E-Motor Cooling Lubricant Solutions

A hybrid powertrain cooling and lubrication system that combines water and oil cooling to improve heat dissipation and lubrication efficiency. The system features a water cooling module with separate passages for the drive motor and reducer, and an oil cooling module with a pump, oil cooler, and delivery passages to lubricate and cool the motor, reducer, and range extender.

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Heat transfer fluid for cooling electrical components like batteries in electric vehicles that provides superior cooling performance with low electrical conductivity, low flammability, and low freeze point compared to traditional coolants. The fluid is a low-viscosity, low-flammability oleaginous oil like isoparaffinic hydrocarbon or ester with a kinematic viscosity of 0.7-7 cSt at 100°C and a flash point of at least 50°C. This fluid allows immersion cooling of electronic components without electrical shorting risks or freezing issues. It provides better cooling compared to water glycol-based coolants due to its lower thermal conductivity.

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Thermal management system for electric motors, particularly for electrified vehicle powertrains, that cools the rotor core through internal channels rather than relying on external surface cooling. The system features a hollow shaft with radial channels that connect to axial channels within the rotor core, enabling oil to flow through the rotor's internal structure to dissipate heat generated by the motor's operation.

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Electric drive system for vehicles with improved oil circuit efficiency, comprising a casing with a receiving cavity, a motor installed in the cavity, an oil pump to circulate lubricating oil, and a cooler to dissipate heat. The oil circuit includes a first oil supply channel connecting the oil pump to the motor, a second oil supply channel connecting the oil pump to the transmission, and an oil distribution passage connecting the cooler to both channels. The system achieves high oil utilization efficiency by directly injecting cooled oil into the motor and transmission, eliminating heat loss through the oil circuit.

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Lubricant composition for electric vehicle propulsion systems that improves antiwear and anticorrosion properties by combining triazole corrosion inhibitors with amine- and sulfur-based antiwear additives. The triazole compounds like tolyltriazole prevent corrosion of metal components while the amine-sulfur additives like dimercaptothiadiazoles reduce wear. This combination provides simultaneous wear and corrosion protection for electric vehicle motors, bearings, and transmissions.

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A lubricating fluid for electric motor systems in hybrid and electric vehicles, comprising a base oil of lubricating viscosity, a high molecular weight succinimide dispersant, an amine salt of a phosphoric acid ester, an ashless dialkyl dithiophosphate, and a sulfur-providing additive. The fluid has a kinematic viscosity of 4.5 cSt or less, 150-250 ppm total phosphorus, and an electrical conductivity of 37 nS/m or less. The succinimide dispersant is derived from a polyisobutylene with a number average molecular weight of 2000 or greater, and is post-treated with a phosphorus and boron containing compound.

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A lubricant composition for electric and hybrid vehicle motors, comprising a base oil blend of polyalkylene glycol (PAG), poly-alpha-olefin (PAO), and ester, with an additive package including a sulfur-based extreme pressure agent. The PAG provides thermal stability and low viscosity, while the PAO and ester enhance solubility and compatibility with the extreme pressure agent. The composition is optimized for electric motor applications, avoiding additives typically used in conventional lubricants that can degrade performance.

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An electric drive unit with a compact cooling system that combines direct stator cooling and water jacket cooling. The system features a housing with a water jacket, a stator with oil ducts and radial openings, and an oil inlet that extends through the housing. The oil ducts traverse the stator laminations, and the water jacket acts as a heat exchanger for the oil cooling circuit, eliminating the need for an external heat exchanger.

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An electric pump and system that integrates cooling water and oil circulation using a single driving source, with a housing structure that enables efficient external air cooling of the oil. The pump features a cylindrical main body with isolated passages for water and oil circulation, driven by a central motor stator. The system includes a water pump module and an oil pump module, each with a cover, housing, and rotating impeller or rotor, that operate simultaneously to circulate cooling water and oil. External air cooling is achieved through a radiation fin on the main body, while the isolated passages enable efficient heat transfer between the water and oil.

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A lubricating oil composition for electric vehicle cooling systems, comprising a base oil and a fluorine compound, where the base oil is a mineral oil with a 40°C kinematic viscosity of 1-25 mm²/s, and the fluorine compound content is 3-30% by weight. The composition provides both lubricity and cooling performance, enabling efficient heat management in electric vehicle systems.

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A lubricating fluid for electric motor systems in hybrid and electric vehicles, comprising a lubricating oil and additives, including a succinimide dispersant, a sulfur-providing additive, and a detergent system, that provides improved wear protection, oxidative stability, and electrical conductivity while maintaining low viscosity. The fluid is formulated with a specific combination of additives that balance antiwear, friction, and corrosion performance while minimizing electrical conductivity.

