Torotrak will head the new Flybus programme with two consortium partners, Ricardo UK and Optare. Allison Transmission, a manufacturer of medium- and heavy-duty automatic transmissions for commercial vehicles, will also be involved, supporting the project with hardware and integration expertise.
Flybus consortium will utilise Torotrak’s patented Continuously Variable Transmission (CVT) technology together with a high-speed composite flywheel for energy storage which has been developed by Ricardo UK, and which is known as Kinergy. Both technologies have already undergone development as part of a flywheel-based mechanical hybrid KERS which has been designed for use in motor sport. The mechanical hybrid system will offer the commercial vehicle sector a low cost opportunity to cut CO2 emissions and deliver fuel efficiency savings of 20%.
The Technology Strategy Board is to provide GBP0.5m for the Flybus research programme as part of its low carbon vehicles initiative. The aim is to demonstrate a flywheel-based mechanical hybrid system in an Optare eco drive solo bus and to confirm the benefits of mechanical hybrid systems, effectively KERS-based technology, for fitment as original equipment in new commercial vehicles and, also as a retrofit system for updating existing vehicles. The consortium plans to demonstrate the new low emissions and high fuel efficiency vehicle to bus companies, fleet operators and regulatory bodies both in the UK and beyond.
The demonstration project will focus initially on installing an existing Torotrak CVT and Ricardo supplied flywheel in the Optare Solo bus, connecting the mechanical hybrid system directly to the Allison automatic transmission already fitted to the vehicle as standard equipment. The majority of the application, integration, development and test work will be undertaken by Torotrak in partnership with Ricardo, while Optare and Allison – providing, respectively, the test vehicle and an Allison 2000 Series transmission hardware together with control integration support – will also offer their series manufacturing expertise.
Roger Stone, engineering director of Torotrak, said: “Simulation work by Torotrak, based on an Optare Solo bus and using the readily available 60KW system with 400kJ of energy storage capacity proposed for this first demonstrator, produced fuel savings of 20% over the official UK bus test cycle.
“In this initial project, the CVT and flywheel hybrid system will be applied to the vehicle’s driveline through the existing and previously unused Power Take-Off (PTO) facility incorporated within the standard Allison automatic transmission. Further simulation shows that an optimised system, using a 110KW system with 1MJ energy storage capacity, will produce further significant improvements in fuel savings over the same test cycle.”
