ZKL GROUP, Czech Republic launched a new cylindrical roller bearing production line last year. This line produces N, NJ, NU and NUP single-row cylindrical roller bearings, as well as NSF full complement cylindrical roller bearings, with a wide range of hole diameters (d = 50 to 250 mm) and outer diameters (D = 120 to 350 mm). ZKL Group also manufactures cylindrical roller bearings for wagon axles and sealed cylindrical roller bearing units.
New technologies have allowed for the manufacture of cylindrical roller bearings with the optimized NEW FORCE internal design, which achieves greater durability, higher operational accuracy, lower noise and decreased loss of energy. These characteristics are obtained by optimizing the internal geometry of the bearing and using materials that meet the high standards of the NEW FORCE design. Metallurgical processes have been developed together with suppliers to improve their mechanical and fatigue characteristics. Many years of cooperation with leading suppliers guarantee a continuous process of improving the parameters of materials. Quality of the materials is ensured by internal regulations, which specify the chemical composition, purity and microstructure of ZKL bearings.
NEW FORCE cylindrical roller bearings are characterized by higher dynamic and static load capacities that are comparable to the world’s leading bearing manufacturers. Following this innovation, dynamic load ratings increased on average by 25-30% compared to earlier ZKL cylindrical roller bearings. This result was achieved thanks to a completely new design and optimization of internal bearing geometry, which uses an advanced numerical method based on finite element methods. Above all, the profile of the raceway of the bearing rings, rolling surface of the rollers, and the front retaining collars have a positive effect on load capacity, limiting rotational speed and reducing noise of the bearings. The proposed profiles of internal bearing geometry ensure optimal distribution of stress where parts of the bearing come into contact with each other. Thanks to new manufacturing technologies, the structure of the contact surfaces are also improved, which allow for improved formation of a lubricant film that reduces bearing wear. This results in a substantial extension of operational life.
ZKL NEW FORCE cylindrical roller bearings are manufactured as standard with steel and solid brass cages. Cylindrical roller bearings for wagon axles are fitted with solid brass or specially developed composite cages (PA66-GF25), which are characterized by high strength and stability during operation. Generally, ZKL NEW FORCE cylindrical roller bearings possess higher radial and axial load carrying capacities, reduced power loss, quieter operation and increased service life.
Libor Nohal, Ph.D.
Director of the Design and Technical Computing Department