Drum rotating device for laundry care apparatus
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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, 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 radially to increase the gear ratio, allowing for stable operation and synchronized mode switching without motor stoppage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
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 the gear ratio cannot be increased
Solution Approach 1:
The patent divides the sun gear into two separate components: a solid sun gear for torque transmission and a separate coupling mechanism. This segmentation allows the sun gear to maintain a small diameter for high gear ratio while the coupling space is provided by the separate coupling component, resolving the contradiction between compact size and coupling capability.
Solution Approach 2:
The patent employs a nested structure where the coupling mechanism is integrated within or alongside the sun gear assembly. The coupling space is formed by the relative positioning of the sun gear and carrier, allowing the drum shaft to couple to the carrier without requiring a hollow sun gear, thus maintaining small sun gear diameter while enabling proper coupling.
2Ease of manufacture
If a hollow sun gear with a coupling space is used, then the sun gear can be coupled to the rotating shaft, but the durability decreases due to the empty space
Solution Approach 1:
By separating the sun gear from the coupling function, the patent eliminates the hollow structure that compromises durability. The solid sun gear maintains full structural integrity for reliable torque transmission, while the coupling function is achieved through the separate carrier and coupling mechanism, resolving the contradiction between ease of coupling and durability.
3Ease of operation
If the rotating shaft enters the drive area of the gears, then the coupling can be achieved, but the drive area increases and the device becomes larger
Solution Approach 1:
The patent resolves the spatial conflict by changing the dimensional arrangement of components. The drum shaft is positioned axially adjacent to the gear assembly rather than radially within the drive area. The coupling is achieved through axial alignment and engagement features on the carrier, allowing compact radial dimensions while maintaining proper coupling operation.
4Stability of the object's composition
If multiple bearings are arranged along the axial direction to support rotating components, then stable rotation is achieved, but the axial length increases
Solution Approach 1:
The patent reduces axial length by redistributing bearing arrangements in the radial direction. Bearings are positioned to support components at multiple radial locations rather than extending axially, maintaining rotational stability through radial support while minimizing axial footprint of the drum driving device.
Data Source
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AI summary
Proposed are a drum rotating device (100) and a laundry care apparatus including the same. The drum rotating device includes a drum shaft (80) coupled to the drum (30), and a motor (200) including a stator (220) and a rotor (230) that rotates relative to the stator (220). A gear assembly (300) transmits rotational force of the rotor (230) to the drum shaft (80). A carrier (360) constituting the gear assembly (300) and the drum shaft (80) may be coupled to each other in a first area. A sun gear (340), a ring gear (RG) and pinion gears (370) constituting the gear assembly (300) are engaged with each other and rotate in a second area spaced apart from the first area on the basis of the axial direction of the drum shaft (80).