Alkoxylated Alcohol Lubricants for Higher Breakdown Voltage in Bearings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Unintended electric current (parasitic currents) in rolling bearings can cause damage to mechanical components and lubricants due to arcing discharge, particularly in electric vehicles with frequency inverters, leading to issues like crater formation and lubricant oxidation.
Innovation Solution
A lubricant comprising hydrocarbons, 50 to 1000 ppm water, and an alkoxylated alcohol alkoxylated with a hydrophobic epoxide is used to mitigate parasitic currents, enhancing the breakdown voltage and reducing electric discharge machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional lubricants are used in electric vehicles with frequency inverters, then the lubricant provides basic lubrication, but the parasitic currents cause arcing discharge breakdown leading to bearing damage and lubricant oxidation
Solution Approach 1:
The patent introduces an intermediary substance (conductive additive or coated layer) between the bearing components and the lubricant to manage parasitic currents. This intermediary provides a controlled electrical path that prevents uncontrolled arcing discharge, thereby protecting the bearing from electrical damage while maintaining lubrication functionality
Solution Approach 2:
The patent modifies the electrical parameters of the lubricant system by adding conductive substances or coated layers that change the electrical conductivity of the lubricant. This parameter change allows the lubricant to conduct parasitic currents safely rather than allowing arcing discharge breakdown, thus improving bearing reliability under electrical stress
2Object-affected harmful factors
If the lubricant conductivity is increased to prevent arcing discharge, then bearing protection improves, but the lubricant may facilitate unwanted current flow
Solution Approach 1:
The patent applies local quality by creating coated layers on specific bearing surfaces or using additives that locally modify conductivity only where needed. This localized approach provides electrical protection at critical interfaces while maintaining the bulk lubricant's insulating properties, thus preventing arcing discharge without facilitating unwanted current flow through the entire lubricant system
Solution Approach 2:
The patent uses partial action by introducing small amounts of conductive additives or applying thin coated layers rather than making the entire lubricant highly conductive. This partial modification provides sufficient electrical protection against arcing discharge while minimizing the risk of unwanted current flow through the lubricant
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 lubricant effectively reduces parasitic currents, preventing damage to bearings and improving the breakdown voltage, thus protecting mechanical components and maintaining lubricant integrity.
Implementation Method 1
an alkoxylated alcohol, where the alcohol is alkoxylated with a hydrophobic epoxide selected from C4-C20 epoxides
Implementation Method 2
a hydrophobic epoxide selected from C4-C20 epoxides
Implementation Method 3
arcing discharge breakdown of the lubricant
Implementation Method 4
enhancing the breakdown voltage and reducing electric discharge machining
Data Source
AI summary
The present invention relates a lubricant comprising a base stock selected from hydrocarbons, 50 to 1000 ppm water, and an alkoxylated alcohol, where the alcohol is alkoxylated with a hydrophobic epoxide selected from C4-C20 epoxides. The invention also relates to a method for lubricating a mechanical device in an electric vehicle comprising the step of contacting the lubricant with the mechanical device; to a use of the alkoxylated alcohol for increasing the breakdown voltage of a lubricant comprising the basestock selected from the hydrocarbons; and to a use of the alkoxylated alcohol in a lubricant comprising the base stock selected from the hydrocarbons for reducing the electric discharge machining.