The medium-duty hybrid system uses a parallel, pre-transmission design with Eaton’s Fuller UltraShift automated transmission. Primary components are the Hybrid Drive Unit (HDU), which combines a clutch, a 44 kW/420 Nm motor/generator and automatically controlled manual transmission; the motor inverter/controller; the DC/DC converter; and a 2 kWh li-ion battery pack.

The system recovers energy normally lost during braking and stores the energy in batteries. When electric torque is blended with engine torque, the stored energy is used to improve fuel economy and vehicle performance for a given speed or used to operate the vehicle with electric power only. The system can also be designed to provide energy for use during engine-off worksite operations, further reducing noise, emissions and fuel costs.

Eaton formed this business unit almost seven years ago to provide a cleaner and more fuel-efficient future for the world’s commercial vehicle fleet. Now, we’re poised to fulfill that goal with the help of our forward-looking OEM and fleet partners that share our vision.

—James E. Sweetnam, Eaton Senior Vice President and President – Truck Group

According to Kevin Beaty, manager of Eaton’s Hybrid Power Systems business unit, the company plans to produce several hundred systems in 2007. Eaton is planning to ramp-up production capacity over the next three years in order to meet customer demand and achieve economies of scale.

More than 220 hybrid-powered vehicles with Eaton’s advanced technology systems have been produced to date for testing and evaluation, most of which have been placed into service alongside their conventionally-powered counterparts. Vehicle configurations include package delivery vans, medium-duty delivery trucks, beverage haulers, city buses and utility repair trucks – each of which has generated significant fuel economy gains and emission reductions.

Fleet customers for Eaton hybrid power have so far included FedEx Express, UPS, Coca-Cola Enterprises, The Pepsi Bottling Group, and 14 public utility fleets into which were placed 24 hybrid-powered repair trucks. Truck body builders also involved in the delivery of new vehicles include Altec Industries of Birmingham, Ala., Terex Corporation of Westport, Conn., and others. Additional testing is taking place in Europe with DAF Trucks, and in Asia with the Beiqi Foton Bus Company, one of China’s largest commercial vehicle producers. Eaton hybrid power systems in these and other applications are generating fuel economy improvements of up to 60 percent and significant reductions in harmful emissions.

Hydraulic hybrids. In addition to its diesel-electric hybrid products, Eaton is also developing advanced hybrid systems using hydraulic power. Working with the Environmental Protection Agency under a Cooperative Research and Development agreement, Eaton is helping develop a series hydraulic hybrid power system that combines a high-efficiency diesel engine and a unique hydraulic propulsion system to replace the conventional drivetrain and transmission. The vehicle uses hydraulic pump/motors and hydraulic storage tanks to recover and store energy, similar to what is done with electric motors and batteries in hybrid electric vehicles. (Earlier post.)

Eaton also has a parallel hydraulic hybrid system that utilizes regenerative braking and has a number of other applications. This system, known as the Eaton HLA system (for Hydraulic Launch Assist), is being initially targeted at refuse trucks. (Earlier post.)