Magnetic Gear Drum Drive for Quiet, Beltless Laundry Torque
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Solution Overview
Problem
Conventional laundry treatment apparatuses face issues with noise, belt failure, difficult assembly, motor efficiency deterioration, and heat emission due to eddy currents in magnetic flux variations during high-speed rotation, particularly in belt-drive and direct-drive types.
Innovation Solution
A magnetic gear device with a rotational magnetic field generator, a magnetic flux converter, and a magnetic rotator, where the magnetic flux is altered to adjust rotational speed and torque without contact, using variable and stationary magnets to reduce noise and eddy currents, and improve assembly efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a belt-drive speed-reduction mechanism is used, then torque transmission is achieved, but noise is generated by belt rotation
Solution Approach 1:
The patent replaces the mechanical belt-drive system with a magnetic gear device that uses magnetic fields for torque transmission. The magnetic gear includes a first magnetic gear unit with permanent magnets and a second magnetic gear unit with variable magnets, which interact through magnetic fields to transmit torque without physical contact, thereby eliminating noise generated by belt rotation while maintaining effective torque transmission.
2Power
If a belt is used for speed reduction, then torque is transmitted, but the belt may be cut
Solution Approach 1:
The patent eliminates the mechanical belt component entirely by implementing a magnetic gear system. The torque transmission is achieved through magnetic field interaction between the first magnetic gear unit with permanent magnets and the second magnetic gear unit with variable magnets, removing the reliability issue of belt cutting while maintaining torque transmission capability.
3Power
If pulleys and belt are provided inside the cabinet, then speed reduction is achieved, but assembly becomes difficult
Solution Approach 1:
The patent merges the speed reduction function directly into the motor assembly by integrating the magnetic gear units within the motor structure. The first magnetic gear unit is coupled to the motor shaft, and the second magnetic gear unit is coupled to the drum, eliminating the need for separate pulleys and belts inside the cabinet, thereby simplifying assembly while achieving speed reduction.
4Power
If belt contact with pulleys occurs during high-speed rotation, then torque is transmitted, but motor efficiency deteriorates due to friction
Solution Approach 1:
The patent replaces the friction-based mechanical belt-pulley contact system with a magnetic field-based transmission system. The magnetic gear units transmit torque through magnetic field interaction without physical contact, eliminating friction losses and improving motor efficiency while maintaining torque transmission capability.
5Power
If excessive load is applied to the power unit, then torque demand increases, but the motor is at risk of burning out
Solution Approach 1:
The patent implements a dynamic magnetic gear system where the second magnetic gear unit contains variable magnets that can adjust their magnetic field strength. This dynamic adjustment capability allows the system to handle excessive load conditions by modulating the magnetic interaction, protecting the motor from burning out while still meeting torque demands.
6Productivity
If the output magnetic gear unit rotates at high speed, then power transmission increases, but eddy currents generate heat
Solution Approach 1:
The patent applies local quality optimization by using variable magnets in the second magnetic gear unit that can be selectively activated or deactivated. This allows the magnetic field distribution to be optimized locally, reducing eddy current generation in specific areas during high-speed rotation while maintaining overall power transmission efficiency, thereby minimizing heat emission.
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 magnetic gear device reduces vibration and noise, prevents belt failure, simplifies assembly, enhances motor efficiency, and minimizes heat emission by controlling magnetic flux and eddy currents, leading to improved power transmission efficiency.
Implementation Method 1
a rotational magnetic field generator (100) fixed inside the cabinet for generating a rotational magnetic field
Implementation Method 2
a magnetic flux converter (200) spaced apart from the outer circumferential surface of the rotational magnetic field generator (100) by a prescribed distance for changing the magnetic flux of the rotational magnetic field generated by the rotational magnetic field generator (100)
Implementation Method 3
a magnetic rotator (300) rotatably spaced apart from the outer circumferential surface of the magnetic flux converter (200) by a prescribed distance, the magnetic rotator (300) being rotated by the magnetic flux changed by the magnetic flux converter (200)
Implementation Method 4
At least a portion of the input magnetic gear may include a variable magnet, magnetic force of which is variable by a magnetic field
Data Source
Figure 1
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AI summary
Disclosed are a laundry treatment apparatus and a magnetic gear device. The laundry treatment apparatus includes a cabinet for defining an external appearance of the laundry treatment apparatus, a drum rotatably provided inside the cabinet for accommodating laundry therein, and a power unit for rotating the drum. The power unit includes a rotational magnetic field generator fixed inside the cabinet for generating a rotational magnetic field, a magnetic flux converter provided radially outside of the rotational magnetic field generator for forming a magnetic path, and a magnetic rotator provided radially outside of the magnetic flux converter, the magnetic rotator having at least one permanent magnet inside thereof.