The Trend Toward Self-Lubricating Bearings

GGB metal-polymer bearings on the production line

As mentioned previously, many plain bearing models are used in aerospace applications—most of them self-lubricating. Self-lubricating bearings utilize a pre-applied dry lubricant, usually PTFE, in place of traditional liquid lubricants. Dry lubricants do not require reapplication and thus entail less maintenance than traditional bearings. This makes them extremely effective in applications where re-lubrication maintenance would prove difficult. Dry lubricants are also able to operate in conditions where fluid lubricants are ineffective, such as environments susceptible to corrosive gases, dirt, and dust; high temperatures; cryogenic temperatures; radiation; extreme pressures; or vacuums—all of which are hazards found in the aerospace industry. Due to these benefits, it is no surprise self-lubricating bearings are being used over traditional metal bearings both here on Earth and beyond in the following applications:

In aircraft landing gear struts, or shock absorbers, where they eliminate ladder cracking and heat damage on the strut rod surface. GGB’s DU-B bronze-backed metal-polymer bearings were chosen by one of the world’s leading commercial aircraft manufacturers to be used in all current production of their landing struts due to their high load capabilities, resistance to corrosion, and increased component life.

The filament winding process for fiber reinforced bearing manufacture.

In aircraft ground support, which requires reliable equipment to ensure flights leave safely and on time. According to Klepach, “GGB’s HSG [High-Strength GAR-MAX®] FRC bearings are found in scissor-lift-type applications, which handle significant loads during intermittent operations, often while being exposed to harsh environmental conditions.” This type of bearing offers ultimate compressive strength up to 620 MPa (90,000 PSI) and more consistent friction than greased bronze bearings—with the added benefit of being both abrasion and corrosion resistant. This helps extend maintenance intervals and improve the efficiency of aircraft ground support services.

Metal polymer bearings on the manufacturing line, after visual inspection.

In NASA’s Curiosity Rover, the largest and most successful Mars Rover to date. As Ricci says, “Curiosity’s arm-drill required bearings that could withstand the harsh Martian temperatures—ranging between -153°C and 20°C—and atmosphere. DU® bearings were chosen due to their high wear resistance, ability to operate comfortably in the temperatures of Mars, and resilience towards dust and debris.” The operation of this arm-drill was critical to the discovery that Mars once had conditions suitable for microbial life.

GGB has also worked with Airbus, Airbus Helicopters, Boeing, Lockheed Martin, private spaceflight companies, the military, and other private aircraft manufacturers to create custom solutions for their plain bearing needs.

Plain bearing solutions provide the aerospace industry with weight and space reduction, enhanced energy efficiency, improved strength and safety, and increased operating temperatures for its ground, air, and outer-space applications.

This article was written by GGB Bearing Technology (Thorofare, NJ). For more information, Click Here.