Read the telegram channel Russian Technician @rustechnic. All the most interesting things are here: the history of domestic and world industry, thoughts about the past of technology and criticism of modern technical innovations, as well as bringing to light both our and Chinese unscrupulous manufacturers. Using the example of bearings of the Japanese company NSK, we will consider the question: is it necessary to independently fill sealed bearings with grease. I will not consider options when there are doubts about the authenticity of the bearing, about this - in the following videos. In fact, there are only two reasons when it is recommended to replace the grease. The first is if it is more than five years old. Look at the date. The month and year of manufacture are indicated on the bearing box. And the second good reason for replacing the grease is if it does not meet the parameters for operating conditions. There is such a parameter as the filling of the internal volume of the bearing with grease. In NSK bearings, it is designated by the Latin letters KLSMF, located at the very end of the suffix. All my bearings have the letter S, which means filling half the volume with grease. This is a standard suitable for most cases. Accordingly, at high speeds (more than 3000 rpm) the filling is reduced, otherwise there will be overheating, and at low speeds - you can safely fill the bearing to the brim. Information about lubrication is at the end of the designation. PS2 is the type of lubricant, Look at the NSK table, by the way, you can easily find it on Google - this is KYODO YUSHI MULTITEMP PS2 grease with a lithium thickener based on synthetic oil. Designed to operate at extremely low temperatures down to - 60 degrees. Let's open the bearing from the other side. This is a 50 percent filling, universal, suitable for most cases. We see that the filling is only on one side .. The second bearing, 205th. At the end of the designation - the symbols NS7S NS7 is the type of lubricant. This is KYODO YUSHI MULTITEMP SRL with a lithium thickener based on synthetic oil. Wide temperature range, anti-noise, anti-corrosion properties and is considered a universal grease for ball bearings. Suitable for most tasks. Fill level - 50% Next, 206 bearing. Here the grease type is A2S. We open it. This is Shell Alvania C2 grease. It has a lithium thickener and is based on mineral oil. Good high-temperature and anti-corrosion properties. Fill level - 50% And the last one is the 6010 bearing. As you can see, here is a grease with the EEM index. This is EXON-MOBIL polyrex EM on a polyurea thickener. It is recommended for electric motors and fans. It tolerates high temperatures well. The conclusion from all this is that the original bearings of a reputable manufacturer are lubricated with the necessary and sufficient amount of high-quality grease and need to be replaced only in extreme cases.