Pump Holder Flow Channels for Cooling and Lubrication

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Solution Overview

Problem

Household appliance pumps, such as those in dishwashers and washing machines, face challenges with inefficient cooling and lubrication due to poor liquid circulation, leading to issues like air and vapor bubble accumulation, reduced service life, and increased noise, especially when using chemically active washing liquids.

Innovation Solution

A pump design featuring a rotatably mounted rotor with a permanent magnet ring and a plastic injection-molded holder containing flow channels that circulate liquid and guide out air/vapor bubbles, ensuring effective cooling and lubrication while preventing corrosion and improving the rotor's fixation on the motor shaft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the rotor magnet is positioned close to the stator winding to achieve high electromagnetic efficiency, then electromagnetic efficiency is improved, but liquid circulation becomes poor leading to air and vapor bubble accumulation

Engineering Contradiction:
Improveelectromagnetic efficiencyVSAvoidliquid circulation
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The holder is segmented to include integrated flow channels that divide the liquid circulation path into distinct regions, allowing liquid to reach areas that would otherwise be inaccessible due to the compact rotor-stator arrangement. This segmentation enables both efficient electromagnetic coupling and adequate liquid circulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flow channels are positioned at different radial distances from the motor shaft, creating a multi-dimensional circulation architecture. The channels extend completely inside the sleeve section at radial distances that optimize both electromagnetic efficiency and liquid flow access to all wet space areas.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If flow channels are added to improve liquid circulation and remove air bubbles, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveliquid circulationVSAvoidholder structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flow channels are merged directly into the holder structure during plastic injection molding, eliminating the need for separate circulation components. This integration achieves reliable liquid circulation while minimizing device complexity by combining multiple functions into a single molded part.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The holder serves multiple functions simultaneously: it supports the rotor magnet, provides structural integrity, and incorporates flow channels for liquid circulation and air bubble removal. This multi-functionality reduces overall device complexity while achieving reliable circulation.

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

3Strength

If the holder sits completely on the motor shaft with flow channels extending inside the sleeve section, then fixation strength is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveholder fixationVSAvoidflow channel positioning
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The plastic injection molding process inherently creates the flow channels within the holder structure during manufacturing. The molding process itself serves to both form the holder and integrate the flow channels, reducing the need for subsequent precision machining or assembly operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The flow channels are designed with specific radial distances and geometries that are optimized during the molding process. By adjusting molding parameters and channel design, the system achieves both strong holder fixation and adequate manufacturing tolerances for reliable liquid circulation.

Inventive Principle:
Principle #35Parameter changes

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 design enhances the pump's efficiency, service life, and noise reduction by ensuring proper liquid circulation and preventing air/vapor bubble accumulation, while also providing a strong and reliable holder attachment to the motor shaft, even in chemically active environments.

Implementation Method 1

a rotor which is rotatably mounted in the field of the stator winding (10) in a wet space (22) of the drive motor (8)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The liquid in the wet room serves, among other things, to cool and/or lubricate the rotor or the bearings of the rotor

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

The liquid in the wet room serves, among other things, to cool and/or lubricate the rotor or the bearings of the rotor

Methodology Applied
Scientific EffectHydrodynamic lubrication: Lubrication

Data Source

PatentEP3011663B1Pump having at least one flow channel and household appliance having such a pump
Publication Date: 2017.08.09 BOSCH SIEMENS HAUSGERATE GMBH
  • EP3011663B1 patent drawingFigure 1
  • EP3011663B1 patent drawingFigure 2
  • EP3011663B1 patent drawingFigure 3a~3c

AI summary

The invention relates to a pump (1) having a drive motor (8) having a stator coil (10) that can be electrically actuated and having a rotor (13) mounted in a rotationally drivable manner in the field of the stator coil (10) in a wet chamber (22) of the drive motor (8), which rotor (13) has a motor shaft (7), a rotor magnet (15) and a holder (14), which is fastened to the motor shaft (7) and held onto the rotor magnet (15), and the holder (14) comprises a sleeve section (17) extending between the motor shaft (7) and the rotor magnet (15) which has at least one flow channel (26) which is designed to transport liquid in the wet chamber (22) through the holder (14), wherein the at least one flow channel (26) extends completely in the interior of the sleeve section (17) at a radial distance (A) to the motor shaft (7). The invention further relates to a household appliance, in particular a dishwasher or a washing machine, having such a pump (1).