Thursday, 4 September 2014
Electric turbos for diesel and gasoline engines
An electrically controlled turbocharger (ECT) developed by EcoMotors International Inc. of Allen Park, Michigan can be use on both gasoline and diesel engines.
According to executive chairman Don Runkle EcoMotors has built 2.5kW and 5kW turbochargers for use of 300bhp engines.
He claims to have a couple of potential partners in the turbo business who want to build it.
We hope to get a turbocharger for ourselves as well as for our customers”, he said.
EcoMotors developed the electric turbocharger on the back of its own opposed-piston, two-stroke diesel and gasoline engine (opoc) developments.
Turbocharging is essential for a two-stroke gasoline engine to achieve high (over 90 per cent) levels of scavenging efficiency to achieve a clean combustion volume. With diesel engines both superchargers and turbochargers can be used, Runkle noted., adding that the IP for EcoMotors’ design has been tied up.
The EcoMotors design combines a mechanical compressor and exhaust driven turbocharger into a single mechatronik solution by placing a high-speed motor between the compressor and turbine wheels. The result is an independently controlled air and energy handling system in a small, low cost package.
The direct-mounted electric motor assembly complements conventional turbocharger technology and creates an additional tuning parameter key to achieving engine performance and emissions goals.
The motor operates over the entire speed and temperature range as a conventional turbocharger thanks to advancements in cooling, rotordynamics, assembly techniques, and controls patented by EcoMotors.
The motor can function in both additive and regenerative modes increasing boost energy in the absence of sufficient exhaust energy and harvesting excess exhaust energy respectively. In additive mode, the ECT complements engine downsizing by allowing the use of larger turbocharger trims to yield high power per unit of engine displacement, without suffering poor low end pick-up. In regenerative mode, ECT can be part of a larger mechatronik system that connects with crankshaft energy and electrical storage mediums to create a mild hybrid architecture.
The ECT builds upon traditional turbocharger components and assembly techniques with up to 70 per cent of parts carryover from a non-ECT design, and the three-phase brushless motor is claimed to be “service free with no moving parts to wear out”.