Pump Impeller Elastomeric Coating to Reduce Wear from Foreign Objects

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Solution Overview

Problem

Pump impellers in household appliances, such as washing machines and dishwashers, are prone to damage from objects carried in the fluid being pumped, leading to changes in geometry that affect pump performance and reduce operational reliability over the service life, while requiring a simple and inexpensive manufacturing process.

Innovation Solution

A pump impeller with impeller blades made from a solid plastic base material reinforced with glass fibers, coated with a permanently elastic jacket material for impact protection and sealing, which maintains the pump's performance and prevents wear from foreign objects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pump impeller is made from a simple solid plastic structure, then the manufacturing cost is low and the structure is simple, but the impeller is damaged by objects in the fluid leading to geometry changes and performance degradation

Engineering Contradiction:
Improveoperational reliabilityVSAvoidimpeller structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pump impeller combines a rigid base material (polyoxymethylene or polypropylene reinforced with glass fibers) providing structural strength with an elastomeric coating material (Shore hardness 40-120) providing impact protection and sealing. This composite structure resolves the contradiction by integrating both protective and structural functions into a single component that maintains reliability without excessive complexity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The elastomeric coating is applied selectively to specific regions of the impeller blades and housing that contact the fluid and objects, rather than coating the entire impeller. This localized application provides protection where needed while maintaining the overall structural integrity and minimizing added complexity.

Inventive Principle:
Principle #3Local quality

2Strength

If the pump impeller uses a reinforced base material with elastomeric coating, then the protection against impacts and wear is improved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveimpeller strengthVSAvoidmanufacturing process
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The base material is first molded with the impeller geometry, then the elastomeric coating is applied in a subsequent coating step. This sequential manufacturing approach allows each material to be optimized for its specific function while using standard manufacturing processes, avoiding the need for complex integrated manufacturing.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If the elastomeric coating is applied to the impeller blades, then the protection against foreign objects is improved, but the sealing function requires additional complexity

Engineering Contradiction:
Improveprotection against foreign objectsVSAvoidsealing structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The elastomeric coating performs multiple functions simultaneously: it cushions impacts from foreign objects, provides wear protection on blade surfaces, and creates sealing contact with the pump housing. This multi-functionality resolves the contradiction by eliminating the need for separate sealing components while maintaining protection against harmful factors.

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

The solution ensures constant pump performance and extended service life by protecting the impeller from wear and damage, maintaining the original pressure-flow rate ratio, and reducing noise and current spikes during operation.

Implementation Method 1

The jacket material can have a cushioning effect against objects striking the pump impeller

Methodology Applied
Scientific EffectImpact absorption: Damping

Implementation Method 2

The base material is at least partially coated with a permanently elastic jacket material

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3751042A1Pump impeller, lye pump, household appliance and method for manufacturing the pump impeller
Publication Date: 2020.12.16 BSH HAUSGERATE GMBH
  • EP3751042A1 patent drawingFigure 1
  • EP3751042A1 patent drawingFigure 2
  • EP3751042A1 patent drawingFigure 3

AI summary

The present invention relates to a pump impeller (1) with impeller blades (2) for a household appliance, wherein the pump impeller (1) is formed from a base material, and wherein the base material is at least partially coated with a permanently elastic jacket material which is softer than the base material.