Case Study- Improved Gearbox Lubrication

Custom Gearbox Dilema 

A manufacturer of food processing equipment developed a custom built gearbox featuring helical steel gears. Designed for a meat slicing operation, the gearbox experienced higher than normal operating temperatures from 71 to 82°C (160 to 180°F). The manufacturer performed numerous tests on different types of available food-grade gear and chain oils but found that none could withstand these operating conditions.    They settled on a non-food grade, ester-containing, extreme-pressure (EP) synthetic oil. They found this was the only type of assembly fluid that could withstand the systems various operating degrees of temperatures. For nearly four years they used this lubricant type even though it came into close proximity with unpackaged meat. Although this type of oil operated well within the temperature range of the gearbox, it would break down quickly, requiring maintenance personnel to perform oil checking and changeover every 30 days. The maintenance operation proved to be extensive. Maintenance personnel were required to perform nearly 50 percent disassembly of the slicing mechanism to complete the oil change. If it were not changed frequently enough, the alternative oil could  lead to varnish deposit, which would shorten gearbox lifetime and require premature rebuilding.

Solution

To improve gear lubrication and simplify assembly system maintenance, the plant switched to MOLYKOTE® L-1115FM Gear Oil – ISO 150, a DuPont product. Unlike other lubricants types made in conventional fractionation processes, this synthetic oil is made by combining smaller molecular “building blocks” to meet targeted performance specifications and to minimize impurities.

The custom-blended polyalphaolefin (PAO) MOLYKOTE® ISO-150 synthetic oil provides excellent lubrication at varying degrees of temperature, reduces volatility, and is compatible with equipment designed for use with mineral oils. This grade of MOLYKOTE® is also H1 certified for incidental food contact. In addition, it also has properties to prevent rust and oxidation (R&O) as well as prevent wear (AW).

Tests during evaluation revealed the MOLYKOTE® L-1115FM oil maintained high lubricity even after extended exposure to the demands of the application. Friction within the gearbox was prevented to such an extent that the operating temperature during production dropped 11°C (20°F).

MOLYKOTE® L-1115FM offers a highly stable molecular structure. The result is a more stable lubricant that lasts longer. Gearbox operating life has been extended three times with this gear oil. Since the manufacturer converted to the FM type gear oil, end-users of the meat-slicing equipment have not experienced any lubrication problems.

Benefits of MOLYKOTE®

New scheduled maintenance procedures on the gearboxes, which are used on a production basis around the world, involve routine disassembly only every 90 days. On over a thousand such machines, maintenance personnel have found this oil does not require changing prior to this scheduled downtime. Plant management adopted a policy of using only food approved synthetic PAO products for MRO needs. Although in many cases these products exceed the unit cost of the conventional mineral oils they replace, their superior performance more than makes up for the difference. Standardizing on food-grade products eliminates the possibility that plant workers will confuse one type of oil with another.