Posted on May 20, 2025 John Symond
Among the many elements present in aircraft and spacecraft, bearings are integral for supporting the performance of numerous mechanical assemblies. Situated everywhere from flight control surfaces to engine components, these precision-engineered parts serve to reduce friction between moving elements and efficiently manage various load conditions. In this blog, we will explore the types of bearings commonly used in aerospace, some of the assemblies they are present in, and how their specialized designs support peak performance under the demanding conditions of flight.
Ball bearings are characterized by spherical rolling elements positioned between inner and outer raceways, enabling low-friction rotation while supporting both radial and axial loads. Though simple in nature, they allow for high-speed operation, consistent motion, and minimal energy loss. Additionally, their design minimizes surface contact, which helps reduce heat generation and mechanical wear during sustained use.
Roller bearings utilize cylindrical rolling elements to increase the contact area between bearing surfaces, translating into higher load-carrying capacity under heavy radial stress and higher speeds, as well as effective force management in continuously rotating systems. Moreover, tapered variants further bolster performance by supporting combined axial and radial loads. On the other hand, aerospace versions are typically built with hardened raceways and precision-matched rollers to ensure uniform distribution of stress and long-term wear resistance.
Spherical bearings consist of an inner ring with a spherical convex outer surface and an outer ring with a matching concave inner surface, allowing for self-alignment and angular motion without losing load capacity. As such, these bearings are able to absorb structural variations and dynamic movement without producing undue stress on surrounding components. Their internal construction also promotes smooth articulation, and aerospace-grade versions are often enhanced with tight radial clearances and anti-friction liners or inserts for prolonged service life under variable conditions.
Rod end bearings integrate a spherical bearing within a threaded or otherwise mountable housing, forming a compact, articulating joint capable of managing both angular motion and load transmission. The internal spherical component permits a degree of rotation and misalignment, while the external housing provides a secure connection point within assemblies. This variant’s inherent alignment flexibility and ability to operate under continuous mechanical stress makes it especially beneficial in applications where space is limited or where components must operate across shifting motion paths.
Thrust bearings are built to carry loads parallel to the shaft axis rather than perpendicular. They usually feature flat or slightly contoured rolling elements arranged between hardened races to evenly distribute axial forces and maintain rotational alignment, ensuring dependable performance under significant mechanical stress and preventing displacement in rotating assemblies.
Bearings are prized for aircraft control surfaces like ailerons, elevators, rudders, and flaps, as these elements rely on precise, low-friction movement to adjust aerodynamic forces during flight. Rod end bearings are commonly employed here due to their ability to handle misalignment while transmitting motion between linkages. In spacecraft, similar mechanisms for attitude control and positioning of solar arrays also depend on bearing assemblies to enable precise maneuverability in zero-gravity environments.
Jet engines, gas turbines, and auxiliary power units (APUs) are high-speed rotating systems that demand components that can manage extreme temperatures, high loads, and intense centrifugal forces. Ball bearings and roller bearings are often employed in these settings, with variants specifically designed to withstand heat and maintain stable operation at tens of thousands of revolutions per minute to serve thrust generation and energy conversion systems.
The deployment and retraction of landing gear systems require robust mechanical actuation, and bearings are central to these operations. Spherical bearings are frequently used here for their strength and ability to accommodate angular misalignment under heavy loads. They support hinge points, rotary actuators, and damping systems, absorbing shock loads and facilitating motion during takeoff and landing.
Beyond critical flight systems, bearings are also used in aircraft cabin equipment like overhead bin latches, seat recliners, and galley mechanisms, typically being miniaturized and lightweight variants. While the demands on these bearings are significantly less extreme than those in engines or flight control systems, they are still essential for supporting smooth, reliable motion in high-use, passenger-facing assemblies.
Unlike bearings used in standard applications, aerospace versions are custom-engineered to meet the extreme demands of the troposphere and beyond, which include temperature shifts, high G-forces, vibrations, and in the case of spaceflight, vacuum exposure. They are also subjected to intensive dimensional inspections, load testing, non-destructive evaluation, and certification to industry standards like AS9100 and MIL-SPEC, all to ensure consistency and safe performance.
To optimally balance the demands for low weight, high precision, and durability under severe operational stresses, aerospace bearings are made from high-performance materials like M50 steel, 440C stainless steel, or advanced ceramic composites. Additional enhancements like shields, seals, and integrated lubrication systems are also commonly implemented to safeguard internal components from moisture, debris, and corrosive exposure. In spacecraft specifically, materials must be vacuum-compatible and non-outgassing, making dry-lubricated surfaces and carefully engineered compositions essential for reliable performance in orbit.
Sourcing reliable, high-performance bearings is non-negotiable for operators and maintenance professionals across the aerospace sector. ASAP Semiconductor, through its purchasing platform Buy NSN, serves as a trusted partner in this domain. We reduce sourcing complexity by offering access to a wide selection of industry-compliant bearings and other aerospace components, all sourced from vetted manufacturers and subjected to rigorous quality assurance measures. Paired with a commitment to competitive, efficient, and customized procurement, we deliver solutions you can trust every time. If you are interested in seeing how we can seamlessly meet your needs, reach out to our specialists at your convenience!
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