Household appliance comprising a recirculating pump system

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Solution Overview

Problem

Household appliances, such as washing machines, often require separate pumps for pumping water in and out, leading to complex designs and lack of active foreign body detection and treatment.

Innovation Solution

A pumping system with a single pump capable of operating in two directions, utilizing three valve flaps for hydraulic control and self-cleaning backflushing, along with a filter unit and level sensor, to enable efficient water circulation and foreign body management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate pumps are used for pumping water in and out, then pumping functions are reliable, but device complexity increases

Engineering Contradiction:
Improvepumping function reliabilityVSAvoidpump system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate pumping functions (pumping water in and pumping water out) into a single pump unit. The pump housing integrates both suction and discharge functions, with the pump impeller capable of moving water in both directions. This merging eliminates the need for separate pump assemblies while maintaining reliable pumping operations for both filling and emptying the drum.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single pump is designed with multi-functionality to perform both pumping water into the drum and pumping water out of the drum. The pump system includes a common housing with integrated suction and discharge pathways, and the impeller can rotate in both directions or move water bidirectionally to serve dual pumping purposes, making one component perform multiple functions.

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

2Device complexity

If a single pump is used for both pumping directions, then device complexity is reduced, but control of water flow direction becomes more difficult

Engineering Contradiction:
Improvepump system complexityVSAvoidwater flow direction control
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent employs hydraulic principles through the use of a suction valve and discharge valve that automatically open and close based on water pressure and flow direction. The valves are positioned and designed to respond to hydraulic conditions, allowing the single pump to efficiently direct water flow in the correct direction without complex mechanical control mechanisms. The valve flaps utilize pressure differential to control flow direction automatically.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Ease of manufacture

If pump housing is integrated with common housing, then manufacturing is simplified, but foreign body detection and treatment is not implemented

Engineering Contradiction:
Improvepump housing integrationVSAvoidforeign body detection
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The patent extracts the foreign body management function from the integrated pump housing by incorporating a separate filter unit and foreign body container. The filter unit is positioned to capture foreign bodies from the water flow, and a dedicated foreign body container collects and stores these objects. This extraction allows the pump housing to remain integrated and simple to manufacture while adding specialized components for foreign body detection and treatment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a filter unit as an intermediary component between the pump and the water flow. This filter acts as a mediator that captures foreign bodies before they can enter or block the pump mechanism. The filter unit includes a filter element and a foreign body container that work together to detect, capture, and store foreign objects, providing a solution to foreign body management without complicating the integrated pump housing design.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Simplifies the appliance design, allows efficient water conveyance in both directions, prevents foreign body accumulation, and enables self-cleaning, reducing the need for additional drive motors and enhancing reliability.

Implementation Method 1

the pump comprises an axial or semi-axial pump impeller... the pump can be driven in a first direction of rotation and a second direction of rotation... the direction of flow of the water can be changed by changing the direction of rotation

Methodology Applied
Scientific EffectImpeller rotation: Impeller

Implementation Method 2

the valve flaps implement a hydraulic valve flap control with pumping over and self-cleaning backflushing functions

Methodology Applied
Scientific EffectHydraulic control: Hydraulic Press

Implementation Method 3

the household appliance comprises a filter unit for filtering the water in the pumping direction

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3172371B1Household appliance comprising a recirculating pump system
Publication Date: 2021.02.24 BSH HAUSGERATE GMBH
  • EP3172371B1 patent drawingFigure 1
  • EP3172371B1 patent drawingFigure 2
  • EP3172371B1 patent drawingFigure 3

AI summary

The invention relates to a household appliance having a recirculating pump system which comprises a pump (101) for pumping water (103) in an outer tub (105) in a draining direction and a recirculating direction and further comprises a first valve gate (107-1) for sealing a bottom chamber (113) of the outer tube (105) in the recirculating direction, a second valve gate (107-2) for sealing a filter inlet orifice (109) in the draining direction, and a third valve gate (107-3) for sealing a discharge duct (111) in the recirculating direction.