Due to its superior structure, sheetfed offset presses are increasingly becoming the main products of printing machinery, and the requirements for printing quality are constantly improving. Domestic offset press manufacturers have also developed from the production of original monochrome and two-color machines to four-color machines and multi-color machines. Each color set of a sheetfed offset press consists primarily of a plate cylinder, a blanket cylinder, a pressure roller, a transfer cylinder, and other ink and accessory systems. The running accuracy of the main drum directly affects the quality of the printing, and there is no direct relationship between whether the overprinting, the netting and the coloring will occur. Domestic and foreign well-known printing machine manufacturers have higher and higher requirements for the running accuracy of the main drum. Bearings that support the main drum play a vital role. In order to improve the quality of the printer and increase the added value, many printer manufacturers have to increase the bearing requirements at all costs.
With the history of sheetfed offset presses, the main roller bearings have undergone many changes. From the previous brass plain bearings to roller bearings, from needle bearings to roller bearings, from single bearings to combined bearings, from two-ring bearings to three-ring eccentric bearings. The accuracy of the roller bearing is getting higher and higher, the installation is more convenient, and the maintenance is more and more simple.
One. Needle bearing
The rigidity of the needle bearing is much better than that of the tapered roller bearing because of its small roller diameter, and the double-column needle roller bearing developed by the bearing company makes the rigidity comparable to that of the copper sleeve sliding bearing. Compared with ordinary needle bearings, the needle roller grouping of the needle roller bearings used for the printing machine drum support is higher than ordinary. The needle roller grouping of a conventional needle bearing is in units of 2 μm, and the needle roller grouping used in the printing machine is in units of 1 μm. In this way, by selecting the appropriate needle grouping, the working clearance of the bearing can be less than 1 μm, which is required for high-quality printing machines. And the needle roller grouping used by the printing machine can be more than the grouping group of the ordinary needle bearing, so that the processing requirements for the wallboard can be naturally reduced.
Two. Roller bearing
The use of needle bearings still makes printer manufacturers annoyed with the need for high-precision jackets and the need for experienced installers to find the right needle roller group. In order to solve this problem, the bearing manufacturer developed a roller bearing support with an outer ring integrated flange. Roller bearings can be pre-tensioned for good precision and rigidity. A tapered inner ring can also be used to arbitrarily adjust the bearing working clearance. This solution fully meets the need for zero clearance of the printer roller bearings. Moreover, the flanged outer ring solves the problem of installation and lubrication for the printer manufacturer. This bearing is widely used in Manroland, Heidelberg, Japan's Liby, and domestic Beiren models. Its roller bearing support scheme has become the mainstream solution for roller support in printing presses.
three. Integrated unit
Like the automotive industry and other industries, printer manufacturers need precision-product suppliers like bearings to provide simpler modular components to reduce factory assembly errors and time, and reduce rework rates, thereby increasing efficiency and reducing costs. In order to meet this demand, bearing manufacturers provide roller support units with higher precision and easier installation and maintenance. Such as the three-ring eccentric bearing unit developed by the bearing company. The bearing unit integrates the bearing and the eccentric sleeve, and not only has the function of supporting the roller, but also realizes the function of the roller clutch pressure and registration. Its superiority has been widely accepted by printer manufacturers.
KBA, Manroland's models and Heidelberg's new models have already used this bearing unit on plate or blanket cylinders. In the modification of the old model, this three-ring bearing support has become the first choice. There is currently no better solution for performance, installation, and maintenance than this bearing unit. The use of labyrinth seals and cylindrical rollers allows them to be oil lubricated, grease lubricated and maintenance free for life. Excellent lubrication also makes the life of this bearing the longest in any solution. It has enabled printer manufacturers to move from their own processing and installation lines to their own production lines for precision products such as bearings. This is also in line with the intensification of modern industry. The above are various solutions for the main drum support of the printing machine. Due to its own precision requirements, the printing machine has high requirements for the support of rotating and linear moving parts. The above solutions can completely solve the needs of domestic printer manufacturers to develop their own more distinctive products.
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