2
  • EP3558850B1 patent drawingFigure 3~4

AI summary

The invention relates to a back-plate for a cooling machine in a reefer container with an improved fan grille, where a grille or grating (2) defines a section formed integral with the back-plate (1). The grille or grating (2) defined in the back-plate (1) can comprise layers of fibreglass forming the back-plate (1). The grille or grating (2) can surround holes provided by drilling, cutting or another suitable machining of the back-plate (1) after casting. The grille or grating (2) can be provided by a mesh structure having different mesh sizes (3, 4). The grille or grating (2) can be provided with a more dense mesh structure in one or more local areas (4) compared to a remaining part (3) of the grille (2). The grille or grating (2) is provided at an upper part of the back-plate (1).