By repairing the pinion gear of a mining crane in-situ with the SIFCO Process®, industrial gearing manufacturer Horsburgh & Scott Co. was able to return the crane to service with minimal downtime and extend the working life of the gear components.
This in turn has improved the time between failure rates of the part and saved significant cost compared to alternative repair methods.
A Gouging Problem
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 and gall the bearing journal. Removal of the seized bearing often results in additional gouging damage to the bearing journal surface.
When Horsburgh & Scott Co. approached SIFCO ASC with this problem, they worked together to look for a solution that would minimise the downtime as well as the cost of the repair.
A Selective Solution
Using the SIFCO Process®, a portable plating process used to selectively electroplate localised areas; defects are typically repaired with one or more layers of copper, and then covered with a wear resistant deposit.
For this application in which the gouge in the journal was filled with copper, no machining was required and only one layer of nickel was plated to achieve the desired journal dimension. This resulted in a repair that was significantly less expensive that other alternatives requiring pre and post-process machining.
Dave Niederhelman, chief metallurgist, Horsburgh & Scott Co. said: "SIFCO ASC is a well-established partner of Horsburgh & Scott and their ability to work on-site is highly attractive. Over the years they have helped us to find the most efficient ways to repair and maintain our customers’ equipment and this has added up to thousands of dollars, hours of downtime, and manpower time saved.
"In this application the SIFCO Process® has extended the working life of the gear and improved the failure rate due to the nature of the nickel coating on the journal. The cost of manufacturing and material to replace the gear would have been expensive in comparison, as well as causing weeks of downtime."
Lee Shelton, managing director of SIFCO ASC said: "At SIFCO ASC, we understand the inconvenience caused when critical components fail and need urgent repair. The portability of the SIFCO Process® makes it a versatile solution used for numerous demanding repair and OEM applications.
"The localised plating process works well in an industrial environment. The plated deposits withstand considerable stress and strain, while maintaining excellent adhesion."