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Electric motor with a cooling system for rotor and stator, comprising a housing with a stator and rotor on a shaft, an oil cooling circuit with an oil sump and pump, and a water cooling circuit connected to a cooler. The oil circuit passes through the housing space and has passages for oil entry and exit, while the rotor shaft has a wave channel forming a section of the oil circuit and oil injection openings for injecting oil into the housing space.

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A lubricating fluid composition for electric drives that prevents corrosion of electrical components while maintaining high efficiency in transmissions. The composition comprises 10-88% by weight of a low-viscosity synthetic oil, 0.1-5% by weight of a borated succinimide dispersant, 0.1-5% by weight of a 2,5-alkyl-thiadiazole compound, and 0.1-5% by weight of a phosphorus-containing additive. The composition has a dynamic viscosity of 0.8-4.0 mm2/s at 100°C and is suitable for use in electric motors, transmissions, and battery-operated vehicles.

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Heat transfer fluids based on at least partly re-refined lubricating oils for use in various systems, including cooling systems for thermal or electric motors, refrigerators, boilers, air conditioners, and thermal solar collectors. The fluids are formulated using re-refined lubricating oils obtained from used lubricating compositions, which have been subjected to one or more re-refining treatment steps to eliminate contaminants. The re-refined oils are characterized by their composition and physicochemical properties, which are distinct from virgin base oils. The fluids can be used as a coolant in mobile or stationary motor systems, and can be formulated with additives to promote compatibility with system materials.

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The paper presents the results of studies aimed at defining the effect of the cooling properties of oil lubricants used in various metalworking processes. The design and a brief description of the installation are given, which allows to obtain temperature-time, temperature-velocity dependencies of various liquids. The use of this installation gives the opportunity to select lubricants according to its cooling properties, depending on the temperature range required by the process. The assessment results of lubricant cooling properties at UZS-2 installation, manufactured according to the requirements of international standards ISO 9950, ASTM D6200 - 01 and ASTM D6482 06 are presented. The dependences of tribo-engineering properties of the tested oil lubricants on their cooling characteristics are found out. It is shown that with an increase in the temperature at which the maximum cooling rate of the lubricant is provided, its extreme pressure and anti-wear properties determined according to GOST on a four-ball friction machine increase.

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Efficient cooling design is a necessary condition for improving motor performance and extending motor life. This article outlines the current research status of high efficiency liquid cooling technology for high power density motors, including indirect liquid cooling, direct liquid cooling, and hybrid cooling. It analyzes and discusses the specific implementation methods, characteristics, and application scenarios of various cooling technologies. Finally, it summarizes the development trends and key technologies.

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Lubricating oil composition for electric drive units, comprising a base oil, a phosphite compound, a metal detergent, a viscosity index improver, and an extreme pressure agent, wherein the base oil contains a branched alkyl group with 3-20 carbon atoms, the phosphite compound has a sulfur-containing group, and the extreme pressure agent is a thiadiazole compound. The composition provides balanced scuffing resistance and copper corrosion protection for electric drive units, particularly gearboxes and motors.

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Lubricant compositions for vehicle engines that improve antiwear properties while reducing the content of conventional antiwear additives. The compositions contain diester additives of the formula R1OOC-R2OOC-R3, where R1, R2, and R3 are hydrocarbon groups, and conventional antiwear additives such as zinc dialkyldithiophosphates. The diester additives enhance antiwear performance while enabling lower levels of phosphorus-based and sulfur-based additives that can damage engine components and emissions control systems.

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Lubricating and cooling fluids for electric and hybrid-electric vehicle drivelines that provide improved durability of insulated magnet wires in electric motors. The fluids contain a detergent system providing at least 50 ppm metal and a base oil system including a lubricating viscosity base oil blended with an ester base oil, with a ratio of metal to ester groups of 70 or less. The fluids are compatible with insulation coatings on magnet wires, including polyamides, polyimides, and poly(amide/imide) materials, and maintain electrical properties while providing cooling and lubrication.

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In the cooling system of electric drive assembly, cooling fluid often only flows through the motor and controller, which cannot effectively dissipate heat from the motor bearings and reducers. This paper proposed a new water-cooled structure that can effectively dissipate heat from the motor and reducer. The structure at different parameters were simulated using CFD-FLUENT to investigate the temperature of the motor bearing seat and reducer end face. The simulation results show that when L1: L2=1:1, the cooling efficiency is the highest. In addition, research has shown that adding spoiler columns to the new structure will result in a more uniform distribution of fluid velocity and better heat dissipation effect.

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