Laundry Drum Torque-Based Speed Control to Prevent Fabric Damage
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Solution Overview
Problem
Conventional laundry care appliances fail to provide gentle laundry care as they often attempt to reach maximum rotational speed when laundry is jammed, leading to increased torque and potential damage.
Innovation Solution
A laundry care appliance with a torque detection device and controller that adjusts the rotational speed of the drum drive, reducing speed when torque exceeds a threshold to prevent damage and allowing maximum speed when torque is below the threshold, ensuring gentle and effective laundry care.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drum drive rotates the laundry drum at maximum rotational speed, then productivity is improved, but the laundry may be damaged when torque exceeds threshold
Solution Approach 1:
The patent applies dynamics by making the rotational speed of the laundry drum variable rather than fixed at maximum speed. The controller dynamically adjusts the rotational speed based on real-time torque detection, reducing speed when torque exceeds the threshold to prevent laundry damage, and restoring maximum speed when torque is within safe limits. This dynamic adjustment resolves the contradiction between maintaining high productivity and preventing harmful effects on laundry.
Solution Approach 2:
The patent implements feedback control through a torque detection device that continuously monitors the torque of the laundry drum and provides this information to the controller. The controller uses this feedback to adjust the rotational speed accordingly - reducing speed when torque exceeds the threshold and maintaining or increasing speed when torque is acceptable. This closed-loop feedback system enables the system to automatically balance productivity and laundry protection.
2Reliability
If the drum drive attempts to reach maximum rotational speed when laundry is jammed, then the system maintains operational consistency, but torque increases causing laundry damage
Solution Approach 1:
The torque detection device provides continuous feedback to the controller about the actual torque conditions in the drum. When laundry is jammed and torque exceeds the threshold, the controller receives this feedback and automatically reduces rotational speed to prevent damage. This feedback mechanism maintains operational reliability by adapting the system's behavior to actual conditions rather than blindly following a fixed operational profile.
Solution Approach 2:
The patent changes the operational parameter of rotational speed based on detected torque conditions. Instead of maintaining a fixed maximum speed, the system varies the rotational speed parameter in response to torque threshold exceedance, thereby preventing laundry damage while maintaining operational consistency through adaptive control.
3Object-affected harmful factors
If the rotational speed is reduced when torque exceeds threshold, then laundry damage is prevented, but washing efficiency decreases
Solution Approach 1:
The system dynamically adjusts rotational speed rather than maintaining a permanently reduced speed. When torque exceeds the threshold, speed is reduced to prevent laundry damage. When torque returns to acceptable levels, the controller restores maximum rotational speed to maintain washing efficiency. This dynamic approach minimizes the impact on productivity while providing protection when needed.
Solution Approach 2:
The feedback control system continuously monitors torque and adjusts rotational speed accordingly. Speed reduction occurs only when and as long as torque exceeds the threshold, and speed is restored when torque returns to acceptable levels. This ensures that washing efficiency is maintained at maximum levels during normal operation while providing protective speed reduction only when necessary to prevent laundry damage.
Data Source
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AI summary
The invention relates to a laundry care appliance (100) with an inner tub (107) for receiving laundry, a drum drive (123) for rotating the inner tub (107), also comprising a torque detection device (127) for detecting torque of the inner tub (107) and a controller (121) for controlling the drum drive (123). The controller (121) is designed to control the drum drive (123) during a rotational period in order to rotate the inner tub (107) at a first rotational speed (155) when the detected torque falls below a torque threshold value (157). The controller (121) is designed to control the drum drive (123) during the rotational period in order to rotate the inner tub (107) at a second rotational speed when the detected torque exceeds a torque threshold value (157), the second rotational speed being lower than the first rotation speed (155), and the controller (121) is designed to control the second rotational speed in accordance with the detected torque of the inner tub (107) in order to prevent the laundry (109) in the inner tub (107) from being damaged.