Canned Motor Pump Rotor Can Damping for Higher Efficiency

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Solution Overview

Problem

The existing design of wet-running electric motors in pump units, with a can separating the stator and rotor, increases the gap between them, reducing motor efficiency due to the impact on the magnetic field.

Innovation Solution

The implementation of axial and radial damping parts between the rotor can and the surrounding support structure allows for reduced rotor can thickness without transferring vibrations to the surrounding pump structure, thereby maintaining efficiency and reducing noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the rotor can thickness is reduced to decrease the gap between rotor and stator, then motor efficiency is improved, but vibrations occur in the rotor can

Engineering Contradiction:
Improvemotor efficiencyVSAvoidvibrations
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent introduces damping parts as intermediary elements between the rotor can and the support structure. These damping parts absorb and dissipate vibrations, preventing them from propagating through the pump housing while allowing the thin-walled rotor can to maintain its structural integrity and magnetic field efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful vibrations caused by the thin-walled rotor can into a beneficial damping effect. By strategically placing damping parts at vibration nodes, the structural flexibility that causes vibrations is transformed into a feature that reduces noise and vibration transmission to the pump housing and surrounding components.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Loss of energy

If the rotor can thickness is reduced to improve motor efficiency, then the gap between rotor and stator decreases, but vibrations are transferred to the surrounding pump structure

Engineering Contradiction:
Improvemotor efficiencyVSAvoidnoise
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The damping parts serve as intermediary elements that intercept vibration transmission paths between the rotor can and the pump housing. By placing these damping parts at critical locations where vibrations are transmitted, the system blocks the propagation of noise and vibrations to surrounding components while maintaining the thin-walled rotor can design.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If damping parts are added to reduce vibrations, then noise reduction is achieved, but device complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoidnumber of components
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges multiple damping functions into integrated damping parts that simultaneously provide axial and radial vibration damping. By combining these functions into unified components rather than separate elements, the design reduces the overall number of parts while achieving comprehensive vibration control in multiple directions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The damping parts are designed to perform multiple functions simultaneously: they provide axial damping, radial damping, and noise reduction all through single integrated components. This multi-functionality reduces the total number of separate parts needed in the system while achieving comprehensive vibration and noise control.

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

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

This configuration enables a thinner rotor can, enhancing motor efficiency while minimizing vibrations and noise, thus maintaining the structural integrity and performance of the pump unit.

Implementation Method 1

there is arranged at least one axial damping part between an axial surface of the can and the support structure. Furthermore, there is arranged at least one radial damping part between an outer circumferential surface of the can and the support structure. The axial and the radial damping part allow a support of the can in axial and radial direction via a damping part arranged therebetween. The damping parts avoid vibrations occurring in the rotor can to be transferred to the surrounding support structure.

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP4549738A1Canned motor pump
Publication Date: 2025.05.07 GRUNDFOS HLDG
  • EP4549738A1 patent drawingFigure 1
  • EP4549738A1 patent drawingFigure 2~3
  • EP4549738A1 patent drawing

AI summary

The invention refers to a pump unit comprising at least one impeller (4) and an electric motor connected to the at least one impeller (4) and comprising a stator (12), a rotor (8) and a can (18) between stator (12) and rotor (8), wherein the can (18) on its first axial end is in engagement with a support structure (10), wherein at least one axial damping part (32) is arranged between an axial surface (26) of the can (18) and the support structure (10), and at least one radial damping part (34) is arranged between an outer circumferential surface of the can (18) and the support structure (10).