After a motor with large vibration is disassembled, the grease in the bearing becomes silver-gray (originally milky white). What is the problem? Is the color change of the bearing grease normal? What color is normal? What is the color? The degree is normal. Some bearing greases also change color, from milky white to brown, and the discolored parts are around the rolling elements. What is the reason? If it becomes silvery gray, it is due to tight fit, small clearance and large friction. But the same bearing has the phenomenon of running the outer ring. Why is this?
Grease is discolored in the bearing, and it will change color even if it is not placed in the bearing. This is because:
First, there is an oxidation problem with the grease. When the grease is placed (or operated) for a period of time, it will have a lot of contact with oxygen, and at the same time, the metal (the bearing itself) acts as a catalyst in this oxidation reaction. Therefore, when calculating the replenishment time interval of the grease in the bearing, the problem of oxidation should also be considered. Many greases now have antioxidant additives. This does not mean that it will not oxidize.
Second, the bearing itself, the temperature (the bearing itself, or the environment) will change, which causes the base oil in the grease to continuously enter and exit the thickener, and each time the base oil returns, it may not completely return. After a long time, the performance of the grease will change and the lubrication will not be satisfied, so re-lubricate. Grease with insufficient base oil may change color. Also, if the temperature is abnormal, the performance of the grease changes greatly, and thus, there is discoloration. If the temperature is high, it will carbonize. The color will become darker.
Third, during the operation of the bearing, impurities are mixed inside the grease. This kind of impurity may be caused by the bearing itself peeling off, or it may be entered by the outside world. It may be solid and may be liquid, which can affect the properties of the grease.
In addition, you said that the tight fit, the clearance is small, resulting in discoloration of the oil. This reasoning should be like this: tight fit, small (remaining) clearance, increased bearing load area, and heat, resulting in oil denaturation, resulting in a change in grease color. And you said that the running circle, the first may have problems with the cooperation of your bearing room, and second, the internal clearance is too small, the friction is large, leading to running circles. The latter possibility cannot be achieved by adjusting the fit. The worse you get, the worse.
Also, what you are saying is based on the color of the grease to determine whether the situation is normal. This judgment is very difficult. Different greases have different internal additives, different operating conditions, and different temperature ranges. It is impossible to have a uniform standard. Even with the same grease, the recipe may vary slightly depending on the batch being played. Please do not use this color change as a basis for unreliable.
Concerned about surprises
Label: Hardware Interpretation: Causes of grease discoloration caused by bearing clearance
Previous: How did the hardware stamping accessories come from? Next: Inspection of wheel hub maintenance and scratch repair wheel bearings and
LEXXISO® series Isomeric Alcohol Ethoxylates are high performance nonionic surfactants which can be used in textile auxiliaries, leather auxiliaries, detergents, paint additives, paper additives, pesticide adjuvant and other chemical industries. They are very effective dispersing, wetting and Emulsifying Agents, and perform very well as substitutes for Alkylphenol Ethoxylates and STPP in textile auxiliaries and detergents.Moreover, they give better performance than natural alcohol ethoxylates. And Lexxiso can be Lutensol XP/XL/TO/ON counter.
Isomeric Alcohol Ethoxylates
Isomeric Alcohol Ethoxylates,Alcohol Ethoxylate,Emulsifying Agents,Textile Auxiliary Agent
NINGBO LUCKY CHEMICAL INDUSTRY CO. LTD , https://www.chinaluckychem.com