In addition to good anti-friction and anti-wear properties, the requirements for lubricating materials for automobile transmission shaft universal joint cross bearings should also have good mechanical stability, high temperature resistance, corrosion resistance, water resistance and oxidation stability.
The high temperature and water resistance of gear oil cannot meet the requirements. In addition to calcium-based greases, there are also lithium-based greases, aluminum-based greases, and sodium-based greases. In fact, lithium-based grease has always been used for the lubrication of automotive powertrains, because lithium-based grease has a higher dropping point and better thermal stability than calcium-based grease.
The technical requirements for disassembling cross needle roller bearings are relatively high. Generally, it is necessary to go to an auto repair shop to be completed by a professional repairer. The lubrication of the cross shaft of the drive shaft is a routine maintenance item. If every maintenance is to the repair shop, this will undoubtedly increase the economic burden of the car owner; if each car is equipped with a special hydraulic filling equipment, it is also unrealistic . With grease lubrication, only an ordinary grease gun is needed for the driver to complete, which is time-saving and economical.
However, if the operation method is not correct, the grease cannot enter the bearing.
The correct operation method is: press the oil outlet of the grease gun firmly on the grease nipple, and continuously operate the grease gun to make the grease enter the internal oil passage of the cross shaft through the grease nipple under pressure, fill the needle bearings, and simultaneously The degraded grease and impurities remaining in the needle bearing are squeezed out from the oil seal. After all the degraded grease and impurities in each bearing are extruded, the operation is completed. If the grease cannot be pressed into the bearing during operation, replace the grease nipple or remove the cross shaft to clean the oil passage, and then refill it to ensure driving safety.
In addition, with the continuous development of the automotive 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 colloidal aluminum disulfide to lithium-based grease or complex calcium-based grease. Molybdenum disulfide is a flake crystal, and its sulfur atom has a strong affinity for metal, so it is easy to form a firm lubricating oil film on the friction surface of bearing supplier.