Engine downsizing is a trend within the automotive industry which is receiving considerable interest, due to the benefits of lower fuel consumption/cost and reduced emission pollutants while retaining sufficient performance. Technology developments to engine downsize include variable valve actuation and new methods for fuel injection and charging. One of the most cost effective methods is to increase engine charging using technologies such as turbo- and super-charging that allows the appropriate level of performance when required. The compressor for the charging system must be low cost, low noise, reliable, clean and efficient in order to meet the requirements of service. Positive displacement compressors, including the screw, are typically belt driven from engine, providing simplicity but lacking controllability and reliability. The alternative,mechanically-driven conventional radial turbo compressors are compact and efficient, but still not entirely independent of engine speed.
Advantages can be gained by having a boosting system entirely independent of engine speed. This may be achieved using an electrically driven charging system. However turbo- and super-charger systems do not lend themselves to electric drive. The TurboClaw® innovation, when electrically-driven, is particularly suited for using alongside a turbocharger in small engine applications because of low speed operation and low cost of manufacture.
In 2009, a TSB-funded project (REF:BS088J) to develop an electrically driven supercharger (EDS) based on TurboClaw® technology was awarded to DBS, AVL Powertrain UK, and Turbocam Europe. An EDS system was designed by DBS and manufactured by TurboCam. The compressor was then tested on a test bench and was subjected to standard drive cycle conditions. This real test data was utilized by AVL, along with engine test data to produce predicted torque curves of multiple charging arrangements. This project was successfully completed in October 2010. Engine test bed validation will be performed in 2011.
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| TurboClaw® EDS provides up to 35% Torque improvement over the Turbocharged and Naturally Aspirated 1.0L engine at low speeds. | |