Bearings play a crucial role in the aerospace industry, as detailed below:

Application in aircraft

Engine system: Aircraft engines are the core components of aircraft, and bearings play a key supporting and transmission role in the engine. For example, in turbine engines, spindle bearings need to work stably in extreme environments of high temperature, high pressure and high speed. These bearings are usually made of high-performance alloy materials, such as high-temperature alloy steel or ceramic materials, to withstand gas temperatures up to thousands of degrees Celsius and tremendous centrifugal forces. High-precision bearings are also required for the blade adjustment mechanism of the engine. These bearings enable precise adjustment of the blade angle to optimize the performance and efficiency of the engine. For example, the use of micro ball bearings or needle bearings, with high reliability and low coefficient of friction, ensures the accuracy and sensitivity of blade adjustment. The engine's fuel pump and lubricating oil pump are also supported by bearings. These bearings need to ensure the normal operation of the pump under high pressure and high speed working conditions to provide a stable supply of fuel and lubricating oil to the engine.

Flight Control System: The flight control system of an aircraft includes components such as the rudder surface, ailerons, elevators, etc. The motion control of these components needs to rely on high-precision bearings. For example, in the rotation mechanism of the rudder surface, specially designed articular bearings or ball screw bearings are used, which can withstand the aerodynamic and handling forces during flight, while ensuring the precise movement of the rudder surface. Miniature bearings are also required for sensors and actuators in the flight control system. For example, bearings in sensors such as gyroscopes and accelerometers need to have extremely high accuracy and stability to ensure accurate measurement of flight data. Bearings are also required for electric motors and hydraulic pumps in the actuators to ensure their normal operation.

Landing gear system: Aircraft landing gear bears huge loads during take-off, landing and ground taxiing, and bearings are one of the key components of the landing gear system. For example, the bearings between the main struts of the landing gear and the wheel axle need to have high load-bearing capacity and impact resistance to ensure the safety and stability of the aircraft during take-off and landing. The retracting and retracting mechanism of the landing gear also needs to use various types of bearings. These bearings need to achieve smooth retracting and locking of the landing gear in complex mechanical structures, and to be able to adapt to different flight attitudes and environmental conditions. For example, the use of tapered roller bearings or sliding bearings with self-locking function ensures the safety and reliability of the landing gear during flight.

Cabin and cargo systems: In the cabin and cargo hold of an aircraft, the operation of various equipment and facilities is also inseparable from bearings. For example, the seat adjustment mechanism of the cabin, the sliding mechanism of the luggage rack, and the cargo handling equipment of the cargo hold all require the use of different types of bearings. These bearings need to have good durability and low noise characteristics to provide a comfortable riding and working environment. The fans and motors in the air conditioning and ventilation system of the aircraft also need the support of bearings. These bearings need to maintain stable performance under long-term operation conditions, and they need to have good dustproof and waterproof performance to adapt to the special environment inside the aircraft.

Applications in spacecraft

Launch vehicle: The engine of a launch vehicle is a key power unit that propels the rocket into the air, while bearings play an important role in key components such as the turbine pump and oxidant pump of the engine. For example, bearings in a turbine pump need to work in high-speed rotation and high-temperature and high-pressure environments, withstanding tremendous centrifugal and axial forces. These bearings are usually made of special high-temperature alloy materials and advanced manufacturing processes to ensure their reliability and stability under extreme conditions. High-precision bearings are also required for the navigation and control system of a launch vehicle. For example, bearings in sensors such as gyroscopes and accelerometers need to have extremely high precision and stability to guarantee precise navigation and attitude control of the rocket. These bearings are usually made of special ceramic materials or magnetic levitation technology to reduce friction and improve accuracy. Various types of bearings are also required for the interstage separation mechanism and fairing release mechanism of the launch vehicle. These bearings need to withstand tremendous impact and vibration during the launch of the rocket, and to be able to accurately realize the separation and release action at critical moments. For example, special bearings with explosive bolts or hydraulically driven spherical bearings are used.

