Correct maintenance of needle roller bearing of universal joint cross shaft

In addition to good friction resistance and wear resistance, cross bearings of automobile drive shafts should also have good mechanical stability, high temperature (high drop point), corrosion resistance, water resistance and oxidation stability, etc.

The high temperature and water resistance of gear oil can not meet the requirements. In addition to calcium based grease (hereinafter referred to as calcium based grease), there are lithium based grease (hereinafter referred to as lithium based grease), aluminum based grease and sodium based grease, etc. In fact, automotive driveline lubrication has always been the use of No. 2 or 3 lithium grease, because lithium grease has a higher drop point than calcium grease (lithium grease is 170℃-190℃, calcium grease is 90℃-100℃) and better thermal stability.

The technical requirements of disassembling cross needle roller bearings are higher, and the patent agency generally needs to go to the auto repair shop to be completed by a professional repair master. The lubrication operation of the transmission shaft cross shaft belongs to the daily maintenance project. Generally, it will be maintained once every driving 2000km. If every maintenance goes to the repair shop, it will undoubtedly increase the economic burden of the owners. If each car is equipped with a special hydraulic filling equipment, it is not realistic. With grease lubrication, just an ordinary butter gun, the driver can complete, save time and economy.

However, some drivers do not operate correctly, which will cause the grease to be unable to enter the bearing. The right operation method is: will grease gun oil closemouthed on butter mouth, continuously operating grease gun, make the grease under pressure through the internal oil grease fitting into the cross shaft, then reach the shaft 4 journal of end face, full of the needle roller bearing, and at the same time will be residual metamorphic needle bearing grease and impurities from the oil seal. After the deterioration of grease and impurities in each bearing are all extruded (see fresh grease is extruded), the operation is completed. If the grease can not be pressed into the bearing during operation, the grease nozzle should be replaced or the cross shaft should be removed to clean the oil channel, and then the filling should be done to ensure driving safety.

In addition, with the continuous development of the automobile industry, molybdenum disulfide grease has been widely used in the automotive industry. The so-called molybdenum disulfide grease is made by adding a small amount of colloid aluminum disulfide in the lithium base grease or complex calcium base grease. Molybdenum disulfide is a sheet crystal, and its sulfur atoms have a strong affinity for metals, so it is easy to form a firm lubricating oil film on the friction surface.