Drum rotating device and laundry care apparatus including same
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Solution Overview
Problem
Existing drum driving devices for washing machines face challenges in miniaturization due to the need for high-torque and low-torque rotational forces, increased size from hollow sun gears, reduced durability from hollow sun gears, and inefficient mode switching with clutches causing vibration and noise.
Innovation Solution
The drum rotating device separates the input and output shafts axially, reduces the sun gear diameter, and arranges components in overlapping radial configurations to enhance efficiency and stability, allowing clutch mode switching without motor stoppage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a hollow sun gear with a coupling space is used to connect to the rotating shaft, then the sun gear can be coupled to the drum shaft, but the diameter of the sun gear increases and durability decreases
Solution Approach 1:
The patent extracts the coupling function from the sun gear by introducing a separate coupling member that connects to the drum shaft. The sun gear becomes solid without any coupling spaces, while the coupling member handles the connection task, thereby improving sun gear durability while maintaining coupling capability.
2Ease of manufacture
If the sun gear diameter is increased to provide coupling space, then coupling is enabled, but the gear ratio cannot be increased and torque output is limited
Solution Approach 1:
The coupling function is extracted from the sun gear and assigned to a separate coupling member. This allows the sun gear diameter to be reduced, enabling a larger gear ratio between the sun gear and ring gear, which in turn increases the torque output to the drum shaft while maintaining the coupling capability through the separate coupling member.
3Stability of the object's composition
If multiple bearings are arranged along the axial direction to ensure stable rotation, then rotational stability is improved, but the axial length of the device increases
Solution Approach 1:
The patent rearranges the bearing arrangement from an axial configuration to a radial configuration. The bearings are positioned radially around the input shaft rather than along its axis, which maintains rotational stability while significantly reducing the axial length of the drum driving device.
4Loss of time
If the clutch operates while the motor is rotating to enable mode switching, then switching time is reduced, but gears collide during switching causing vibration and noise
Solution Approach 1:
The patent introduces a synchronization mechanism as an intermediary between the clutch and the gear system. Before the clutch engages, the synchronization mechanism adjusts the rotational speed of the clutch to match the motor speed, preventing gear collision during mode switching while maintaining fast switching times and eliminating vibration and noise.
Data Source
AI summary
A drum rotating device of a laundry care apparatus includes a drum shaft coupled to a drum, and a motor including a stator and a rotor that rotates relative to the stator. A gear assembly transmits rotational force of the rotor to the drum shaft A carrier constituting the gear assembly and the drum shaft is coupled to each other in a first area. A sun gear, a ring gear (RG), and pinion gears constituting the gear assembly are engaged with each other and rotate in a second area spaced apart from the first area based on the axial direction of the drum shaft.