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Numerical Analysis of the Influences of Wear on the Vibrations of Power Units

Goethe-Universität-Lars Hedrich
Robert Bosch GmbH-Yashwant Kolluru, Rolando Doelling
  • Technical Paper
  • 2020-01-1506
To be published on 2020-06-03 by SAE International in United States
Numerical Analysis of the Influences of Wear on the Vibrations of Power Units Yashwant Kolluru, Rolando Doelling eBike Department Robert Bosch GmbH Kusterdingen, Germany yashwant.kolluru@de.bosch.com rolando.doelling@de.bosch.com Lars Hedrich Institute of Informatics Goethe University Frankfurt Frankfurt, Germany hedrich@em.informatik.uni-frankfurt.de The prime factor, which influences vibrations of electro-mechanical drives, is wear at the components. This paper discusses the numerical methods developed for abrasion, vibration calculations and the coupling between wear and NVH models of drive unit. Wear is a complex process and understanding it is essential for vibro-acoustics. The paper initially depicts finite element static model used for wear calculations. The special subroutines developed, aids in coupling the wear equations, various contact and friction formulations to the numerical model. The vibration domain model initially, focuses on calculations of mechanical excitation's at the gear shafts, which are generated via a nonlinear dynamic model. Furthermore, the bearings are studied for the influences on its stiffness and eventually its impact on harmonics of the drive trains. Later, free and forced vibrations of the complete drive train are simulated via steady-state dynamic…
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Aero-thermal analysis of ventilated passage in a brake disc

Veermata Jijabai Technological Institute-Akshay Mhaske, Sampattakumar Gunadal
  • Technical Paper
  • 2020-28-0011
To be published on 2020-04-30 by SAE International in United States
In this paper, the numerical investigation of a brake disc is done for studying its aero-thermal behaviour and finding alternatives that perform better. In a disc brake, the heat generated due to friction has to be dissipated by one or the other modes of heat transfer. Out of the three modes of heat transfer, convection is to be maximized as others may cause deterioration of neighbouring parts. The disc is of ventilated type and hence the turbulence and mass flow rate through this ventilated area is to be optimized so as to improve the convective heat transfer coefficient. An in-depth study of various design changes previously done for improving heat transfer coefficient in ventilated disc is done and these changes are incorporated in the existing design. Various design combinations using different design tweaks for improving heat transfer coefficient are made and simulated in component testing like conditions, which are validated against previously done actual experiments. Total of 12 different design iterations were simulated and the one with the highest heat transfer coefficient was analysed in…
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Comparative Analysis of Thermally Induced Seizure Regimes between Accelerated Simulation Test and Long Term Vehicle Operation in Metal V-belt CVT

Honda R&D Co., Ltd.-Kenji Matsumoto, Tatsuya Tokunaga, Jun Mori
Tokyo City University-Yuji Mihara
  • Technical Paper
  • 2020-01-0907
To be published on 2020-04-14 by SAE International in United States
Honda is currently developing and operationalizing a measurement device that allows the state of lubrication to be understood by measuring the in-oil particle distribution. This is a new attempt to detect burn-in and abnormal friction in advance, thus making it possible to suspend actual vehicle tests before breakdown and investigate causes. Seizure was therefore simulated, and in-oil abrasion powder was examined. The results showed that a large amount of scale-shaped abrasion powder was produced due to fatigue during normal operation, while little scale-shaped abrasion powder was detected following the simulation test. This suggests that when a high-load test is performed in order to shorten the test time, the test does not simulate driving conditions in the market, because the state of the loads on the sliding surfaces differs from market conditions.
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Comparative Study on the Effects of the Tread Rubber Compounds on Tire Tractive performance on Ice

