The sand making machine manufacturer explains how to solve the oil leakage problem of the vibrating screen spindle group. Vibrating screen is a common auxiliary equipment used in mine production, and is widely used in chemical, food, building materials and other industries. The main shaft set is an important component of the vibrating screen. It is mainly assembled from parts such as pulleys, balance wheels, eccentric shafts, bearings, bearing housings and outer casings. It transmits the rotary motion of the motor to the screen box and converts it into a composite vibration of the screen box.
The vibrating screen works outside for a long time, the vibration is large, and the torque transmitted by the main shaft is also large. Therefore, the performance requirements of the main shaft bearing are also high, especially the bearing lubrication is required to be in place, and the lubrication effect is very good. There are two ways to lubricate the spindle bearings: one is to install an oil cup on the bearing housing, and the bearing is lubricated by manual filling of the grease; the other is to inject the full loss system oil into the closed cavity of the main shaft, through the full loss system. Use oil to flow into the bearing for lubrication.
However, no matter what kind of lubrication method is used, or when the two methods are used at the same time, after the vibrating screen works for a period of time, we will find oil leakage on the end faces of the left and right bearing housings, and sometimes even the oil leakage is serious. Disassemble the bearing housing and inspect the bearing end caps and seals without any damage or cracks. So what is the cause of the oil spill? SBM Heavy Industry analyzes for you!
For the above two lubrication methods, the reasons for the oil leakage are as follows:
In the first case, the bearing is lubricated by manual filling of grease through the oil cup. Since the grease is a solidified body, if it is to leak, in the case of eliminating any damage and cracks in the bearing end cap and the sealing ring, two conditions must be met. First, the bearing temperature rises sharply, and the grease changes from a solid state. The liquid state increases the fluidity; the second is that the medium in the closed cavity of the main shaft group generates an outward pressure, forcing the liquid grease to be squeezed outward to form a leak.
After clarifying the two conditions that a grease leak should have, the focus of our analysis turned to two questions: The first question is how does the bearing temperature rise? The second question is how does the medium (air) in the closed cavity of the main shaft group produce an outward pressing force? The inner and outer rings of the bearing heat up due to rolling friction. If the lubrication is not in place, the heat rises sharply, causing the bearing temperature to rise. At the same time, because the main shaft (eccentric shaft) repeatedly compresses and expands the medium in the closed cavity during the rotation process, not only the medium in the closed cavity generates a relatively large pressing force, but also causes the temperature of the medium to rise. , which is transmitted to the bearing, causing the bearing temperature to rise even higher. Therefore, the influence of the eccentric shaft on the medium in the closed cavity during the rotation of the eccentric shaft is an important cause of the leakage of the lubricating oil.
In the second case, the full loss system oil is poured into the closed cavity of the main shaft, and the oil flows through the full loss system and penetrates into the bearing for lubrication. In this case, the medium in the closed cavity is the oil for the full loss system. When the vibrating screen is in operation, the eccentric portion of the eccentric shaft is continuously compressed and expanded by the oil for the full loss system due to the rotation, so that the full loss system uses the oil to move violently in the closed chamber, continuously separating, twisting, tearing and Friction, the oil temperature rises sharply, the fluidity increases sharply, and an outward pressing force is also generated, which causes the full loss system to continuously penetrate the oil leakage through the assembly gap of the bearing.
Through the analysis of the above reasons for oil leakage, SBM Heavy Industry believes that to solve the oil leakage problem, two points must be achieved: one is to ensure that the spindle bearing is maintained at a suitable temperature; the other is to eliminate the eccentric portion of the eccentric shaft in the closed cavity during the rotation process. The effect of the medium (air or total loss system oil). And these two points are complementary, especially the latter has a relatively large impact on the former.
Through practice test, the grease is added to the oil cup, and at the same time, the full loss system oil is filled in the closed cavity to lubricate the main shaft bearing at the same time, and the effect is the best. On the one hand, the lubrication performance of the grease is good, and it can block the bearing assembly gap and prevent oil leakage. On the other hand, the oil loss of the full loss system is good, and the cooling effect is good, which ensures that the spindle bearing is in an optimal work. surroundings.