Damper, especially friction damper

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Solution Overview

Problem

Friction dampers in washing machines with spin cycles experience undesirable rattling noises due to manufacturing tolerances leading to excessive play and movement of the plunger within the housing.

Innovation Solution

Incorporating flexible compensating elements, such as wave-shaped or linear slats, on the plunger or housing to stabilize the plunger's displacement along the central longitudinal axis, reducing play between the plunger and housing walls, and providing support to eliminate rattling noises.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a clearance is provided between the plunger and housing walls to enable frictionless displacement, then the plunger can move smoothly, but excessive clearance due to manufacturing tolerances causes play and rattling noises

Engineering Contradiction:
Improvesmooth displacement of plungerVSAvoidrattling noises
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent employs flexible compensating elements (thin-walled structures or films) that are attached to the plunger or housing. These elements flexibly compensate for the clearance between the plunger and housing walls, eliminating play and rattling noises while preserving the smooth displacement capability. The flexible nature of these elements allows them to adapt to the clearance without restricting the plunger's movement.

Inventive Principle:
Principle #30Flexible shells and thin films

2Ease of manufacture

If the plunger is designed with a simple cylindrical shape for easy manufacturing, then production is straightforward, but manufacturing tolerances lead to excessive play between plunger and housing

Engineering Contradiction:
Improvesimple plunger designVSAvoidplay between components
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent segments the plunger or housing structure by introducing compensating elements as separate components. These elements can be attached to the plunger or housing and are designed to compensate for manufacturing tolerances. This segmentation allows the main plunger body to remain simple for easy manufacturing, while the added compensating elements address the play issue without complicating the core design.

Inventive Principle:
Principle #1Segmentation

3Object-generated harmful factors

If compensating elements are added to eliminate play and reduce rattling, then acoustic properties improve, but device complexity increases

Engineering Contradiction:
Improverattling noisesVSAvoidstructure with compensating elements
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The compensating elements are designed as flexible thin-walled structures or films that can be easily attached to the plunger or housing. This design minimizes the added complexity while effectively eliminating play and rattling noises. The flexible nature of these elements allows them to be integrated into the existing damper structure without requiring major design changes or complex assembly procedures.

Inventive Principle:
Principle #30Flexible shells and thin films

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 compensating elements effectively reduce rattling noises by stabilizing the plunger's movement, ensuring a stable displacement and preventing undesirable tilting or movement, thereby enhancing the acoustic properties of the damper.

Implementation Method 1

The at least one compensating element is in particular flexible, in particular compensating, in particular elastic, and/or in particular resilient

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A friction lining is held on the plunger, which rubs against opposing housing walls

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4286707A1Damper, especially friction damper
Publication Date: 2023.12.06 SUSPA
  • EP4286707A1 patent drawingFigure 1
  • EP4286707A1 patent drawingFigure 2~3
  • EP4286707A1 patent drawingFigure 4

AI summary

A damper, in particular for washing machines with a spin cycle, comprises a housing (2) having a central longitudinal axis (3) and enclosing a housing interior (21) at least partially by means of housing walls (25), a plunger (4) which is displaceable in the housing (2) along the central longitudinal axis (3) and extends out of the housing (2), fastening elements (7, 10) arranged at free ends (5, 9) of the housing (2) and the plunger (4) and at least one compensating element (28) for compensating for any play between the housing walls (25) and the plunger (4).