Background: Mikasa, a manufacturer of dinnerware, fine china, and crystal, has a state-of-the-art distribution center in Charleston, S.C. The plant is entirely automated, incorporating over 16 miles of intelligent conveyors flanked by dozens of computer-controlled handling stations.
The problem: When material moves via conveyor, almost everything depends on the integrity of the drive system, usually a series of geared motors. In this case, gears throughout the plant continually leaked oil, which not only contaminated boxes and packages, but also led to costly plant shutdowns due to gear failures on critical conveyors.
Solution: Solving the problem was largely a matter of finding gears that incorporate better seals. The replacement units, manufactured by Nord Gear Corp., Waunakee, Wis., employ “quadrilip” sealing technology; four rubber beams seal off all shafts, keeping oil in and contaminants out. To facilitate the changeover, Nord is also supplying several custom brackets, three types in all, to compensate for footprint and alignment variations.
Additional benefits: Besides running cleaner, the replacement gears also are running cooler. Unlike the originally installed worm gears, which rub and produce friction, the new gears are the helical-bevel type, where contacting surfaces roll on each other rather than rub. Rolling engagement of gear teeth is accompanied by less friction and, thus, less heat buildup. This, in turn, means that the rubber seals and contact areas do not deteriorate as fast. It also means that the oil inside lasts longer. Ultimately, a cooler running gear can be made to run faster, and that’s exactly how Mikasa capitalized on the situation. What’s more, Nord gearboxes are totally repairable in the field, down to their bearings and seals.
