Drum Washing Machine Alternating Torque for Lower Laundry Damage
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Solution Overview
Problem
Conventional drum type washing machines lack effective methods to enhance washing performance while minimizing laundry damage and wear on machine parts, particularly in varying laundry loads and types.
Innovation Solution
The washing machine employs a controlled drum rotation system with alternating forward and reverse directional torques, combined with braking techniques like negative-phase and dynamic braking, to lift and drop laundry at optimized angles and speeds, maximizing impact and reducing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drum rotates continuously in one direction, then the washing process is simple, but the washing performance is insufficient and laundry damage increases
Solution Approach 1:
The drum rotation is controlled to alternate between forward and reverse directions in periodic cycles. The controller switches the drum between forward rotation (lifting laundry), braking (dropping laundry for washing), and reverse rotation phases, creating periodic mechanical action that enhances washing performance while controlling complexity through automated sequencing
Solution Approach 2:
The drum rotation system dynamically adjusts its operation by changing rotational direction and speed based on the washing cycle phase. The controller modulates the motor to provide variable torque and speed control, transitioning between acceleration, constant speed, and braking phases to optimize both washing effectiveness and laundry care
2Productivity
If the drum rotates at high speed, then the washing efficiency increases, but laundry damage and wear on machine parts increase
Solution Approach 1:
The controller applies braking action before the drum completes a full rotation to prevent excessive speed buildup. By introducing controlled deceleration phases, the system counteracts the tendency toward high-speed rotation that would cause laundry damage, while maintaining sufficient wash cycle throughput through optimized phase timing
Solution Approach 2:
The washing cycle uses periodic alternation between high-speed forward rotation (for lifting laundry efficiently) and braking/reverse phases (for dropping laundry with controlled impact). This periodic pattern allows high-speed operation during beneficial phases while limiting damage during transition phases, achieving both productivity and laundry protection
3Reliability
If the drum rotates forward and reverse alternately, then washing performance improves, but energy consumption increases
Solution Approach 1:
The controller utilizes the drum's momentum and kinetic energy during rotation phases rather than continuously applying motor torque. By allowing the drum to coast during reverse phases and using regenerative braking when switching directions, the system converts what would be wasted kinetic energy into useful braking force, reducing overall energy consumption while maintaining effective forward-reverse washing action
Solution Approach 2:
The alternating forward-reverse rotation creates periodic energy demand patterns that allow the motor to operate in bursts rather than continuously. The controller synchronizes motor activation with required direction changes, allowing energy recovery during deceleration phases and minimizing idle power consumption, thereby reducing total energy use while preserving washing effectiveness
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 improves washing performance by increasing the impact of laundry drops, minimizing damage, and reducing wear and tear on machine parts through controlled motion and braking strategies.
Implementation Method 1
the washing method comprises: applying a first directional or forward torque to a drum so that laundry in the drum is rotated in a first or forward direction and lifted to a maximum height greater than half a height of the drum; braking the drum so that the laundry is dropped
Implementation Method 2
braking the drum so that the laundry is dropped
Implementation Method 3
braking techniques like negative-phase and dynamic braking
Data Source
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AI summary
A washing machine (100) and washing method therefor are provided. The washing method may include applying a first directional torque to a drum (130) so that laundry in the drum is rotated in a first direction and lifted to a maximum height greater than half a height of the drum, braking the drum so that the laundry is dropped, applying a second directional torque to the drum so that the dropped laundry is rotated in a second direction and lifted to a maximum height greater than half a height of the drum, and braking the drum so that the laundry is dropped.