Gearbox Lubrication | Part 6 | The War on Wear

Final part in a 6 part series on lubrication of gearbox applications

Lubrication Excellence by Trico

Your Path to Lubrication Excellence

Temperature, pressure, contaminants, aeration, water, metal particles, and agitation all help to accelerate the oxidation process (destruction) of the lubricant. Combine that with the destructive nature of solid particles trapped between rolling elements, raceways and gear teeth, and emulsions created (lack of lubricating properties) by ingested water will ultimately result in the sacrifice of equipment performance and reliability. Mitigation of these conditions is not only possible, but leads to more upside in the bottom lines of nearly every organization that has implemented a gearbox lubrication management program.

Proper gearbox lubrication means:

  • Maintaining headspace quality
  • Operating within the designed operating conditions
  • Use of dedicated and/or portable filtration for contamination control
  • A competent oil analysis program for maintaining the specific physical, chemical and cleanliness standards throughout the life of the lubricant.

Gearbox lubrication is only the beginning. Every aspect of the process from bringing lubricants into storage to adding them to the equipment and beyond can benefit from best practice utilization. Smart maintainers have explained this to us in great detail and we’ve been able to take nearly 100 years of industrial experience and boil that down to exactly what works in every situation. When you put your trust and confidence in Trico, you’ve made a choice to the up-side that will make your industry competitors think you’re moving to the next level.

In reality you have.

The crystal clear bottom line will be increased company profits by maintaining the functionality of the equipment for production.

Contact a business development member of the Trico team today to start to learn more about lubrication management practices that can elevate your maintenance operation to a new level.

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Gearbox Lubrication Filtration | Part 5 | The Wear on Wear

Gearbox Applications | Part 5 - Filtration | The War on Wear

Gearbox Lubrication Filtration

High-Viscosity Filter Cart SystemOnce contaminants are in the fluid, settling, gearbox lubrication filtration/separation and fluid replacement may reduce contamination. For settling to occur, a contaminant must have a density greater than the fluid transporting it. The lower the density of a contaminant particle, the more buoyant it will be in a fluid. Many gearbox manufacturers have designed the gearbox housing to allow the contaminants to settle out in areas that will not allow them to be redistributed into the system. Removal of these contaminants requires thorough flushing of the housing during the replacement of the lubricant. The best way to flush is to use compatible low-viscosity base oil, or a low-viscosity variation of the service oil that can be applied in a method that ensures that all the dead zones are cleaned and any debris is dislodged.

Maintaining the lubricant throughout its in-service life requires some form of filtration for the removal of accumulated contaminants. A properly designed high viscosity filtration system must be utilized that will supply the correct flow rate to perform the function of removing the targeted contaminants in a reasonable time frame. Re-circulating, kidney loop or auxiliary filtration, consists of a pump, filter, motor, cooler (if required) and appropriate hardware connections. Fluid is continuously pumped out of the reservoir, through the filtration system, through an incorporated temperature regulating system (if required), and back to the reservoir ensuring fluid conditioning regardless of the operating condition of the main system. These systems can be either portable or permanently retrofitted to the gearbox/reducer housing. The choice comes down to the need for reliability, safety and severity/penalty of failure.

Smaller, portable filter carts, and hand-held pump/motor/filter units are ideal for pre-filtering, flushing or transferring fluids into reservoirs. These off-line portable carts can be adapted to service many different gearbox/reducer housing in the same family of lubricants by adapting quick-connect self sealing fittings on the drain and fill ports. Care must be taken in selecting the right pump flow rate, filters, and conductor sizes to operate at higher viscosity gear oils. A properly designed filtration system will minimize operating costs by reducing lubricant and equipment damaging contaminants while assisting in extending lubricant life and ultimately the mean time between failures.

High-Viscosity Filter Cart SystemTo measure and trend the contaminants and the effectiveness of the gearbox lubrication filtration system, an oil analysis program should be incorporated into the planned maintenance program. To initiate this program, strategically located test ports should be installed to provide trouble-free, repetitive and representative sampling of the lubricant contaminants along with consideration of monitoring the health of the equipment. This sampling method should allow the equipment to be tested under its typical operating condition while being non-obtrusive and maintaining a safe sampling method for the technician.

