Robotic Mower Airflow Management for Thermal Control

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Solution Overview

Problem

Robotic lawn mowers face overheating issues due to high cutting loads and ambient temperatures, which can damage electrical components and Lithium-ion batteries, particularly in hot climates, and existing designs lack effective cooling solutions due to power constraints.

Innovation Solution

A battery-operated robotic lawn mower with an active airflow management system featuring strategically positioned vents, a fan or impeller, and cooling air channels, which enhances air flow and debris removal, while preventing water ingress and moisture damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling fans are added to battery operated robotic lawn mowers, then cooling effectiveness is improved, but power consumption increases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidpower consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The airflow management system dynamically adjusts air intake and exhaust pathways based on operational status. During operation, the system channels air through the motor housing to provide cooling during high-power consumption periods. When idle, the system switches to passive convection cooling through strategically positioned vents, eliminating the need for continuous fan operation and reducing overall power consumption while maintaining effective temperature management.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the outer shell is used for collision detection, then safety is improved, but heat dissipation is worsened due to reduced venting

Engineering Contradiction:
Improvecollision detection safetyVSAvoidheat dissipation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The outer shell is segmented into different functional zones: collision detection panels on the front for safety, and strategically positioned vent openings in specific areas for heat dissipation. This segmentation allows the shell to simultaneously provide protective collision detection coverage while maintaining effective thermal management pathways for heat escape from the motor and battery compartments.

Inventive Principle:
Principle #1Segmentation

3Temperature

If air vents are added for cooling, then temperature management is improved, but water ingress risk increases

Engineering Contradiction:
Improvetemperature managementVSAvoidwater ingress risk
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The air vents are pre-configured with integrated water ingress prevention features including angled positioning to promote water runoff, protective grilles or meshes that block water entry while allowing air passage, and placement in locations where water accumulation is minimized. These preliminary protective measures are built into the vent design itself, enabling effective cooling while preemptively preventing water damage to internal components.

Inventive Principle:
Principle #10Preliminary action

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 more powerful cutting and extended operation duration by effectively cooling the mower's components, even in high temperatures, and assists in the mulching process by directing air flow to prevent debris re-ingestion and promote soil nourishment.

Implementation Method 1

a fan or impeller, and at least one cooling air channel, the at least one second vent having a lower air flow capacity less than an air flow capacity of the at least one cooling air channel, such that, in operation of the motor, a greater volume of air is drawn from the first vent than the second vent and wherein an airflow path is defined between the first and the second vents

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

the at least one second vent is positioned in an opposing side of said mower, to enable convection cooling of the mower when the motor is not in operation

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the lawn mower further comprises an enveloping outer shell, to define an insulating layer between said mower and ambient atmospheric conditions

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentEP2656719B1Airflow management
Publication Date: 2014.11.26 ROBERT BOSCH GMBH
  • EP2656719B1 patent drawingFigure 1
  • EP2656719B1 patent drawingFigure 2
  • EP2656719B1 patent drawingFigure 3

AI summary

The present invention relates to an airflow management system, particularly for a lawn mower, especially a robotic lawn mower. We describe a battery-operated robotic lawn mower with an active airflow management system, said active airflow management system comprising: at least one first air vent (303) positioned on an underside of said mower; at least one second air vent (302); an internal housing surrounding a motor (102); a fan (201); and at least one cooling air channel located within said housing and around said motor. An air flow path is defined between the first (303) and the second (302) vents; and said at least one second vent (302) has a lower air flow capacity than an air flow capacity of said at least one cooling air channel, such that in operation, a greater volume of air is drawn through the first vent (303) than the second. (302)