Virginia Tech-Hoda Mousavi, Corina Sandu
  • Technical Paper
  • 2020-01-1228
To be published on 2020-04-14 by SAE International in United States
Mechanical and thermal properties of the rubber compounds of a tire play an important role in the overall performance of the tire when it is in contact with the train. Although there are many studies conducted on the properties of the rubber compounds of the tire to improve some of the tire characteristics such as the wear of the tread, there is a limited number of studies that focus on the performance of the tires on ice. This study is part of a more comprehensive study to investigate the effect of rubber compounds on performance of the tire on ice. In this study three tires that are completely identical in terms of tire parameters (such as tire dimensions, treat pattern, tire structure, inflation pressure, etc., but have different tread rubber compounds have been investigated. Several tests have been conducted for the chosen tires in three modes: free rolling, braking, and traction using the Terramechanics Rig at TMVS at Virginia Tech. In this presentation we will only focus on the result for the traction tests. The…
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Modeling and Identification of an Electric Vehicle Braking System: Thermal and Tribology Phenomena Assessment

Siemens Industry Software NV-Thomas D’hondt, Bart Forrier, Mathieu Sarrazin
Università degli Studi di Firenze-Tommaso Favilli, Luca Pugi, Lorenzo Berzi, Riccardo Viviani, Marco Pierini
  • Technical Paper
  • 2020-01-1094
To be published on 2020-04-14 by SAE International in United States
A rapidly shifting market and increasingly stringent environmental regulations require the automotive OEMs to produce more efficient and low-emission electric vehicles. Regenerative braking has proven to be a major contributor to both objectives, enabling the charging of the batteries during braking on one side, and a reduction of the load and wear of the brake pads on the other side. The optimal sizing of such systems requires the availability of good simulation models to improve their performance and reliability at all stages of the vehicle design. This enables the designer to study both the integration of the braking system with the full vehicle equipment and the interactions between electrical and mechanical braking strategies. The present paper presents a generic simulation framework for the thermal and wear behavior of a mechanical braking system, based on a lumped parameter approach. The thermal behavior of the system is coupled back to the friction coefficient between the pad and the disc to assess its effect on braking performance. Additionally, the effect of wear and temperature on the generation of…
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Improved Wear Resistance of Austempered Gray Cast Iron Using Shot-Peening Treatment

Oakland University-Yu Liu, Gary Barber
Zhejiang Sci-Tech University-Weiwei Cui, Bingxu Wang
  • Technical Paper
  • 2020-01-1098
To be published on 2020-04-14 by SAE International in United States
In this research, ball-on-plate reciprocating sliding wear tests were utilized on austempered and quench-tempered gray cast iron samples with and without shot-peening treatment. The wear volume loss of the gray cast iron samples with different heat treatment designs was compared under equivalent hardness. The phase transformation in the matrix was studied using metallurgical evaluation and hardness measurement. It was found that thin needle-like ferrite became coarse gradually with increasing austempering temperature and was converted into feather-like shape when using the austempering temperatures of 399°C (750°F). The residual stress on the surface and sub-surface before and after shot-peening treatment was analyzed using x-ray diffraction. Compressive residual stress was produced after shot-peening treatment and showed an increasing trend with austempering temperature. In sliding wear tests, austempered gray cast iron had lower wear volume loss than quench-tempered gray cast iron before and after shot-peening treatment. The wear tracks were examined using scanning electron microscopy. Delamination and smearing were the main wear mechanisms on the gray cast iron samples.
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Development of JASO GLV-1 0W-8 Low Viscosity Engine Oil for Improving Fuel Efficiency considering Oil Consumption and Engine Wear Performance

Aichi Machine Industry Co.,Ltd.-Keisuke Yoshida
Nissan Automotive Technology Co., Ltd.-Satoshi Kawamura
  • Technical Paper
  • 2020-01-1423
To be published on 2020-04-14 by SAE International in United States
Engine oil with viscosity lower than 0W-16 has been needed for improving fuel efficiency in the Japanese market. However, lower viscosity oil generally has negative aspects with regard to oil consumption and anti-wear performance. The technical challenges are to reduce viscosity while keeping anti-wear performance and volatility level the same as 0W-20 oil. They have been solved in developing a new engine oil by focusing on the molybdenum dithiocarbamate friction modifier and base oil properties. This paper describes the new oil that supports good fuel efficiency while reliably maintaining other necessary performance attributes.
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Development of Ultra Low Viscosity 0W-8 Engine Oil

