Drum Support Hub Interlocking Design to Prevent Drive Shaft Loosening
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Solution Overview
Problem
Existing washing machines face issues with the loosening connection between the drive shaft and drum support member, leading to axial and radial movement, water ingress, and rusting problems due to the difficulty in achieving a firm connection between composite material drum support members and steel drive shafts.
Innovation Solution
A secure connection is achieved through a recessed perforated surface on the hub and a protruding surface on the drive shaft, specifically with diamond or polygon shapes, which interlock to prevent loosening and water ingress, using a drum support member made of composite materials like PA6-65% Glass fiber and a steel drive shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If molding or injection molding is used to connect the drive shaft and drum support member, then the connection is initially secure, but it loosens over time causing axial and radial movement
Solution Approach 1:
The connection interface is segmented into multiple interlocking features: the recessed part with perforated surface on the hub and the protruding surface on the drive shaft head. This segmentation creates multiple contact points and mechanical interlocks that distribute stress and prevent loosening over time, resolving the contradiction between initial security and long-term durability.
Solution Approach 2:
The connection transitions from a simple radial fit to a multi-dimensional interlocking structure. The recessed part extends axially with a perforated surface that interlocks with the protruding surface, adding axial dimension to the connection. This multi-dimensional engagement prevents both radial and axial movement, maintaining reliability throughout the operational duration.
2Reliability
If a tight connection is configured between composite drum support member and steel drive shaft, then movement is prevented, but the connection becomes difficult to configure
Solution Approach 1:
Instead of making the entire hub complex, the invention applies local quality by adding the recessed part with perforated surface only at the specific connection zone where the drive shaft head interfaces with the hub. This localized feature provides the necessary interlocking capability without complicating the overall simple star-shaped drum support member structure, resolving the contradiction between connection security and configuration simplicity.
3Ease of manufacture
If loose connection exists between drum support member and drive shaft, then manufacturing is easier, but water ingress causes breakdowns and rusting
Solution Approach 1:
The recessed part with perforated surface is pre-formed as an integral feature of the hub during molding. This preliminary action creates a built-in protective structure that prevents water ingress from the outset, eliminating the need for additional sealing components or complex assembly steps. The interlocking design inherently blocks water pathways while maintaining ease of manufacture through single-piece molding, resolving the contradiction between manufacturing simplicity and protection against harmful factors.
Data Source
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AI summary
The invention relates to a washing machine (1) comprising a housing (11) for enclosing a drum (13) rotatably disposed for receiving items, characterized in that the drum (13) is supported by a drum support member (14) comprising pluralities of arm parts (141) extending away from a hub (142) for receiving a drive shaft (15) with a head (151). As an improvement, the hub (142) further comprises a recessed part (1421) forming a perforated surface (1422) and the head (151) of the drive shaft (15) comprises a protrusion (1511) forming a protruding surface (1512) for combining to the hub (142).