Transmissions – Embracing Today

Transmissions – Embracing Today

Decoding Technology April 2020 Transmissions Embracing Today
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Techniques to transmit power to the wheels in a vehicle have changed significantly with the new mobility paradigms. The types of transmissions are ingeniously evolving and adapting to cater to this changing ecosystem. The ecosystem for an autonomous vehicle, shared mobility, electric mobility, XEV or a flexible platform is different from that of the conventional vehicles.

The fossil fuel powered-vehicles were coupled to a variety of transmissions based on the application, and end user demands. The early days of mobility and pretty much for a long time after, were using manual transmissions that progressed to automatic, semi-automatic, dual-clutch and multiple combinations. These transmissions were coupled to the prime mover and designed to operate in complex terrains, hostile environment, varied operation & load cycles and driver behaviours.

In conventional mobility, the prime mover plays a significant role in determining the deployment of the type of transmission that is being coupled for providing power to wheels in a vehicle platform. The powertrain, coupling of a prime mover with the transmission, influences the user experience satisfaction level, vehicle driving behaviour, fuel efficiency, tail pipe emissions and eventually the carbon footprint of any vehicle. Mainly, powertrains have been using fossil fuels ranging from gasoline, diesel, bio-diesel, CNG, LNG and the like.

MOBILITY PARADIGMS

In the new age mobility paradigms, vehicle specifications are different though few of the conventional specifications have an overlap. Most of these vehicles are operating in micro markets, on predefined routes and city centre perimeters. Few e-mobility applications are catering to expressways’ consumers and suburban driving, but most of the others are operating at low speeds, non-hostile terrains, regulated loads and time periods.

Powertrains in such cases are not subjected to extremes unlike in mature conventional mobility. This is an apt transition window for redesigning transmissions in this new ecosystem. This window provides a superb opportunity for use of a variety of materials that cannot be used in otherwise harsh operating environments. In any case, the usage of copper is much higher and at least twice or more, compared to conventional transmissions. The use of lubricants, thermal management and weight are better manageable in this paradigm. This is also a reset in reviewing the recycling techniques and ELV regulations.

The operating cycles in e-mobility see higher loads at launch, braking and regenerating. Variation and peaks during accelerating and decelerating are much higher with expectations of a quicker response to the vehicle system controller. During the remaining cycle it is almost steady load management. The transmission becomes an important peg in energy management in these applications. To manage regenerative energy, the controls, software protocols and architectures are more complex than conventional transmissions.

The newer paradigm orientation is around more electronics, battery and software. The ease of scalability is lot higher in these transmissions since the prime mover is the e-motor. The variables in e-motors are the architecture and type of technology. As such, the turnaround time in manufacturing and design delivery is quicker compared to the current state. For sure, in some XEV powertrains, the complexity of manufacturing is higher.

CONVENTIONAL TRANSMISSIONS

Though transmissions of new mobility paradigms are changing fast, conventional transmissions are very advanced and can cater to almost all mobility and cargo carrying demands. The evolution of technologies and techniques – mechanical, electronics, tribology, thermal management, communication protocols, innovative materials and software – have catapulted transmissions of the new paradigm. This leap to ‘embrace today’ has been possible due to decades of research and development, and engineering over the past decades.

Transmissions in conventional and new-mobility paradigms will be experiencing that interesting inflexion in the foreseeable future. They will however, co-exist, and naturally draw perimeters of operation to cater to consumer likes and dislikes to maintain their sustainability.