Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1449093
30 | January - February 2022 | www . machinerylubrication.com Why Equipment Fails And What You Can Do To Prevent It Ray Garvey, Matthew Fergusson and Mike Rostosky MECHANICAL FAILURE Unplanned repairs and unplanned downtime are ten times more expensive than planned repairs and planned downtime. In addi- tion to being expensive, unplanned downtime is unproductive, disrup- tive, distracting and sometimes causes collateral damage. Planned is manageable; unplanned is not. Planning repairs to equipment requires advance notice months before critical components fail. To this end, one must understand the following: • Why do equipment components fail? • What are likely failure mecha- nisms for those components? • What are the factors that initiate and accelerate the failure mech- anisms? • What are factors that mitigate or avoid the failure mechanisms? • What proactive condition moni- toring methods can identify contributing factors that accel- erate failure mechanisms? • W hat predictive condition mon itoring met hod s c a n measure failure progression from incipient to catastrophic? Failure Mechanisms Abrasion, adhesion, fatigue, electric discharge, corrosion and deposition are common failure mechanisms from the referenced literature. Characteristics of these failure mechanisms are listed in Table 1 and described below. Abra sion affects nearly all mechanical systems. It begins when silica dust particles are transported by the lubricant to a narrow clear- ance between moving surfaces. Hard pa r ticles that are too large to pa ss t h r o u g h b e c o m e embedded into one surface and cut the other. e shear force between the lubricated hard particles and the moving surface cut a V-notch into the moving metal surface. is cutting process emits a spec- trum of mechanical vibration from the point of abrasion and generates abrasive wear debris, which is carried away by the lubricant. is mecha- nism generally is not self-propagating and is easily offset by contamination control. It can be triggered by a surge in the circulating system or by a defective breather. Adhesion (or boundary wear) impacts nearly all mechanical systems with loaded components. Adhesive wear and other boundary "Unplanned repairs and unplanned downtime are ten times more expensive than planned repairs. "