**1. Introduction**

Modern automobiles have made a significant contribution to the growth of society and humankind. Automobile vehicles and power train technology refined over the century of focused hard work by automobile engineering and scientist. Modern internal combustion engine propelled automobiles have satisfied multiple needs humankind in everyday life. It is difficult to imagine a world without automobiles in the present time [1]. The contribution of bearing to enhance the performance of automobiles is also immense. Bearings play's a critical role in the enhancement of any rotating systems performance by bearing loads and facilitating the load transfer

with minimum friction in addition to other functions. All rotating components of automobile systems require bearings to do its functions appropriately. Bearings improve the performance of the automobiles by supporting heavy loads and reducing friction. Major automobile sub-systems where bearings are implemented are internal combustion engines, transmissions, wheels, steering, pumps, and other electrical systems.

However, the popularity of automobiles, population density in the urban areas as well as rapidly growing urbanization has negatively impacted the environment. It raised health-related concerns to humans as well as other habitats. Internal combustion engines played the critical role of being prime mover for automobiles however, it is also a major source of pollution in urban areas due to the burning of fossil fuels and its by-products like CO2, NOx, etc. In recent times focus on emission control from regularity bodies, country specific laws are increasing which is pushing researchers to look for solutions beyond internal combustion engines. In recent times electric powertrains, hybrid powertrains have already proven to be the strong alternatives to conventional engines.

#### **1.1 Mega trends in automotive industry**

Present time, the global automobile industry is focusing on clean transportation solutions including hybrid and battery electric drives. Automobiles are typically considered person-driven, personal transportation internal combustion engine (fossil fuel) propelled and independently operated transportation medium. In present times automobiles (passenger vehicles) are majorly part of personal transportation, however, incoming times the way automobiles are being utilized in practice is transforming toward shared mobility, autonomous vehicles.

The automobile industry is experiencing a major technology shift. Connected, Autonomous, Shared, and Electrified (CASE) are major technology trends in the automobile utilization and technology development (**Figure 1**).

Shared mobility is more of productive utilization of vehicle and related technology which connects vehicle or operator via internet-based communication for sharing the vehicle. Basically, vehicle ownership and utilization are extended for more productive utilization vehicle. Modern information technology, internet, and availability of electronic hardware making it feasible to ensure vehicle to vehicle, vehicle to device communication, and improve vehicle utilization to improve the uptime of vehicles. Modern automobiles are expected to utilize to its maximum potential, so it is becoming imperative to monitor the health of the system in real-time.

**Figure 1.** *Mega trends in automobile industry.*

#### *Role of Bearings in New Generation Automotive Vehicles: Powertrain DOI: http://dx.doi.org/10.5772/intechopen.94222*

The electrification of the powertrain is another megatrend in the automobile industry. The electric vehicle powertrain is a major shift from fossil fuel-based prime mover (engine) to battery operated electric motors as a prime mover. Electrified vehicles are more efficient, less polluting making it a more transportation friendly solution. Electrification of powertrains is a major technology shift in which the propulsion of vehicles needs a lesser number of rotating parts as well as it simplifies the complete powertrain. Electric powertrains operate at lower cost as well.

In the present time, commuting to work in dense traffic is putting additional stress on vehicle operators and waste of precious productive time. Autonomous operation is the solution to these new challenges. Automobiles are using more electronics hardware than ever before due to these added functionalities. Driver assisted operation as well as complete autonomous drive powertrains are implemented in practice in modern automobiles. Real-time health monitoring of vehicle is important for the trouble-free operation as well as the safety of passengers in modern era vehicles.

As the automobile powertrain technologies are changing it is also percolating to critical components/subsystems like bearing. Modern vehicle bearings are far refined and technologically superior compare to traditional automobiles bearings. They are having multiple additional functionalities over the primary bearing functions. This chapter is about understanding the role of bearings in modern automobiles vehicles to achieve the mega technology shift in the automobile industry. The subsequent text introduces bearing technology research focus areas like reliability improvement, power-dense solutions, integrated functions, friction optimization, sealing/lubrication solutions [2], adoption of sensors, and also special applicationspecific eMotors bearings.

#### **1.2 Modern automobiles powertrains and its significance**

Modern automobile powertrains are working on the same engineering principles however, they are having far superior performance compare former powertrains. Modern powertrains are an integrated mechanical, electrical and electronics system to achieve the objective of lesser emission, better fuel efficiency, and higher overall efficiency. The modern powertrain can be classified into two major categories: Hybrid powertrain and battery electric powertrain.

Hybrid powertrains are having dual power sources like internal combustion engine and motor + battery arranged in multiple layouts like parallel, series, balanced, etc.

**Figure 2** is a typical layout of a hybrid powertrain. It can be observed in the figure that the complete powertrain is having all the systems of a conventional powertrain including an internal combustion engine, transmissions and additionally it is also having a battery and motor to support the vehicle propulsion.

In a hybrid powertrain number of bearings are more compare to the conventional powertrain. The bearings are used in the engine, transmission, motors, and transfer case. The hybrid powertrains are having more rotating parts however, this powertrain runs efficiently as all special events in operations like peak power requirements are fulfilled by the battery powered electric motor.

Full battery-electric vehicle powertrains are simpler in construction and having lesser rotating components. Battery electric vehicle powertrains are also having multiple configurations like traction motor + transmission, independent in-wheel motors for each wheel, etc.

**Figure 3** is a typical layout of a battery-electric powertrain, in which it is having a floor-mounted battery pack and traction motor drive for driving the wheels. Compare to conventional ICE vehicles this layout is simple and efficient. A lesser

**Figure 2.** *Typical hybrid powertrain layout [3].*

**Figure 3.** *Typical full battery electric powertrain layout [4].*

number of rotating parts means there are lesser possibilities of parts damage due to wear and tear and hence the system life is higher. This is one of the reasons Battery Electric vehicles are claimed to have higher life as well as OEMs offers longer warranty period. However, electric vehicles are having other challenges like higher speed, higher operating temperatures of parts, and risk of fire due electric system. It is important to mention here that batteries used in electric vehicles need proper cooling to operate at prescribed temperature limit to have extending time for battery discharge as well as minimizing other risks.

Refer **Figure 4**, which is indicating the battery packs construction in battery electric vehicles and its stacking, connection to electric motors.

**Figure 4.** *Typical battery pack in battery-electric powertrain [5].*
