SwRI initiates clean diesel consortium
A consortium organized by engineers at Southwest Research Institute (SwRI) is developing low emissions strategies that diesel engine manufacturers can use to improve air quality and meet stringent regulations. The four-year, $5.9 million Clean Diesel III program is composed of 18 participating engine manufacturers, component suppliers, and petroleum companies from eight countries.
"Our goal is ambitious – to reduce emissions by 90% over the next four years," said Program Manager Daniel W. Dickey, a Director in SwRI's Engine and Vehicle Research Division.
The diesel engine is an efficient internal-combustion engine. Its reputation for durability is excellent, but it produces oxides of nitrogen (NOx) and particulate matter (PM) emissions that can be harmful to the environment. A three-way catalyst, such as that used on gasoline engines, isn't available to reduce those emissions on diesels.
"NOx emissions have already been reduced by a factor of five," said Dickey. "Despite this, an increase in the number of diesel vehicles on the road has caused emissions to actually rise over the last 10 years."
The consortium members select the areas of investigation and, as such, have opted to pursue five technologies that show promise for reducing diesel-engine emissions. One of the most successful has been "water + exhaust gas recirculation (EGR)." In traditional EGR, a portion of the exhaust is routed back to the intake manifold, helping to reduce the combustion flame temperature, which, in turn, lowers NOx emissions. SwRI recently developed and patented an EGR valve that is being considered by commercial clients to meet 2002 regulations.
NOx emissions are reduced easily with EGR technology; however, PM emissions increase during the process. PM emitted by diesels is a suspected carcinogen. Several researchers are looking at the use of exotic fuels, such as dimethyl ether, to help reduce the occurrence of PM in various EGR schemes. SwRI's approach uses water, a much more readily available liquid. The addition of water to the EGR process serves two functions. It acts as a diluent to reduce peak flame temperature and thus reduce NOx. Water also tends to boil before fuel, breaking up and reducing particulates. A unique metering system developed by SwRI and Delphi mixes the water with diesel before injecting it into the engine.
Other technologies being researched by the consortium include a novel direct-injection homogeneous-charge-compression-ignition system, model-based engine controls, variable-valve actuation systems, and medium-duty gasoline engines. Additional projects will be addressed following completion of these tasks.
Jean L. Broge
Inside view from Johnson Controls
The
interior of the all-new 2001 Pontiac Aztek presents a functional, recreational
environment. Johnson Controls Inc. assembled the cockpit module (which includes
instrument panel, steering wheel, steering column, all gauges, HVAC, audio,
glove box, and brake and accelerator pedals) and seating areas within the rear
liftgate trim panel.
The 2001 Pontiac Aztek GT model.
"The tailgate has a plastic panel covering the sheet metal in the shape of two seating depressions," said William Vanoss, JCI Platform Program Manager. Audio system controls are easily reached within the left rear quarter-panel assembly. "With the accessory switch activated on the steering column, the radio functions can be operated from the rear section of the vehicle," said Vanoss.
The
cockpit module is delivered to the GM Ramos Arizpe assembly center in Mexico
from the supplier's plant via a bridge constructed exclusively for Johnson Controls'
just-in-time sequencing.
JCI supplies the cockpit for the
2001 Pontiac Aztek.
A removable cooler, made primarily of polyethylene and polypropylene, doubles as a center floor console. "When the cooler handle is rotated toward the passenger seat, the lid can be opened to access objects within the cooler," Vanoss said. Twelve beverage cans can be kept cold in the insulated cooler, which also has a removable compact disc/tape holder and coin holder as well as a storage tray. (The cooler is standard on Aztek GT models and latches into an open bin via the handle.)
Johnson
Controls also supplies the seats. Bucket seats are standard in the front, while
the rear-seat configuration is either a three-passenger 50/50 split-bench or
dual captain's chairs. The rear bench seat is a lightweight modular design that
can be folded, flipped forward, or removed from the vehicle to expose 2642 L
(93.5 ft3) of cargo space. Captain's chairs have fold-down seat backs
that recline and are removable.
The Pontiac Aztek's portable console/cooler.
Front door panels sport removable utility packs for carrying small items such as sunglasses and cellular phones.
"As the first interior created with outdoor enthusiasts in mind, it combines the best features of a car, a minivan, and sport utility vehicle," said Jeff Edwards, Group Vice President of Customer Business Units for Johnson Controls.
Aztek,
sold in front- or all-wheel drive, is powered by a 3.4-L V6 that produces 138
kW (185 hp) at 5200 rpm and 285 N•m (210 lb•ft) at 4000 rpm.
The door-panel-packaged rear
audio system of the 2001 Pontiac Aztek.
Johnson Controls is also supplying interior systems to Aztek's sister vehicle, the 2002 Buick Rendezvous.
Kami Buchholz
A smart material from Railko
Engineers from the UK plastic-bearing specialist Railko Ltd. have developed a new plastic that the company claims contains properties more advanced than the plastics suited for tiny components that play a crucial role in keeping vehicles reliably on the move throughout rigorous working lifetimes that can stretch beyond two decades and a million miles.
In the past, these unseen but vital components relied on conventional bushings and bearings made of alloy, steel, or heavy-duty plastic, or a combination of all three. Inevitably, the joints of a vehicle's essential "limbs" would degrade with use, ultimately leading to costly routine renewal or even more costly consequences if they failed on the road.
This
latest plastic is also self-lubricating, enabling the subassembly in which it
fits to function efficiently and reliably, whatever the rigors of the road for
the lifetime of the vehicle.
Railko claims its new plastic is
suited for bearings, bushings,
and other key components that
take the brunt of punishment in
steering linkages, gearshifts, and control pedals.
Known as an acetal copolymer, this new breed of plastic contains millions of tiny micro-pockets throughout its structure, each encapsulating a minute amount of mineral oil. The company claims the plastic's structure ensures a controlled level of self-lubrication for the life of the product, as well as good friction and wear characteristics and a high degree of dimensional stability.
Ford, Jaguar, Massey Ferguson, and Rover are among UK-based manufacturers using RailkoÕs plastic for pumps and self-lubricating bushings. Vehicle manufacturers and major subassembly suppliers in other parts of the world are adopting the technology. Railko provides OEMs and parts suppliers with bearings, bushes, ball joints, sliding-door rollers, seals, and other lifelong parts that the company claims bring them significant long-term savings compared with using older, less durable equipment.
Plastic bearings are simple in construction, making them easy and quick to assemble and inexpensive to buy. A key advantage of plastic bearings is the moderate production cost of large quantities of molded or extruded bearing components, with minimal waste of material. Plastic bearings also ensure low levels of friction and noise.
This smart new plastic is a product of Railko's research and development team and evolves from larger, heavy-duty plastic bearings developed for use in marine and rail applications. These include massive bearings for ships' rudders and steering-gear support and in the stem-tube propeller-shaft assemblies of merchant and marine vessels. Twenty-five navies worldwide operate ships with Railko plastic bearings.
Jean L. Broge
