Washing Machine Water Recirculation Control for Pump Noise
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Solution Overview
Problem
Washing machines experience increased acoustic noise due to water and air entrainment in the recirculation pump when the drum rotates in a specific direction, leading to insufficient water supply, which affects washing performance.
Innovation Solution
The water recirculation pump is controlled based on the direction of drum rotation, stopping it when the drum rotates in the direction that causes water retention and starting it when the drum rotates in the direction that maintains sufficient water supply to the pump, thereby preventing water and air entrainment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the water recirculation pump is operated continuously during drum rotation, then water circulation is maintained, but water and air entrainment occurs causing increased acoustic noise
Solution Approach 1:
The patent applies dynamics by making the pump operation adaptive rather than static. The control unit dynamically adjusts the pump operation based on real-time detection of drum rotation direction and water level conditions. When the drum rotates in the first direction and water level drops below the threshold, the pump is automatically stopped to prevent noise, and restarted when conditions improve, thus dynamically optimizing both noise reduction and water circulation reliability.
Solution Approach 2:
The patent implements feedback through a detection device that continuously monitors the water level in the lower part of the washing tank and the drum rotation direction. This feedback information is sent to the control unit, which adjusts the pump operation accordingly. The closed-loop feedback system ensures the pump operates only when water levels are sufficient, preventing air entrainment and noise while maintaining circulation when conditions permit.
2Productivity
If the drum rotates in the first direction, then washing action is provided, but water quantity in the lower part of the washing tank decreases causing pump entrainment
Solution Approach 1:
The system dynamically responds to water quantity changes during drum rotation. When the drum rotates in the first direction and water is retained on the drum perimeter, the detection device identifies the low water level condition and triggers the control unit to stop the pump, preventing air entrainment while allowing the washing action to continue.
Solution Approach 2:
The patent applies preliminary anti-action by detecting the tendency for water level to drop during drum rotation in the first direction and preemptively stopping the pump before air entrainment occurs. The detection device monitors water level trends, and the control unit anticipates the problematic condition, stopping the pump in advance to prevent the harmful effect of air and water entrainment.
3Object-affected harmful factors
If the water recirculation pump is stopped to reduce noise, then acoustic noise is reduced, but washing performance may be affected
Solution Approach 1:
The patent applies partial action by operating the water recirculation pump only during specific conditions (when water level is sufficient and drum rotates in favorable directions) rather than continuously. This partial operation is optimized to provide adequate water circulation for washing performance while avoiding operation during conditions that cause noise, achieving sufficient washing action without excessive pump runtime.
Solution Approach 2:
The system changes the operational parameters of the pump based on detected conditions. The control unit adjusts pump operation timing and duration according to drum rotation direction, water level threshold, and entrainment risk. This parameter adaptation ensures the pump operates at optimal levels for washing performance while minimizing noise-generating operation.
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 solution reduces acoustic noise and maintains effective washing performance by ensuring a sufficient water supply to the recirculation pump, minimizing noise and maintaining efficient operation.
Implementation Method 1
a water recirculation pump circulating the water inside the washing tub
Implementation Method 2
a water retention zone formed at least in part on the peripheral contour of the drum drives the water located in the lower part of the washing tank
Implementation Method 3
causing a phenomenon of water and air entrainment in the water recirculation pump
Data Source
Figure 1~2
Figure 3~4
AI summary
Washing machine (1) comprising a body (2); a washing tub (5); a drum (7) mounted for rotation in said washing tub (5), said drum (7) having an opening for loading and unloading laundry being closed by a door (9); a water retention zone (18) formed at least in part on the peripheral contour of the drum (7) and a water recirculation device (10) comprising a water recirculation pump (11) circulating the water inside said washing tub (5); said water recirculation pump (11) is stopped when said drum (7) is driven in rotation in a first direction of rotation and put into operation when said drum (7) is driven in rotation in a second direction of rotation, where the first direction of rotation produces a decrease in the quantity of water in the lower part of said washing tub (5) greater than the second direction of rotation.