The running force in the imported bearing leads to the bearing running failure, and at the same time the grease of the consistency of the grease suffers from the mechanical force of the broken body destruction and the loss of oil separation to reduce the oil content of the grease, and also has the possibility of oxidation and deterioration. Therefore, for bearing grease, if the base oil content in the grease is lower than 60-70% after work (i.e. the base oil is lost 30-40% due to evaporation or oil splitting), the grease will reduce or even lose lubrication energy and oxidation and deterioration will affect the running bearing work. Meet one of the following, that is, bad and make the thickener of the fibers become broken, shorter, reduce the ability to maintain the structure of the grease, that is, the consistency change, if the consistency changes a lot will produce the phenomenon of loss from the work surface, and at the same time in the operation of the work of the grease will be affected by the temperature rise, the base oil will produce evaporation and reduce or part of the base oil due to grease gel for failure:.
1, the consistency change, to ± (15 ~ 20) %, generally need to change grease.
2, drop point change, for soap-based grease, the following is judged as aging failure.
Lithium-based grease below 140℃, sodium-based grease below 120℃
Calcium-based grease 50 ℃ or less, compound aluminum 180 ℃ or less
Compound lithium 200℃ or less, others, change more than ±20% 3, acid value change
The acid value of grease >3mgKOH/g is invalid 4, mechanical impurity content.
The following is failure Fe>1% or Cu>3% or ash content change rate>50%