High-Performance Bearings For Aircraft

Each piece of an aircraft is responsible for its safe and effective functioning, and while we tend to focus on the glamorous exteriors and fancy gadgets, it’s the unsung hero, the bearing, that keeps everything moving and in its place. 

Whether in engines, landing gear, flight control systems, or other avionics equipment, bearings support the movements and loads of important components. As aviation processes continue to amaze, there is no time like the present for the need for extremely high-performance bearings for aircraft, and these are the companies making it happen.

The Role of Bearings in Aircraft Systems

Bearings are mechanical components designed to reduce the friction between moving parts and to support radial and axial loads. In aeronautics, they’re used in a wide array of applications, for example:

• Jet engines: Bearings facilitate the rotation of turbine shafts at high speeds, even under isothermal conditions and large loads.

• Landing gears: Bearings reduce the mechanical forces of heavy impacts during take-off and landing cycles.

• Flight control actuators: Bearings facilitate the reactive movements of control surfaces, such as the rudder, aileron, or elevator.

• Avionics and cabin systems: Despite their non-critical nature, bearings play a crucial role in the propulsion of certain equipment, such as fans or seats, or in the interface with other systems, like displays.

These operations require critical applications bearings to operate perfectly over a long lifetime and in severe operating conditions.

What Defines a “High-Performance” Bearing?

Not all bearings are created equal, especially when it comes to the aerospace industry. High-performance bearings are specially designed to take the punishment of high stress, high heat, and a host of other challenging factors. The top bearings in the field will have the following qualities:

• Temperature Resistance: Jet engines and other aircraft are designed to operate at temperatures from -70°C to temperatures in excess of 300°C. Bearings have to be able to sustain those temperatures while on the ground and throughout the flight.

• Corrosion Resistance: Bearings have to be able to withstand exposure to corrosives like hydraulic fluids, salt air, and humidity.

• Load Capacity: Planes experience significant amounts of radial and axial stress on their bearings, especially on takeoff, landing, and during maneuvers.

• Low Weight: Everything about aerospace parts has to be lightweight: it makes for better fuel economy and cuts back on overall weight, a particularly big concern in aerospace.

• Fatigue Life: The bearings in an aircraft must be rated to withstand hundreds of thousands of cycles without failure.

To achieve these sorts of performance expectations in products, bearing designers use a combination of advanced materials, precision manufacturing techniques, and testing technologies.

Materials Used in Aerospace Bearings

Just as important as the design are the materials chosen for high-performance bearings. Materials vary, but these are the most common aerospace-compatible options:

• M50 Tool Steel: Known for its high hardness, wear resistance, and thermal stability.

• Silicon Nitride (Ceramic): Offers lower weight and higher speed capability, often used in hybrid bearings with steel races and ceramic balls.

• 440C Stainless Steel: Provides corrosion resistance with decent load-handling capacity.

• Titanium Alloys: Occasionally used in applications requiring ultra-low weight and high strength.

Service life matters. While lube is an easy factor of the bearing design, material choice, and loads to understand, bearing life is a system-level need. A bearing may be a good fit for a design, but if it fails in simulation, redesign with a new material, lube type, or different bearing options becomes necessary.

Applications of High-Performance Bearings in Aircraft

Aircraft systems require high-performance bearings to operate effectively. Jet engines rely on high-speed bearings to maintain shaft alignment and handle the heat generated by high speeds. Bearings in the landing gear absorb shock and allow the landing gear to handle dissymmetrical loads.

Flight control swivels and bearings reduce friction for precise flight control. Helicopter bearings transfer complex loads while enabling efficient rotor operation. The bearings supporting a rotor head must handle widely varying loads, from the mild conditions of hovering flight to intense vibrations produced by a sudden maneuver or a steep climb.

High Performance Bearings for Aircraft

The next generation of aircraft, from electric VTOLs to hypersonic jets, will require more from their mechanical systems than ever. And at the core of those systems will be aircraft bearings.

Whether these bearings are needed for ailerons, engine shafts, or landing gear, aircraft bearings will continue to enable flight through engineering, precision, and performance quietly. As the aviation industry expands the envelope of speed, efficiency, and sustainability, bearings will be a core technology advancing every dimension of aerospace.