BMG’s technical services team recently conducted a condition monitoring case study to assess continuous health on rock winder headgear sheave wheel bearings. The objectives of this condition monitoring study included the prevention of unplanned failures on sheave wheel bearings and the elimination of secondary and collateral damage to shaft components and employees.
“BMG’s SPM HD technology provides reliable forewarning to plant personnel to allow them to either perform required maintenance or to schedule a planned component replacement, thus minimising repair costs and reducing downtime,” says Pieter van Zyl, BMG condition monitoring manager. “The team encountered challenges during this case study, which included rope-slap, variable speed, changing loads and shifting load zones. These have been the biggest challenges in the past, when attempting to perform predictive maintenance effectively on this application.
“These obstacles were efficiently overcome by utilising patented filters and algorithms such as a disturbance rejecter, symptom enhancer and HD order tracking. Slow rotational speeds of mining headgear sheave wheels make this application especially suitable for our SPM HD technology, which monitors both the bearings’ mechanical and lubrication condition.”
Shock pulse sensors were permanently installed on the over and underlay sheave wheel bearings of a rock winder, in conjunction with a frame mounted speed sensor. The sensors were all connected to an SPM Intellinova continuous monitoring system. The SPM HD technique, in combination with a shock pulse transducer, is perfectly suited to the monitoring of speed applications as low as 1 rpm. An integrated lubrication system, which continuously measures lubrication condition, automatically lubricates a bearing in the event that a lack of lubrication is identified.
Based on the results of this case study, it is evident that the shock signal was influenced by the speed, loading and direction of rotation, which would be expected. This is seen in the resultant ‘double trend’ of a defective bearing. Towards the end of bearing life, the delta value between the mechanical condition trend and lubrication condition trend decreased.
This condition monitoring system offers continuous bearing and lubrication condition information to complement regular interruptive inspections that are legally required, by giving the responsible certified engineer critical information about the physical health of the sheave wheel bearings while in operation.
During this test, defective bearings were identified and have subsequently failed.
BMG offers condition monitoring products for users at every level. The company’s portfolio of SPM condition monitoring equipment extends from basic hand-held instruments, to high-level on-line systems.
For more information contact Pieter van Zyl, BMG, +27 (0)11 620 1570, pieterva@bmgworld.net, www.bmgworld.net
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