Torotrak Technology Supports Volvo-led Flywheel Hybrid Project

Volvo’s project, part-funded by the Swedish Energy Agency, will bring together Torotrak’s variable drive technology and Flybrid Systems (UK) flywheel technology, working with SKF of Sweden and Volvo Powertrain. In addition to the mechanical hybrid projects that Torotrak is already working on as announced on 25 May 2011, this will provide another powerful opportunity to demonstrate the contribution that mechanical hybrids can make to reduce emissions and improve fuel economy, considerably more cost effectively than electrical hybrid solutions.

Torotrak chief executive Dick Elsy said: “We sense real momentum in the rapidly growing markets for efficiency-enhancing devices to reduce CO2 emissions. The industry needs cost-effective hybrid solutions and using a Torotrak variable drive transmission in conjunction with a mechanical flywheel has demonstrated the capability for double-digit improvements in fuel economy.”

In a statement issued by Volvo Car Corporation (VCC) Derek Crabb, Vice President VCC Powertrain Engineering, said: If the tests and technical development go as planned, we expect cars with flywheel technology to reach the showrooms within a few years. Flywheel technology is relatively cheap. It can be used in a much larger volume of our cars than top-of-the-line technology such as the plug-in hybrid. This means that it has potential to play a major role in our CO2-cutting ‘DRIVe Towards Zero’ strategy.

Torotrak’s compact CVT, part of its portfolio of proven traction drive technologies, has emerged as an effective transmission solution in flywheel-based mechanical hybrid systems. Compared to conventional electric hybrid systems, mechanical flywheel hybrids reduce the number of inefficient conversions during the recovery and re-use of braking energy. Instead of converting kinetic energy into electricity to be stored in an expensive battery pack, energy is stored in a high-speed flywheel with power transfer controlled by a compact CVT.

Mechanical hybrids can also be used to boost the low-end torque of downsized engines and can provide immediate torque for vehicles with stop-start strategies.