Laundry Machine Induction Heater for Low-RPM Spinning Efficiency

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Solution Overview

Problem

Conventional laundry machines with washing and drying functions lack flexibility in drying options, efficiency in spinning performance, especially at low RPM, and stability, leading to suboptimal performance and user satisfaction due to fixed heating temperatures and limited power usage.

Innovation Solution

A laundry machine with a convection heating method using an induction heater that allows users to select between heat-spinning and normal spinning, featuring a user interface for course selection and option settings to control drum RPM and heater output, enabling diverse drying conditions and silent operation modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the spinning duration is increased to remove more water from laundry, then the water separation efficiency is improved, but the energy consumption increases and the maximum momentary power limit is exceeded

Engineering Contradiction:
Improvewater separation efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the physical state of water in laundry by heating it during spinning. By raising the temperature of water contained in laundry, the viscosity is reduced and water separation efficiency is improved without requiring extended spinning duration or excessive motor power, thus resolving the contradiction between productivity and energy consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies periodic heating action during the spinning cycle, where heating is performed in intervals rather than continuously. This allows the system to maintain effective water separation while managing power consumption within the maximum momentary power limit, balancing productivity improvement with energy constraints.

Inventive Principle:
Principle #19Periodic action

2Productivity

If the heater output is increased to improve heat-spinning efficiency, then the water content reduction is improved, but the maximum momentary power limit is exceeded

Engineering Contradiction:
Improveheat-spinning efficiencyVSAvoidheater output power
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent optimizes the heating temperature parameter during spinning to achieve effective water separation. By controlling the temperature to rise water viscosity reduction without excessive heating, the system improves heat-spinning efficiency while keeping heater power output within acceptable limits that do not exceed the maximum momentary power constraint.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial heating action during spinning rather than excessive continuous heating. Heating is applied sufficiently to reduce water viscosity and improve separation, but not to the extent of consuming excessive power or exceeding the maximum momentary power limit, thus resolving the contradiction between productivity and power constraints.

Inventive Principle:
Principle #16Partial or excessive action

3Productivity

If the heating temperature is increased to improve water separation, then the spinning efficiency is improved, but the system stability deteriorates due to thermal deformation

Engineering Contradiction:
Improvespinning efficiencyVSAvoidsystem stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent optimizes the heating temperature parameter within a safe range that does not cause thermal deformation of the tub and bearing system. By controlling the temperature increase to be sufficient for water viscosity reduction but below the threshold that causes system component deformation, the patent improves spinning efficiency while maintaining system stability.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If the drum rotation speed is increased to improve water separation, then the centrifugal force is increased, but the power consumption and vibration increase

Engineering Contradiction:
Improvewater separation efficiencyVSAvoidmotor power consumption
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent changes the physical state of water by heating it during spinning, which reduces water viscosity and allows for effective water separation at lower drum rotation speeds. This approach improves water separation efficiency without requiring high motor power consumption or high-speed rotation, thus resolving the contradiction between productivity and power consumption.

Inventive Principle:
Principle #35Parameter changes

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 enhances spinning and drying efficiency, reduces water content effectively at low RPM, provides flexible drying options, and ensures stable operation with variable heater output, meeting user needs for quiet and efficient performance, including midnight usage.

Implementation Method 1

an induction heater that is provided in the tub and heats an outer circumferential surface of the drum located in opposite

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a laundry machine which may heat a drum by means of an induction heater

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 3

The spinning means that the water contained in the laundry by using a centrifugal force of the drum rotating at a high rotation speed

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3666958A1Laundry machine having induction heater and control method of the same
Publication Date: 2020.06.17 LG ELECTRONICS INC
  • EP3666958A1 patent drawingFigure 1
  • EP3666958A1 patent drawingFigure 2
  • EP3666958A1 patent drawingFigure 3

AI summary

Embodiments of the present disclosure relate to a laundry machine, more particularly, a laundry machine which may heat a drum by means of an induction heater, and a control method of the same. The laundry machine includes a tub; a drum that is rotatably mounted in the tub and holds laundry; an induction heater that is provided in the tub and configured to heat an outer circumferential surface of the drum located in opposite; a motor that is configured to drive so as to rotate the drum; a user interface comprising a course selection unit that is configured to allow a user to select one of courses; and an option selection unit that is configured to allow the user to select option information that is related with the course selected from the course selection unit; and a processor that is configured to control the drum RPM and the drive of the induction heater, wherein the course selection unit comprises a wash-drying course that performs heat-spinning by default, the heat-spinning configured to heat the drum by driving the induction heater, when the drum rotates in the spinning.