Vibration damping device

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Solution Overview

Problem

Existing vibration damping devices for washing and drying machines are expensive and complex to manufacture, particularly the free-stroke radial dampers which require high frictional forces during specific stages of operation.

Innovation Solution

A vibration damping device with a variable articulation system that provides frictional resistance through a bushing and lug configuration, allowing for a free-stroke length where no frictional force is exerted, and adjustable frictional force based on the distance between rotation axes, using a high-compression material like expanded polyurethane for the friction element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If free-stroke radial dampers are used to reduce vibration and noise, then vibration damping performance is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvevibration and noise transmissionVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The damping device is divided into three separate articulating pieces (first, second, and third) connected through multiple articulations. Each piece can be independently manufactured and assembled, simplifying the manufacturing process while maintaining the complex damping functionality. The friction articulation is segmented into a bushing and a lug with a friction element, allowing independent production of each component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The distance between rotation axes of the articulating piece is made variable, allowing the device to adapt its frictional force dynamically. The articulation provides frictional resistance only when needed (when distance exceeds free-stroke length), reducing continuous wear and complexity while maintaining effective vibration damping during critical phases.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If frictional force is increased to damp vibrations during acceleration and deceleration, then vibration damping performance is improved, but wear and tear increases

Engineering Contradiction:
Improvevibration damping during acceleration/decelerationVSAvoidlifespan of damping device
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of moving object

Solution Approach 1:

The friction articulation operates periodically rather than continuously. Frictional resistance is applied only during acceleration and deceleration phases when vibration damping is most needed, while during stable rotation the device operates in free-stroke mode without friction contact. This periodic engagement reduces cumulative wear and extends device lifespan.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The friction element is made of high-compression material (such as expanded polyurethane) that can withstand high compressive forces during friction engagement while maintaining durability. The variable distance between rotation axes allows the friction parameter to be dynamically adjusted, applying high friction only when necessary and reducing wear during normal operation.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If variable distance between rotation axes is implemented to adjust frictional force, then adaptability to different operational stages is improved, but device complexity increases

Engineering Contradiction:
Improveadaptability to operational stagesVSAvoidarticulation system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple functions are merged into the articulating piece structure. The same articulating piece that connects the tub to the housing also provides the variable distance mechanism for friction adjustment and serves as the friction articulation itself. The bushing and lug with friction element are integrated into the existing articulation structure, avoiding additional separate adjustment mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

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 device effectively reduces vibration and noise transmission by adapting frictional force to operational stages, extending the lifespan of the damping device by absorbing omnidirectional vibrations without wear and tear, and reducing manufacturing costs.

Implementation Method 1

the articulation providing frictional resistance to rotation comprises a bushing which is crossed in the rotation axis by a bolt fixedly arranged at at least one lug, so that a friction element is arranged being trapped between the bushing and the bolt

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3303681B1Vibration damping device
Publication Date: 2019.12.18 BSH HAUSGERATE GMBH
  • EP3303681B1 patent drawingFigure 1
  • EP3303681B1 patent drawingFigure 2
  • EP3303681B1 patent drawingFigure 3~5

AI summary

A vibration damping device (1) of the radial type for a tub (36) of a washing machine (44) having three articulations (4, 5, 6) that rotate about their corresponding rotation axes and wherein at least one of the articulations provides frictional resistance to rotation. The distance between the first rotation axis and the second rotation axis and/or the distance between the second rotation axis and the third rotation axis is variable, while the articulation(s) (4, 5, 6,) that provide frictional resistance to rotation do not exert frictional force. In this manner, the noise can be reduced while the machine (44) is moving, since the vibration damping device (1) has free movement.