Bayonet Fitting Sealing Ring for Pump Impeller Maintenance

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Solution Overview

Problem

Existing sealing ring units for pump impellers, particularly in multistage pumps, are difficult to replace during maintenance due to complex assembly and design, leading to inefficiencies in maintenance and potential leakage.

Innovation Solution

A sealing ring unit with a bayonet fitting mechanism allows for easy assembly and disassembly, featuring a sealing ring with a first and second portion and an annular back portion, mounted on a supporting member with radially extending projections and notches, enabling axial fitting and rotational locking for secure positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the sealing ring is made as a separate replaceable component, then the ease of repair is improved, but the device complexity increases due to the need for assembly and disassembly mechanisms

Engineering Contradiction:
Improveease of sealing ring replacementVSAvoidcomplexity of sealing ring unit
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The sealing ring unit is divided into two main segments: the sealing ring itself and the supporting member. This segmentation allows the sealing ring to be replaced independently without replacing the entire unit, improving ease of repair while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bayonet fitting mechanism provides a dynamic assembly and disassembly system that transitions between locked and unlocked states. This dynamic feature enables easy replacement of the sealing ring through simple rotational movement, balancing ease of repair with minimal structural complexity.

Inventive Principle:
Principle #15Dynamics

2Volume of moving object

If the sealing ring unit is made compact, then the volume is reduced, but the ease of operation for maintenance decreases

Engineering Contradiction:
Improveaxial length of sealing ring unitVSAvoidease of sealing ring replacement
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The bayonet fitting mechanism utilizes rotational movement to achieve locking and unlocking, allowing compact dimensions while maintaining ease of operation. The rotational action provides mechanical advantage that enables simple maintenance operations within a compact axial length.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The bayonet fitting acts as an intermediary mechanism between the sealing ring and supporting member, enabling easy connection and disconnection despite the compact size. This intermediary mechanism translates simple rotational motion into secure mechanical engagement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the sealing ring is securely fixed to prevent leakage, then the reliability is improved, but the ease of repair deteriorates due to difficulty in removal

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddifficulty of sealing ring removal
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The bayonet fitting provides a dynamic locking mechanism that secures the sealing ring during operation through rotational engagement of protrusions with recesses, ensuring reliability. The same mechanism allows easy removal by reversing the rotational action, preventing the sealing ring from becoming permanently fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The bayonet fitting replaces traditional threaded or welded mechanical connections with a simpler rotational locking system. This substitution maintains secure fixation for reliability while enabling tool-free removal for ease of repair.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3181909B1Compact sealing ring unit
Publication Date: 2020.04.08 WILO SE
  • EP3181909B1 patent drawingFigure 1
  • EP3181909B1 patent drawingFigure 2~3
  • EP3181909B1 patent drawingFigure 4

AI summary

The invention relates to a sealing ring unit (1) for radially sealing the suction mouth (5) of a pump impeller (4), in particular for a multistage pump, the unit comprising a sealing ring (3) and a supporting member (2) removably carrying the sealing ring (3), the supporting member (2) having an annular inner portion (10) defining an opening (22) for receiving the suction mouth (5) of the impeller (4), the sealing ring (3) having a first portion (16) and second portion (17) and an annular back portion (15) to face the suction mouth (5) connecting the first and second portion (16, 17) with each other, the annular inner portion (10) being accommodated between the first and second portion (16, 17). According to the invention the sealing ring (3) being mountable on the supporting member (2) by means of a bayonet fitting (11, 17). Thus, an easy change of the sealing ring is enabled.