Dual-Drum Washing Machine Motion for 3D Laundry Tumbling
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Solution Overview
Problem
Conventional drum-type washing machines limit laundry motion to two-dimensional circumferential motion, leading to inefficient washing, increased washing time, and entanglement issues, which result in wrinkles and difficulty in removing laundry.
Innovation Solution
A washing machine design featuring two drums with a dual-rotor motor system, allowing independent rotation of the main drum and sub-drum to induce three-dimensional motion of laundry through relative speed differences, enhancing washing efficiency and preventing entanglement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single drum is rotated to move the laundry, then the structure is simple, but the laundry motion is limited to two-dimensional circumferential motion without axial-direction motion
Solution Approach 1:
The patent employs a nested drum configuration where an inner drum is placed inside an outer drum, both capable of independent rotation. This nested structure enables three-dimensional laundry motion (circumferential + axial directions) while maintaining a compact overall form factor, effectively resolving the contradiction between enhanced motion capability and structural complexity.
Solution Approach 2:
The washing drum is segmented into two independently rotatable drums (inner and outer drums). Each drum can rotate in different directions and at different speeds, allowing the laundry to experience complex three-dimensional motion patterns including lifting, dropping, tumbling, and axial movement, thereby achieving versatile laundry motion without excessive structural complexity.
2Productivity
If a single drum is used for washing, then the device complexity is low, but the washing efficiency is limited due to restricted laundry motion
Solution Approach 1:
The nested dual-drum configuration allows both drums to rotate simultaneously in different directions and speeds, creating three-dimensional laundry motion that enhances washing efficiency through increased physical forces (friction, impact, tumbling). This structure achieves improved productivity without proportionally increasing device complexity.
Solution Approach 2:
The system employs dynamic control where the inner and outer drums can rotate at variable speeds and directions. During washing, both drums rotate to create tumbling motion; during dehydration, they rotate in opposite directions to prevent laundry entanglement. This dynamic operation maximizes washing efficiency while managing structural complexity.
3Productivity
If high-speed rotation is used for dehydration, then dehydration efficiency is improved, but laundry becomes entangled and stuck on the drum surface
Solution Approach 1:
During dehydration, the inner and outer drums rotate in opposite directions, creating relative motion that prevents laundry from sticking to the drum surface. This counter-rotation generates friction and movement that continuously redistributes the laundry, preventing entanglement and wrinkles while maintaining high dehydration efficiency through centrifugal force.
Solution Approach 2:
The system employs periodic reversal of drum rotation directions during dehydration cycles. By alternating between high-speed rotation in opposite directions, the laundry experiences periodic disturbance that prevents it from settling and becoming entangled on the drum surface, thereby maintaining dehydration efficiency without harmful entanglement.
4Force
If circumferential motion only is provided, then the drum structure is simple, but the physical force applied to laundry is insufficient for effective washing
Solution Approach 1:
By segmenting the drum into inner and outer independently rotatable components, the system generates multiple force vectors through differential rotation. The laundry experiences enhanced physical forces including lifting forces from drum rotation, impact forces from dropping motion, friction forces from surface contact, and tumbling forces from three-dimensional movement, all achieved through the segmented dual-drum structure.
Solution Approach 2:
The dual-drum configuration adds axial-direction motion to the traditional circumferential motion, creating three-dimensional laundry movement. This dimensional enhancement generates additional force components including axial friction forces, vertical impact forces, and radial tumbling forces, significantly increasing the total physical force applied to laundry without excessive structural complexity.
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
The three-dimensional motion improves washing performance, reduces washing time, and prevents laundry entanglement, facilitating easier removal and reducing wrinkles.
Implementation Method 1
The outer rotor and the inner rotor include rotor teeth, a permanent magnet and a bushing, spaced from an inner circumference of the stator and rotates centering around a rotor shaft by magnetic force.
Implementation Method 2
The rotor teeth form magnetic fluxes with the stator so as for the rotor to have a rotational force.
Implementation Method 3
The laundry is rotated along the inner circumferential surface of the drum by a centrifugal force responsive to the rotation of the drum
Implementation Method 4
a frictional force generated between the drum, which is rotated by a driving force transferred from a driving motor, and the laundry
Implementation Method 5
the laundry also performs a circular motion along the inner circumferential surface according to rotation speed of the drum and a falling motion from an upper side of the drum by the force of gravity
Data Source
AI summary
A washing machine includes a driving motor having a stator, an outer rotor connected to the inner shaft and rotatable outside the stator, and an inner rotor connected to the outer shaft and rotatable inside the stator. Stator slots, which are fixedly-installed as a coil are wound on stator teeth. The outer rotor and the inner rotor include rotor teeth, a permanent magnet and a bushing, spaced from an inner circumference of the stator and rotates centering around a rotor shaft by magnetic force. The rotor teeth includes a teeth extension portion extending from a side end of an outer circumference of the rotor teeth in a circumferential direction, a cut recess cut in a concaved manner from the outer circumference of the rotor teeth toward the center of the rotor shaft, and an insertion recess cut in a concaved manner in a radial direction from an inner circumference of the rotor teeth.