Drive Axle Oil Filter Assembly With Gravity-Driven Backflow Control

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Solution Overview

Problem

Traditional oil filters for axles, such as magnetic drain plug filters, are limited in their ability to filter out non-magnetic impurities, requiring frequent oil changes and the addition of external pumps, which increases complexity and cost.

Innovation Solution

An oil filter assembly with a filter housing that allows gravity-driven oil flow, featuring a baffle element to prevent backflow and an array of apertures for effective particulate filtration, which can be mounted externally for easy maintenance and includes an optional magnetic filter for enhanced contaminant capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a magnetic drain plug filter is used, then magnetic impurities can be filtered out, but non-magnetic impurities accumulate requiring frequent oil changes and the system becomes more complex with additional pumps

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

Solution Approach 1:

The oil filter assembly utilizes the natural flow of oil through the axle assembly to pass through the filter element, eliminating the need for external pumps. The gravity-assisted flow from inlet to outlet and the self-cleaning mechanism where oil continuously flushes the filter element embody self-service operation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention combines magnetic and non-magnetic filtration capabilities into a single integrated filter assembly. The filter element captures non-magnetic particulate contaminants while the magnetic drain plug handles magnetic impurities, merging previously separate functions into one unified system

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If an external pump is added to force oil through a filter element, then filtration efficiency improves, but cost and system complexity increase

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system uses the existing oil circulation within the axle assembly to drive oil through the filter element naturally. The oil flow is generated by the operation of the axle itself, requiring no external pumping system and reducing manufacturing costs

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the pumping function from the system by utilizing natural oil flow and gravity-driven circulation. The filter assembly is designed to be passively operated by the existing oil movement, removing the need for expensive external pump components

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If a traditional drain plug filter is used, then installation is simple, but maintenance requires regular removal and cleaning which is time-consuming

Engineering Contradiction:
Improveinstallation simplicityVSAvoidmaintenance time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The filter element is nested within the filter housing in a modular configuration that allows the entire assembly to be removed as one unit. The nested structure enables easy replacement of the filter element without disassembling the housing, reducing maintenance time

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The filter assembly is segmented into distinct components (filter housing, filter element, magnetic drain plug) that can be independently serviced. The mounting arrangement allows the filter housing to be easily detached from the axle assembly for maintenance

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If the filter inlet is positioned below the outlet, then oil flow is easier, but gravity cannot assist filtration and backflow occurs on uneven ground

Engineering Contradiction:
Improveoil flow easeVSAvoidfiltration reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The filter housing is designed with an asymmetric internal configuration where the inlet is positioned above the outlet. This asymmetric arrangement creates a one-way flow path that utilizes gravity to assist oil movement through the filter element while preventing backflow

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The baffle element is positioned to preemptively block potential backflow paths before they can occur. The asymmetric inlet-outlet configuration also prevents reverse flow by making the upward path against gravity difficult, providing preliminary protection against contamination

Inventive Principle:
Principle #9Preliminary anti-action

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 eliminates the need for external pumps, reduces oil change intervals, and improves filtration efficiency while maintaining additive retention, with a 96% filtration efficiency achieved after 65 hours of operation.

Implementation Method 1

providing a filter assembly where the inlet is positioned above the outlet allows oil to flow therethrough under the force of gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

the baffle element is configured to restrict backflow of oil from the lower chamber into the upper chamber

Methodology Applied
Scientific EffectGravity-driven flow: Gravitation

Implementation Method 3

These drain plugs work to magnetically attract the magnetic impurities (i.e. ferrous metal particles) in the oil

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP3378548B1An oil filter assembly
Publication Date: 2022.05.04 J C BAMFORD EXCAVATORS LTD
  • EP3378548B1 patent drawingFigure 1
  • EP3378548B1 patent drawingFigure 2
  • EP3378548B1 patent drawingFigure 3

AI summary

An oil filter assembly for a differential housing, the oil filter assembly comprising: a filter housing for releasably mounting in a drive axle housing, the housing defining an internal volume for containing oil to be filtered; a mounting arrangement for releasably securing the filter assembly to a drive axle housing; and a filter element for filtering particulate contaminants from oil in a drive axle, wherein the filter housing comprises an inlet on an upper portion thereof and an outlet on a lower portion thereof to define an flow path therethrough, further wherein the filter element is located downstream of the inlet.