The role of gear oil in cross shaft universal coupling?Universal coupling grease degenerates and evaporates to form a harder soap. Not only can it not provide lubrication, but it also hinders the rolling of the needle; in addition, the joint has no oil discharge device, which makes the grease deteriorated. It cannot be discharged, and it is inconvenient to inject new grease.During maintenance operations, the injected grease cannot enter the middle of the plastic needle, but is squeezed out from the safety valve. The grease in the bearing is basically still injected for the first time, and it has become degraded soap. Can not get good lubrication.Due to the poor toughness of the butter oil film, the cross-shaft universal coupling has to withstand greater torque and alternating loads during operation, so it is difficult to form a good oil film in the bearing.Therefore, the lubrication of the cross-shaft universal joint should not be greased, but gear oil should be added.
      Calcium-based grease is composed of thickener calcium and base lubricating oil, and its structure is relatively dispersed.If the car continues to run under heavy load for a long time, most of the base lubricating oil in the oil film will be separated, and the oil film will basically not exist.Moreover, the fluidity of butter at room temperature is very poor, and the roller needle can only rotate in place during work.Therefore, when the original oil film fails, it is difficult to form a new oil film immediately, causing the needle roller bearing and the cross shaft to be in a semi-dry friction or dry friction state.
      Cross-shaft universal joints bear large torque and alternating loads during work. The main damage forms are the wear of the cross-shaft journal and needle roller bearing, and the working surface of the cross-shaft journal and needle bearing bowl. Creasing and peeling.In the vehicle maintenance specifications, it is stipulated that the sliding fork teeth and intermediate bearings use calcium-based grease (butter); the needle roller bearings of the cross shaft and the intermediate bearings of the three-axle drive vehicle use gear oil.However, in actual work, because the grease nipple of the cross shaft is the same as the grease nipple, sometimes it is for easy operation and sometimes there is no filling equipment. Many drivers and maintenance personnel erroneously dare to use grease lubrication on the needle roller of the cross shaft. Cause early damage to the cross shaft.