Bearing capacity and rated life of printing machine bearings

First, determine the size of the bearing. In most cases, the size of the bearing depends on the requirements for bearing capacity, rated life and working reliability. In addition to these standards, printing press bearings must also meet the requirements of high rigidity and zero clearance. To determine the rating life, the influence of preload on the bearing must be considered. However, the rating life is also largely affected by shaft misalignment, part tolerances, and lubrication and contamination. Consult Schaeffler Group Industrial Services for bearing layout design recommendations using BEARINX®, and use the calculation software BEARINX® to optimize bearing layout design, see Figure 1 and page 15, Figure 2. This calculation software can perform high simulation analysis on even very complex roller bearing systems. For three-ring and four-ring bearings, usually only rotating cylindrical roller bearings are considered. It bears the greatest load. The swing bearing mainly bears static load. Following the recommended coordination, the permissible safety factor is far from being achieved under the force normally generated by the printing press. Even under relatively high dynamic loads, such as the impact load caused by neutral jump in a printing press without a shoulder iron, the swing bearing has proven its high reliability in practice. Rated life of printing machine bearings: Printing machine bearings are usually designed for a rated life of at least 10 years. Depending on the working hours of the machine, this means 40,000 hours to 60,000 hours for web printing press bearings. The bearings of sheet-fed offset printing presses are usually designed for a working life of at least 200 million printed sheets. Because its application is very flexible, it is often re-adjusted to adapt to new jobs and work at various speeds, so it is more appropriate to express life with printed sheets than in hours. Extended modified rated life: The calculation of extended modified rated life Lnm is standardized in DIN ISO 281 2010. Contact pressure has a decisive influence on the rated life of printing machinery bearings.