Bearing capacity and rating life of printing presses

First, determine the bearing size. In most cases, the bearing size depends on the requirements for bearing capacity, rating life and operational reliability of the bearing arrangement. In addition to these standards, printing press bearings must also meet high rigidity and zero clearance requirements. To determine rating life, the effect of preload on the bearing must be considered. However, rating life is also greatly affected by shaft misalignment, component tolerances, and lubrication and contamination. Advice for bearing arrangement design with BEARINX Consult the Schaeffler Group Industrial Services, Optimum design of bearing arrangements with the calculation software BEARINX, Fig. 1 and page 15, Fig. 2. This calculation software enables high simulation analysis of even very complex roller bearing systems. For three-ring and four-ring bearings, usually only rotating cylindrical roller bearings are considered. It carries the maximum load. The swing bearing mainly bears static load. Adhering to the recommended fit falls far short of the permissible safety factor under the forces normally generated by the press. Oscillating bearings have proven their high reliability in practice even under high dynamic loads, such as shock loads caused by neutral jumps in printing presses without shoulder irons. Rating life of printing press bearings: Printing press bearings are typically designed for a rated life of at least 10 years. Depending on the operating hours of the machine, this means 40 000 hours to 60 000 hours for web-fed press bearings. Bearings for sheetfed offset presses are typically designed for a working life of at least 200 million sheets. Because its application is very flexible, it is often re-adjusted for new jobs, and it works at various speeds, so it is more appropriate to express life in terms of sheets rather than hours. Extended corrected rating life: The calculation of the extended corrected rating life Lnm is standardized in DIN ISO 281 2010. The contact pressure has a decisive influence on the rating life of printing machinery bearings.