Planetary Gear Assembly for Compact High-Ratio Washing Machine Drive
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Solution Overview
Problem
Existing washing machine driving systems face challenges in achieving a high reduction ratio while maintaining a compact size, maximizing drum volume, and ensuring efficient assembly, particularly due to the constraints of planetary gear and clutch assembly arrangements.
Innovation Solution
The washing machine driving system incorporates a planetary gear assembly with a carrier coupled to the drum shaft and a sun gear connected to the motor, utilizing a key bolt and bearing assemblies to constrain the axial freedom of the drum shaft, allowing for a compact design and high reduction ratio without increasing the sun gear size, and positions the clutch for minimal space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the drum shaft is installed to pass through a carrier and a sun gear shaft of a planetary gear assembly, then the drum shaft can be driven, but the diameter of the sun gear accommodating the drum shaft increases, resulting in a small reduction ratio
Solution Approach 1:
The drum shaft is separated from the sun gear shaft, with the drum shaft passing through the carrier instead. This segmentation allows the sun gear to be smaller while maintaining the required reduction ratio, as the drum shaft no longer needs to accommodate the sun gear's diameter.
Solution Approach 2:
The drum shaft is repositioned to pass through the carrier in a different spatial arrangement, changing the dimensional relationship between the drum shaft, sun gear, and carrier. This allows the sun gear to be smaller while still achieving the desired power transmission and reduction ratio.
2Volume of moving object
If the planetary gear assembly and clutch assembly are arranged in series on the axis of the drum shaft, then the drum shaft can be driven through both components, but the volume of the drum is reduced
Solution Approach 1:
The planetary gear assembly and clutch assembly are arranged in parallel rather than in series along the drum shaft axis. This spatial reconfiguration reduces the axial length occupied by these components, thereby increasing the available drum volume while maintaining the necessary mechanical connections.
3Volume of moving object
If the sun gear of the planetary gear assembly is separated from the drum shaft of the drum assembly, then the sun gear size is not affected by the drum shaft outer diameter, but the drum shaft and sun gear must be fastened inside the drum assembly
Solution Approach 1:
The sun gear and drum shaft are separated as distinct components, with the drum shaft passing through the carrier instead of the sun gear. This segmentation allows the sun gear to be optimized independently of the drum shaft diameter, while the fastening is simplified by using the carrier as the connection point.
4Stability of the object's composition
If a planetary gear assembly is placed between the drum shaft and motor with the drum shaft and motor separated, then the axial degree of freedom of the drum shaft can be constrained, but the space required for arrangement increases
Solution Approach 1:
The carrier serves multiple functions simultaneously: it supports the drum shaft, provides the reduction mechanism through the planetary gears, and constrains the axial degree of freedom of the drum shaft. This merging of functions reduces the overall space required compared to separate components for each function.
Data Source
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AI summary
A planetary gear assembly included in a washing machine driving system includes a gear housing (320), a carrier (310) including a carrier flange (310a) positioned inside the gear housing (320), and a carrier shaft (310b) extending in an axial direction from the carrier flange (310a), protruding toward a front side of the gear housing (320), and coupled to a drum shaft (25), and integrally rotating with the drum shaft (25); a sun gear (330) including a front end that is coupled to the carrier (310) while spaced apart from a back end of the drum shaft (25), and a back end that protrudes toward a back side of the gear housing (320) and is coupled to a rotor frame of a motor (600); a key bolt (360) including a bolt head (360a) coupled to the front end of the sun gear and a bolt shaft (360b) extending backward along the axial direction and penetrating the sun gear.