Drum Washing Motion Control Using Alternating Torque Braking

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Solution Overview

Problem

Conventional drum type washing machines lack variability in washing motions, which can lead to inadequate cleaning performance and potential damage to laundry, while also resulting in excessive wear and heat generation due to inefficient braking methods.

Innovation Solution

The washing machine employs a controller to alternately pivot the rotary drum using forward and reverse torque, incorporating negative-phase and dynamic braking techniques to control the drum's rotational speed and direction, creating specific motions that optimize laundry lifting and dropping to enhance cleaning efficiency and minimize damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional drum type washing machines use simple rotation without alternating torque, then the device complexity is reduced, but the washing performance becomes inadequate and laundry may be damaged

Engineering Contradiction:
Improvewashing performanceVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The washing machine controller alternately applies forward and reverse torque to the drum in periodic cycles, creating varied washing motions that lift and drop laundry repeatedly. This periodic action enhances washing performance by preventing stagnation and improving cleaning effectiveness without requiring complex mechanical modifications to the drum structure itself.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the drum's rotational characteristics by switching between forward and reverse torque application. This dynamic control creates adaptive washing motions that respond to different laundry types and washing stages, improving reliability while using the existing motor and controller infrastructure.

Inventive Principle:
Principle #15Dynamics

2Reliability

If conventional washing machines use inefficient braking methods, then the device complexity is reduced, but excessive wear and heat generation occur

Engineering Contradiction:
Improvecomponent wearVSAvoidbraking control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical braking systems with electrical braking methods implemented through the motor controller. By using negative-phase braking and dynamic braking techniques, the system achieves effective drum speed control and stopping without excessive mechanical wear or heat generation, substituting electrical control for mechanical friction-based braking.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The controller implements braking control based on feedback from motor current and drum rotation state. The system monitors operational parameters and adjusts braking torque accordingly, enabling precise control that minimizes wear and heat generation while adapting to different washing conditions and laundry loads.

Inventive Principle:
Principle #23Feedback

3Reliability

If drum rotation is continuous without speed variation, then the ease of operation is improved, but washing performance becomes inadequate due to lack of motion variability

Engineering Contradiction:
Improvewashing performanceVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The controller implements periodic variations in drum rotation by alternating forward and reverse torque application. This creates a rhythm of acceleration, deceleration, and direction change that generates varied washing motions, lifting and dropping laundry repeatedly to enhance cleaning performance while maintaining simple operational control through automated sequencing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system applies reverse torque as a preliminary anti-action to counterbalance the forward rotation, creating controlled deceleration and direction reversal. This preliminary opposing action prevents excessive speed buildup and creates optimal conditions for laundry dropping and re-lifting, improving washing performance without requiring complex manual intervention.

Inventive Principle:
Principle #9Preliminary anti-action

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 approach increases the impact on laundry for improved washing performance, reduces damage, allows for adaptable motion based on laundry type, and minimizes wear and heat generation through effective braking.

Implementation Method 1

applying forward torque to the drum so that laundry in the drum is rotated and lifted; braking the drum; and applying forward torque to the drum so that the dropped laundry is rotated and lifted again

Methodology Applied
Scientific EffectTorque: Torque

Implementation Method 2

incorporating negative-phase and dynamic braking techniques to control the drum's rotational speed and direction

Methodology Applied
Scientific EffectNegative-phase braking:

Implementation Method 3

incorporating negative-phase and dynamic braking techniques to control the drum's rotational speed and direction

Methodology Applied
Scientific EffectDynamic braking:

Implementation Method 4

creating specific motions that optimize laundry lifting and dropping to enhance cleaning efficiency

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2149634B1Washing machine and washing method therefor
Publication Date: 2013.09.25 LG ELECTRONICS INC
  • EP2149634B1 patent drawingFigure 1
  • EP2149634B1 patent drawingFigure 2
  • EP2149634B1 patent drawingFigure 3

AI summary

A washing machine and washing method therefor are provided. In the washing method, in which a drum of a drum type washing machine is rotated in a first direction, the method includes applying a first directional torque to the drum so that laundry in the drum is rotated and lifted; braking the drum so that the laundry is dropped; and then again applying the first directional torque to the drum so that the dropped laundry is rotated and lifted again.