Know About Common Causes of Gearbox Failure

Gearbox failure is one of the most common reasons of machinery malfunction. These gearboxes fail several times, even though it is the last desired thing in an industrial operation. In order to prevent gearboxes from failure, engineers must identify the cause of failure. There are several different factors that may cause a gearbox failure. Thus, a gearbox repair and maintenance engineer has to consider all the possibilities of gearbox failure in order to identify the correct one. Also, the consideration of causes of gearbox failure at an early stage of the gear design process helps in designing the gearboxes for reliable and durable operation. Owing to the benefits of gearbox failure cause identification, it is essential to know about all the causes of gearbox failure, so that the failure can be prevented. This post discusses all the possible causes of gearbox failure.

Different Potential Causes of Gearbox Failure
A gearbox being a driving assembly of a mechanical equipment system, it is subjected to multiple functional failure factors. The following are some potential reasons behind gearbox failure acknowledged by industry experts during gearbox failure analysis procedures.

  • Wear: Each moving mechanical component is exposed to wear and tear damage. The gearboxes are no exception to this problem. The gearbox can go under several types of wear which over time can result in component failure, gear breakdown, or gear assembly failure. The following are some types of wear that are proven to be the reasons behind gearbox failure.
  • Abrasive Wear: This takes place due to friction between two elements of gearbox assembly. It causes radial scratches, groves, deep material removal from the friction exposed sports on the gear. If this abrasion wear goes excessive at addendum or dedendum of the gears, it becomes a cause of gearbox failure.
  • Corrosive Wear: The metal surface of the gearbox is exposed to chemicals, oil, and rust, which causes corrosive wear. Corrosive wear deteriorates the strength of gear material. This can cause abrupt breaking of the gear surface.
  • Inadequate Lubrication: Inadequate lubrication increases friction in gearbox operation. Friction generates heat, pitting (contact fatigue), and abrasive wear which further results in gearbox failure.
  • Misalignment: Gear assemblies are designed for specific meshing curve, contact points, fit on the shaft, torque and backlash. Therefore, slight misalignment of any gearbox component can cause overlapping of the component travel path. This can cause assembly blockage, abrupt and permanent failure of gearbox.
  • Overloading: As gears are subjected to load from several directions. However, gears and gear assemblies are specifically designed for a significant amount of load tolerance. If the gear assembly is overloaded, it can suffer bending fatigue, which results in tooth-breaking, addendum and dedendum cracks, and complete failure in extreme overloading cases. The bending fatigue can reduce impact resistance of the gear and the shaft and mounting it is assembled on which may result in a sudden breakdown.
  • Installation and Handling Errors: Installation errors can result in instant malfunctioning of the gearbox assembly. 17.7% of gearbox failures are caused by installation errors. Whereas, inappropriate handling, or rough handling, sudden assembly turndown, etc are handling errors. These handling errors if not reduced soon, they can damage the gearbox assembly in long run. 2.8% of gearbox failures are recorded due to handling errors.
  • Scuffing: This is inter-transfer of material from gear to the pinion or vice versa. Scuffing results in defective surface composition, defective surface finish and gear profile damage, this is one of the causes of gearbox failure.
  • Frosting: Frosting takes place when the lubricant layer breaks due to excessive heating. It causes micro-pitting, which increases friction and eventually gearbox failure.
  • Surface Contamination: Gear surface contamination with dust and metal chips, can damage the surface. It can create scratches, cavities, scratches on the surface and can increase friction and heat generation which may result in gearbox failure.

Considering the above-mentioned causes of gearbox failure, it is important to source good quality gearboxes from trusted suppliers like Motor & Gear Engineering, Inc. For over 45 years, the company has been providing gearbox repair and rebuilding services for Falk, Horsburgh & Scott, Philadelphia gearboxes, etc.