Pendant plusieurs décennies, les boîtiers de roulements des poulies de convoyeurs ont été protégés de l’environnement grâce à des méthodes d’étanchéité de type labyrinthe. Bien qu'il y ait eu des itérations au fil des ans, elles adoptent fondamentalement une approche de scellement basée sur un « chemin tortueux et rempli de graisse ».
DASH Engineering est un consultant impartial et indépendant en roulements situé à Perth, en Australie occidentale, spécialisé dans l'analyse des défaillances des roulements. Après avoir mené des centaines d'enquêtes sur les défaillances de poulies de convoyeurs, la majorité des défaillances étant attribuées à la pénétration de contamination, DASH Engineering a prouvé que les méthodes d'étanchéité traditionnelles et la norme industrielle – « Solution à trois barrières » – ne sont pas efficaces pour empêcher la pénétration de saleté et d'eau dans le roulement. logement. Des tests indépendants et de nombreuses études de cas ont démontré que la graisse agit comme un vecteur de contamination plutôt que comme une barrière. De plus, les méthodes d'étanchéité traditionnelles ne prennent pas en compte le désalignement et le flottement requis dans les applications de poulies de convoyeur.
…”c’est un changement radical dans le secteur minier” – Manager-Asset Management
With the overwhelming majority of DASH Engineering failure reports recommending to ‘review sealing methods’, it became evident that there was no other effective method of keeping contamination out of the bearing housing, sparking the development of the SAPO® Seal.
…” savings will be comparable to AutoHaul” – Site-based Project Manager
The Self-Aligning Pressurised Oil (SAPO®) Seal is a patented, engineered sealing solution that will accommodate misalignment requirements without compromising on sealing effectiveness. Furthermore, SAPO® Seals are fully maintainable, monitorable and predictable providing peace of mind to the end user.
In order to effectively maintain positive sealing, the SAPO® Seal is designed to float with respect to the housing as well as remain parallel with the shaft. This unique design allows for articulation to the allowable misalignment limits of spherical roller bearings.
The SAPO® Seal does not rely on grease as a sealing medium. Positive pressure oil is used to ensure the oil seal lips remain lubricated and simultaneously captures fine dust particles. Regular oil sampling and flushing ensures seal performance is monitored and maintained throughout its life.
…” we need to make them all like this” – Fitter-Site Installation Team
Current plummer block sealing methods tend to damage shafts – often damaged beyond repair. SAPO® Seals eliminate this problem with a simple solution. The units are designed to run on wear sleeves to prevent abrasive damage to shafts.
SAPO® Seals are fully maintainable, monitorable and predictable with state-of-the-art intra-bearing housing endoscopic monitoring via the SAPO® Scope. Maintenance personnel are able to visually monitor the housing cavity for contamination ingress and excessive bearing greasing whilst the machine is fully operational. This type of visual monitoring is truly unique in providing peace of mind and removes any doubt in regard to contamination ingress.
SAPO® Seals can also be used to assist with pulley alignment during installation, reducing set-up time and risk, increasing safety and efficiency. A simple yet effective technique allows for on-the-go visual alignment guidance and final quality assurance checks to remove any doubt during pulley install.
…” most significant benefit will be that we finally have effective, multi-level monitoring of bearing condition as risk mitigation against unplanned failures” – Site Engineer
The implementation of SAPO® Seals have enabled multiple critical pulleys to achieve upwards of two times the previous mean time between failure (MTBF) across Australia’s Pilbara iron ore operations. Case studies on high grade iron ore conveyor systems have resulted in:
increased production
elimination of unplanned downtime
cost savings in the order of tens of millions of dollars
SAPO® Seals allow clients to switch from time-based maintenance techniques to condition-based maintenance methods.
A large 2m diameter pulley weighing approximately 28 tonnes on a system conveying bulk material across the Pilbara was changed out every six months due to repeated rapid
contamination ingress related failures. The site team decided to make the switch to SAPO® Seals and have experienced reliability and predictability to another level.
Une autre poulie critique sur un système de convoyeur de chargement de navire rencontrait des problèmes de fiabilité qui provoquaient des temps d'arrêt imprévus coûtant des centaines de milliers de dollars. La poulie a été équipée de joints SAPO ® à la prochaine occasion et fonctionne de manière fiable depuis le changement.
La mise en œuvre des joints SAPO ® n'a nécessité aucune modification des boîtiers de roulements standard de type « SD ».