The work frame sits between pedestals, Rummell explained. Each pedestal carries a Planocentric drive from Peerless-Winsmith Inc. of Springville, N.Y. The drives combine planetary and eccentric gear trains.

Internal and external gears, which differ by only a few teeth, absorb backlash, which is the bane of every precise automated assembly.

The work frame moves the work along three axes: vertical, rotary, and skew. The C-frame rivet head provides the remaining longitudinal and transverse motions. Manipulating the work or the tooling along these five axes makes the riveter dextrous enough to drill the frame and buck a rivet at any point along the airframe. All the while, the C-frame and workpiece hold to a strictly perpendicular relationship, Rummell said.

By absorbing backlash, the Planocentric drive keeps the rivets going in at all the right places. A single ring gear and planet, with a difference of only a few teeth between them, mesh against counterfacing tapers, said Werner Heller, Winsmith's engineering manager.

The drive uses spacers of precise thickness for setting the depth to which one tapered gear engages the other. This limits backlash. The tighter the backlash, however, the faster the gear teeth wear, Heller explained.

Continuously moving chains carry pairs of rollers spaced closely together. The rollers carry the pallets, until a pneumatic stop sticks a barrier in the way. The chains continue to move beneath the stopped pallet, Avon said. It is then released from the workstation either automatically or manually.

Allison Transmission division of GMC in Indianapolis uses six such assembly conveyors as sublines to the main transmission assembly lines. One assembly conveyor shuttles pallets through a series of press operations to build one of two rotating fluid clutches for truck transmissions, said Allison's Michael Gloye.

The clutch assemblies, 12 inches long and 18 inches in diameter, travel a three-leg conveyor circuit aboard the pallets. Two parallel legs, each 40 feet long, join through a 10-foot-perpendicular conveyor section. Transfer stations stop the pallets, then shift them on to subsequent conveyors.

Some workstations require high precision, Gloye said. At one operation, a press pushes a piston into the clutch assembly, then checks leak decay. To ensure that the assembly lines up with the press, a wedge engages a bushing on the pallet.

Avon said the assembly conveyors can be arranged in ovals, rectangular loops, or side by side—even over and under.

Cushioned stops are available in a number of styles. Pallet capacity ranges from 10 to 3,000 pounds. Line speeds vary from 10 to 70 feet a minute.

At least one company sees a sales opportunity in cleaner diesels. Winsert of Marinette, Wis., manufactures valve seat inserts for diesel engines of 8 liters or greater displacement. According to Kevin Myers, Winsert's vice president of engineering, lower sulfur will reduce soot formation. That's the idea. But with less soot comes less chance for the valves and seats to build up a protective coating, he explained. They will wear faster.

Cleaner fuels will run dryer, he said. They will have fewer lubricating oils. Valve and seat wear will accelerate in diesel engines in much the same way it did in auto engines after gasoline and lead divorced.

Valve-seat inserts manufactured from cobalt alloys are one way that engine builders might deal with harsher operating conditions. But they can be pricey, Myers said, especially if the $3 to $5 apiece that they cost is multiplied by the number of inserts needed to fill an engine.

Winsert began developing a less expensive alternative to cobalt-based inserts as part of its work with builders of natural gas engines, Myers said. Seven years ago, the company began preparing for the coming diesel fuel regulations.

Today, the company offers hybrid M2 tool steel inserts that sell for $1 or $2 each. "Our new alloys are already approved for use in four major diesel engine programs and are in test in eight other engine programs," Myers said.

Cummins will furnish its QSK 19R diesel, an in-line engine that generates 650 bhp at 2,100 rpm, Peckitt said. Each car will carry its own Cummins engine slung low beneath the carriage. The engines will drive Voith transmissions. Cardan shafts with knuckle joints will connect the engine and gearbox.

Intercity cars, Peckitt said, need strong acceleration to be able to move quickly away from their many stops. Top speed is not as important, he said. But the low-end torque the engines develop can transmit torsional vibration to the transmission, so Cummins engineers use a rubber-in-compression coupling between the engine and the 6-inch-diameter driveshaft.

The couplings, from Renold Hi Tec Couplings of Halifax, England, use rubber support bearings. Another coupling, this time a rubber-in-shear design, attaches to the opposite end of the crankshaft and transmits engine power to auxiliary equipment used for lighting and brakes. Neither of the two lightweight couplings needs lubricating.

Minimal service is required at 500,000-mile intervals, according to the manufacturer.

More so in Europe than elsewhere, small jobs of 200 boxes are fairly commonplace. The ability to change print plates quickly—on the fly, even—can generate a big difference in the final production numbers. That's what Langston engineers were after when they designed the four-color printer section of the new box-making line for the European market.

Print plates can be pulled out and changed without causing any disturbance to other printers' printing or the box maker making boxes.

Boxes are not often printed in four colors, Patragnoni said. But four presses on the box-making line might mean that two could be operating while the other two were being set up for the next job. If only Langston engineers could find a way to get the idle machines out of the line without disturbing the production run.

The first thing that had to go, of course, was the connection to the geartrain. The draw-out design of the new printers would preclude driving the print cylinder with meshing teeth.

A servo drive and gearhead eventually severed the mechanical connection between cylinders and the gear-train. The first servo drive suffered under the heat of the high-speed machine, which makes 250 boxes a minute, Patragnoni said.

Replacement gearheads from Alpha Gear Drives Inc. of Elk Grove Village, Ill., held up better under the heat, according to Alpha's general manager, Tim Herbst. A secondary treatment process, for which the company is currently seeking a patent, lets the gears run without additional oil or grease, Herbst said. Eliminating a contact seal at the input shaft removes one source of heat.

"Our high-speed gearheads mount directly to servomotors running continuous-duty cycles," Herbst said. "The gearhead operates at a lower temperature than the servomotor, so it actually draws heat away from the motor."

Patragnoni said that the draw-out cylinder design created other demands on the engineers. With cylinders as long as 50 inches, that weight would have been tough starting and stopping, not to mention support-ing it in a cantilevered, drawn-out position. Carbon fiber rescued the printer from an unmanageable burden; it let the drive drop down a size as well.

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