Drain pump and clothes dryer having a drain pump

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Solution Overview

Problem

Conventional drain pumps in clothes dryers are prone to clogging due to foreign substances being sucked in, which increases the load and can lead to damage, and existing lint removal methods do not effectively prevent this issue.

Innovation Solution

A drain pump design with a circular hub impeller and tangentially oriented discharge port, combined with a lint filter cleaner that uses water to remove lint, minimizes clogging by guiding water and foreign substances away from the impeller and discharge port, preventing them from being wound around the impeller shaft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional drain pump is used to discharge water and lint, then the drain pump can remove lint from the dryer, but foreign substances block the suction hole or are wound around the impeller causing clogging and increased load

Engineering Contradiction:
Improvelint removal capabilityVSAvoiddrain pump operation stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The pump housing is divided into an upper housing and a lower housing that can be separated. This segmentation allows easy access to the impeller and suction area for cleaning accumulated lint and foreign substances, thereby maintaining reliable operation without compromising lint removal capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The impeller is designed as a removable component that can be easily extracted from the pump housing. This allows users to remove and clean the impeller of wound foreign substances, preventing clogging and maintaining consistent pump performance for lint discharge

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If the drain pump operates with clogged suction holes or impeller, then foreign substances are removed from the dryer, but the load of the drain pump increases leading to damage

Engineering Contradiction:
Improveforeign substance dischargeVSAvoiddrain pump load
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The pump housing includes a removable cover that provides preliminary access to the suction hole and impeller area. This allows users to clean accumulated foreign substances before they cause significant clogging and load increase, maintaining efficient operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The design accepts that lint and foreign substances will accumulate and requires periodic simple cleaning operations. The easy-access structure enables quick maintenance without complex disassembly, making the system robust against load increases from normal operation

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

3Ease of operation

If water is sprayed through nozzles to remove lint from the lint filter, then lint is removed from the filter, but the water and lint are introduced into the drain pump causing clogging

Engineering Contradiction:
Improvelint filter cleaningVSAvoiddrain pump operation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A lint trap or screen is positioned in the water flow path between the spray nozzle and the drain pump. This intermediary component captures lint and foreign substances from the cleaning water before they reach the pump, preventing clogging while maintaining easy lint filter cleaning operation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design separates the lint removal function from the water discharge path by providing direct access to the lint filter or a removable lint collection chamber. This allows lint to be removed without necessarily pumping large volumes of water through the pump, reducing clogging risk

Inventive Principle:
Principle #2Taking out (Extraction)

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 minimizes the likelihood of foreign substances blocking the drain pump, reducing power consumption and the risk of damage, while ensuring smooth discharge of debris, thus maintaining efficient operation.

Implementation Method 1

an impeller, which comprises a circular hub, a plurality of blades extending radially outwardly from the outer circumferential surface of the impeller shaft and the lower surface of the hub, the edge of each blade including a linear portion and an extension portion which is gradually rounded from an end of the linear portion toward an edge of the hub

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

The lower surface of the hub is rounded. The hub has a longitudinal cross section in which a thickness of the hub is gradually increased from the central portion of the lower surface of the hub toward the edge of the hub, to allow the water to be guided downward while being radially discharged along the lower surface of the hub

Methodology Applied
Scientific EffectFluid flow guidance:

Data Source

PatentEP3209827B1Drain pump and clothes dryer having a drain pump
Publication Date: 2020.03.25 LG ELECTRONICS INC
  • EP3209827B1 patent drawingFigure 1
  • EP3209827B1 patent drawingFigure 2~3
  • EP3209827B1 patent drawingFigure 4~5

AI summary

A drain pump is provided that may include a pump motor; an impeller connected to a rotational shaft of the pump motor. The impeller may include a circular hub, an impeller shaft that extends from a center of a lower surface of the hub, and a plurality of blades that extends from an outer circumferential surface of the impeller shaft and the lower surface of the hub in a radial direction of the hub. The hub may have a longitudinal cross section in which a thickness of the hub gradually increases from the center of the lower surface toward an edge thereof.