Washing Machine Pump Control for Water Jacket Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In washing machines, highly absorbent laundry causes excessive water loss during spinning, leading to incomplete drainage and increased mechanical stress due to repeated spin cycles and the formation of a 'water jacket', which existing pump operation methods fail to efficiently address.
Innovation Solution
The method involves varying the pump's delivery rate based on the washing liquid level, with temporary boosts in delivery capacity during critical phases to prevent water jacket formation and reduce mechanical stress, using a frequency converter to supply increased power to the pump motor, allowing for demand-oriented operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump operates at a constantly high delivery rate during spinning, then the drainage efficiency is improved, but the mechanical stress on highly absorbent laundry increases and the motor may be damaged due to excessive load
Solution Approach 1:
The pump's delivery rate is dynamically adjusted based on the detected liquid level in the tub. During spinning, the pump operates at high delivery rate only when the liquid level exceeds a predetermined threshold, and reduces delivery rate when the level falls below the threshold, creating a dynamic response to changing conditions rather than constant operation
Solution Approach 2:
A level sensor detects the liquid level in the tub and provides feedback to the control unit, which then adjusts the pump's delivery rate accordingly. This closed-loop control ensures the pump operates efficiently when needed while avoiding excessive mechanical stress when the liquid level is low
2Productivity
If the pump operates at high delivery rate continuously, then the drainage speed is improved, but the motor may be damaged due to time-limited excessive load
Solution Approach 1:
The pump operates in periodic cycles of high and low delivery rates based on liquid level detection. The control unit alternates between high delivery rate operation (when liquid level is high) and reduced delivery rate operation (when liquid level is low), preventing continuous excessive loading of the motor while maintaining effective drainage
Solution Approach 2:
The system proactively reduces the pump's delivery rate before the motor can be damaged by excessive load. When the liquid level falls below the threshold, the control unit immediately reduces the delivery rate, cushioning the motor from potential damage before it occurs
3Object-affected harmful factors
If the spin cycle is interrupted to allow water level to fall, then the water jacket formation is prevented, but the washing program duration is increased
Solution Approach 1:
The pump operates continuously throughout the spinning phase without interrupting the spin cycle. By dynamically adjusting the delivery rate based on liquid level detection, the system maintains continuous drainage action while preventing water jacket formation, eliminating the need for spin cycle interruptions
Solution Approach 2:
The pump's delivery rate parameter is changed based on liquid level conditions. The control unit adjusts the delivery rate between high and low settings according to whether the liquid level is above or below the threshold, allowing the system to adapt to changing conditions without interrupting the overall washing program
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 ensures optimal drainage without prolonging the washing program, reduces mechanical stress on laundry, and prevents water jacket formation by dynamically adjusting the pump's operation according to liquid levels, effectively managing the increased load without damaging the motor.
Implementation Method 1
supplying said motor with increased electrical power suitable for bringing about an increased delivery rate of the pump for a predetermined period of time
Implementation Method 2
a pump (12a) with an electric motor (12d) for conveying washing liquid (19) in a water-bearing device
Implementation Method 3
spinning is interrupted until the washing liquid in the tub has fallen below a predetermined level due to the centrifugal force that occurs
Data Source
Figure 1
Figure 2
Figure 3a~3c
AI summary
The method involves providing washing fluid (19) to a washing container (2) in a washing phase for treating washing goods (8). The fluid is discharged from the container via a discharging device (12) of a water guiding device (1) at an end of the washing phase. An upper level (Krit) and a lower level (Min) of the fluid in the container are detected by a sensor (20), and conveying capacity of a pump i.e. discharging pump (12a) and flow pump (17a), is varied depending on the detected levels of the fluid in a continuous or discontinuous manner. Independent claims are also included for the following: (1) a method for operating a washing machine (2) a frequency converter for supplying current to an electronically commutated motor (3) a mechantronic system comprising a frequency converter (4) a washing machine comprising a mechantronic system.