Heavy Duty Trucking, January 2018

a high speed generator built into the compressor side of a turbocharger to generate electricity to charge batteries Hybridization through electric motors in the drivetrain or as some manufacturers like Dana Meritor and others are thinking about electric powered drive axles in a 6x2 arrangement Ryan Laskey vice president driveline and commercial vehicle engineering at Dana Inc sees 48 volt architecture lending itself to hybridization of on highway trucks as a bridge between diesels and pure battery electric vehicles We see axle mounted electric propulsion units possibly acting in a start up or boosting application with downsped drivelines he says That would take some load off the engine possibly opening the potential for lower horsepower engines or another source of tractive effort in a 6x2 setup Bear in mind that such a system would be used only for short periods of time as needed not run constantly so the 48 volt architecture would support that kind of application We havent discussed batteries here but the size and type of battery used with a 48 volt system will have a major bearing on how this advanced technology works There are several technology contenders including lead carbon nickel metal hydride lithium ion lithium polymer carbon nanotube and even lead acid Depending on the 48 volt method used it could consist of a 48 volt battery source and E E system one 48 volt battery source and one 12 volt battery source with two E E systems or one 48 12 volt battery source combination and two E E systems notes the TMC 48 volt discussion paper While a wholesale switch to 48 volts could take a decade some of the technology may be here much sooner than you think Eaton is working with a couple of major OEMs now and were tentatively targeting some of this technology for production in 2021 says Jacobs There are really no technical roadblocks to implementing it We want to ensure the technology is ready for the market and the market is ready for the technology Its a major change Major indeed especially when you consider the impact on the supplier side of the industry Still its all part of the evolution of the heavy truck powertrain and it should all prove beneficial in the long run even if it is expensive Theres opportunity ahead of us to harvest more energy as efficiently as possible from smaller or less polluting engines says Optronics Jenkins We need to understand the reason for the change and that the change is for the positive Its for our futures and for the environment its not just for the sake of change FUTURE ELECTRICAL HDT JANUARY 2018 64 WWW TRUCKINGINFO COM If the radiator could be moved to a side position on the truck with the big cooling fan replaced by several smaller electric fans you eliminate the need for a large relatively square front to the truck All the pumps and compressors we drive off the engine today could be replaced with electric pumps and located elsewhere on the chassis and controlled so that they operate only as needed That nearly eliminates the need for the drive mounts on the front of the engine while reducing the parasitic losses associated with turning compressors fans and pumps that not in use With electric air compressors or power steering pumps you energize them only when theres demand And that power comes not from the engine but the battery If you take a lot of that stuff away from the front of the engine it would give the OEMs a lot of freedom they never had before to redesign the front of the truck Jacobs says Taken to its ultimate potential as explained in the TMC paper its likely that wed see engine camshafts disappear replaced by electro mechanical valve actuators that would give very precise and independent control of the operation of the intake and exhaust valves to optimize the combustion process It could also facilitate a sort of internal EGR process where not all the spent gas is ejected from the cylinder before the next intake stroke eliminating the need for troublesome EGR valves and coolers and the associated plumbing Here are just some of the other potential innovations that will come with 48 volt electrical systems and the off boarding of current engine mounted components Smaller and lighter HVAC systems that can be packaged independently of the engine likely leading to a single set of evaporators and condensers rather than the separate cab and sleeper systems used today Integrated starter generator units likely built into the transmission can provide much more efficient power generation than current belt and pulley systems while being unobtrusively packaged Because the transmission is always turning while the vehicle is in motion it allows for energy generation even if the engine is not running as could be the case in coasting situations Electric turbo compounding could use Generator peal power of average commercial vehicle watts POWER DEMAND FROM THE AVERAGE CLASS 8 HIGHWAY TRUCK OVER A 100 YEAR SPAN OF TIME SOURCE TMC Theres opportunity ahead of us to harvest more energy as efficiently as possible from smaller or less polluting engines Mathew Jenkins Optronics International