Roulements - 28/08/2009
NSK SAVES BAKERY CHAIN €102.863 PER ANNUM; SOLVING CONTINUOUS FAILURE PROBLEM WITH NEW DESIGN OF SPHERICAL ROLLER BEARING
Substituting NSK’s new HPS™ Series of spherical roller bearings (SRB) for conventional SRB on a baking dough mixing machine is providing cost savings of €128.038 per annum, plus extended product life, improved productivity and reduced maintenance for a major UK bakery chain.
The failure problems were due to high loading on dough mixing spindles, causing premature wear due to deflecting shafts; and ‘Swashing’, or reciprocating motion within the SRB bearings, resulting in continuous failures. The cost of these failures was considerable: the yearly total for bearings, maintenance, engineering time and lost production, amounting to of €154.973
An engineer from NSK was called in to evaluate the problem and suggest a solution that would reduce the ongoing costs. The engineer’s response was to suggest replacing the existing SRB units with a totally new design: the NSK HPS™ Series of high performance SRB.
Crucially with its HPS™ design, NSK has clarified for the first time in the world the mechanism that causes slippage and creates high friction on the bearing surfaces of SRB, leading eventually to damage due to surface fatigue. This was verified by extensive testing; that 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. Based upon these findings, NSK developed HPS bearings, which can minimise /slippage, prolonging running life by more than twice that of conventional products.
Following NSK’s recommendation HPS™ series bearings were fitted to the dough mixing machine for trials. To-date the trial has run for 9-months with no failures; this compares with the regular 2-3 months lifespan of the original non NSK units.
Based upon this performance the customer has calculated savings of €102.863 per annum. This figure has been reached after a projected (as there have been no failures to date) cost saving breakdown, which showed a total cost for the new design – including bearings, production time and maintenance of €26.890 /annum (technical support and engineering time is no longer required).