Development History of the Patented Variable Torque Motor

Sure you want to read all this? Have some coffee first. Here goes. VTM evolved from a problem: Need to maintain torque over wider range of rpm's.

Situation :

Electric motors, like internal-combustion engines, have a defined operating range. Without a transmission, vehicle speed is limited. Imagine your car or truck with only one gear. If you needed low-end torque, then top-end speed would be limited. If you needed top-end speed, then low-end torque would be limited.

What prompted the development of the Variable Torque motor was a call from one of the airlines. The airline needed to pull a number of baggage carts up relatively steep ramps at selected airports. Thus, the challenge -- develop an electric drive system with low-end torque and top-end speed.

The project started in 2000 at Electric Vehicles, Inc., Fort Wayne, IN. EVI builds a series of ground-support equipment for airlines and industrial vehicles. Project manager for motor development was Larry Zepp, who had joined EVI as VP-Chief Engineer and had extensive background in motor development, including a number of patents.