General Information

A hybrid electric vehicle (HEV) has both a diesel engine and an electric motor. Engine torque is augmented with electrical torque. The electric motor is powered by batteries, which are charged by regenerative braking and, on vehicles equipped with the ePTO option, the diesel engine.

The batteries cannot move the vehicle for long distances at highway speeds. In the event of a diesel engine failure, drive the vehicle to a safe location as quickly as possible.

Eaton Corporation developed and supplies the hybrid electric system for Freightliner Trucks. The primary system components are the hybrid drive unit (or "HDU", which includes the electric generator/motor and automated transmission), power electronics carrier (PEC), and the motor inverter/controller. Electric power take-off (ePTO) and auxiliary power generator (APG) components are optional on the HEV system.

Freightliner Trucks designed the stand-alone liquid cooling system required to support the operation of Eaton's HEV system. Its primary system components are the electric water pump, reservoir/expansion tank, radiator, electric radiator fan, and coolant plumbing.

Body builders will develop the components for the PTO, the PTO plumbing, and a safety switch to prevent the diesel engine from starting when the hood is open.