PLANT DESIGN
Hanson’s Molong Quarry has been in continuous operation for almost 30 years.
BLOCK UNIT OVERHAUL BEATS BEARING, SHAFT FAILURES
A Hanson operation in the central west of New South Wales has turned to solid block housed units to address numerous bearing and shaft failures in its conveyor tail pulleys.
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maintenance program to replace all conveyor bearings with Timken SRB solid block housed units (previously known in the industry as Blue Brute housed bearings) has meant an end to bearing and shaft failures in the tail pulleys at the Hanson aggregate quarry at Molong in New South Wales’ central west region. In continuous operation for almost 30 years, Molong Quarry has been an integral part of Hanson Australia since 2005. One of the leading sites in the group, the quarry produces aggregate for construction and building projects throughout the central west region. A series of bearing and shaft failures, predominantly in the conveyor tail pulleys, initiated a search for a reliable replacement in the tough working environment. “By its very nature, a quarry is tough on components such as bearings,” said Molong Quarry’s manager Chris Cooke. “They are generally covered in dust all the time. And each time a bearing or shaft failed meant a couple of days’ lost productivity while the damaged component was removed and the replacement fitted.” Cooke said the removal and replacement process would affect the site’s run of materials and also occasionally delay deliveries. Designed to operate in the toughest of environments, the SRB solid block housed units (SBHU) are considered ideal for heavy32
Quarry August 2019
An SRB SBHU installation.
duty operating environments. They offer continual extreme load and speed capacity due to the size and number of the two rows of rollers. They are designed to allow for limited shaft and housing misalignment (up to 1.5 degrees from centre) and still work at full capacity. The bearings are distributed nationally through the BSC branch network. “Around the time failures started we were invited to a workshop at the local BSC branch, where they were demonstrating the SRB SBHU product,” Cooke said. “After having a good look at what they [the SRB SBHUs] had to offer, we didn’t need
much convincing. The benefits were easy to see and gave us the solution we needed.” The Molong Quarry uses the two-bolt pillow block unit, one of seven housing styles available. Four locking styles and seven seal types combine to offer a range of housed bearings to suit virtually any industrial work site and environment. The range will suit shaft sizes from 35mm to 180mm. To improve maintenance access, Cooke installed greasing lines to the bearings. “Some of the bearings are hard to get to, so we have installed grease lines to make them accessible from ground level,” he said. “The
