Shock Absorber Friction Element for Low-Noise Washing Machine Damping
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Solution Overview
Problem
Existing shock absorbers in washing machines are inefficient in noise reduction and manufacturing cost, as they fail to effectively dampen vibrations and distribute dynamic loads, leading to noise disturbances and higher production costs.
Innovation Solution
A shock absorber design featuring a tubular casing with a longitudinally movable piston and a friction element alignment member that encapsulates a friction element with protrusions, which compresses between the inner surface of the alignment member and the piston, providing enhanced damping and centering capabilities while maintaining low noise and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional friction elements are used in shock absorbers, then the manufacturing cost is reduced, but the dampening capacity and noise reduction efficiency deteriorate
Solution Approach 1:
The friction element is segmented into multiple friction strips arranged circumferentially around the piston rod. Each strip independently contacts the piston rod surface, distributing the friction force across multiple contact points. This segmentation enhances the overall dampening capacity while maintaining a simple strip structure that is easy to manufacture and install.
Solution Approach 2:
The friction element is configured to wrap around the piston rod in a circumferential direction, adding a dimensional aspect to the friction contact. This circumferential arrangement increases the contact area between the friction element and piston rod, thereby improving dampening capacity without significantly complicating the manufacturing process.
2Object-affected harmful factors
If conventional friction elements are used in shock absorbers, then the device complexity is reduced, but the noise reduction efficiency deteriorates
Solution Approach 1:
The friction element consists of multiple discrete friction strips spaced circumferentially around the piston rod. This segmentation creates multiple distributed friction contact zones that effectively dampen vibrations and reduce noise. The segmented structure remains simple in design, requiring only basic assembly steps without complex mechanisms.
3Reliability
If the alignment member is made movable between stop bearings, then the dampening effectiveness is improved, but the device complexity increases
Solution Approach 1:
The alignment member is designed to be movable between two stop bearings, allowing it to dynamically adjust its position in response to vibrations and movements of the piston rod. This dynamic capability enables the friction element to maintain optimal contact with the piston rod throughout the range of motion, enhancing dampening effectiveness. The mechanism remains simple, relying on passive movement constrained by the stop bearings rather than active control systems.
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 design achieves robust damping and noise reduction by centering the piston within the casing, reducing radial deflections and vibrations, resulting in a cost-efficient and low-noise shock absorber that effectively attenuates drum oscillations in washing machines.
Implementation Method 1
a friction element wrapped around said second portion... a friction element is provided in the manner to be compressed between the inner surface of said friction element alignment member and the outer surface of the second portion
Data Source
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AI summary
A shock absorber (11) comprising a tubular first portion in the form of a shock absorber casing (12) telescopically receiving a tubular second portion in the form of a piston (13) is disclosed. The first portion has an alignment member (15) which encapsulates a friction element (17) wrapped around said second portion. The alignment member (15) is longitudinally movable in between a first stop bearing (18) and a second stop bearing (19). The novel friction element (17) has a plurality of tips or protrusions (25) which extend, parallel to the longitudinal direction of the piston (13), towards the two stop bearings (18,19) and which hit either of said bearings (18,19) during the oscillatory back and forth movement of the alignment member (15) during operation.