The main drive motor in an electric drive system is the component used to convert electrical power into mechanical power to drive the vehicle's wheels. TransPower's first generation electric drive system relies on proven heavy-duty electric motors manufactured by Siemens. Manufactured under the “ELFA” brand name, these are among the most proven and reliable motors and controllers in the industry. Since the 1990s, when Siemens began using these components in low-floor electric buses in Europe, more than 1,000 heavy-duty buses and trucks worldwide have been equipped with ELFA motors and inverters.

Siemens heavy-duty electric truck drive motor.

Responding to the power needs of very heavy trucks, the latest generation ELFA motor (shown at left) provides 250 kW of continuous power and 4,500 newton-meters of torque - more than adequate to meet the most demanding truck requirements. Torque and speed characteristics have been designed specifically to enable the motor to be connected directly to the truck differential, eliminating the need for a transmission or gearbox - additional components that add cost and complexity to the drive system. This is a new generation motor that has been used to date only in a small fleet of hybrid refuse trucks developed by TransPower partner ISE in collaboration with Crane Carrier, and in a fleet of 60-foot hybrid transit buses built by ISE, in collaboration with Wright & Sons, for use in Las Vegas. TransPower is the first company to develop an all-electric drive system for large trucks using this motor. However, the motor uses core technologies and parts proven by Siemens in two decades of electric and hybrid vehicle sales, minimizing the risks involved in expanding the use of this component.

» For more information about Siemens motors please visit:

www.siemens.com