Engineers at UQM Technologie Frederick, Colo. (www.uqm.com), have developed an Integrated Electric Traction System (Intets) that puts the electric equivalent of an internal-combustion engine, transmission, and differential into a package that measures just 15 in. long with an 11-in. diameter, and weighs 163 lb. It can be used as the sole propulsion source in midsized vehicles or as an axle-drive for larger ones and should be maintenance-free for 60,000 miles, according to the manufacturer.
The device relies on a brushless permanent-magnet motor to develop 30-kW (41-hp) continuous power and 75-kW (100-hp) peak power on input voltages ranging from 250 to 400 V. The 91% efficient system is much smaller than comparable internal-combustion engines. By using an integrated approach and avoiding uncommon components, such as large-diameter bearings, Intets is also less costly than electric wheel motors. Rather than use exotic materials, UQM used an advanced liquid cooling system to handle thermal loads incurred by packaging the entire system in the small enclosure. Intets is CAN compatible, and microprocessor or DSP controlled. Maximum speed is 1,400 rpm, power density is 0.58 hp/lb, and it has regenerative braking.