Rotatable Bayonet Ring Reduces Filter Housing Torque

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Solution Overview

Problem

Filter elements in fluid filters often experience high frictional resistance when coupled to the filter housing, making replacement difficult due to the need for high torque when screwing or unscrewing the housing cover, which requires significant effort.

Innovation Solution

The filter element features a bayonet ring that can rotate about its longitudinal axis, allowing for rotational adjustment with the housing cover without inhibiting the bayonet lock, reducing the torque required for unscrewing and screwing, and enabling easier removal by allowing the filter element to be moved out along its axis with reduced force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filter element is sealed radially against the filter housing to ensure sealing performance, then sealing reliability is improved, but frictional resistance increases making replacement difficult

Engineering Contradiction:
Improvesealing performanceVSAvoidreplacement effort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention divides the coupling system into two independent functional parts: a bayonet coupling mechanism for rotational attachment and a radial sealing element for sealing. The bayonet locking elements engage with corresponding elements in the filter housing to provide mechanical coupling, while the sealing element independently provides sealing without interfering with the bayonet rotation. This segmentation allows the sealing function to be maintained while eliminating the frictional resistance that previously hindered replacement operations.

Inventive Principle:
Principle #1Segmentation

2Strength

If high torque is applied to overcome frictional resistance during screwing, then the housing cover can be attached, but the operation requires considerable effort

Engineering Contradiction:
Improveattachment forceVSAvoidscrewing effort
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The bayonet coupling mechanism acts as an intermediary that transfers the attachment function from a high-friction radial sealing interface to a low-friction rotational interface. By engaging the bayonet locking elements first, the system creates a mechanical advantage that allows the housing cover to be attached with reduced effort, as the bayonet mechanism guides the engagement and reduces the effective friction that must be overcome during the attachment operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3544714B1Filter element and fluid filter comprising a rotatable bayonet ring
Publication Date: 2020.08.12 MANN HUMMEL GMBH
  • EP3544714B1 patent drawingFigure 1~2
  • EP3544714B1 patent drawingFigure 3
  • EP3544714B1 patent drawingFigure 4

AI summary

The invention relates to a filter element (10) for filtering a fluid, particularly a fuel or oil, arranged such that it can be replaced in a filter housing (52). Said filter element (10) comprises first bayonet closure elements (26) by means of which the filter element (10) can be coupled to second bayonet closure elements (64) of the filter housing (52). The first bayonet closure elements (26) are, according to the invention, positioned on a bayonet ring (22) which is mounted on the filter element (10) such that it can rotate relative to the longitudinal axis (18) of the filter element (10). The invention also relates to a fluid filter, particularly a fuel or oil filter, particularly for an internal combustion engine comprising such a filter element (10).