JXTG Nippon Oil & Energy Corp.-Shintaro Kusuhara, Yu Misaki
Toyota Motor Corporation-Kazuo Yamamori, Yuta Uematsu, Kazuyoshi Manabe, Itsuki Miyata
  • Technical Paper
  • 2020-01-1425
To be published on 2020-04-14 by SAE International in United States
Further fuel economy improvement of the internal combustion engine is indispensable for CO2 reduction in order to cope with serious global environmental problems. Although lowering the viscosity of engine oil is an effective way to improve fuel economy, it may reduce the wear resistance. Therefore, it is important to achieve both improved fuel economy and reliability. We have developed new 0W- 8 engine oil of ultra-low viscosity and achieved an improvement in fuel economy by 0.8% compared to the commercial 0W-16 engine oil. For this new oil, we reduced the friction coefficient under boundary lubrication regime by applying an oil film former and calcium borate detergent. The film former increased the oil film thickness without increasing the oil viscosity. The calcium borate detergent enhanced the friction reduction effect of molybdenum dithiocarbamate (MoDTC). By applying these technologies, an engine oil was developed which successfully achieved desired fuel efficiency and reliability. The developed oil also met the new JASO GLV-1 specification.
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Estimation of the Mechanism to Suppress Water Degradation of 1K Heat-Curing Epoxy Adhesive with High Durability

Aisin Chemical Co., Ltd.-Kazumasa Sakaguchi
  • Technical Paper
  • 2020-01-0227
To be published on 2020-04-14 by SAE International in United States
In recent years, structural adhesives have been used to improve the rigidity, shock resistance, etc. of joints, and the requirements for these characteristics are expected to expand further. However, heat, loads, water, etc. can become deterioration factors for adhesives, and the consequent loss of strength is known to occur. In this study, the author has focused on water absorption deterioration, considered as one of the largest deterioration factors for adhesives, and has succeeded in providing high-water resistance to a one-component(1K) heat-curing epoxy adhesive through the addition of appropriate additives. This adhesive exhibited no hydrolysis during the 14-day 70 °C, 100% RH deterioration acceleration test, and strength retention and cohesive failure rates of 100% have been confirmed. In this study, the factors that provide high durability to the adhesive are identified, and the mechanism of how these factors suppress water absorption deterioration has been estimated.
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Development of RC-IGBT with a New Structure That Contributes to Both Reduced Size of Power Control Unit and Low Loss in Hybrid Electric Vehicles

Toyota Central R&D Labs, Inc.-Hiroko Iguchi, Sachiko Kawaji
Toyota Motor Corporation-Koichi Murakami, Tasbir Rahman, Keisuke Kimura, Masaki Konishi
  • Technical Paper
  • 2020-01-0596
To be published on 2020-04-14 by SAE International in United States
In order to improve the fuel efficiency of Hybrid Electric Vehicles (HEVs), it is necessary to reduce the size and power loss of the HEV Power Control Units (PCUs). The loss of power devices (IGBTs and FWDs) used in a PCU accounts for approximately 20% of electric power loss of an HEV. Therefore, it is important to reduce the power loss while size reduction of the power devices. In order to achieve the newly developed PCU target for compact-size vehicles, the development targets for the power device were to achieve low power loss equivalent to its previous generation while size reduction by 25%. The size reduction was achieved by developing a new RC-IGBT (Reverse Conducting IGBT) with an IGBT and a FWD integration. As for the power loss aggravation, which was a major issue due to this integration, we optimized some important parameters like the IGBT and FWD surface layout and backside FWD pattern. As a result, it was possible to avoid the snapback characteristic (IGBT loss aggravation). In addition the substrate thickness was reduced…