Sheet-fed offset printing machine because of its structure, the advantages of more and more become the main products of printing machinery, but also to the requirement of printing quality.Domestic offset press producers from the original monochrome machine, two-color machine production to the four-color machine, multi-color machine development.Sheet-fed offset press each color group is mainly composed of plate cylinder, rubber roller, pressure roller, transfer roller and other system of ink and accessories.The main drum of running accuracy directly affect the printing quality, as to whether can produce set of English checker, uneven color has a direct relationship.Domestic and foreign well-known printing machine producers for the main roller turn precision demand is higher and higher.And the supporting roller bearing plays a crucial role, in order to improve the quality of printing machine and increase the more added value, a lot of printing machine production agent at any cost increase bearing requirements. With the development of the history of sheet-fed offset press, the main roller bearing has also undergone many changes.From early brass to roller bearings, sliding bearings from the needle roller bearing roller bearing, from a single bearing to combination bearings, three-ring eccentric bearing from two ring bearings.The precision of the roller bearing is higher and higher, more and more convenient installation and maintenance is more and more simple. A needle bearing Needle roller bearing rigidity rather than because of the small roller diameter taper roller bearing, and development of double row bearing company dislocation of needle roller bearings Make its rigidity can be equivalent to that of copper set of sliding bearing.Compared with ordinary needle roller bearing, is applied to the printing machine roller support needle grouping of needle roller bearing is higher than normal.Ordinary needle grouping of needle bearing with 2 microns as a unit, and printing machine using needle grouping to 1 mu m as a unit.Like this, by selecting the proper needle grouping, can cause the bearing working windage is less than 1 microns, the running accuracy is high quality printing machine.And printing machine using needle grouping can grouping group more than ordinary needle roller bearing, so that nature can be reduced for wall panel processing requirements. 2. Roller bearing The use of needle roller bearing, still make the printing machine manufacturer bothers to need high machining accuracy of coat, and need experienced installer to find suitable needle group.In order to solve this problem, the bearing producers developed integrated flange outer roller bearing support.Roller bearing can be preloaded achieve good precision and rigidity.And tapered inner ring, can also be used to adjust bearing clearance work.This solution can completely realize the printing machine roller bearing zero clearance requirements.And flanged outer ring for printing machine makers have solved the problem of installation and lubrication.Man Roland, Heidelberg, Japan than and domestic especially northerners models widely use this bearing.The roller bearing support scheme has become the mainstream of drum support scheme in printing machine. 3. Integrated unit Like automobile industry and other industry, printing machine manufacturers also need like bearing precision products suppliers to provide more simple modular components to reduce the error of the factory assembly and time, reduce the rework rate, so as to improve efficiency, reduce cost.In order to meet this requirement, the bearing producers mainly drum support provides higher accuracy, is more simple and easy installation and maintenance of drum support unit.Such as bearing company development three-ring eccentric bearing unit.The bearing unit integrated bearing and eccentric sleeve, not only with supporting roller, and can realize the roller clutch pressure and alignment of the function.Its advantages have been widely printing machine makers.Global group and Heidelberg, man Roland models of new models, are already on the plate cylinder or rubber cylinder using the bearing unit.In the old type modifications, this kind of three-ring bearing support has become the first blindfold before and no in performance, installation, use, maintenance, have a better solution than the bearing unit.And the labyrinth seal and the use of cylindrical roller, make its can be oil lubrication, also can undertake grease lubrication, and lifetime maintenance free.Excellent lubrication and prolong the life of the bearing is the longest in the various options.It makes the accuracy requirement of the printing machine manufacturers to from its own processing, installation of the production line Moved into the production of precision products of bearing bearing production line.This also conforms to the modern industrial factory.The above main drum support to seal all kinds of solutions.The accuracy requirement of the printing machine because of its own, the support of rotating and linear motion, there is a high requirement.The solution of the above Can solve all the domestic printing machine makers need to learn and develop their special products.