Three-Point Spin Mop Cleaner for Stable Straight-Line Travel

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Solution Overview

Problem

Existing robot cleaners face issues with stability and traveling performance due to two-point support, varying frictional force, and difficulty in maintaining a straight path, especially near walls, and struggle to perform both wet and dry mopping efficiently.

Innovation Solution

A cleaner design featuring a first cleaning module with left and right spin mops that generate frictional force on a clockwise or counterclockwise rotation, supported by a second cleaning module for enhanced stability and load distribution, allowing for both wet and dry mopping operations without a separate driving wheel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the robot cleaner is supported by a pair of left and right mops in a two-point support manner, then the structure is simple, but stability in the forward-and-backward direction is deteriorated

Engineering Contradiction:
Improvestructure simplicityVSAvoidstability in forward-and-backward direction
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The cleaner divides the support function into two separate modules: a first cleaning module with left and right mops for lateral support and propulsion, and a second cleaning module with a front mop for forward support. This segmentation provides three-point support contact with the floor, significantly improving stability in the forward-and-backward direction while maintaining structural simplicity through functional division

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the robot cleaner moves by rotation motion of a pair of left and right mops, then the structure is simple, but the frictional force frequently varies making it difficult to travel straight

Engineering Contradiction:
Improvestructure simplicityVSAvoidtraveling straightness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The bottom surfaces of the left and right mops in the first cleaning module are inclined at different angles relative to the rotation axis, creating asymmetric local quality. This asymmetric inclination optimizes the frictional force distribution at different locations of the mops, ensuring more consistent and reliable frictional force generation during rotation, which enables the cleaner to travel straighter

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If the weight of the robot cleaner is dispersed to a plurality of support points, then stability is improved, but the frictional force generated by operation at some support points is reduced, degrading traveling performance

Engineering Contradiction:
ImprovestabilityVSAvoidtraveling performance
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The cleaner employs asymmetric weight distribution and functional assignment among the three support points. The first cleaning module with left and right mops carries more weight and serves as the primary propulsion system through rotation, while the second cleaning module with the front mop carries less weight and provides auxiliary support and sliding-based forward propulsion. This asymmetric design ensures that the support points generating frictional force bear sufficient load to maintain effective traveling performance while still providing three-point support for stability

Inventive Principle:
Principle #4Asymmetry

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 design improves stability and traveling performance by optimizing frictional force distribution, enabling the cleaner to move straight and perform thorough and efficient mopping operations.

Implementation Method 1

a left spin mop and a right spin mop configured to come into contact with the floor while rotating in a clockwise direction or in a counterclockwise direction... a point on the bottom surface of the left spin mop that receives the largest frictional force from the floor... a point on the bottom surface of the right spin mop that receives the largest frictional force from the floor

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4144275B1cleaner
Publication Date: 2024.06.26 LG ELECTRONICS INC
  • EP4144275B1 patent drawingFigure 1
  • EP4144275B1 patent drawingFigure 2
  • EP4144275B1 patent drawingFigure 3

AI summary

A cleaner is disclosed. The cleaner includes a first cleaning module including a left spin mop and a right spin mop configured to contact the floor while rotating in a clockwise direction or in a counterclockwise direction when viewed from an upper side, a second cleaning module configured to contact the floor in front of the first cleaning module, and a body supported by the first cleaning module and the second cleaning module. A point on the bottom surface of the left spin mop that receives the largest frictional force from the floor is located on a left-front side of the rotation center of the left spin mop, and a point on the bottom surface of the right spin mop that receives the largest frictional force from the floor is located on a right-front side of the rotation center of the right spin mop.