Eight common causes of gear failure

The cause of gear failure can stem from many issues, but the most common is due to wear, which occurs for different reasons.
By David Manney, L&S Electric September 26, 2016

The cause of gear failure can stem from many issues, but the most common is due to wear and that occurs for different reasons. Courtesy: L&S ElectricMachinery breakdowns are often the result of gear failure. The cause of gear failure can stem from many issues, but the most common is due to wear. Any component within the machine is going to wear down from constant use. If it occurs with gears, it can have a detrimental impact on the equipment’s operation.

Gear failures due to wear may occur for different reasons. The reasons listed below are some of the more common causes for gear failure:

1. Moderate wear: This type of where leaves contacts patterns that show the metal has been affected in the addendum and the dedendum area. Issues with inadequate lubrication commonly cause it, but it may also be due to contamination in the lubrication as well.

2. Excessive wear: This is wear that has continued to be a problem until a significant amount of material has been affected on the surfaces. You may see pitting on the surface with excessive wear, typically caused by not seeing the first wear early enough, and it continues to progress.

3. Abrasive wear: In gears that are showing signs of abrasive wear, it may appear as radial scratch marks, grooves or some other identifier that would show contact is a problem. One of the most common reasons why abrasive wear takes place is due to foreign bodies in the lubrication. This issue could include metallic debris from the bearings or gear system, rust, sand or weld spatter. It is common in new systems before the filter can clean the system.

4. Corrosive Wear: Chemical action deteriorates the surface of the gear, such as through acid, additives or moisture in the lubrication oil. As the oil breaks down, the chemicals that exist in the lubricant attack the surfaces. It tends to result in uniform, fine pitting on the two surfaces.

5. Frosting: This issue usually shows up in the dedendum area of the driving gear. The wear pattern gives a frosted appearance, which are many micro pits on the surface. Frosting is a common issue when the heat breaks down the lubrication film.

6. Spalling: Although it is similar to severe pitting, the pits tend to be shallow and larger in diameter. Additionally, the area that is showing spalling does not tend to be uniform. It is a common problem when high contact stress exists.

7. Pitting: A problem with pitting can be labeled as either initial, in which the surface is experiencing small pits to destructive, in which the pits are larger in diameter. Initial pitting may be a problem with the gears not fitting together properly. Destructive pitting is typically an issue with surface overload.

8. Breakage: It is possible for the entire tooth or a piece of the tooth to break away. It often leaves evidence of the focal point of the fatigue that led to the break, which results from any number of issues, including high stress or excessive tooth loads.

When an issue with the gears takes place, it is necessary to determine if a rebuild, upgrade or replacement is the best choice available. We can help you to make the best decision according to the problems that exist and care for the work for you to ensure that your equipment is up and operating again.

David Manney is a marketing administrator at L&S Electric. This article originally appeared on L&S Electric Watts New BlogL&S Electric Inc. is a CFE Media content partner.