Robot Cleaner Driving Wheel Assembly for Stable Floor Traction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional robot cleaners face challenges in maintaining consistent frictional force between driving wheels and floor surfaces across various conditions, leading to inconsistent traveling performance due to the wide range of pressure applied by tension coil springs, which also increase the installation space required.

Innovation Solution

A driving wheel assembly utilizing a compression coil spring with a shorter change in length compared to the displacement of the driving wheel, where the spring applies pressure in the tangential direction through a specific positioning relative to the rotation shaft, allowing for compact design and stable mobility on different floor surfaces.

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 can be pressed towards the floor surface, but the applied pressure varies widely according to driving wheel displacement and the spring length must be increased to reduce this range, thereby increasing installation space

Engineering Contradiction:
Improveapplied pressure to driving wheelVSAvoidinstallation space for spring
Core Design Contradiction:
ForceVSVolume of stationary 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 to press against the driving wheel from the opposite side, fundamentally changing the force application mechanism. This inversion allows the spring to maintain more consistent pressure over the displacement range while occupying less space.

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

Solution Approach 2:

The patent changes the operational parameters of the spring system by selecting a compression spring with specific characteristics (shorter length, different stiffness) that operate in compression rather than tension. This parameter change enables the spring to provide more stable pressure application across the driving wheel's displacement range without requiring increased installation space.

Inventive Principle:
Principle #35Parameter changes

2Reliability

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

Engineering Contradiction:
Improveconsistency of applied pressureVSAvoidinstallation space for spring
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent resolves this contradiction by inverting the spring configuration from tension to compression type. The compression coil spring achieves consistent pressure application without requiring increased length, as it operates within a more compact displacement range suitable for the available installation space.

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

3Reliability

If a compression coil spring with smaller length change is used, then the pressure application becomes more stable across floor surface variations, but the design complexity increases

Engineering Contradiction:
Improvestable traveling performanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent achieves stable traveling performance by carefully selecting the compression spring parameters (stiffness, initial length, pre-compression) to match the driving wheel's displacement characteristics. This parameter optimization ensures the spring maintains consistent pressure without requiring complex control mechanisms or additional components.

Inventive Principle:
Principle #35Parameter changes

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

This configuration ensures stable traveling performance on various floor surfaces while minimizing the space required for the pressure application structure, enabling a compact-sized robot cleaner with improved mobility.

Implementation Method 1

a compression coil spring disposed between the housing and the second unit to apply pressure to the second unit

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2570064B1Driving wheel assembly and robot cleaner having the same
Publication Date: 2015.04.01 SAMSUNG ELECTRONICS CO LTD
  • EP2570064B1 patent drawingFigure 1
  • EP2570064B1 patent drawingFigure 2
  • EP2570064B1 patent drawingFigure 3

AI summary

A driving wheel assembly and a robot cleaner having the same includes a main body and 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.