Rotary Damping Linkage With Variable Friction for Washing Machines

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Solution Overview

Problem

Existing damping devices for household appliances, such as washing machines and dryers, face challenges in providing variable damping coefficients efficiently, leading to increased complexity, costs, and maintenance issues, while also being bulky and unreliable.

Innovation Solution

A rotary damping device with a lever arm and support arm articulated between each other, incorporating a rotational damper and a secondary body with a mechanical pulling connection, allowing for adjustable damping coefficients through varying arm angles and secondary body positions, reducing wear and enabling modular design without electronic controls.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If damping devices with variable damping are incorporated, then damping performance is improved, but device complexity increases

Engineering Contradiction:
Improvedamping performanceVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the Dynamics principle by making the damping coefficient variable through mechanical adjustment. The damping device allows changing the position of the secondary body along the arm to modify the damping coefficient according to different operational phases, eliminating the need for complex electronic controls while achieving adaptive damping performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements Parameter changes by varying the damping coefficient through mechanical means. The secondary body can be positioned at different locations on the arm, and the arm angle can be adjusted, which changes the effective damping parameter. This mechanical parameter adjustment provides variable damping without electronic complexity.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If free stroke damping devices are used, then damping force is reduced during low amplitude oscillations, but axial length increases

Engineering Contradiction:
Improvedamping force during low amplitude oscillationsVSAvoidaxial length
Core Design Contradiction:
Object-generated harmful factorsVSLength of moving object

Solution Approach 1:

The patent transitions from axial/linear damping to rotary/dimensional damping. Instead of moving parts along the axial direction, the invention uses rotational movement of arms and positioning of secondary bodies in a radial plane. This dimensional change allows achieving variable damping without increasing axial length, as the damping mechanism operates in a different spatial dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If rotational dampers are incorporated in articulations, then damping moment is generated, but wear increases

Engineering Contradiction:
Improvedamping capabilityVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies the Self-service principle through the mechanical pulling connection that engages and disengages based on operational conditions. The secondary body is pulled into position by the arm's movement itself, and the mechanical connection automatically engages only when needed. This self-regulating mechanism reduces unnecessary friction and wear while maintaining damping capability when required.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If electronic controls are used for variable damping, then damping precision is improved, but manufacturing costs increase

Engineering Contradiction:
Improvedamping control precisionVSAvoidmanufacturing costs
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces electronic control systems with a purely mechanical solution. The variable damping is achieved through mechanical positioning of the secondary body and mechanical pulling connections that engage based on arm movement. This mechanical substitution eliminates electronics, sensors, and control circuits, significantly reducing manufacturing costs while maintaining sufficient damping precision through mechanical geometry.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 rotary damping device provides a continuously variable damping coefficient, reducing wear and costs, and simplifying construction, while offering improved reliability and adaptability to different operational phases of the appliance.

Implementation Method 1

these rotary damping devices incorporate a rotational friction damper. These damping devices are described, for example, in the publication WO 2011/070092 A1. In contrast to axial damping devices, in rotary damping devices the damping is exerted through a damping moment generated in the corresponding articulation, in particular a friction moment

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2852775B1Rotary damping device for electrical household appliance
Publication Date: 2016.05.04 BSH HAUSGERATE GMBH
  • EP2852775B1 patent drawingFigure 1~2
  • EP2852775B1 patent drawingFigure 3~4
  • EP2852775B1 patent drawingFigure 5~6

AI summary

Rotary damping device for electrical household appliance, such as a washing machine 1 or a dryer, where the device 18 comprises an arm 20, 21 articulated according to a principal articulation axis 23, 26, 28, optionally by means of at least one principal rotational damper 40, particularly a friction damper. The device 18 is characterized in that it comprises at least one secondary body 30 articulated with respect to an secondary axis of articulation by means of a secondary rotational damper 41, particularly a friction damper, and being connected, in particular mechanically, to an arm 20, 21 of the device 18.