Electrical and Conventional Automobile Tribology: New Trends and Applications

Elektrikli ve Konvansiyonel Otomobil Tribolojisi: Yeni Eğilimler ve Uygulamalar

Abstract

Over 1 billion automobile moves in the traffic throughout the world and approximately 35 million new automobile is added to this number every year. This causes a great energy consumption and environmental pollution. Tribology defined as ''friction, wear, lubrication science and technology'' has a great importance in terms of automotive industry. Major part of the energy consumed in automobiles is used to create frictions or overcome the frictions. Likewise the most important factor determining the lives of automobile and their components is the wear occurred on the surface of the material and meant as unwanted material loss. Automobiles are like a wide gallery of tribological elements and they consist of a large number of tribological components having different movements and contact forms. In this study, tribological components in the automobiles are examined in a systematic way and a new window is opened in the automobile tribology in the light of the latest trends. Within the scope of the study, gains derived from engine, brake, clutch, drive train, lubrication, basic effects and material are evaluated depending on the fundamental data of tribology science. Hybrid and electric vehicles provide important gains in also tribological terms besides the benefits for ecological, economic energy use etc. These new vehicle technologies open highly productive working areas and new horizons for the tribologists. Here, high efficiency of electric machines (M/G) and advantages of electric vehicles in energy recovery (operable in generator mode, regenerative braking, making use of gravity, compliance with electromechanical battery systems etc.) are critical. Particularly in electric vehicles, tribology based noises are reduced to a large extent like mechanical, aerodynamic and road-tire contact. Apart from that, general tribological studies in automotive industry are conducted separately and/or interactively in design, manufacturing, usage, maintenance and repair fields. In manufacturing stages of automobiles; it will provide important gains like selection of materials with high machinability, formability and manufacturing capabilities, using manufacturing method and processes with low energy need; application of functional surface modifications and coatings; using manufacturing processes with low ratio of waste; expanding die manufacturing instead of machining; application of manufacturing just in time technologies etc. For usage stages of automobiles; it's required to develop and apply autonomous driving systems that minimize the driver's initiative to reduce driver errors and performance decreasing applications. In maintenance-repair stages of automobiles; developing and applying new maintenance-repair technologies, integrating protective maintenance applications with in-vehicle diagnosis system. Inclusion of instant situations of tire pressures, lubricants and bearings into on-vehicle diagnostic system. Tribology constitutes the important key technology to obtain high performance in providing the stability of vehicle dynamic under critical conditions; efficiency of air-conditioning system in the vehicle, acceleration and deceleration and ensuring ideal driving conditions. Designing philosophy of automobile components are changed through tribological approach. General aim in tribological design of the automobile components, in other words tribo-design and in selection of general parameters of the tribological system is directed towards optimization instead of maximization and minimization. As a result, tribology based studies constitute the major part of the research, development and innovation activities carried out in automotive industry today.

Özet

Otomotiv sektörü, günümüzde teknolojik açıdan öncü ve önemli bir çalışma alanıdır. Aynı şekilde “sürtünme, aşınma, yağlama bilimi ve teknolojisi” olarak tanımlanan triboloji de otomotiv sektörü için büyük bir ağırlığa sahiptir. Otomobillerin ve bileşenlerinin çalışma performansını ve ömürlerini belirleyen temel bileşenler, triboloji esaslıdır. Bu çalışmada otomobillerdeki tribolojik bileşenler; sistematik bir şekilde incelenerek, güncel çalışmalar ve yeni eğilimler ışığında otomotiv tribolojisine yeni bir bakış penceresi açılmıştır. Çalışma kapsamında otomobillerdeki motor, fren, lastik, aktarma organları, yağlama, termal etkiler ve malzeme açısından sağlanan kazanımlar; triboloji biliminin temel verileri esas alınarak değerlendirilmiştir. Ayrıca tribolojik açıdan önemli avantajlar sağlayan elektrikli taşıtlar, içten yanmalı motora sahip otomobillerle tribolojik açıdan karşılaştırmalı olarak analiz edilmiştir.