Radially Nested Bellows Air Filter for Combustion Engine

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Solution Overview

Problem

Existing air filters for internal combustion engines require complex construction and maintenance, compromising filtration performance and ease of service.

Innovation Solution

A filter device featuring a main filter element designed as a multiple bellows filter with radially nested star-shaped filter bellows, sealed by a TPE double-lip sealing ring, allowing radial and axial fluid flow with efficient separation of clean and dirty gas sides, and featuring a cyclone pre-separator and fine filter for enhanced filtration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional air filter design with multiple separate components is used, then the filtration performance can be maintained, but the device complexity and maintenance effort increase

Engineering Contradiction:
Improvefiltration performanceVSAvoidconstruction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple filtration stages (pre-separator, main filter element, and fine filter) into a single integrated filter cartridge that can be installed as one unit. The main filter element features radially nested bellows structures with filter folds arranged in multiple stages, merging what would traditionally be separate components into one unified assembly, thereby reducing device complexity while maintaining comprehensive filtration performance

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The filter element employs radially nested bellows structures where inner bellows are positioned within outer bellows. This nesting arrangement allows multiple filtration surfaces to be compactly arranged in a radial configuration, maximizing filtration area within a constrained axial space while simplifying the overall construction by eliminating the need for multiple separate filter housings

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If a complex multi-component filter system is implemented, then filtration effectiveness is improved, but the ease of operation and maintenance deteriorates

Engineering Contradiction:
Improvefiltration effectivenessVSAvoidmaintenance effort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent integrates the pre-separator, main filter element, and fine filter into a single replaceable cartridge assembly. This merging allows the entire multi-stage filtration system to be installed and maintained as one unit, significantly reducing maintenance effort compared to traditional systems requiring separate handling of multiple components, while preserving comprehensive filtration effectiveness through the multi-stage design

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If axial flow through the filter element is used, then the construction is simplified, but the filtration performance and flow distribution are compromised

Engineering Contradiction:
Improveconstruction simplicityVSAvoidfiltration performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent transitions from purely axial flow to a combination of radial and axial flow paths. The filter folds are arranged radially with their end edges extending axially, creating flow chambers that guide fluid radially through the filter material while maintaining axial progression. This radial-axial flow configuration improves filtration performance and flow distribution compared to simple axial flow, while the integrated bellows structure keeps construction relatively simple

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

4Area of stationary object

If multiple filter bellows are arranged radially, then the filtration area is increased, but the device complexity increases

Engineering Contradiction:
Improvefiltration areaVSAvoidstructural complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent arranges multiple filter bellows in a radially nested configuration where inner bellows are positioned within outer bellows. This nesting strategy increases the total filtration area by creating multiple radial flow paths through different bellows, while simultaneously reducing structural complexity by eliminating the need for separate housings for each bellows. The shared cylindrical structure provides support for all nested bellows, achieving both increased filtration area and simplified construction

Inventive Principle:
Principle #7Nested doll (Nesting)

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 high filtration performance with simplified construction and easy maintenance, ensuring efficient air filtration for internal combustion engines while minimizing operational effort.

Implementation Method 1

A cyclone pre-separator is installed upstream of the filter cartridge, which is used to separate coarse dirt particles

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Implementation Method 2

at least one filter bellows is to flow through in the radial direction and between the filter bellows a flow chamber for the fluid is formed

Methodology Applied
Scientific EffectRadial filtration: Filter (physical)

Data Source

PatentEP2878355B1Main filter element and filter device, especially air filter for a combustion engine
Publication Date: 2018.06.27 MANN HUMMEL GMBH
  • EP2878355B1 patent drawingFigure 1
  • EP2878355B1 patent drawingFigure 2~3
  • EP2878355B1 patent drawingFigure 4~5

AI summary

The invention relates to a main filter element (22) for a filter device (10), in particular an air filter for an internal combustion engine, which can be arranged in a filter housing (12). A fluid to be filtered flows through this housing. The main filter element (22) is designed as a multi-bellows filter with at least two radially nested filter bellows (32, 34), wherein at least one of the filter bellows (32, 34) is designed for radial flow. A flow chamber (44) for the fluid is formed between the filter bellows (32, 34). This chamber communicates with an end face of the main filter element (22), each of the filter bellows (32, 34) being designed as a star filter with star-shaped filter pleats. A seal (36) for sealing against a filter housing (12, 104) is located on at least one end face of the main filter element (22).