This in turn has improved the time between failure rate of the part and saved costs, compared to alternative repair methods.

Horsburgh & Scott is based in Cleveland, Ohio, and designs, manufactures, services and rebuilds industrial gearing and gear drives for industry-specific needs. The company has a long-standing relationship with Sifco ASC and has been working with them to solve various component repair issues for 20 years.

The pinion gear is an essential part of a gear train assembly. In this application, the pinion gear was part of the boom driveline of a dragline excavator crane used in the surface mining of coal. If not maintained regularly, lubricant in the pinion gear can leak out of the seal and potentially cause the bearing to seize.

Removal of the seized bearing often results in additional gouging damage to the bearing journal surface.

When Horsburgh & Scott approached Sifco ASC with this problem, the two worked together to look for a solution that would minimise the downtime as well as the cost of the repair.

Traditionally, this type of damage is rectified by component replacement or by repairing the damaged area. Typical repair options include sleeving, welding, metal spray and tank plating. Component replacement can be costly and result in a four to six-week lead-time.

Welding can weaken the strength of the substrate. All of these repair processes require the part to be removed from the equipment and taken off-site for both pre-processing machining operations to remove the defects in the journal and then post-processing machining operations for dimensional restoration.