Washing Drum Active Balancing for High-Speed Spin Vibration
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Solution Overview
Problem
Conventional horizontal axis washing machines face challenges in balancing loads during high-speed spin cycles, leading to noise and vibrations due to unbalanced wash loads, which existing suspension systems and balancing methods only partially address, especially at higher speeds where system responses become unpredictable.
Innovation Solution
A laundry machine with a drum supported at spaced apart locations, equipped with sensors providing force, acceleration, and angular velocity data, and a controller that continuously calculates and applies balance corrections, accounting for acceleration, angular momentum, and the axial location of the load's center of mass to dynamically adjust the balance mass at specific locations along the drum axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high spin speed is used to extract water from washed articles, then drying time is reduced, but noise and vibrations increase due to unbalanced load
Solution Approach 1:
The balancing system performs preliminary detection and correction of load imbalance before the spin cycle begins. Sensors detect the distribution of laundry load, and balance masses are positioned in advance to counteract detected imbalances, allowing high-speed spinning without excessive vibrations or noise
Solution Approach 2:
The system changes the physical parameters of the balancing mechanism by adjusting balance mass positions and quantities based on detected load distribution. This dynamic parameter adjustment enables the system to adapt to different load conditions and maintain optimal balancing at various spin speeds
2Object-affected harmful factors
If suspension assemblies with springs and dampers are used to isolate vibrations, then vibration isolation is improved, but internal clearance increases and load capacity is lost
Solution Approach 1:
The invention extracts and eliminates the complex suspension assembly with springs and dampers, replacing it with a simpler rigid support structure combined with an active balancing system. This removes the need for large internal clearance while still achieving vibration control through balance mass adjustment
Solution Approach 2:
The passive mechanical suspension system is replaced with an active control system using sensors and adjustable balance masses. This substitution allows vibration control without requiring the physical clearance needed for spring and damper assemblies
3Object-affected harmful factors
If suspension assemblies are used to withstand imbalance forces, then vibration isolation is improved, but manufacturing cost increases
Solution Approach 1:
The expensive suspension assembly is extracted and replaced with a cost-effective combination of rigid supports and simple balance mass mechanisms, significantly reducing manufacturing costs while maintaining vibration control through active balancing
Solution Approach 2:
The invention uses simple, inexpensive balance masses and basic sensors instead of costly suspension components. These simpler components can be easily replaced or adjusted, providing an economical solution for vibration control
4Object-affected harmful factors
If load distribution is improved prior to spinning, then imbalance is reduced, but imbalance cannot be completely eliminated at high speeds
Solution Approach 1:
The system uses sensors to continuously monitor load distribution and provides feedback to the control system. Based on this feedback, balance masses are automatically adjusted to counteract detected imbalances, achieving complete balance correction even at high spin speeds where manual distribution is insufficient
Solution Approach 2:
The balancing system performs preliminary detection and correction of load imbalance before the spin cycle begins. This preliminary action, combined with real-time feedback during spinning, ensures complete balance correction that goes beyond what manual load distribution can achieve
5Object-affected harmful factors
If axial balance correction is applied at single location, then static imbalance is corrected, but dynamic imbalance along the axis cannot be corrected
Solution Approach 1:
The balancing system is segmented into multiple independent balance mass units distributed along the drum axis. Each unit can be independently adjusted to correct imbalances at different axial locations, enabling correction of both static and dynamic imbalances that cannot be addressed by a single-location system
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 effectively minimizes vibrations and noise by accurately compensating for both static and dynamic imbalances, allowing the machine to operate at higher speeds with improved balance accuracy and reduced operational costs by eliminating the need for suspended tubs and complex suspension systems.
Implementation Method 1
sensors collectively providing: output from which the force component of the supporting force on parallel axes at the two spaced apart support locations can be derived
Implementation Method 2
output from which the acceleration component of acceleration of the two spaced apart support locations on the parallel axes can be derived
Implementation Method 3
output from which the angular velocity of said drum rotation axis about an axis through its centre of mass, perpendicular to its rotation axis and parallel to the force component axes can be derived
Implementation Method 4
When an object of some shape or form is spun about a particular axis, the object mass exhibits static and dynamic imbalance. Static imbalance is where the axis of rotation does not pass through the centre of gravity (CoG) of the object.
Implementation Method 5
the calculation accounting for: a) the effect of acceleration of the sensor locations on the measured forces, b) the effect conservation of angular momentum has on the measured forces due to angular velocity of the drum rotation axis
Implementation Method 6
When mounted to have a horizontal rotation axis, and allowed to rotate under the influence of gravity, an object with a static imbalance will rotate until its CoG lies vertically under its axis of rotation.
Data Source
AI summary
A laundry machine includes a drum supported at least two spaced apart support locations for rotation about a rotation axis. A balance correction system is able to apply a variable amount of a balance correction mass at a selectable angular location of the drum at least two spaced apart locations along the drum rotation axis. A controller receives outputs of a set of sensors, and is programmed to continuously calculate balance corrections to apply.