The double-lip sheet-steel-reinforced seal is manufactured either from nitrile rubber or hydrogenated nitrile rubber and specifically engineered to prevent contaminants from entering the bearing’s critical rolling contact area. Depending on operating and ambient conditions, up to 90-percent reduction in grease consumption can be realized using these sealed bearings as part of the three-barrier solution. This can be attributed to the small quantity of grease required to lubricate a sealed spherical bearing inside the sealed housing, compared with relatively large amounts of grease necessary to purge contamination from an open, unsealed bearing.

Automatic lubrication technology

Sometimes, bearings will have to be lubricated periodically and, when they are, problems may arise, especially when they are lubricated manually. Bearings must receive the right lubricant in the right amount at the right time to minimize wear and promote longer service life. Too often, excessive (or not enough) lubrication may be applied; lubricant consumption may increase due to overuse; and maintenance time, energy, and costs can spiral.

Single-point automatic lubricators can be gas driven (left) or electro-mechanical driven (right).

These lubricators can deliver the proper pre-set amount of lubricant for bearings and can prevent too much or too little lubricant being used. Single-point automatic lubrication technology is becoming more widespread as a practical delivery system to prevent the problems typically associated with manual lubrication. (Automatic lubricators also can be incorporated into a three-barrier solution to lubricate a bearing when needed in extreme operating conditions without using excessive amounts of grease.)

Single-point automatic lubricators in service 24/7 can serve as timely and accurate hands-off solutions to deliver the proper pre-set amount of lubricant for bearings. (Some systems have even been tested and approved for use in mines and underground areas, among other applications.) Standard versions usually will be offered either as gas-driven feed types or electro mechanical-driven systems and engineered for reusability. They can especially come in handy at hard-to-access or potentially hazardous lubrication points.

Automatic lubricators (typically sized from 60 milliliters to 250 milliliters, depending on manufacturer and model) offer particularly welcome solutions when equipped with user-friendly features that can make life easier along the line. When evaluating options, users should consider whether the lubricator:

• Provides for flexible and user-adjustable dispense settings over long periods of time to minimize time and effort;

• Integrates transparent lubricant containers to allow for visual inspection of dispense rate, enabling timely refills to be made as needed; and

• Contains high-quality lubricant specially formulated for the application and supplied ready-to-use to avoid potentially detrimental mismatches.

The ramifications of harsh operating environments encountered by conveyors in the aggregate industry have paved the way for new thinking to address — and remedy — age-old problems. The latest innovations in bearing-related technology carry new solutions to help keep lubricant in and contaminants out of critical bearings, increase conveyor uptime, minimize lubricant use, significantly reduce maintenance time and money, and maximize an operation’s overall productivity and profitability.

James A. Oliver is director-sales support engineering for SKF USA Inc. He can be reached at 267-436-6516 or via e-mail at james.a.oliver@skf.com.

Joe Esmoer is manager, industry specialists for mining and metals for SKF USA Inc. He can be reached at 520-749-6618 or via e-mail at joe.a.esmoer@skf.com.