COMMON QUESTION
You are here:Home > SERVICES CENTRE > COMMON QUESTIONHow do you judge that bearing lubricating grease lose effect in application?
Published：2014-11-26 16:19:32Sources：This siteViews：1373
There are manyperformance indicators for lubricating grease for bearings mainly composed ofcolloid stability (oil distribution quantity), mechanical stability (100K timesshear test, and prolonging working cone penetration value) and oxidationstability. The integrated result of these three indicators is the service lifeof bearings:
The lubricatinggrease when bearings are running will make gelatinizer fiber cracked or shorterafter destruction by mechanical force, which has reduced the ability tomaintain the structure of lubricating grease, namely, changes in the denseness.If there is great change in the denseness, it will make loss of workingsurfaces. Moreover, in the running operation, lubricating grease will beaffected by a rise in temperatures, and base oil will become less due toevaporation or part of base oil will suffer reduction of oil content due toloss of oil distribution destroyed by grease colloid, and there is also thepossibility of oxidation and deterioration.
Therefore, for lubricatinggrease for bearings, if the base oil content in grease after operation is lowerthan 60%-70% (i.e. loss of base oil by 30-40% due to evaporation or oildistribution), it will reduce or even lose the lubrication ability causingfailure in running bearings. Meanwhile, a drop in the denseness of grease andoxidation and deterioration thereof will affect bearing operation when it isrunning.
Generally, it isrequired to use the lubricating grease with high dropping point, good extremepressure performance and water resistance. It is the composite aluminum basegrease with extreme pressure, extreme pressure composite lithium base grease oruramino lubricating grease, etc, which can all meet the operation requirements.
The lubricatinggrease when bearings are running will make gelatinizer fiber cracked or shorterafter destruction by mechanical force, which has reduced the ability tomaintain the structure of lubricating grease, namely, changes in the denseness.If there is great change in the denseness, it will make loss of workingsurfaces. Moreover, in the running operation, lubricating grease will beaffected by a rise in temperatures, and base oil will become less due toevaporation or part of base oil will suffer reduction of oil content due toloss of oil distribution destroyed by grease colloid, and there is also thepossibility of oxidation and deterioration.
Therefore, for lubricatinggrease for bearings, if the base oil content in grease after operation is lowerthan 60%-70% (i.e. loss of base oil by 30-40% due to evaporation or oildistribution), it will reduce or even lose the lubrication ability causingfailure in running bearings. Meanwhile, a drop in the denseness of grease andoxidation and deterioration thereof will affect bearing operation when it isrunning.
Generally, it isrequired to use the lubricating grease with high dropping point, good extremepressure performance and water resistance. It is the composite aluminum basegrease with extreme pressure, extreme pressure composite lithium base grease oruramino lubricating grease, etc, which can all meet the operation requirements.