he majority of electric vehicles are currently equipped with a single speed, so there are clear implications for the next generation of electric vehicles,” says Antonov’s business development manager David Paul. “Our analysis shows that with a single speed gearbox there is significant variation in drive cycle efficiency, whereas a multispeed transmission tends to be more consistent with better overall cycle efficiency.”
Antonov has been invited by the Technology Strategy Board (TSB) to present its findings at the UK’s leading low carbon vehicle event LCV2011 being hosted by Cenex this week at the Rockingham Motor Speedway in Corby, Northamptonshire. The TSB has helped fund several transmission research and development projects with the company’s involvement.
“The results are consistent with the multispeed transmission keeping an electric motor operating in its peak efficiency range,” says Paul. “Inevitably, there is a compromise with a single speed gearbox particularly in terms of low speed acceleration, hill climbing and high speed cruising. The 10 per cent step change improvement in efficiency can be achieved with just two ratios, but technical compromises remain in other areas. Three or more ratios are better, delivering additional improvements in performance and refinement as well as efficiency, with each additional ratio providing small incremental gains in cycle efficiency.”
Antonov has developed its latest analytical tools, which use sophisticated computational modelling, to help demonstrate the performance and efficiency benefits of its powershift multispeed transmission to electric vehicle manufacturers. It means the company can determine the ideal motor and transmission combination, as well as optimising the gear ratios and final drive ratio for any given electric vehicle application. The analysis supports real world vehicle trials.
Antonov is supplying Smith Electric Vehicles, the UK’s leading manufacturer of commercial EVs, with a prototype of its multispeed transmission for a TSB funded research and development project. The ‘E-Van’ electric vehicle demonstrator is based on Smith’s Edison 3.5 tonne delivery van, with Antonov’s 3-speed transmission currently being installed for test and evaluation.
Antonov’s multispeed transmission was first evaluated in a Jaguar Limo-Green research vehicle as part of a consortium project with Jaguar Land Rover and MIRA. This research and development project was also part funded by the TSB.
Now looking at a wide range of vehicle applications, particularly commercial vehicles, Antonov says the technology with its seamless shift quality has strong potential for further development as a 4 or 5-speed transmission, with virtually the same packaging. The design of Antonov’s powershift electric vehicle transmission is such that additional ratios can be easily added. It is also scalable to different classes of vehicle ranging from family cars to light commercial vehicles, taxis, delivery trucks and public transport buses.
Antonov has received two major innovation awards for the development of its multispeed transmission. In November 2010 it received the Innovation Award for Transport from theInstitution of Engineering and Technology. And in June this year it received an IDTechEx technology award for the most significant global electric vehicle development over the past two years.
There has since been significant interest in the technology from a number of potential partners for a variety of applications. Further information on Antonov is available at www.antonovplc.com. Further information on the Cenex LCV2011 event is available at http://www.lcv2011.co.uk