Water-Based Lubrication in Mobile Machine Tools for Friction and Heat

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Solution Overview

Problem

Handheld power tools experience significant friction and temperature increases due to moving parts, leading to performance losses and safety risks, and existing solutions fail to provide energy-efficient alternatives.

Innovation Solution

A mobile machine tool with a drive unit utilizing an aqueous lubricant containing at least 5% water, which reduces friction and wear, allowing for increased energy efficiency and performance, and features a sealing geometry resistant to water and steam to prevent lubricant escape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional lubricants are used in mobile machine tools, then friction between moving parts is reduced, but energy efficiency remains insufficient and temperature increases occur

Engineering Contradiction:
Improveenergy efficiencyVSAvoidfriction losses
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent changes the chemical composition parameter of the lubricant by incorporating water-based compounds with specific molecular structures (containing oxygen, hydrogen, and optionally carbon chains of 1-10 atoms). This parameter change in lubricant composition results in reduced friction coefficients and improved energy efficiency, directly addressing the energy loss problem without causing temperature increases

Inventive Principle:
Principle #35Parameter changes

2Reliability

If friction is reduced through lubrication, then wear is reduced, but temperature increases still pose safety risks

Engineering Contradiction:
Improvewear resistanceVSAvoidtemperature increases
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the lubricant's thermal properties by using water-based compounds with specific heat capacities and thermal conductivities. These parameter changes enable the lubricant to effectively dissipate heat while maintaining wear protection, thereby reducing temperature increases that pose safety risks while preserving reliability

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If water content in lubricant is increased to reduce friction, then lubricant may escape or mix with external water, but performance improvement is achieved

Engineering Contradiction:
Improveenergy efficiencyVSAvoidlubricant stability
Core Design Contradiction:
Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent introduces hydrophobic protective coatings or barrier layers as intermediaries between the water-based lubricant and the external environment. These intermediary layers prevent lubricant escape and mixing with external water while allowing the high water-content lubricant to maintain its friction-reducing performance inside the machine tool

Inventive Principle:
Principle #24Intermediary (Mediator)

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 use of a water-based lubricant significantly reduces friction and wear, enhancing the energy efficiency and performance of handheld power tools, extending their lifespan and reducing maintenance needs, while maintaining flexibility and safety.

Implementation Method 1

the drive unit comprises a water-based lubricant and/or wherein the drive unit is configured for operation with a water-based lubricant

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3991919A1Mobile machine tool with a water-containing lubricant and use of the mobile machine tool
Publication Date: 2022.05.04 HILTI AG
  • EP3991919A1 patent drawingFigure 1
  • EP3991919A1 patent drawingFigure 2
  • EP3991919A1 patent drawing

AI summary

The invention relates to a mobile machine tool, for example a hand-held power tool (10), with a drive unit (20). It is characterized in that the drive unit (20) comprises a water-based lubricant (26) and/or that the drive unit (20) is configured for operation with the water-based lubricant (26), wherein the water-based lubricant (26) comprises at least 5 percent, preferably at least 15 percent, water. The mobile machine tool exhibits particularly high energy efficiency.