When industrial machinery fails – either a single component or a complete system – it costs a company resources, time and money. Machinery failure or malfunction suggests that the machine has stopped functioning in the way it was designed or intended. Generally, any malfunctions that cause machinery to underperform – in whole or in part – are considered machine failures. Failures can happen quickly if equipment is not properly cleaned, lubricated, and maintained.

Causes of Machine Failure

Machinery failure is also known as “loss of usefulness” of a machine or component. Loss of usefulness can be broken down into three main categories: accidents, obsolescence, and surface degradation. 

Accidents / Incidents

Accidents and incidents account for 15% of machinery failures. A piece of machinery being handled or operated in an incorrect manner can lead to internal parts becoming damaged, causing failure. This can also happen due to improper training or human error or misuse/abuse of equipment by machine operators.

Obsolescence

Similar to accidents, 15% of machinery failures happen due to a machine’s obsolescence, or more precisely, functional obsolescence. A piece of equipment that’s functionally obsolete has lost it’s value and usefulness because of reduced efficiency and high cost of maintenance. It’s often more cost effective to replace the machinery or component versus trying to maintain it.

Surface Degradation

Surface degradation of parts and components is the most common cause of loss of usefulness and accounts for 70% of machinery failures. The primary sources of surface degradation are corrosive wear and mechanical wear.

Corrosive Wear

Corrosion of machine parts can occur because of

• Water-contamination which can cause rust and increase an oil’s oxidation rate.
• Acid formed from reactions between additives in the lubricating oil and water.
• Contamination from additives leaking onto other components.

Mechanical Wear

As the name suggests, mechanical wear occurs because machine surfaces are wearing against each other. The primary types of mechanical wear are adhesion, abrasion, surface fatigue, and erosion.

• Adhesion – Adhesive wear occurs when a lubricant film has broken down to the point where two surfaces are coming into contact. This is also known as severe sliding wear. The two surfaces come into contact and generate enough heat to weld together momentarily. A break then occurs at the weakest point (usually not the weld line).
• Abrasion – Abrasive wear occurs when particle contaminants are typically larger and harder than the lubricated surface resulting in cutting or gouging of the surface material.
• Surface Fatigue – Fatigue wear occurs when particles are caught between two surfaces under load causing dents and cracking. After several cycles where such stresses have occurred, the metal typically becomes brittle, the cracking spreads, the metal surface fails, and additional particles are released.
• Erosion – Erosive wear occurs when high velocity particles impinge on a component’s surface or edge and remove material. This is similar concept to sand blasting – which you do not want in your machinery.

Failure prevention is the key goal of any machinery maintenance program. This can prevent the high repair costs and lost production time due to equipment breakdown. Proper lubrication of machine components, contamination control, proactive maintenance, timely parts replacement, and proper operator training all help to reduce the possibility of machinery failure.