Washing machine having a circulation pump

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Solution Overview

Problem

Existing washing machines fail to evenly soak laundry due to fixed spray patterns and lack of consideration for laundry movement, leading to inefficient washing and rinsing processes.

Innovation Solution

A washing machine with a processor-controlled circulation pump system that alternates the rotation speed of the washing motor and circulation pump motor to dynamically adjust the spray pattern and direction of water jets, ensuring thorough soaking and reduced washing time by tracking laundry movement and varying water flow depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the circulation pump rotation speed is increased to widen the spray range, then the water coverage area is improved, but the laundry soaking uniformity deteriorates because the laundry movement is not synchronized with the spray pattern

Engineering Contradiction:
Improvespray rangeVSAvoidlaundry soaking uniformity
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The circulation pump rotation speed is dynamically adjusted according to the drum rotation speed and laundry movement state. The controller synchronizes the spray pattern changes with laundry movement, transitioning between concentrated spray (when laundry is stationary) and dispersed spray (when laundry is moving), thereby maintaining uniform soaking across the entire laundry load while utilizing the full spray range.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the circulation pump rotation speed parameter in response to changes in drum rotation speed and laundry state. During high-speed drum rotation when laundry is stuck to the drum wall, the pump speed is increased to maximize spray range. During low-speed rotation when laundry is moving freely, the pump speed is adjusted to concentrate spray on the laundry, optimizing soaking uniformity throughout the washing cycle.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the drum rotation speed is increased to make laundry stick to the drum, then the water penetration effect is improved, but the washing time increases because the spray range becomes limited

Engineering Contradiction:
Improvewater penetration effectVSAvoidwashing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system employs periodic alternation between high-speed rotation (laundry stuck to drum) and low-speed rotation (laundry moving freely). During high-speed phases, the circulation pump operates at high speed to maximize water penetration into the laundry adhering to the drum. During low-speed phases, the pump speed is reduced to concentrate spray on the moving laundry, ensuring comprehensive coverage. This periodic cycle repeats throughout the washing process, achieving both penetration and coverage efficiency.

Inventive Principle:
Principle #19Periodic action

3Quantity of substance

If the circulation pump operates at constant high speed, then the water supply amount is sufficient, but energy consumption increases and spray pattern adaptability deteriorates

Engineering Contradiction:
Improvewater supply amountVSAvoidenergy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The circulation pump rotation speed parameter is dynamically changed based on the drum rotation speed and laundry state. During high-speed drum rotation, the pump operates at high speed to supply sufficient water for penetration. During low-speed rotation, the pump speed is reduced to match the laundry movement, maintaining adequate water supply while significantly reducing energy consumption compared to constant high-speed operation.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If the circulation pump speed is varied to match laundry movement, then soaking performance is improved, but device complexity increases due to additional control mechanisms

Engineering Contradiction:
Improvesoaking performanceVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The controller receives feedback signals from the drum rotation speed sensor and determines the laundry state (stuck or moving) based on the drum speed. This feedback mechanism enables the controller to automatically adjust the circulation pump speed without requiring additional sensors for direct laundry movement detection, thereby improving soaking performance while limiting the increase in device complexity to only the control algorithm.

Inventive Principle:
Principle #23Feedback

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 system ensures even soaking and reduced washing time by adjusting water flow to match laundry movement, preventing overflow and improving washing efficiency.

Implementation Method 1

a circulation pump configured to pump water discharged from the water tub to at least one nozzle for spraying the water into the drum

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

water is sprayed into the drum through at least one nozzle... water needs to pass through the laundry in a centrifugal direction

Methodology Applied
Scientific EffectJet: Jet

Implementation Method 3

a first rotation step of rotating the drum at 45rpm at which laundry is not stuck to the drum, and a second rotation step of rotating the drum at 100rpm with the laundry stuck to the drum

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3933090B1Washing machine having a circulation pump
Publication Date: 2024.08.21 LG ELECTRONICS INC
  • EP3933090B1 patent drawingFigure 1
  • EP3933090B1 patent drawingFigure 2
  • EP3933090B1 patent drawingFigure 3

AI summary

Disclosed is a washing machine comprising: a tub configured to contain water; a drum rotatably provided in the tub; at least one nozzle configured to spray water into the drum; a washing motor configured to rotate the drum; a circulation pump having a circulation pump motor and configured to pump water discharged from the tub to the at least one nozzle; and a processor configured to alternatively repeat acceleration and deceleration of the washing motor such that the washing motor is accelerated to make laundry in the drum rotate along with the drum while stuck to the drum owing to a centrifugal force, and the washing motor is decelerated to make the laundry separated from the drum; and operate the circulation pump motor to spray water through the at least one nozzle, wherein the circulation pump motor is accelerated and decelerated. The acceleration and deceleration of the circulation pump motor is performed in response to the acceleration of the washing motor and the braking of the washing motor, respectively. The circulation pump motor is a variable speed motor whose rotation speed is controllable, and the respective acceleration and deceleration of the circulation pump motor is performed with a certain gradient.