Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/136253
online. There should also be application support staff available by phone as well as field sales staff who can provide guidance. Improper Lubricant These bronze gear teeth have been worn smooth after prolonged exposure to a lubricant with EP additives. For any given gearbox, there is no physical reason a unit may not be mounted in the worm-over or worm-under orientation so long as proper lubrication levels are maintained. One of the problems that results from insufficient lubrication is that failure is not immediate. The unit will perform well for a time, perhaps a few weeks or a month, depending upon the application. As a result, a technician may not make the connection between too little lubricant and the unit failure, and may repeat the error. Determining how much lubrication is required for a gearbox in a specific mounting orientation is relatively easy. Gearbox manufacturers provide this information in their catalogs, manuals and A second common cause of failure in gearboxes is the use of inappropriate lubrication. Gearbox manufacturers have identified and tested specific lubricants for use in their products. Whenever possible, it is best to follow these recommendations. The selections they have made are based upon the goal of providing the best possible unit life for the customer. Like lubrication amounts, this information is readily available in catalogs, manuals, online or via phone support. Beyond having the "best" lubricant for a given gearbox, there are specific lubricant characteristics that are known to damage gears. In worm gearboxes, typically the worm is made of steel and the gear of bronze. Lubricants that include extreme-pressure (EP) additives of sulfur or chlorine will sometimes soften the bronze gear surface, with the result being a reduction in unit life. Many lubricants that are classified as EP will include these chemicals. While it may seem intuitive that an EP lubricant will be appropriate for gearing, in this case it is actually the opposite, as EP additives will accelerate wear on the bronze gear by softening the gear teeth. In conclusion, since right-angle worm gearboxes are common tools for reducing speed and/or magnifying torque in a wide array of applications, it is important to verify that they are lubricated with the proper type and amount of lubrication. By taking these simple but critical steps, a maintenance staff can help ensure the longest life from their installed gearboxes. www.machinerylubrication.com | May - June 2013 | 29