**2. Role of bearings in modern powertrains**

In modern powertrain, bearings are utilized not only for primary functions i.e. supporting the load and reducing the friction but also bearings are used with multiple other integrated functions like signal transmitting device on the motor, rotor positioning sensing bearings, etc.

In conventional powertrain bearings, functions are limited to its primary functions to support operating load on the shaft and facilitate the torque transfer smoothly.

Additional functions like lower the noise, the vibration of the system, and providing stiffness to the shaft system are few of the expected functions of bearing in the powertrain.

However, modern powertrains are having different requirements from the bearing considering constrains like lower weight, space as well as demanding operating conditions includes higher temperatures, speeds, inability to lubrication as well as longer service intervals, or no service for the design life of the system. The role of bearing is changing in modern automobiles. This demanding operating requirements putting immense pressure on bearing performance and achieving the desired specifications of the bearings. The role of bearing is moving from shaft support component to system solution to achieve multiple performance parameters in the intended aggregates. Bearing plays the role of catapult for the system health monitoring utilizing the vibration signature on bearing for identifying, predicting, and proactively preventing the potential breakdown of the system. The modern electronics hardware and miniaturization of the sensors facilitate integration pf the same with bearing to achieve many other intended functionalities.

Battery electric powertrains run at higher rotational speed and having a higher operating temperature. Being an electric system ensuring the lubrication to rotating parts is one of the major challenges. Hence, maintenance-free silent operation is one of the critical technical requirements for the bearings. The bearing design must fulfill the criteria of high-speed operation, lower NVH characteristics, high-performance lubrication, and robust sealing to retain the lubrication inside the bearing as well as protecting the bearing raceways from foreign contaminations.

Modern powertrains, particularly motors operates at a higher rate of acceleration as well as decelerations and to facilitate the same bearing design should be capable to handle the acceleration requirements. Inappropriately design of bearings can experience the functional as well as reliability issues in the system which may leads to system breakdown or reduced life the powertrain or also invite unwanted services of the system.

Bearing load carrying capacity is required to be higher considering the higher power of the prime movers and availability of less space due to lower weight expected from the system. The design of bearing from geometry, material selection, and manufacturing process plays a critical role to achieve higher load carrying *Role of Bearings in New Generation Automotive Vehicles: Powertrain DOI: http://dx.doi.org/10.5772/intechopen.94222*

**Figure 8.** *Conventional ICE automatic transmission [6].*

**Figure 9.** *Traction motor EV powertrain.*

capacities in smaller envelope dimensions. The reduced the size of bearings facilitate lower overall system weight.

Bearings are playing a mission-critical functions in modern automotive powertrains. A deeper understanding of applications and expected functionalities play a crucial role to design of appropriate bearing for the modern automobile systems.

**Figure 8** illustrates the internal combustion engine vehicles' conventional transmission. It can be observed that bearings in this transmission are having comparatively different technical requirements. The bearings are well lubricated, having comparatively lower speeds of operation.

**Figure 9** is one of the EV power train configuration of modern electric vehicle transmission. Compare to conventional IC Engine vehicles the transmission layout is simpler in modern electric automotive vehicles. However, technical specifications and performance requirements of bearings are demanding.
