Research May Lead To Multi-Purpose Grease, Landing Gear Solution
WRIGHT-PATTERSON AIR FORCE BASE, Ohio (USTCNS) - A low-cost replacement grease Air Force Research Laboratory experts developed for cruise missile bearings could help eliminate C-5 maintenance costs caused by corrosion, rust and wear, saving the service big dollars.
AFRL Materials and Manufacturing Directorate experts spearheaded research that led to the grease, known as MIL-PRF-32014 military qualifying grease, which could protect C-5 Galaxy landing gear assemblies. These assemblies contain wheel bearings and many other parts that are exposed to moisture, rain, air, bacterial decontaminants and other phenomena that encourage corrosion.
These parts are coated in grease and lubricated regularly to make them more effective, however changes in the chemical or physical properties of the grease that coats these unique systems also occur under these environmental conditions, according to Ed Snyder, materials and manufacturing directorate researcher.
The grease discovery came as representatives from Hill Air Force Base, Utah, recently asked AFRL researchers to analyze wear and rusting challenges plaguing the C-5 aircraft, Snyder said. Laboratory experts determined that a unique grease they'd developed to solve a problem in cruise missile bearings may provide a solution.
"Because we maintain important relationships with aircraft operators, maintainers and systems program office representatives, they frequently call on us for support with lubricating greases, oils, fluids, solvents and other non-metallic, non-structural materials," said Snyder.
So, Snyder said, when the Hill representatives contacted him, he and his crew performed rigorous analysis and testing and suggested a solution that would improve aircraft performance.
The anticipated applications for the new grease are many, which will also provide significant benefits to manufacturers who meet "military" grease requirements and commercialize a suitable product, he said.
Greases are used in military applications to minimize corrosion, wear and failure in areas where metal components and moving parts function or interact with each other. When compared to liquid lubricant systems, grease systems provide significant weight and design advantages because they are self-contained, which eliminates the need for pumps, tubing, heat exchangers and other extra hardware that increases the weight and design requirements of a system, Snyder said.
In the late 1980s, researchers from the material and manufacturing directorate's nonstructural materials branch began working with various grease companies to find a commercial source of grease to replace a mineral oil sodium soap thickened product used in cruise missiles. While in storage, the mineral oil product reacted with air moisture and bled out of bearings.
Because of the high cost to overhaul the missiles and re-grease bearings, researchers sought grease that could be stored in adverse conditions. Snyder said the grease also had to meet operational requirements, which included allowing the bearing to operate at 30,000 rpm, under an extreme load of 135 kilograms and in temperatures ranging from 175 to 225 degrees Celsius.
"It was extremely difficult to find a grease in the commercial arena that was an appropriate solution to the missile challenge," Snyder said. "No one was making a grease that met the requirements, and there was little incentive for anyone to start because of the small volume of grease the Air Force needed: 1.7 grams per engine, packed every 18 months."
Taking the initiative to meet this challenge, directorate researchers and contractors at the former AMOCO Petroleum Products Co. in Naperville, Ill. (now affiliated with British Petroleum, Inc.), designed the lubricating grease, ultimately assigned the MIL-PRF-32014 military specification. They incorporated anti-oxidant, anti-wear and anti-rust ingredients, and AMOCO custom made and delivered the lubricant to the Air Force in 1994.
Snyder said if continued testing, such as the C-5 flight testing that is in the beginning stages, is successful, researchers expect the grease to replace currently used lubricants and become "near-universal."
AFRL Materials and Manufacturing Directorate experts spearheaded research that led to the grease, known as MIL-PRF-32014 military qualifying grease, which could protect C-5 Galaxy landing gear assemblies. These assemblies contain wheel bearings and many other parts that are exposed to moisture, rain, air, bacterial decontaminants and other phenomena that encourage corrosion.
These parts are coated in grease and lubricated regularly to make them more effective, however changes in the chemical or physical properties of the grease that coats these unique systems also occur under these environmental conditions, according to Ed Snyder, materials and manufacturing directorate researcher.
The grease discovery came as representatives from Hill Air Force Base, Utah, recently asked AFRL researchers to analyze wear and rusting challenges plaguing the C-5 aircraft, Snyder said. Laboratory experts determined that a unique grease they'd developed to solve a problem in cruise missile bearings may provide a solution.
"Because we maintain important relationships with aircraft operators, maintainers and systems program office representatives, they frequently call on us for support with lubricating greases, oils, fluids, solvents and other non-metallic, non-structural materials," said Snyder.
So, Snyder said, when the Hill representatives contacted him, he and his crew performed rigorous analysis and testing and suggested a solution that would improve aircraft performance.
The anticipated applications for the new grease are many, which will also provide significant benefits to manufacturers who meet "military" grease requirements and commercialize a suitable product, he said.
Greases are used in military applications to minimize corrosion, wear and failure in areas where metal components and moving parts function or interact with each other. When compared to liquid lubricant systems, grease systems provide significant weight and design advantages because they are self-contained, which eliminates the need for pumps, tubing, heat exchangers and other extra hardware that increases the weight and design requirements of a system, Snyder said.
In the late 1980s, researchers from the material and manufacturing directorate's nonstructural materials branch began working with various grease companies to find a commercial source of grease to replace a mineral oil sodium soap thickened product used in cruise missiles. While in storage, the mineral oil product reacted with air moisture and bled out of bearings.
Because of the high cost to overhaul the missiles and re-grease bearings, researchers sought grease that could be stored in adverse conditions. Snyder said the grease also had to meet operational requirements, which included allowing the bearing to operate at 30,000 rpm, under an extreme load of 135 kilograms and in temperatures ranging from 175 to 225 degrees Celsius.
"It was extremely difficult to find a grease in the commercial arena that was an appropriate solution to the missile challenge," Snyder said. "No one was making a grease that met the requirements, and there was little incentive for anyone to start because of the small volume of grease the Air Force needed: 1.7 grams per engine, packed every 18 months."
Taking the initiative to meet this challenge, directorate researchers and contractors at the former AMOCO Petroleum Products Co. in Naperville, Ill. (now affiliated with British Petroleum, Inc.), designed the lubricating grease, ultimately assigned the MIL-PRF-32014 military specification. They incorporated anti-oxidant, anti-wear and anti-rust ingredients, and AMOCO custom made and delivered the lubricant to the Air Force in 1994.
Snyder said if continued testing, such as the C-5 flight testing that is in the beginning stages, is successful, researchers expect the grease to replace currently used lubricants and become "near-universal."
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