ALT-POWER
TRANSFERRING POWER
FROM DIESEL TO ELECTRIC The next decade is going to be about moving across to new drivelines, to be compatible with alternative power sources, and a large amount of energy is going to be needed in transferring power from diesel to electric.
T
he migration across from internal combustion engine (ICE) powered drivelines to those using electric power to drive the wheels is going to happen, whether the preferred power source is hydrogen fuel cells or battery electric, or something else. If technology like hydrogen internal combustion engines take hold they will be able to use adaptations of existing diesel power trains. There are a lot of different aspects and layout options for an electric driveline and each one will have to be designed to suit a particular task. There may well not be one single solution for electrified trucks in Australia it may well be the case that a variety of systems and layouts will need to be employed. In recent years Dana has been moving ahead in this space anticipating the growth in demand for electric drivelines. These may not just be in new trucks, operators may seek to repower existing trucks with an electric driveline, as the economic and environmental climate changes. The company has been developing and acquiring the technology to be a major player in this space. As an indication of the growing interest in this area, Dana has recently opened the company’s largest facility of its kind in Europe in Åmål in Sweden to build electric motors for the vehicle industry, increasing, what it calls, ‘Dana’s ability to deliver clean-energy technologies and fully integrated e-Propulsion systems across all mobility markets.’ Of course, Australia is going to be lagging behind the developments in Europe, but we will be following more advanced countries down this route (Australia is a technology taker). This is a major transition of technologies and the process is going to take a long time as suppliers have to gear up and the industry
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POWERTORQUE January/February 2022
The Dana_Zero-8_Tandem eAxle.
needs to be aware of the novel technical challenges which will confront it.
AN ELECTRIC DRIVELINE At its simplest the electric driveline consists of some basic components. There is the battery which stores electrical energy, whether it comes from a charging station or an onboard hydrogen fuel cell is immaterial. A DC current goes from the battery to an AC/DC converter to produce an AC supply for the electric motor. From this electric motor, mechanical power travels down a driveshaft to a transmission. The transmission then processes the original mechanical power and torque into the right kind of torque for the drive axle to propel the truck along the road. The inclusion of a transmission is not necessarily the case, especially at the smaller end of the truck market. The electric trucks currently on sale in Australia, from SEA and Fuso, do not have a transmission, these are the simplest
drivelines with a direct drive from electric motor to rear differential. Another component supplier, Eaton is already developing transmissions where they are needed for the truck makers. “We have got some smaller two and four speed transmissions that can go behind electric motors,” says Graeme Weston, Business Unit Manager at Eaton. “We are integrating with electric motors and that’s a growing part of our business. Talking to some of the electric vehicle makers, we are finding it is hard to get the spread of ratios, in order to get the right torque for launch, but you also run the electric motor at a sweet spot, at a higher rpm. “Essentially you can downsize the motor, so you can get the torque multiplication for launch, with the advantage of going to a two-speed option, as opposed to a single speed, being that you can run a smaller electric motor. You can still get the torque, but then finely tune the other gear to get the most out of the rpm the motor runs at.” This is why the two-speed transmission
