Magnetic Pump Impeller Spigot-Ferrule Connection to Prevent Loosening

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Solution Overview

Problem

Existing magnetic pumps face issues with loose connections between the magnet can and impeller due to high-speed rotation or reverse rotation, leading to potential clattering and increased assembly/disassembly time, and integral designs require both components to be replaced together, raising costs.

Innovation Solution

A spigot-ferrule connection between the magnet can and impeller, combined with a restraining member, ensures a firm and easily assembled/disassembled connection, using a simple mechanism with rotational bearings as essential constituents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If fixing pins are used to connect the magnet can and impeller, then the connection strength is improved, but the assembly time and labor hours increase

Engineering Contradiction:
Improveconnection strengthVSAvoidassembly time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The invention removes the fixing pins from the connection structure between the magnet can and impeller. Instead of using pins that require insertion and securing operations, the patent employs a direct fitting connection where the impeller is inserted into the magnet can housing, eliminating the time-consuming pinning operation while maintaining connection strength through the fitted design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention combines the connection function and structural support function into a single fitted interface between the magnet can and impeller. The fitting structure serves both as the connection mechanism and as the structural element that maintains relative positioning, eliminating the need for separate fixing pins and reducing assembly complexity.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the number of fixing pins is increased to prevent looseness, then the connection reliability is improved, but the assembly complexity and labor hours increase

Engineering Contradiction:
Improveconnection reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the fixing pins entirely from the connection system and replaces them with a fitted interface design. The magnet can housing includes a recess that receives the impeller, creating a stable connection without requiring multiple pins or complex fastening mechanisms, thereby reducing assembly complexity while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention segments the connection interface into a housing portion (magnet can) and a received portion (impeller), with the housing containing a recess and the impeller containing a protruding portion. This segmentation allows for a simple yet reliable fitted connection that prevents looseness without requiring multiple separate fixing elements.

Inventive Principle:
Principle #1Segmentation

3Strength

If the magnet can and impeller are formed integrally, then the connection strength is improved, but the replacement cost increases when one component is damaged

Engineering Contradiction:
Improveconnection strengthVSAvoidreplacement cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention maintains segmentation between the magnet can and impeller as separate components that connect through a fitted interface. This allows the impeller to be replaced independently of the magnet can if damaged, avoiding the need to replace both components together as would be required with an integral design, thereby reducing replacement costs while maintaining connection strength through the fitted connection.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If a fitted connection is used between magnet can and impeller, then the assembly ease is improved, but the connection strength deteriorates due to looseness under high-speed rotation

Engineering Contradiction:
Improveassembly easeVSAvoidconnection strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The invention segments the connection into a housing portion with a recess and a received portion with a protruding portion that fits into the recess. This fitted design provides easy assembly through simple insertion while the precise geometric match between the protruding and recessed portions prevents looseness and maintains connection strength under high-speed rotation and reverse rotation conditions.

Inventive Principle:
Principle #1Segmentation

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 spigot-ferrule connection provides a strong, stable connection that prevents looseness and clattering, allows easy assembly and maintenance, and enables individual replacement of components, reducing assembly time and costs.

Implementation Method 1

a magnetic pump configured to perform a pump operation by allowing a rotational force of the driving-side magnet to be transmitted to the driven-side magnet in a noncontact state by means of a magnetic force

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP3943752B1Magnetic pump and rotary body for the magnetic pump
Publication Date: 2025.08.06 WORLD CHEM CO LTD
  • EP3943752B1 patent drawingFigure 1
  • EP3943752B1 patent drawingFigure 2
  • EP3943752B1 patent drawingFigure 3~5

AI summary

A magnetic pump that is a magnet-coupling type pump that generates a liquid transportation force by rotating an impeller (1) disposed at a driven-side magnet by rotating a driving-side magnet, and a rotary body for a magnetic pump, the magnetic pump configured so that the driven-side magnet is housed in a magnet can (2), and the magnet can is attached to a shaft fixed in a pump casing through a rotational bearing (3), and the impeller is attached and fixed to an end side in a rotational-shaft direction of the magnet can. The impeller and the magnet can are attached and fixed together such that a socket (11) formed at either one of a part of the impeller and a part of the magnet can that face each other and a spigot (21) formed at a remaining one of the part of the impeller and the part of the magnet can are fitted together in the rotational-shaft direction in a spigot-ferrule manner, and are twisted and turned with respect to the rotational shaft, and are then inhibited from reaching a loosened state while restraining return of a turned state, and, as a result, a connection between the impeller and the magnet can is fixed.