# How do you calculate bearing grease

## Calculate & Optimize, Grease Lubrication Practices at Your Fingertips

LubeCoach is an innovative and easy to use device that can help with machine lubrication calculation by assigning the correct volume and frequency to grease lubricated element bearings. 80% of grease lubricated bearings fail to achieve minimum life-cycle levels due to issues with lubricant supply, contamination, and degradation. Our reliable machine lubrication calculator through LubeCoach is your answer.

This lubrication calculation technology will enable the user to quickly and accurately calculate & define how much and how often re-lubrication is needed to maximize reliability. Many companies will be able to reduce machine lubrication cost at the same time greatly enhance bearing, lubricant, and labor performance.

## More About Grease Relubrication Practices

Grease relubrication practices for your machines should be handled with care. Precise grease volumes and carefully calculated intervals will help the reliability, professional reduced outages, reduce costs, improve machine performance and enjoy a less stressful career. The formulas provided in our article here are either directly or indirectly associated with bearing supplier recommendations. The LubeCoach, a machine lubrication calculation expert,  is intended to provide insight without stepping in to sophisticated spreadsheet construction.

Bearing manufacturers have provided a significant amount of detailed advice for lubricant selection, application and replenishment. Formulas used by the machine designers incorporate details that are typically not readily available to the maintenance practitioner, namely load rating and ratio, grease L 10 lifecycle, and specific bearing dimensions. The bearing diameters (OD, ID) may be satisfactorily estimated, but there are multiple bearing models for a bearing type that will share a bore dimension. Without the correct bore and outer diameter it is impossible to arrive at an exact replacement volume.

Grease viability drives replacement frequency. Grease Viability is best determined by testing. Per DIN 51825, greases can be evaluated under laboratory conditions to deliver a provisional expected lifecycle, with results reported in either L 10 or L 50 values. The grease’s L 10 and L 50 values depict operating hours to 90% and 50% viability. Grease viability is determined by frictional measurement of a loaded bearing in the FE8 test stand. When the grease can no longer separate and protect surfaces during test conditions it is evidenced by an increase in friction beyond a threshold. At this point the test hours are noted and the grease is assigned a value in hours for grease viability. These values are not often published for customer use. Without these discrete pieces of information for the greased bearing, estimating the best replacement frequency is challenging. If the machine owner wants to use machine lubrication as a leading practice to improve machine reliability, then the machine owner must invest time to fully calculate and define the bearing and lubricant details in order to calculate appropriate volumes and intervals to deliver reliability centric lubrication practices.

President Mike Johnson has written a paper that presents the engineering principles for bearing grease relubrication, including consideration for open, single, and double shielded bearing configurations, and will include both theoretical methods and general advice useful to calculate both volumes and intervals when the exact details are not available. The machine lubrication calculations presented here are also used to define volume and frequency for operating conditions. Read the full article here!

Either too much or too little grease, and/or inappropriately high or low oil viscosity causes viscous drag and/or destruction of the bearing surfaces and lubricant within the bearing.