3 Most Common Gearbox Failures

Each year, companies invest hundreds and thousands into their operations. Many of these operations use industrial gearboxes from brands like Sumitomo Drive Technologies. Even with proper maintenance and regular operating conditions--sometimes gearboxes fail.

The most common failures we see at our gearbox repair facilities are:

1. Gear Failure

Within the gearbox, the gears transmit force and determine the output shaft's specific ratio. Several factors can lead to gear failures within the housing, including:

  • Oil contamination causing micro pitting or fretting within the gearbox
  • Gears that are misaligned
  • An excessive amount of heat

Most gearbox failures are caused by contamination of the gearbox fluid. Mechanical failures within the unit can cause this - for instance, metal shavings from a failed bearing. As these metal particles work their way between the gears, they cause minor fractures in the metal, leading to either slippage, overheating, or failure. The gears can also fail due to misalignment. In most cases, this is the result of an incorrectly serviced gearbox.

Curious about learning more about Oil Analysis? Download this Whitepaper.

2. Bearing Failure

It is estimated that a premature bearing failure causes more than 50% of all gearbox failures. It is common for bearings to fail due to excessive axial or radial loads, improper lubrication, or over-lubrication.

In some cases, loading issues can be caused by mechanical failures, depending on the specific application. Overloading the gearbox's output shaft will cause the force to be transmitted to the bearing, resulting in bearing damage. This is identified by analyzing the fatigue or "spalling" on the ball path within the bearings races. Failures can also be caused by improper lubrication. Over-lubrication of the gearbox can result in excessive heat due to friction between internal fluids. In the event of under-lubrication, friction between metals will eventually cause a catastrophic mechanical failure.

3. Sealing Component Failure

Several factors can lead to sealing component failures, including:

  • The seal material has been eroded by dirt, sand, metal, or other abrasive materials
  • Incorrectly sized seals installed during maintenance
  • An excessive amount of heat

Contamination is the leading cause of seal failure on gearboxes. In the gearbox, dirt, and debris tend to accumulate at the seal and shaft seams as they rotate. With time, this dirt tears into the seal and creates a leak. As a result of leaks in the gearbox, it loses lubrication, which can lead to other failures. Furthermore, if the gearbox gets too hot, the seals will warp.


About Sumitomo Drive Technologies 

Sumitomo Drive Technologies has been trusted by many to provide quality products and innovative solutions to help our customers solve their complex challenges. This rich history has made us a leading manufacturer of power transmission and control products such as gearmotors and industrial gearboxes for a wide variety of applications for leading brands around the globe. For more information about our products and services, please contact us.

Related Content