Drainage System for Fluid Filter with Single Sealing Ring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current drainage systems for fluid filters, such as fuel or oil filters, often result in uncontrolled fluid spilling during maintenance due to the need for full removal of the drain plug or require costly and malfunction-prone dual sealing rings for ventilation and drainage functions.

Innovation Solution

A drainage system with a single sealing ring on a drain plug that has a drain channel and a separate ventilation channel, allowing for controlled fluid drainage and ventilation while maintaining a secure seal, reducing manufacturing costs and preventing uncontrolled spilling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the drain plug is fully removed from the filter housing, then the drainage function is achieved, but uncontrolled fluid spilling occurs leading to environmental contamination and user exposure

Engineering Contradiction:
Improvedrainage functionVSAvoiduncontrolled fluid spilling
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The drain plug is segmented into functional zones: an upper sealing portion that maintains the seal during partial removal, and a lower drainage portion that opens the drain hole when removed. This segmentation allows the plug to provide both sealing and drainage functions through controlled axial movement, preventing uncontrolled spilling while enabling drainage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drain plug transitions from a static sealing component to a dynamic control mechanism. By allowing axial movement between a seated position (maintaining seal) and a partially removed position (opening drainage), the system dynamically controls fluid flow, enabling drainage without full removal and preventing uncontrolled spilling.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If two distinct sealing rings are used on the drain plug for ventilation and drainage functions, then both functions are achieved, but manufacturing costs and malfunction frequency increase

Engineering Contradiction:
Improveventilation and drainage functionsVSAvoidnumber of sealing rings
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single sealing ring is designed with multi-functionality to perform both sealing and ventilation tasks. The sealing ring includes a continuous sealing surface that seals the drain hole when the plug is seated, and incorporates ventilation channels that allow air passage when the plug is partially removed. This universal design eliminates the need for separate sealing rings for different functions, reducing part count and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If a single sealing ring is used on the drain plug, then manufacturing costs are reduced, but reliable sealing during both normal use and drainage operations becomes difficult

Engineering Contradiction:
Improvemanufacturing costVSAvoidsealing reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sealing ring incorporates local quality variations through different radial profiles and sealing surfaces. The upper portion of the sealing ring has a specific profile for sealing against the housing during normal operation, while the lower portion has different geometry for maintaining seal integrity during drainage. This localized differentiation of sealing characteristics within a single ring enables reliable sealing under multiple operational conditions.

Inventive Principle:
Principle #3Local quality

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 system provides reliable sealing and controlled fluid drainage, minimizing environmental contamination and user exposure, while being cost-effective and easy to manufacture with a bistable spring-like sealing ring and axial pretensioning for secure sealing.

Implementation Method 1

The sealing ring sealingly abuts against the filter housing in an axial and a radial direction when the drain plug is positioned in its closing position

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

the drain plug has a drain channel for the fluid to be drained from the inside of the housing element, the drain channel having an inlet opening located at a lateral side of the drain plug and an outlet opening located at a first (lower) end of the drain plug

Methodology Applied
Scientific EffectGravity-driven flow: Gravitation

Implementation Method 3

due to the separate ventilation channel provided in the drain plug, a steady ventilation of the interior side of the filter housing element for pressure compensation and thus a steady flow off of the fluid via the drain channel can be realized

Methodology Applied
Scientific EffectPressure equalization:

Implementation Method 4

a bistable spring-like sealing ring and axial pretensioning for secure sealing

Methodology Applied
Scientific EffectElastic pretensioning: Elasticity

Data Source

PatentEP3292901B1Drainage system for a fluid filter
Publication Date: 2020.05.27 MANN HUMMEL GMBH
  • EP3292901B1 patent drawingFigure 1~2
  • EP3292901B1 patent drawingFigure 3~4
  • EP3292901B1 patent drawingFigure 5~6

AI summary

The invention relates to a drainage system (10), in particular for a water trap of a fuel or oil filter comprising a filter housing element (12) with a drain hole (14) for fluidly connecting an inside (18) of the housing element (12) with an outside (20) of the housing element, a drain plug (26), a sealing ring (28) seated on the drain plug (26) for a fluid-tight closure of the drain hole. The drain plug is provided with a drain channel (46) and a ventilation channel (56). The sealing ring sealingly abuts against the housing element (12) in an axial and a radial direction when the drain plug (26) is positioned in its closing position; upon an axial movement of the drain plug (26) from the said closing position into a drainage position, a radially inward edge portion (70) of the sealing ring (28) is dislodged from its axially sealing abutment against the filter housing (12) by the drain plug (26) while a sealing abutment of an outer edge portion (66) of the sealing ring (28) against the housing element (12) and a sealing abutment of a radially inward edge portion (70) of the sealing ring (28) against the drain plug (26) is maintained such that the drain hole is fluidly connected both to the inlet opening (48) of the drain channel (46) and the second orifice (60) of the ventilation channel (56).