Five Precautions In Bearing Operation
Five Precautions In Bearing Operation
2021年12月16日
Cylindrical Roller Bearing
Cylindrical Roller Bearing
2021年12月17日

Performance Change Of Lubricating Grease During Mixing

The mixing of different greases in the use of lubricating grease is inevitable, but it should be noted that the change of properties after mixing will not affect the use. The high-grade long-life grease is used for the sealed earth bearing. When sealed at one time, it can prolong the life of the grease and prevent contamination, and avoid the trouble of regular greasing. However, some bearings must be fag bearings, which must be open type, and the grease must be supplemented according to the regulations. In this case, the mixing of different greases is sometimes inevitable. However, accidents caused by mixing grease that should not be supplemented as required are also common. The properties of some different greases mixed with each other are not arithmetical addition as expected, but unexpected performance changes, especially some performance deterioration. In order to master the changes during mixing and prevent deterioration accidents, it is necessary to keep in mind the property changes and laws of several main common greases after mixing, so as to facilitate lubrication and give full play to the characteristics of greases.

Performance change of general soap base grease after mixing

(1) When the lubricating grease is mixed with sodium, barium and lithium base grease, the mixing will not have a bad impact on the performance, and may also improve its temperature resistance and durability. When mixed with 20% ~ 40% sodium base frog grease, the drop point will decrease, while when mixed with 70%, the drop point will increase significantly.

(2) Mixing 10% calcium, barium or lithium base grease into sodium base grease has little effect, but when it is mixed with 20%, it has a greater effect. Mixing bentonite grease or silica gel grease has almost no effect on the performance. Only when the mixing amount is large, it shows the performance of mixing grease. When mixing 50% lithium base grease into sodium base grease, it shows softening phenomenon, and mixing 75% is still compatible.

(3) When lithium base grease is mixed with about 10% sodium base grease or barium base grease, it will have a greater impact on the performance of NTN bearing, mainly manifested in the reduction of drip point and deterioration of service life. However, when lithium base grease is mixed with about 10% calcium base grease, it will have a smaller impact on the performance. The impact when bentonite grease or silica gel grease is mixed is slightly greater than that when calcium base grease is mixed.

(4) When barium grease is mixed with either or a small amount of sodium or lithium grease, it also has an impact on its performance, but when mixed with calcium grease, bentonite or silica gel grease, it has little impact.

(5) When bentonite grease and silica gel gum are mixed with each other, the influence is very small, and when various soap based greases are mixed with each other, the performance changes significantly after mixing, and the performance changes little after mixing

Performance Change Of Lubricating Grease During Mixing
Performance changes of multi effect general grease after mixing

The mixing performance within the range of 25% ~ 75% of the mixing proportion of various greases can be summarized as follows:

(1) The effect of 12 hydroxy fatty acid group on lipid is small, and the adaptability of mixing with each other is very good;

① Generally, lithium stearate has little effect, and it has good adaptability to mix with each other;

② The compound calcium base grease has great influence, and the adaptability of mixing with ina bearing is also poor;

③ The effect of compound aluminum base grease is less than that of calcium base grease;

④ It has little effect on benzoamide ester, and the mixing adaptability is also poor;

⑤ The influence of polyurea base grease is slightly greater than that of p-phenylenedicarbonamide base grease, but the mixing adaptability is good.

(2) P-benzoamide base grease mixed

① Lithium stearate has little effect on 12 hydroxy calcium stearate soap, and the mixture has good adaptability;

② Compound calcium base grease has influence, and the mixing adaptability is also different from that of mixed lithium base grease. The effect of mixing with composite aluminum base grease is smaller than that of composite calcium base grease, but the mixing adaptability is not good. On the contrary, when p-phenylenedicarbonamide grease is mixed into composite calcium base grease or composite aluminum base grease, the influence on calcium base grease is slightly greater and the performance is slightly worse;

③ Although polyurea grease has a certain influence, the suitability of mixed NSK bearing is good.

(3) Polyurea grease mixed

① 12 hydroxystearic acid lithium grease or stearic acid lithium grease has little influence, and the mixing adaptability is good;

② Compound calcium base grease and compound aluminum base grease have influence, especially when mixed with the same amount of compound calcium base grease, and the mixing suitability is also poor;

③ The effect of p-phthalamide base grease is small, and the mixing adaptability is good.