For many years, Alcoa’s fixed plant maintenance personnel have utilised webbed or wire slings wrapped around the circumference of large bearings to lift them into position, or remove them from crushing and conveying equipment.
New or used bearings are nearly always covered in grease and when combined with the smooth metal surface of the bearing, web or wire slings are susceptible to slipping which creates significant potential for serious injury.
At one of the quarterly Alcoa WA Mining, health and safety summits, a maintenance employee mentioned a recent incident where the webbing had slipped on a crusher screen deck bearing.
The fixed plant maintenance group decided this safety risk was not acceptable and drafted a sketch of a lifting clamp during the summit.
The first trial of the finished product involved changing out 400mm diameter (50kg) screen deck bearings and proved extremely successful in holding the bearing throughout the removal and installation process.
The concept of an all in one bearing clamp and lifting device can be applied to any large diameter bearing and the clamp adjusting bolt allows the one clamp to be used for bearings of slightly different sizes.
The bearing lifting jig had the hierarchy of safety control applied and through engineering design, the hazards associated with the previous method were eliminated. This engineering control eliminates the hazard of unsecured loads.