Designed to last last twice as long as conventional spherical roller bearings, even under the toughest of conditions and where limiting speeds are exceeded by up to 20 per cent, NSK's HPS (High-Performance Standard) units are interchangeable with the standard bearing envelope and can be used in a wide variety of applications.
Thire increased performance and extended operating life on offer can extend maintenance schedules on machines where the bearings are fitted as a replacement, and increase the performance of machines where the bearing is specified by the OEM manufacturer. It can also be used to save weight and improve operational efficiency by enabling some products to be made more compact and lighter at the design stage.
Spherical roller bearings (SRB) typically offer a high load capacity and a self-aligning feature that allows for some misalignment of the axis of rotation. The unitised design of NSK's new bearings enables easy handling and installation, making them popular across a wide range of industries, including steel, pulp and paper, transportation, extraction and construction, which all require durability and smooth running performance.
Research into extended bearing life
NSK says it researched the SRB design extensively in order to identify the limiting factors on bearing life, and sought to improve the design in order to address them and deliver the extended life of HPS bearings. Key to the self-aligning performance of SRB is the spherical profile of the bearing rollers acting in the bearing inner and outer ring raceways. However, the research showed that under rotation these geometrical forms interact to produce slippage at the contact surface points between the raceways and rollers.
With its HPS design, NSK says it has clarified for the first time the mechanism that causes slippage and creates high friction on the surface, leading eventually to damage due to surface fatigue. NSK further verified, by theoretical analysis and bench testing, that the friction can be reduced by controlling the motion of rotating rollers; and that a special surface treatment of the outer ring is effective in achieving this.
Initially, 42 sizes with outside diameters ranging from 80mm to 260mm will be marketed globally by NSK for a wide variety of industries and applications.
