Driving wheel assembly

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Solution Overview

Problem

Conventional robot cleaners face challenges in maintaining consistent frictional force between driving wheels and the floor surface across various conditions, leading to inconsistent traveling performance, and the use of tension coil springs increases the installation space required.

Innovation Solution

A driving wheel assembly with a compression coil spring structure that minimizes length change relative to wheel displacement, allowing for stable pressure application and compact design, comprising a housing, driving motor, rotary member, and sensing unit to detect displacement and apply pressure effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a tension coil spring is used to apply pressure to the driving wheel, then the driving wheel is pressed towards the floor surface, but the installation space is increased due to the required spring length

Engineering Contradiction:
Improveapplied pressure to driving wheelVSAvoidinstallation space for spring
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The patent inverts the conventional approach by using a compression coil spring instead of a tension coil spring. The compression spring is positioned between the rotary member and the housing, compressing as the driving wheel moves upward. This inversion allows the spring to be shorter while still providing the necessary pressing force, thereby reducing the installation space required.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the dimensional arrangement of the spring mechanism. Instead of using a long tension spring that extends in one dimension, the compression spring is arranged radially within the housing, utilizing the radial space between the rotary member and housing. This dimensional reorganization reduces the overall space requirement while maintaining the pressing function.

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

2Stability of the object's composition

If the length of the tension coil spring is increased to reduce the range of applied pressure, then the installation space is further increased

Engineering Contradiction:
Improverange of applied pressureVSAvoidinstallation space for spring
Core Design Contradiction:
Stability of the object's compositionVSVolume of moving object

Solution Approach 1:

By inverting to a compression spring system, the patent achieves better pressure stability without increasing space. The compression spring's natural characteristics provide a more consistent force over the displacement range, and the compact radial arrangement allows this stability to be achieved within a smaller volume.

Inventive Principle:
Principle #13The other way round (Inversion)

3Volume of moving object

If a compression coil spring is used with minimal length change, then the installation space is reduced, but the ability to maintain stable pressure across wheel displacement is challenged

Engineering Contradiction:
Improveinstallation space for springVSAvoidapplied pressure stability
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent arranges the compression spring radially between the rotary member and housing, allowing it to compress in the radial direction while the driving wheel moves vertically. This dimensional arrangement enables the spring to maintain stable pressure through radial compression rather than requiring significant axial length change, thus preserving pressure stability within a compact space.

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

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 solution enables stable travel on different floor surfaces with improved mobility and a reduced space requirement for the robot cleaner, enhancing its compactness and cleaning efficiency.

Implementation Method 1

a compression coil spring which applies pressure to the rotary member and has a characteristic that a change in length of the compression coil spring is smaller than a displacement of the driving wheel

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the driving wheels drive the robot cleaner main body using frictional force generated between the driving wheels and the floor surface contacting the driving wheels

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2912982B1Driving wheel assembly
Publication Date: 2017.06.28 SAMSUNG ELECTRONICS CO LTD
  • EP2912982B1 patent drawingFigure 1
  • EP2912982B1 patent drawingFigure 2
  • EP2912982B1 patent drawingFigure 3

AI summary

A driving wheel assembly including a driving wheel, a housing, a driving motor, a rotary member with rotation around a rotation shaft of the driving motor, where the rotary member includes a first unit and a second unit disposed at a position opposite to the driving wheel with respect to the rotation shaft of the driving motor, and a compression coil spring disposed between the housing and the second unit to apply pressure to the second unit, where a distance between a contact point where the compression coil spring and the second unit contact and the rotation shaft of the driving motor is shorter than a distance between a rotation shaft of the driving wheel and a rotation shaft of the driving motor.