Lubrication Considerations for Military Equipment

Proper lubrication of military equipment enhances performance and minimizes maintenance.

December 1, 2008

DuPont Performance Lubricants

Military equipment is subject to increasingly harsh environmental conditions and performance requirements. Simultaneously, engineers and equipment operators are demanding longer service life and less maintenance. The proper approach to lubrication is critical to minimizing equipment failures and meeting rigorous performance specifications. While a multitude of environmental and technical variables may affect lubricant selection and use, the following considerations are important to address whenever a new lubricant is selected:

Understand equipment operating temperatures. Critical to proper lubrication is selecting the right lubricant for the equipment's operating temperature range. Temperature impacts the viscosity of the oil and the capabilities of the additives, ultimately changing how the lubricant performs. Therefore, it is important to know the coldest and hottest temperatures that the equipment could possibly encounter, as well as the standard operating temperature, to ensure the correct lubricant is specified.
Consider speed and load of the equipment. Equipment that turns slowly and/or has a heavy load requires higher viscosity base oil and different additives than equipment with a higher speed or lighter load.
Be aware of environmental factors. The cleanliness of the equipment's operating environment as well as other factors, including exposure to chemicals, moisture, vacuum, etc., will affect lubricant selection and performance under various conditions.
Do not over- or under-lubricate. Excess grease generates heat that can soften seals or cause equipment failure. Too little grease can increase wear on the equipment. Further, different greases deliver optimum results at different fills, so it should never be assumed that a new grease should be applied in the same amount as the existing lubricant.
Do not rely heavily on the equipment's lubrication history. A lubricant is often selected for the wrong reasons or, over time, operating conditions change significantly, making the existing lubricant an inappropriate choice. When selecting a new lubricant, it is important to carefully consider equipment requirements and use the current lubricant only for general guidance.
Use caution when cleaning bearings. The solutions used to clean bearings and the overall cleanliness of the bearings can impact the performance. Cleaners must be compatible with the specific lubricant. This is especially important in high-precision applications, such as aerospace.
Recognize the potential for lubricant interaction with bearing materials. Bearings and seals used in military applications are often made with unique materials. It is important to understand how these compositions could react with various lubricants to ensure there is no chemical reaction that could interact with the lubricant or degrade the bearings.

In addition to these basic considerations, engineers and equipment operators should also avoid common lubrication pitfalls such as mixing greases, which can affect the penetration and overall performance of the lubricant; and introducing dirt from the zerk into the bearings during the initial fill or re-lubrication.

If these best practices are followed and the equipment is otherwise properly maintained, bearings could last years without re-lubrication, significantly reducing maintenance requirements and cost, and promoting optimized equipment performance.

This article was written by Greg Bell, head of technical service and product development for DuPont Krytox® performance lubricants. For more information, Click Here .