The Takeaway

Keeping your gearbox lubricant clean and free of wear debris will help lengthen the cycle of changes. Filtering and oil analysis when used as part of a normal lubrication management program, will not only keep your lubricant clean, but tell the tale of wear within the equipment. Smart maintainers have already incorporated these strategies, but if you have not, it is never too late. If you are not sure where to start with this, contact us and Trico will put you on the right track.

Contamination Control | Part 4 | The War on Wear

Contamination is a leading cause of lube failure, part 4 of 6 on gearbox applications

Contamination Control in Gearbox Applications

Watchdog Desiccant Breather Installed on a Gearbox

Watchdog Desiccant Breather Installed on a Gearbox

Contamination means any substance that enters a system and affects or interferes with the function of the system’s fluid and/or the operation of its components. Solids, water and various gases (primarily air) entering or existing in a system can have mechanical or chemical interactions on the oil and/or the equipment. Fluids must be protected and monitored from such contaminants by a comprehensive contamination-control program incorporating prevention of fluid contamination, removal of contaminants, and fluid-system condition monitoring.

Knowing the contaminants and their origin will provide clues as to how they might be excluded, removed, or their effects neutralized. Contaminants can be built-in due to manufacturing/maintenance processes, or they may enter a system while parts of it are open during construction or repair. Also, they can be internally generated as a result of system operation, such as wear debris, compounds of chemical reactions, or substances resulting from decomposition of the fluid or its additives. The most common entrance of contaminates from the atmosphere is either through breather caps, imperfect seals, or other unplanned openings during normal operation of the equipment. This would include the addition of fluid during initial fills or top-ups.

Original Equipment Manufacturers will provide their own equipment specific requirements for targets and limits of contamination in their maintenance manuals or service bulletins. In most cases, the end user will not obtain these targets unless a further investment into contamination control equipment is provided.

Breathers Can Prevent Infiltration of Contaminants

As system temperatures or environmental temperatures change, the gearbox or bearing housings will have a movement of air. Whether the housing is inhaling or exhaling, the movement of air is always trying to equalize the temperature difference from the inside to the outside of the housing or in reverse direction. Exhaling in many cases will carry a fine oil mist to the outside environment, while inhaling carries the industrial environment along with nature’s environment into the gearbox or bearing housing. The area above the lubricant level but inside the housing is classed, as “Headspace” and managing the quality of the environment in this headspace is one step in controlling the contaminants entering the lubricant.

Watchdog Desiccant Breathers

Breathers come in many sizes for almost any gearbox.

Countless articles have been published, and new research and oil testing techniques are always trying to prove the effects and the destructive nature of contamination on lubricants. Controlling contamination that enters the headspace environment can reduce and in some cases eliminate many of the potential root causes of lubricant failure. Most housings have a planned method or location for breathing; otherwise a build up of pressure would cause seals to fail resulting in external leakage of the lubricant. Since many of the breather systems on gearbox housings are either just a small hole in the cap or a very poor quality strainer style breather, they typically will not prevent the required contaminants from entering the system to maintain the OEM fluid requirements.

Upgrading breathers that control contaminant ingress starts with understanding the environment around the housing. An effort to stop the ingression of water in a continuous hot dry environment will result in an investment, which would not have any financial return on that investment. Stopping only water ingression in an environment of high humidity and excessive airborne contamination will not successfully stop the ingress of the destructive powers of the airborne contamination. Oil sampling and testing, coupled with investigating the surrounding environment should provide a direction in selecting the correct contamination retention method, a method that provides the most economical and effective retention of the known contaminants from reaching the headspace of a specific piece of equipment. In cases of extreme environmental contaminants or considerable air movement within the housing, there could be a need for an external bladder system. The attached chart lists some of the breather exclusion methods along with the contaminants that they restrict from entering the housing headspace.

At some point, all styles of breathers that are not maintained will become plugged with debris resulting in an increase of internal pressure of the housing and the ultimate failure of the seals. Leaking seals in gearbox housings have become a common complaint in industry and the end result is typically the rework of the shafting material and the replacement of the seals due to the hard aggressive wear created by the abrasive particles attracted to the leaking lubricant. In too many cases the root cause (blocked or plugged breather) is not identified as the condition of the breather and is not monitored or replaced on a planned maintenance schedule.

The Takeaway

Contamination is one of the main reasons for lubricant degradation, and the number one cause of premature lubricant failure. Breathers can protect critical equipment from contamination via the exchange of air between the gearbox and the outside environment. Check out Trico solutions for gearbox applications and you will find one that fits your contamination control needs.