Engine and Drivetrain Special Program on Electric Vehicles

Session 1K | Engine and Drivetrain Special Program on Electric Vehicles I
Monday, May 4, 2020 | 8:00 am - Noon | Room Michigan 1

Session Chair: H. Ghaedina, Gehring Group, Farmington Hills, MI
Session Vice Chair: B. Lotfi, ExxonMobil, Baytown, TX

8:00 - 8:30 am
Study of Vibration Wear in Plug-In Hybrid Vehicle Engine
by Weizi Li, Shell (Shanghai) Technology Limited., Shanghai, China, Yunfei Wang, Qinhao Fan, Zhi Wang, Tsinghua University, Beijing, China, Robert Taylor, Shell Global Solutions UK, London, United Kingdom

At times plug-in hybrid vehicle (PHEV) is powered only by electricity, hence engine does not operate and is not lubricated well, subsequently is under severe stress of vibration on road. Thus, this study initiated by Shell and Tsinghua University is aimed to identify possible lubrication challenge in such case. As first step, vibration data acquisition from a PHEV is done through dynamometer and real driving, amplitude and frequency characteristics of engine vibration are analyzed. Next, in order to simulate extreme conditions in pure electricity mode, the PHEV engine is installed on a specifically designed rig to produce accelerated aging resulting from vibration. Lastly, engine is teared down for measurement and rating. The test results suggest fretting wear can be intensified in PHEV as we find corrosion-like wear pattern on the journal bearing close to fly wheel and scratches which indicated abrasive wear on con-rod bearings.

8:30 - 9:00 am
Thermal Management in Battery Electric Vehicle (BEV)

by Dean Tomazic, FEV North America Inc., Auburn Hills, MI

In this presentation, an insight into EDU and battery thermal management techniques and challenges will be described in greater detail. Furthermore, an in-depth review of the advanced direct cooling techniques of EDU and Battery will be outlined. Additionally the advancements in integrated power electronics and high voltage conductors and the associated thermal management techniques will be presented. Towards the conclusion, the presentation will outline the future trends in EDU, power electronics and battery technology and how the thermal management is becoming a critical step in system design and optimization.

9:00 - 9:30 am
A Model for Prediction of Power Losses in Electric Vehicle Transmissions

by Amir Kadiric, Joseph Shore, Imperial College London, London, United Kingdom

Transmission power losses provide a major contribution to the overall energy loss in an electric vehicle. In relative terms, this contribution is much larger than in an equivalent IC-powered vehicle. Consequently, the ability to predict and minimise transmission losses provides an important avenue for improving the efficiency and thus extending the range of EVs. This paper describes a model for prediction of EV gearbox efficiency including the influence of lubricant properties. The approach utilises a thermally-coupled gear lubrication model to accurately predict gear teeth friction as well as bearing and churning losses. The model uses experimentally obtained lubricant rheology parameters as input which allows it to differentiate between different lubricant formulations in terms of overall gearbox efficiency. Results are presented to illustrate the trends in transmission losses with a selection of oils and over a range of operating conditions typical of EV transmissions.

9:30 - 10:00 am
Test Facility to Investigate Function and Efficiency of the Speed4E Hyper-High-Speed Electromechanical Powertrain

by Lukas Pointner-Gabriel, Hermann Pflaum, Karsten Stahl, Technical University of Munich, Garching, Bavaria, Germany

High-speed transmission concepts are increasingly used in BEVs (battery electric vehicles) to improve the power density of the whole drivetrain. Within the joint-project "Speed4E", an innovative drivetrain prototype capable of input speeds of up to 50,000 rpm is developed and will be installed in a BEV for road driving experience. In order to evaluate the overall function and efficiency of the drivetrain, extensive investigations on a test rig are planned. For this purpose, the powertrain is operated on a modern test rig and equipped with a variety of sensors. Especially the required high-precision input torque measurement at the above-mentioned speed range represents a major challenge. The presentation gives a detailed insight on the developed test rig concept as well as the used measurement methods.

