Bimodal Engine Oil Blend Reduces Traction Coefficient

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Solution Overview

Problem

Large low and medium speed engines face challenges in fuel efficiency and emissions due to the limited oxidation stability and nitration resistance of lubricants, which also affect the cleanliness of critical engine components.

Innovation Solution

A bimodal blend of base oils with a significant difference in kinematic viscosity is used, comprising low viscosity Group I, II, III, or IV oils and high viscosity Group IV oils, to reduce the traction coefficient of the lubricant, thereby improving fuel economy and reducing engine emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a single base oil is used in the lubricant formulation, then the formulation is simple, but the traction coefficient is higher and fuel efficiency is lower

Engineering Contradiction:

Improvefuel efficiencyVSAvoidbase oil formulation complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The lubricant formulation is segmented into multiple base oil components with distinct viscosity characteristics. The patent specifies using a first base oil with viscosity of 2-12 cSt at 100°C and a second base oil with viscosity of 38-1000 cSt at 100°C, creating a bimodal viscosity distribution that reduces traction coefficient and improves fuel efficiency while managing formulation complexity through defined ratios

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a composite base oil system combining two different base oil types in specific proportions (first base oil: 30-70 wt%, second base oil: 30-70 wt%). This composite approach leverages the complementary properties of low-viscosity and high-viscosity base oils to achieve optimal traction reduction and fuel economy performance

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If the kinematic viscosity difference between base oils is small, then the formulation is easier to control, but the traction coefficient reduction is insufficient

Engineering Contradiction:

Improvefuel economyVSAvoidviscosity blending precision

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent fundamentally changes the viscosity parameter distribution by selecting base oils with a minimum viscosity difference of 30 cSt at 100°C. This parameter change creates a bimodal viscosity profile that significantly reduces traction coefficient. The formulation controls precision by specifying exact viscosity ranges for each base oil component and their proportioning ratios, balancing traction reduction with manufacturability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The bimodal viscosity blend creates dynamic lubrication characteristics that adapt to varying engine operating conditions. The combination of low and high viscosity components allows the lubricant to maintain optimal film strength across different temperatures and speeds, dynamically responding to engine demands while reducing overall traction

Inventive Principle:

Principle #15Dynamics

3Reliability

If conventional base oil blends are used, then the lubricant maintains adequate stability, but oxidation resistance and nitration resistance are insufficient

Engineering Contradiction:

Improvelubricant lifeVSAvoidoxidation and nitration damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces specific additives as intermediaries to protect the base oil from oxidation and nitration. The additive package includes anti-oxidants and metal deactivators that act as mediators between the base oil and harmful chemical reactions, extending lubricant life in high-temperature engine environments while preserving the beneficial traction-reducing properties of the bimodal blend

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 bimodal blend achieves a lower traction coefficient, leading to improved fuel economy and reduced emissions in large low and medium speed engines, enhancing the lubricant's resistance to oxidation and nitration, and maintaining cleanliness within high-temperature engine environments.

Implementation Method 1

lubricating said engines using an oil of reduced traction coefficient, said lubricating oil comprising a base oil comprising a bimodal blend of two different base oils

Methodology Applied

Scientific EffectLubrication: Lubrication

Implementation Method 2

the combination of the first and second base oils having a kinematic viscosity at 100° C. of 20 cSt (mm2/s) or less

Methodology Applied

Scientific EffectViscosity reduction:

Implementation Method 3

enhancing the lubricant's resistance to oxidation and nitration

Methodology Applied

Scientific EffectOxidation resistance: Oxidation

Implementation Method 4

enhancing the lubricant's resistance to oxidation and nitration

Methodology Applied

Scientific EffectNitration resistance: Nitriding

Data Source

PatentUS8759267B2Method for improving the fuel efficiency of engine oil compositions for large low and medium speed engines by reducing the traction coefficient

Publication Date: 2014.06.24 EXXONMOBIL TECHNOLOGY & ENGINEERING CO

AI summary

The present invention is directed to a method for improving the fuel efficiency of low and medium speed engine oil compositions by reducing the traction coefficient of the oil by formulating the oil using at least two base stocks of different kinematic viscosity wherein the differences in kinematic viscosity between the base stocks is at least 30 mm2/s.