Torotrak Group’s latest technology and product developments to be shared at prestigious industry forum on automotive transmissions and hybrid drives in Berlin (7-10 December 2015)
Low carbon vehicle technology company, Torotrak Group, will present its solution to the conflicting demands of increased urban transport capacity and improved inner-city air quality at the forthcoming CTI transmissions and drives conference in Berlin (7- 10 December 2015). With developing and established markets alike searching for a cost-effective means of improving environmental performance in this area, Torotrak’s research and test experience indicates that using a mechanical KERS (Kinetic Energy Recovery System) to hybridise a bus dramatically reduces cost in comparison to a conventional battery hybrid system.
“Increasing population density in the established markets and growing urban transport needs in developing countries are creating acute pressures for a cost-effective but environmentally aware solution,” explained Tobias Knichel, Torotrak’s Business Development Director. “Our Flybrid® mechanical flywheel system is around a quarter of the cost of traditional battery hybrid technology and is ideally suited to the start-stop urban cycles experienced by public transport vehicles.”
In a paper titled, ‘Developing a cost efficient flywheel hybrid system for city buses’ Knichel will share Torotrak’s experiences of the systematic development and validation of its bus KERS and detail the route from prototype to volume manufacture. The presentation – which is scheduled for Session O of the symposium on the Wednesday afternoon – will focus on the application of the technology to a Wrightbus StreetLite Midi bus which has been running in public service since Q1 2015.
“One of the greatest challenges was to prove the safety of the system; because the safety margins of our flywheel technology are very high, it is very difficult to trigger a failure in either the cyclic fatigue or the single overload cases,” said Knichel. “The Flybrid KERS for buses has a design life of 1,000,000 (one million) km and 8,000,000 (eight million) charge/discharge cycles – effectively equivalent to the working life of the vehicle to which it is fitted.”
Torotrak’s Flybrid KERS uses a high speed flywheel to capture energy that would otherwise be lost as heat in the brakes when the bus is decelerating. This stored energy is then transferred mechanically back to the wheels and used to accelerate the vehicle, offering significant savings in fuel consumption, CO2 and other harmful emissions by reducing the engine power required to propel the vehicle.
“Being a purely mechanical system, Flybrid KERS avoids the inevitable losses that occur when battery-based systems change energy from one form to another, for example mechanical to AC, to DC, to chemical, and back again,” Knichel explained. “Additionally, it overcomes environmental issues regarding end-of-life disposal of batteries containing rare earth metals or acids.”
The cost of the system is also much lower than a full battery electric hybrid, meaning that operators should achieve faster payback times: “Target operator payback is within five years” confirmed Knichel.
Underlining the breadth of Torotrak’s low carbon technology portfolio, the company will present a second paper at Berlin, entitled “Low-cost developments in full-toroidal variator technology”. Chris Gaskell, Design Engineer, Concepts and IP, will firstly announce details of a family of value-engineered Torotrak variator modules being prepared by Univance, which target several of Torotrak’s strategic applications.
In addition to this, Gaskell will reveal two innovative Torotrak technologies for low-cost, high-efficiency variable drives. These low-cost developments were initially piloted for Torotrak’s V-charge variable supercharging technology, but scale well for use in other applications. Further information on these technologies will be released to coincide with the symposium.
Flybrid Bus Kinetic Energy Recovery System
Tobias Knichel, Director of Business Development at Torotrak Group