IAV’s new modular drive unit, presented at the recent Vienna Motor Symposium, combines an 80 kW (50 kW continuous) motor with a transmission, and can support electrification solutions in vehicle classes A to D.
Many of today’s electric drives use a transmission with a fixed gear ratio. This has the advantage of simplicity, but is not optimal in all situations. For example, hill-climbing performance and maximum efficiency demand very different transmission ratios. A fixed ratio also has drawbacks in terms of efficiency. IAV’s drive unit uses a transmission with one to three speeds, and the company says that this increases driving range by five to ten percent.
The system supports hill-climbing ability to a maximum 30% grade, and offers a top speed of 99-115 mph. It’s designed to be flexible, and can be used in EVs, PHEVs or fuel cell vehicles.
IAV’s motor generates constant torque of 150 N·m, which can be increased to 300 N·m for short periods of time. The planetary transmission, which provides a maximum of three speeds, is installed at the side of the motor and is capable of generating output torque levels of up to 3,000 N·m, making it possible to limit the motor’s maximum speed to 8,000 rpm.
“Our modular electric drive unit meets the demands on torque with more speeds than comparable solutions,” said Jens Liebold, Technical Consultant for Electromechanical Drive Systems at IAV. “Instead of a multiple-speed transmission, these use a larger motor, with means they need more package, and encounter problems because of the higher motor speeds involved, such as with noise, vibration and harshness.”
Source: IAV via Green Car Congress