More electrics goal of new Cat program: production in 2005, electric engine-driven components, truck APUs…new HVAC - Technology

There is little doubt that more engine and powertrain components will be driven electrically than mechanically in the future. The future holds more electronics in mobile equipment powertrains, not less.

The application of microprocessor technology has long been expected to move out of the automotive world into heavy-duty engines and equipment, and now the first results of that technology are beginning to be felt in the industrial engine-powered equipment world.

"With electrically driven accessories, we have the ability to provide only the flow, pressure or power required to match actual operating conditions. By continuously adjusting to different operating modes, there are a number of control features and opportunities available," said David Orr, commercial manager of Caterpillar Inc.'s More Electric Initiative Program.

"By managing where and when the power is desired, we can provide fuel savings, emissions and productivity enhancements," Orr said. "With control of an accessory independent of engine speed, we can reduce accessory drag on an engine during engine cranking to enhance cold weather starting. Starting an electric engine oil pump just prior to engine cranking, for example, can provide a pre-lube function

Orr was describing the concept of Cat Electronics' MorElectric system unveiled about a year ago. The MorElectric system is designed to drive a vehicle's air conditioner, brake air compressor, water pump and other accessories electrically, versus being belt or gear driven. The system also includes a newly developed HVAC (heating, ventilation, air conditioning) package as well as an optional diesel-powered auxiliary power unit.

The MorElectric system began lab tests in 2002, and is currently testing in on-highway truck applications. Commercial production is expected in early 2005. Caterpillar expects the system to be used in a variety of trucks as well as off-highway, marine and military applications as well. Ort said Caterpillar is looking for partners for market exposure and field validation testing opportunities beginning this September.

The development of the system grew, in part, out of a Dept. of Energy (DOE) program called "Parasitic Energy Loss Reduction and Enabling Technologies for Class 7/8 Trucks." This 42 month, $4.4 million research program started in May 2000 and brought together Cat Electronics, Kenworth Truck, Engineered Machined Products, a major supplier of water pumps to the heavy-duty diesel business, and Emerson Electric.

The MorElectric system provides heating, cooling and accessory power, including battery charging, without idling the engine. Cat said trucks using the MarElectric technology will be equipped to accept two idling-reduction options. The first is shore power to reduce idling at truck stops, loading docks or fleet terminals where electric power plug-in facilities are available.

The second option will be an onboard auxiliary power unit to provide cab comfort until shore power expands and becomes more widely available, all with an eye on reducing vehicle idling fuel consumption, emissions, and noise.

Engine idling is an increasing concern throughout the engine-powered equipment markets. Specifically in the truck market, with accessories dependent on engine speed, low idle off en doesn't provide adequate air conditioning, 12 Vd.c. electrical power or heat rejection capacity. Trucks use their cruise control to elevate the idle speed which in turn elevates the fuel consumption, emissions and noise issues.

And, considering a truck idling at 850 to 1100 rpm uses 0.8 to 1.2 gph, while Cat's new APU is targeted to achieve 0.2 gph, the reduction in fuel used is an obvious benefit for the trucking business. The DOE indicates that the average heavy-duty truck idles 1800 hours per year, thus the fuel savings could be 1000 to 1800 gal. per year.

"One of the unique features about the Cat-designed APU is that we leverage the power converter technology already onboard as part of the MorElectric system," said Orr. "We operate the APU at high speed for the limited times where a high level of electrical power is needed, while the majority of the time it automatically shifts to a slow speed to maximize life, and reduce fuel, emissions, and noise."

The MorElectric system will use a belt-driven generator, which replaces the automotive alternator to provide the electrical power to drive the accessories integrated into the system. "Eliminating the gear or belt connection," Orr said, "allows for greater flexibility in locating electrically driven components, as they are no longer required to be engine-mounted' The Morfllectric System also encourages the use of modular plug-in subsystems using high volume, cost-effective components, Orr said.

"MorElectric technology reduces various parasitic losses and removes the air conditioner thermal load from the radiator, diminishing the need to redesign radiator packages to handle higher thermal loads," Orr said. He added that the electric power could be leveraged for other purposes such as exhaust aftertreatment or for a variety of devices on the chassis, like a tailgate lift. The system can also supply 110 Va.c., 60 Hz power for hand tools or emergency lights.