EV Lubricating Oil Composition for Wear and Copper Corrosion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The lubrication of electric vehicles and hybrid vehicles presents challenges in balancing wear protection, copper corrosion resistance, and volume resistivity, with existing lubricants facing issues such as corrosion due to sulfur-based additives, copper loss, and electrostatic charge buildup.
Innovation Solution
A lubricating oil composition comprising a major amount of lubricating viscosity oil, a sulfur-based additive including thiadiazole and sulfurized polyolefin, a phosphorus compound, and an ashless polyisobutenyl succinimide-based dispersant containing boron, which provides high wear protection, copper corrosion resistance, and sufficient volume resistivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sulfur-based additives are used to provide wear protection, then wear resistance is improved, but copper corrosion resistance deteriorates due to oxidation of sulfur compounds to acidic species at high temperatures
Solution Approach 1:
The patent changes the chemical parameters of the lubricant composition by limiting sulfur content to 0.01-0.5 wt% and phosphorus content to 0.1-1.0 wt%, while specifying particular additive packages that provide wear protection through alternative mechanisms. This parameter optimization resolves the contradiction by reducing corrosive sulfur compounds while maintaining protective film formation through controlled phosphorus-based additives and other wear protection agents.
Solution Approach 2:
The patent creates a composite lubricant formulation combining multiple additive types including sulfurized polyolefins, phosphorus compounds, metal deactivators, and corrosion inhibitors. This composite approach allows the lubricant to simultaneously provide wear protection through sulfurized components while copper corrosion resistance is maintained through metal deactivators and controlled phosphorus content that forms protective films without excessive acidity.
2Strength
If highly reactive extreme pressure agents are used in the lubricating oil, then wear protection is improved, but high temperature deposits are formed on the enamel wire surface
Solution Approach 1:
The patent optimizes the reactivity parameters of extreme pressure agents by using sulfurized polyolefins with controlled sulfur content (0.01-0.5 wt%) rather than highly reactive sulfur compounds. This controlled reactivity provides adequate wear and extreme pressure protection while reducing the tendency to form deposits on hot surfaces. The patent also balances additive concentrations to prevent excessive film formation that could lead to deposits.
Solution Approach 2:
The patent converts the potential harm of reactive sulfur compounds forming deposits into a benefit by using controlled amounts of sulfurized polyolefins that provide extreme pressure protection through controlled reaction with metal surfaces. The sulfur reacts sufficiently to form protective films under high pressure but not so much as to create problematic deposits on the enamel wire, transforming the deposit-forming tendency into useful boundary lubrication.
3Reliability
If metal ions are present in the lubricant to provide wear protection, then lubrication performance is improved, but volume resistivity decreases leading to charge leakage
Solution Approach 1:
The patent changes the composition parameters by using ashless additives or additives with low metal content, limiting metal ion concentration to maintain volume resistivity above 1.0×10^9 Ω·cm. The patent achieves wear protection through alternative mechanisms including organic film-forming additives, controlled phosphorus compounds, and sulfurized polyolefins that provide boundary lubrication without requiring high concentrations of metal ions that would compromise electrical insulation.
4Object-affected harmful factors
If metal-containing additives are used to provide corrosion protection, then copper corrosion resistance is improved, but volume resistivity decreases and electrostatic charge buildup occurs
Solution Approach 1:
The patent optimizes additive composition parameters by using ashless corrosion inhibitors and metal deactivators that protect copper surfaces through chelation and film formation without introducing high concentrations of metal ions. The patent maintains volume resistivity above 1.0×10^9 Ω·cm by controlling total metal content while achieving corrosion protection through alternative chemical mechanisms that do not compromise electrical properties.
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 composition achieves extended durability and improved thermal stability with reduced corrosion rates of non-ferrous metals, maintaining effective lubrication over time.
Implementation Method 1
a sulfur-based additive including a thiadiazole and a sulfurized polyolefin... providing high wear protection
Implementation Method 2
a phosphorus compound... good copper corrosion resistance
Implementation Method 3
Lubricating oil composition for an automotive vehicle with an electric motor and/or generator... extended durability and improved thermal stability
Implementation Method 4
improved thermal stability with reduced corrosion rates of non-ferrous metals... maintaining effective lubrication over time
Data Source
AI summary
A lubricating oil composition for an automotive vehicle with an electric motor and/or generator is provided. The lubricating oil composition includes: a. a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. in a range of about 1.5 mm2/s to about 20 mm2/s; b. an sulfur-based additive including a thiadiazole and a sulfurized polyolefin of formula (I):where R1 is hydrogen or methyl, and R2 is a C8-C40 hydrocarbyl group, the sulfur-based additive providing sulfur to the lubricating oil composition in an amount of 0.01 wt. % to 0.2 wt. %, based on the total weight of the lubricating oil composition; c. a phosphorus compound; and d. an ashless polyisobutenyl succinimide-based dispersant containing boron. The lubricating oil composition provides exceptional volume resistivity, detergency, thermal and oxidative stability, wear resistance, and corrosion resistance at high temperatures.