Cutaway of Rotrex variable drive supercharger
Rotrak, a 50:50 joint venture between traction-drive specialist Torotrak and centrifugal supercharger producer Rotrex A/S, will introduce its variable drive supercharger system at the 15th Supercharging Conference in Dresden. The uniqueness of the Rotrak system lies in its variable-drive technology, which is claimed to eliminate lag and allow efficient operation throughout the engine's rpm range.
Torotrak engineering manager David Burtt explained the complexities and benefits of the system in this way:
Rotrak envisions its variable-drive supercharger system as one solution that will allow automakers to offer downsized engines without sacrificing driveability. With the market for pressure-charged engines expected to rise dramatically by 2016, Burtt suggests that the combined efforts of Torotrak and Rotrex A/S could pave the way for, "the emergence of a practical and cost-effective way to supercharge small gasoline engines."The need to reduce CO emissions is leading to downsized engines, heavily boosted by turbo- or supercharging. But while these engines easily reach high peak power and torque figures, they struggle to provide the required low-speed response. A fully integrated centrifugal compressor connected to the engine via a variable drive will achieve a unique combination of low- and high-speed performance with a highly cost-effective system.
[Source: Green Car Congress]