WARNING! THESE BEFORE AND AFTER PICTURES ARE A HUGE SUCCESS – NOT A FAILURE! PLEASE READ CAREFULLY…
Already a current valued customer, a paper mill approached W.S. Hampshire, Inc. with a problematic application. The existing design – a bronze sleeve bearing used in the dryer section of their paper machine– was a chronic problem. It seems that would experience lubrication failures with no predictable frequency. When that happened, the bronze bearings would fail and an immediate unplanned outage was needed to prevent costly damage to the housing, journal, and related components. Those of you in the steel, paper, lumber, or any other processing line would understand the pain of this.
When asked for our expertise, WS Hampshire was able to quickly and confidently recommend Ryertex CG, a graphite impregnated material that is “self–lubricating”– meaning in bearing form, it can operate without lubrication for some time– preventing an unplanned shutdown. Designing a like–for–like part enabled the mill to quickly and inexpensively install a test set of bearings. They also evaluated spherical roller bearings, but would have incurred significant cost to redesign and install the bearing housing.
The two pictures above show the bearing upon installation. In the left photo, since this replicated the metal part design, you’ll see that grease grooves were machined in. Also notice the top and bottom collar/flanges. The right photo shows what seems to be a failed bearing – notice the grease groove are gone and the collar/flanges have worn away as well. The material is cracked and charred.
BUT THIS WAS A SUCCESS! Why? The customer intentionally ran the bearing in continuous service for 5 weeks – with ZERO external lubrication – and at temperatures exceeding 550 F – FOR 5 WEEKS (yes that is repeating). A bronze bearing with ZERO lubrication would have lasted a MAXIMUM of 36 hours. The customer estimated that approximately $40,000 – $50,000 in parts, labor, and lost production would have been saved if this was a real time event since the 5 weeks represented a full maintenance cycle.