Case analysis of damage phenomenon of water roller bearing
The Printing Center of Zhejiang News Group currently has 7 SSC web offset printing production lines, 2 of which are composed of 4 paper racks, 3 towers and 1 folding machine. They were installed and commissioned at the end of 2000 and officially launched in March 2001. Put into production; the other 5 lines consist of 2 paper racks, 2 towers and 1 folding machine. They were installed and debugged in September 2003 and put into use at the end of 2003. Generally speaking, the use of the SSC production line is very good, but the rotation structure, seal and the special specifications of the selected bearing of the rubber roller have brought a lot of inconvenience to daily use and increased the cost of use. Because the selected bearing is an imported part, the inner diameter is 19.05mm, which is a non-standard part, and the inner diameter and thickness are the same as the domestic standard bearing 6004. At that time, the purchase price was about 320 yuan. If you use a better water roller, the bearing has a service life of about 3 months; if you use a poor water roller, the shortest service life is only 7 days. 1. The problem lies in the analysis of the damage of the water roller bearing, and it is found that the structure of the water roller has the following problems. (1) The cost is too high. The imported bearing 88y0043C3 is too expensive. As long as the mandrel with a value of about RMB 0 is replaced, the 88y0043C3 can be completely replaced by the domestic standard bearing 6004. (2) There is a problem with the sealing. Especially for water rollers, some shaft ends need to be immersed in dampening solution. When the PH value of the dampening solution is less than 6, the bearing will be corroded quickly and the balls cannot rotate normally, which will eventually cause the bearing to rust and run away from the inner and outer rings. The roller body, bearing and mandrel are all scrapped. (3) The main problem of axial force. In addition to the corrosion and damage caused by the intrusion of fountain solution, the bearing will also have a 'split frame' phenomenon, that is, the bearing balls are scattered from the 'flower basket' to the cylinder, causing serious damage to the surface of the plate cylinder, blanket cylinder, and rubber roller. 2. Solution (1) Homemade mandrel, adjust the size, and replace imported bearing 88y0043C3 with domestic standard bearing 6004. (2) Modify the rubber roller body and set up a reliable sealing structure to prevent the dampening solution from entering the bearing. For the 5 SSC production lines we use, Shanghai Goss has improved the above two problems according to our drawings. (3) Decompose the axial force of the 6004 ball bearing, that is, add a set of 51104 thrust bearings to the shaft end. At present, we are still gradually improving the shaft end structure of the rubber rollers on all SSC production lines. From the use of the improved rubber rollers, the effect is very impressive. Now, whether you use water rollers or ink rollers, as long as there is no problem with the rubber surface, there is absolutely no problem with the shaft end structure and bearing, and it can be used for a long time. Through improvement, in a service cycle (10 hours of printing per day, generally a rubber roller 6), the service life is about 1 year), even if all the bearings are replaced when the rubber roller is replaced, it can save about 600 yuan. Our printing center has 16 towers, each with 48 rubber rollers. After a rough calculation, after the improvement, it can save more than 400,000 yuan for the newspaper in one service cycle.