Pump Unit Circular Wedge Connection Stator

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Pump units with metal cans face efficiency losses due to eddy currents and require thick walls to withstand high pressures, leading to increased manufacturing costs and larger magnetic gaps, which reduce efficiency.

Innovation Solution

A pump unit with a thin-walled can supported by a circular wedge connection to the stator, ensuring secure contact and maintaining precise tolerances, allowing for reduced wall thickness and smaller magnetic gaps, thus enhancing efficiency and internal pressure resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal cans are used to withstand high internal pressures, then the can strength is improved, but eddy currents are generated causing efficiency losses

Engineering Contradiction:
Improvecan strengthVSAvoideddy current losses
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent replaces expensive metal cans with inexpensive plastic cans that are sufficient for the application. The plastic material eliminates eddy current losses entirely while providing adequate strength through proper wall thickness design, achieving both cost reduction and efficiency improvement.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material parameter from metal to plastic, which fundamentally alters the electrical conductivity property. This parameter change eliminates eddy current generation while maintaining structural integrity through optimized wall thickness, resolving the contradiction between strength and energy loss.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If plastic cans are used to avoid eddy current losses, then efficiency is improved, but the wall thickness must be increased to withstand high pressures

Engineering Contradiction:
Improveeddy current lossesVSAvoidcan wall thickness
Core Design Contradiction:
Loss of energyVSLength of stationary object

Solution Approach 1:

The patent optimizes the wall thickness parameter of the plastic can to the minimum necessary value that provides sufficient pressure resistance. By carefully selecting the plastic material properties and optimizing the wall thickness parameter, the design achieves both low eddy current losses and adequate structural strength without excessive thickness.

Inventive Principle:
Principle #35Parameter changes

3Strength

If increased wall thickness is used in plastic cans, then internal pressure resistance is improved, but the magnetic gap increases reducing efficiency

Engineering Contradiction:
Improveinternal pressure resistanceVSAvoidmagnetic gap losses
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent optimizes the wall thickness parameter to the minimum value that provides sufficient pressure resistance, thereby minimizing the magnetic gap. This parameter optimization balances structural requirements with magnetic performance, reducing energy losses while maintaining strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different wall thickness characteristics to different regions of the can structure. By optimizing the wall thickness locally at critical pressure points while maintaining thinner sections where possible, the design achieves sufficient strength with minimal overall thickness, reducing the magnetic gap and improving efficiency.

Inventive Principle:
Principle #3Local quality

4Strength

If larger magnetic material is used to compensate for increased gap, then pressure resistance is improved, but manufacturing costs increase

Engineering Contradiction:
Improvepressure resistanceVSAvoidmanufacturing costs
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the material parameter of the can from metal to plastic, which eliminates the need for increased magnetic material. This parameter change in the can material directly reduces manufacturing costs while maintaining pressure resistance through optimized wall thickness design.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses inexpensive plastic material for the can instead of expensive metal, significantly reducing manufacturing costs. The plastic material provides sufficient pressure resistance when properly designed, eliminating the need for costly magnetic material compensation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 circular wedge connection securely supports the can against the stator, increasing internal pressure resistance, reducing magnetic material usage, and minimizing the magnetic gap, resulting in a more efficient pump unit with lower manufacturing costs.

Implementation Method 1

The outer surfaces of the can are then brought into large-area contact with the inner surfaces of the stator by a relative rotation between the stator and the can. This clamps the can against the stator and creates a uniform, light surface pressure along the circumferential surface of the connection.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2778424B1Pump unit
Publication Date: 2016.06.22 WILO SE
  • EP2778424B1 patent drawingFigure 1
  • EP2778424B1 patent drawingFigure 2
  • EP2778424B1 patent drawingFigure 3

AI summary

The pump assembly has a pump unit and an electric motor for driving the pump unit, which comprises a stator (2) and a rotor. The stator is separated from the rotor space by a split tube turning in the rotor space. A circular wedge connection (4) between the split tube and the stator, is supported to the stator by the split tube. The split tube has an outer peripheral surface which comprises inner circular wedge profile deviating from the circular shape.