APPLICATION TIP Product category: Right-angle Geardrives Industry: Packaging Problem: Premature gear wear Cause: Excessive side loading appllied to shafting by timing belt mechansim Solution: Additional mounting support added to shafting, eleviates side loading effects on gears In applications that employ timing belts, proper support for shafting is key in obtaining optimal performance life of Slide-Rite® right-angle gearboxes When designing any type of motion equipment, be sure to consider the effects that applied torque can cause to integral machine components and accommodate for the results. MINNEAPOLIS, MINNESOTA, USA— Tolomatic’s Slide-Rite gearboxes are used the world over and have a reputation for being reliable, durable components that just keep on working. When premature gear wear surfaced on a bank of units that were in an installed packaging application, there needed to be a good reason why. After reviewing the situation, it was determined that side loads being applied to the shafts were causing the problem. For this particular application, the machinery moves packing lids from one conveyor line to another. A series of Slide-Rite gearboxes were mounted on horizontal and vertical shafting, placed on both sides of a series of lid stacking machinery. The gearboxes provide the 45 degree motion for a flying knife process that selects a lid from the stack and drops them onto a conveyor. A housing, containing a 1:1 ratio timing belt mechanism run by an AC motor, was mounted at one end of the horizontal shafting. The timing belt housing was mounted next to the machine enclosure and supported by one pillow block mount. This illustration shows the mounting configuration of the existing timing belt mechanism, pillow block, and their relation to the first Slide-Rite gearbox on the shaft line.

A closer look at the gear wear of the Slide-Rite units revealed a distinct pattern. The closer the units were to the timing belt mechanism, the greater the gear wear as shown in the photo below. This photo shows the results of the side loading placed on the gears of the Slide-Rite unit closest to the timing belt case. Units that showed the least amount of gear wear were farthest from the timing belt mechanism. In this application, the timing belt mechanism required a considerable amount of tension to keep it operating efficiently and the unit was under constant tensioning and tightening. Although...