Top Aerospace-Grade Bearings and Their Flight Applications

Countless aerospace systems demand uninterrupted rotational or linear motion to function correctly, often relying heavily on bearings to support this movement. Aerospace-grade bearings need to meet far more stringent standards than their standardized counterparts, facing extreme load variations, fluctuating temperatures, vibrations, and more while having to meet specific weight and material specifications. With so many types available on the market, this blog will cover the characteristics and best applications for the most-utilized bearing types in aerospace systems.

Ball Bearings

Ball bearings are versatile for many purposes, offering high speed tolerance and precision capabilities. Comprising an inner and outer race separated by spherical rolling elements, these bearings minimize rotational friction while supporting radial and, in some cases, axial loads. Of the many configurations in use, some notable options include:

• Deep Groove Ball Bearings: These bearings have uninterrupted raceway grooves that allow them to support radial and moderate axial loads in either direction, presenting high-speed capabilities and low friction.
• Angular Contact Ball Bearings: Designed with offset raceways, angular contact ball bearings are capable of handling combined axial and radial loads simultaneously. Their structure enhances load distribution when axial forces are present, and they are typically mounted in pairs or sets to manage forces in multiple directions.
• Self-Aligning Ball Bearings: With a double-row design and a spherical outer ring raceway, self-aligning ball bearings permit limited angular movement to compensate for shaft misalignment.

Standard Applications

• Navigation instruments and control mechanisms
• Helicopter rotor heads
• Flight control actuators

Roller Bearings

Roller bearings use rolling elements in the form of cylinders, cones, or elongated needles rather than spherical balls, enabling them to support much higher radial loads. While they are ideal for use in high-stress aerospace systems, their larger contact surface areas tend to result in more friction, so their implementation often requires precise alignment and consistent lubrication to reduce wear and heat buildup.

Several subtypes of roller bearings are found in aerospace environments, including:

• Cylindrical Roller Bearings: These bearings use straight, cylindrical rollers, resulting in high radial load capacity and low friction during high-speed rotation. Their configuration typically does not support significant axial loads, but they are valued for their efficiency in sustained high-load, high-RPM conditions.
• Tapered Roller Bearings: Featuring conical rollers and raceways, the geometry of tapered roller bearings facilitates effective load sharing for both radial and axial loads.
• Spherical Roller Bearings: These bearings incorporate barrel-shaped rollers that align themselves within a spherical outer raceway, permitting tolerance to angular misalignment and heavy loads along both axes.
• Needle Roller Bearings: Utilizing long, slender rollers, needle roller bearings provide a high radial load capacity within a compact cross-section, serving applications where installation room is limited.

Standard Applications

• Turbine and auxiliary shaft support
• Rotating gearbox assemblies
• Mounts and structural joints subject to vibration or misalignment
• Actuation systems in tight compartments

Spherical Bearings

Spherical bearings contain an inner ring with a spherical outer surface and a matching concave outer ring, allowing for multi-axis rotation or oscillation within a compact form. In addition to supporting high radial and axial loads, they compensate for misalignment caused by structural deflection, mounting variation, or thermal expansion.

Standard Applications

• Landing gear struts and doors
• Flight control linkages
• Thrust reversers and engine nacelles

Plain Bearings

Plain bearings operate without rolling elements, instead using a continuous sliding surface composed of advanced composites, bronze alloys, or other durable materials to support and guide rotating or oscillating shafts. Their straightforward design is an advantage in aerospace assemblies, presenting reduced weight and resistance to shock and vibration. While they are traditionally more prone to wear in high-speed or dry conditions, modern materials and lubrication technologies have bolstered their durability for demanding applications.

Standard Applications

• Aircraft door mechanisms
• Flap and slat actuation systems
• Turbine engines

Hybrid Bearings

Hybrid bearings combine ceramic rolling elements with steel races to leverage the strengths of both materials, offering superior wear resistance, less friction, lower weight, and enhanced speed compared to traditional all-steel bearings. Ceramics are also more corrosion-resistant, impervious to thermal expansion, and non-magnetic, making these bearings optimal for use near high-temperature assemblies or sensitive avionics. Moreover, these qualities all enable hybrid bearings to operate reliably in vacuum or cryogenic conditions, where conventional bearings might fail or require excessive maintenance.

Standard Applications

• Satellite and spacecraft components
• Gyroscopes and inertial navigation systems
• Cryogenic environments

Partner with a Reliable Bearing Supplier

Each type of bearing plays a unique role in maintaining operational continuity in aerospace platforms, and in addition to having good insight to their distinct benefits, sourcing them from dependable procurement avenues is imperative. Aerospace Orbit, an ASAP Semiconductor-operated platform, supports this need with a vast selection of aerospace-grade bearings and other aviation-standard parts.

Through comprehensive quality control practices, documentation, and supply chain visibility, our customers can trust us to simplify sourcing while ensuring that all items meet the performance and compliance standards required of various industries. We also regularly go above and beyond to streamline fulfillment with fast delivery options, present competitive pricing, and address specialized needs. To see how we can serve your particular procurement requirements, peruse our website and get in touch with our experts today!