Laundry Dryer Drum Lockage Detection Using Temperature Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Laundry dryers often experience drum rotation lockage due to stuck laundry, leading to motor overheating and potential belt breakage, which existing technologies fail to detect quickly and prevent effectively.

Innovation Solution

A laundry dryer equipped with a control unit utilizing two temperature sensors to detect drum rotation lockage by measuring temperature differences between the air outlet and the evaporator/condenser, implementing a safety algorithm to free the drum and prevent belt breakage through controlled rotational movements and user alerts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing temperature sensor methods are used to detect belt breaking, then detection is possible, but detection speed is slow and occurs after belt breaking has already happened

Engineering Contradiction:
Improvedetection accuracyVSAvoiddetection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by detecting drum rotation lockage before belt breaking occurs. The control unit monitors the relationship between motor rotation and drum rotation, and when it detects that the drum is not rotating while the motor is rotating (indicating lockage), it immediately stops the motor. This prevents the subsequent belt breaking that would occur with continued operation, thereby detecting the problem before actual belt failure happens.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the motor continues to operate after drum lockage, then the drying process continues, but the belt heats up and may break

Engineering Contradiction:
Improvedrying efficiencyVSAvoidbelt overheating
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback control by continuously monitoring the rotational relationship between the motor and drum. The control unit receives rotation information from both components and compares their operational states. When feedback indicates that the drum is not rotating while the motor is rotating (lockage condition), the control unit immediately stops the motor, preventing belt overheating and breakage while maintaining drying efficiency during normal operation.

Inventive Principle:
Principle #23Feedback

3Device complexity

If no rotation monitoring system is implemented, then the device complexity is low, but drum lockage cannot be detected

Engineering Contradiction:
Improvesystem structureVSAvoidlockage detection
Core Design Contradiction:
Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies universality by using the existing motor rotation sensor to serve dual purposes: both for controlling the drying cycle timing and for detecting drum rotation lockage. The control unit already receives rotation information from the motor for operational control, and this same information is utilized to monitor the relationship between motor and drum rotation, enabling lockage detection without adding separate sensing components.

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

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

Quick detection and prevention of drum lockage reduce the risk of belt breakage, ensuring safe operation and user notification of potential issues.

Implementation Method 1

a first temperature sensor which is disposed at the air outlet of the drum and which measures the temperature of the drying air at the outlet of the drum; and a second temperature sensor which is disposed between the evaporator and the condenser and which measures the temperature of the drying air passed over the evaporator

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 2

an evaporator which dehumidifies the drying air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a control unit which determines whether the rotation of the drum is locked or not by using the temperature difference value between the temperature value received from the first temperature sensor and the temperature value received from the second temperature sensor

Methodology Applied
Scientific EffectTemperature difference detection:

Data Source

PatentEP3933091B1A laundry dryer
Publication Date: 2023.04.12 ARCELIK AS
  • EP3933091B1 patent drawingFigure 1

AI summary

The present invention relates to a laundry dryer (1) comprising a body (2); a drum (3) which is disposed in the body (2) and wherein the laundry is loaded; a motor (4) which drives and rotates the drum (3); a belt (5) which transmits the movement of the motor (4) to the drum (3); a fan (6) which provides the circulation of the drying air in the drying cycle; an evaporator (7) which dehumidifies the drying air; a condenser (8) which heats the dehumidified drying air; a first temperature sensor (9) which is disposed at the air outlet of the drum (3) and which measures the temperature of the drying air at the outlet of the drum (3); and a second temperature sensor (10) which is disposed between the evaporator (7) and the condenser (8) and which measures the temperature of the drying air passed over the evaporator (7).