Session 2K | Monday, May 4, 2020 | 1:30 - 6:00 pm | Room Michigan 1

Engine and Drivetrain Special Program on Electric Vehicles II

Session Chair: H. Ghaedina, Gehring Group, Farmington Hills, MI
Session Vice Chair: B. Lotfi, ExxonMobil, Baytown, TX

1:30 - 2:00 pm
Hybrid/Electric Powertrain Components & Tribology

by Raj Chandramohanan, Tyler Garrard, BorgWarner Inc., Arden, NC

It is clear that the future of transportation will include more electric content. There are multiple factors leading to this conclusion including, lowering or eliminating direct GHG emissions, better transient response and future emissions regulations. BorgWarner Turbo, Emissions & Thermal Systems has electrified and hybrid products which include a motor and/or a generator including the Organic Rankine Cycle expander/generator/pump for passenger car and commercial vehicle markets. Each technology is unique in how it interfaces with the combustion engine in saving/recuperating energy. This paper will cover the fundamentals of how these products function and the distinct challenges they pose for lubrication and tribology.

2:00 - 2:30 pm
Dielectric Fluids for Use in Hybrid and Electric Vehicles

by Bethan Warren, Croda Europe Ltd., East Yorkshire, Goole, United Kingdom, Gareth Moody, Croda, New Castle, DE

With new driveline configurations comes new challenges for lubrication. Many different configurations have been conceived which use different methods of cooling and lubrication. Gear lubrication needs to ensure high efficiency and low wear. Clutch lubrication requires smooth transitions with high durability of the fluid. These conditions could be controlled by base fluid or additive technology. This talk will discuss the excellent thermal properties of esters and how they could be used to both cool and lubricate. It is also possible that they could be used to cool sensitive components such as battery packs, regulating temperature and allowing better efficiency.

2:30 - 3:00 pm
Ultra-Low Viscosity Synthetic Fluids for Electric Vehicles (EVs)

by Babak Lotfi, ExxonMobil Chemical Company, Houston, TX

Government regulations have been pushing automotive industries to lower CO2 emission, which shifted many original equipment manufacturers (OEMs) toward electric vehicles (EV) design. New hardware design along with interest for using lower viscosity fluid for improving energy efficiency demands for EV/driveline fluid development with superior properties for electric vehicles (EV). Base oil plays a critical role in lubricant properties. In this work synthetic base oils have been studied and compared with mineral base oils. Tribological properties, energy efficiency, thermal management, etc. have been presented in this work. Results demonstrate an excellent performance and durability of synthetic molecules comparing to mineral base oils for developing EV fluids.

4:00 - 4:30 pm
Lubricant & Greases Solutions for the Whole Electrical Vehicle Drivetrain Including the Thermal Managment of Batteries

by Torsten Murr, Shell Global Solutions Germany, Hamburg, Hamburg, Germany

In 2019 more then 1.0 mio pure electrical vehicles has been produced, including hybrid vehicles the total production of electrical units is above 5 mio. In addition to the typical PasCar appl, electrical systems are being designed for LD-, HD Truck and Off Hway equipment. Even the highest electrical grade of PTs demands lubes solutions; for red.gears and e-axle systems dedicated trans fluids, for bearings dedicated greases and for battery cooling dedicated liquids with fluid volume from 0.5 to 4.0 l.In red. gear appl. the fluid does not get in contact with the electr propolsion system & only need to fulfill traditional hardware requirements. The wet E-Motor design, needs to consider chem & electromagnetic interactions of the fluid and the hardware components. For the new fluids new test method and screening tests need standardized, i.e Dielectric Breakdown, resitivity. In the area of Thermal management alternative fluids need to be qualified for immersed cooling with test methods describing power density & heat conductivity.

4:30 - 5:00 pm
Effects of Lubricant Additives on Copper in Soaking Test

by Torsten Murr, Shell Global Solutions GmbH, Hamburg, Germany 

Copper materials are widely used in automotive transmissions. Transmission fluids are required to protect these materials for extended time. This study will focus on the effects of common additives on copper in an extended soaking test. End of test (EOT) fluids are analyzed for leached copper and changes in chemistry. EOT coupons are analyzed with energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) to uncover underlying mechanisms. The learnings are then applied to formulate additive packages that provide superior copper protection.