Trouble shooting of main bearing lubrication of mill
Generally, the main bearing operation failure mainly has the following situations:
(1) The temperature of lubricating oil gradually rises, and babbitt alloy streaks are formed on the outer surface of the hollow shaft journal. The deep streaks can reach about 2mm, and the density is uneven. The main reason is that the smoothness of the hollow shaft journal is not enough, so that the contact point of the tile surface is subjected to shear stress, which causes a large area of ??strain (shear failure). The babbitt alloy particles are pasted on the surface of the hollow shaft journal, and when the hollow shaft is turned to the upper part, it meets with the cold lubricating oil and is cold treated, thereby increasing the hardness. When it is turned to the bottom with the hollow shaft, the tile surface is strained and appears Strip marks with unequal spacing. At the same time, the temperature of the lubricating oil of the main bearing gradually rises after the hollow shaft with babbitt alloy particles is circulated and rubbed, resulting in high temperature. At this time, the bearing bush should be pulled out, and the surface of the tile should be scratched again. If the streak is too deep, the homogeneous babbitt alloy should be repaired.
(2) High temperature appears on one side of the bearing bush. This is caused by a small-area contact between the tile surface and the hollow shaft journal, and the static load becomes larger due to a fault in the adjustment of the shoe seat. At this time, the barrel of the mill should be lifted up, check the contact between the spherical tile back and the tile seat, and if necessary, re-grind the tile seat and tile back to make it align freely. At the same time, it is necessary to scrape the tile surface again to completely scrape off the oxide layer, and polish the hollow shaft journal with oilstone. SKF 22328 CC/W33 bearings are online , pls click here :
(3) When the temperature rises, when there is t, the main shaft is gloomy and there is adhesion phenomenon, which is caused by the local high temperature of the tile surface and the glue. At this time, the bearing bush should be scraped; sometimes the main shaft is bright, which is due to oil The oil should be changed due to poor quality and many impurities in the oil.
(4) The oil temperature is high, but there is no babbitt alloy adhesion. The reasons may be as follows: one is that the supply of lubricating oil is low and the viscosity is low, and the oil film cannot be formed; the second is that the oil quality is poor; the third is that the grinding bush does not meet the specification requirements, and the gap between the bushes is too small; the fourth is the bearing bush The cooling water is not smooth. Measures such as oil change, re-scraping and unblocked cooling water can be taken.