Smoother, cleaner, quieter, longer

The unprecedented productivity of U.S. manufacturing workers is largely a product of automation, and supporting the myriad systems that energize it is not a trivial task.

"The technological trends we currently see impacting power transmission result from global competition and domestic economic forces," says Bob Summerlin, group vice president, sales and marketing, Motion Industries (http://www.motionindustries.com). "While the business press reports on migration of manufacturing offshore, we see U.S. plant facilities actively seeking significant solutions to improve production capabilities and reduce costs through industrial automation."

"Customers are making their decisions based on increased process reliability and uptime, lower cost per unit of production and improved asset utilization," says Bob Nemecek, director of marketing, Dodge products, Rockwell Automation (http://www.dodge-pt.com). "There's a huge focus on plant productivity there's not a customer I call on who doesn't know what one point of productivity means on the bottom line."

Take advantage of advances in component quality, power density and design to make your plant's power transmission systems more cost-effective and trouble-free.

Operating environments directly affect the life and reliability of power transmission components. Factors such as inadequate lubrication, poor maintenance, excessive load, increased friction, vibration and debris can result in component failures from wear, fatigue, pitting, scuffing and bending. Advances in metal component compositions and surface treatments are making gears and bearings more tolerant of these hard facts of factory floor life.

For example, spherical roller bearings in the guide rolls of continuous casting machines operate under some of the most severe conditions imaginable: heavy load, ultra-low-speed rolling (only a few rotations per minute), and an environment of water and scale contamination. As a result, the bearings often suffer from uneven wear on their outer ring raceways, leading to cracks and flaking. Outer ring fracture and bearing failure has serious implications for continuous steel production.

"NSK has succeeded in developing a longer-life spherical roller bearing for use in the guide rolls of continuous casting machines," says Bob Highland, western regional sales manager, NSK (http://www.am.nsk.com). "The new Super Wear-Resistant (SWR) bearing has more than twice the life compared to conventional bearing types."

In another example, where paper-machine dryer cylinders are heated by steam injected through the bearing journals, thermal expansion of the hollow shafts would overstress and crack the inner bearing races. This problem was solved by using tougher steel for the races (NSK calls these its TL series bearings).

"Engineered surface technologies exist to improve the wear, fatigue and frictional performance of equipment including bearings, hydrostatics, engine components and gear systems," says Greg VanBuskirk, market development manager, The Timken Co. (http://www.timken.com). The company is able to use specialized vapor-deposited coatings and surface finishes that change the surface material, surface design or subsurface design of a component.

Depending on the application, these surface treatments can:

Maximize torque capacity.

Reduce frictional power losses.

Reduce component wear.

Increase debris resistance.

Address poor lubrication.

Minimize redesign costs.

For example, inadequate lubrication results in scoring and scuffing of tapered roller bearing roller ends and rib faces. "Timken has found that engineered surface tapered roller bearings survive these extreme operating conditions," VanBuskirk says. "This surface coating also combats problems caused by foreign material (bruising and abrasive wear), peeling, electric current (arc pitting or fluting), fatigue spalling and false brinelling."

In another example, treating a sun gear in a power train drive system increased the gear life "in excess of 300%," VanBuskirk says. "And independent tests have shown to increase the scuffing torque limit by as much as 70% and increase the pitting torque limit by as much as 33%."

The upshot is power train components are becoming stronger and more reliable than ever. "With carburized and ground gears, CNC machining and precision grinding, they last longer," says Ron Doll, marketing manager, Falk (http://www.falkcorp.com). "We just don't see replacement gear orders like we did years ago things just don't wear out."

Stronger, more precise gears and bearings, closer assembly tolerances and better lubricants are increasing power component ratings and efficiencies.

The result is smaller reducers and drives. "You can get more torque and horsepower from a smaller cube," Nemecek says.

"Weights and sizes are down to a third of what they were in the 1950s," Doll says. Higher load ratings with smaller gears and bearings also means vendors can cover more applications with fewer form factors. The resulting standard, modular packages save money, reduce lead times and improve parts availability.