Satellites and space stations: Satellites and space stations operate in space, and the normal operation of their various equipment and systems cannot be separated from the support of bearings. For example, the solar panel deployment mechanism and antenna pointing mechanism of satellites need to use high-precision bearings to achieve accurate deployment of solar panels and precise pointing of antennas. These bearings need to work reliably in vacuum, high and low temperature alternating and strong radiation environment for a long time, and have extremely low friction coefficient and good radiation resistance. Parts such as robotic arms and hatches of space stations also need to use special bearings. For example, the articulated bearings of robotic arms need to have high flexibility and high precision, and can realize various complex operation actions. The sealed bearings of hatches need to have good sealing performance and reliability to ensure the safety of the internal environment of the space station. Attitude control and orbit adjustment systems for satellites and space stations also require the use of high-precision bearings. For example, miniature ball bearings or harmonic reducer bearings can be used to achieve precise adjustment and stable control of tiny angles. These bearings need to have good anti-interference performance and low power consumption characteristics in the space environment.

Special requirements and technological innovations for bearings

Special materials and manufacturing processes: Due to the special working environment in the aerospace field, bearings need to adopt special materials and manufacturing processes. For example, high-performance materials such as superalloys, ceramic materials, titanium alloys, etc. are used to meet the requirements of use in environments such as high temperature, high pressure, high speed, and strong corrosion. At the same time, advanced precision machining technologies such as grinding, polishing, ultra-finishing, etc. are adopted to ensure the accuracy and surface quality of bearings. In order to improve the reliability and life of bearings, special heat treatment processes and surface treatment technologies are also required. For example, through heat treatment processes such as quenching and tempering, the hardness and strength of bearing materials are improved; through surface treatment technologies such as surface coating, carburizing, and nitriding, the wear resistance, corrosion resistance, and fatigue resistance of bearings are improved.

Lubrication and sealing technology: In the aerospace field, the lubrication and sealing technology of bearings is crucial. Due to the particularity of the space environment, traditional lubrication methods may not be applicable, so special lubrication technologies such as solid lubrication, self-lubricating materials and magnetic fluid lubrication need to be adopted. These lubrication technologies can ensure the normal operation of bearings in extreme environments such as vacuum, high and low temperature. Sealing technology is also the key to ensure the performance and reliability of bearings. In key parts such as aircraft engines and spacecraft, high-performance seals such as lip seals, labyrinth seals and magnetic seals need to be adopted to prevent impurities such as dust, moisture, fuel and lubricating oil from entering the inside of the bearing and affecting its normal operation. At the same time, seals also need to have good high temperature resistance, high pressure resistance and corrosion resistance.

Testing and detection technology: In order to ensure the safe and reliable use of bearings in the aerospace field, advanced testing and detection technology is required. For example, through high-speed rotation test, simulation environment test and fatigue life test, etc., the performance and reliability of bearings are comprehensively tested and evaluated. At the same time, non-destructive detection technology, such as ultrasonic inspection, magnetic particle inspection and radiographic inspection, is used to detect the internal quality and surface defects of bearings, and find potential quality problems in time. Using sensor technology and data analytics technology, real-time monitoring and fault diagnosis of the running state of bearings are carried out. For example, through temperature sensors, vibration sensors, and pressure sensors installed on bearings, the operation data of bearings is collected in real time, and through data analytics and processing, the working status and health of bearings are judged, and possible failures are predicted in advance so that maintenance measures can be taken in a timely manner.

Future development trend

Applications of high-performance materials: With the continuous development of aerospace technology, the performance requirements for bearing materials are also getting higher and higher. In the future, new high-performance materials such as nanomaterials, composites and smart materials will be continuously developed and applied. These materials have higher strength, hardness, wear resistance and corrosion resistance, and can meet the requirements of use in more extreme environments. For example, nano-ceramic materials have excellent high temperature performance and wear resistance, and will be expected to be widely used in key parts such as aircraft engines and spacecraft. Composite bearings have lightweight, high strength and good damping properties, and will become an important development direction in the future aerospace field.

Intelligent design and manufacturing: Utilize advanced computer technology and simulation software to carry out intelligent design and optimization of bearings. Optimize the structure and performance of bearings and improve their bearing capacity, rotational speed and life by establishing 3D models of bearings, carrying out mechanical analysis, thermal analysis and fluid analysis, etc. Adopt intelligent manufacturing technologies, such as 3D printing, automated processing and robot assembly, etc., to achieve high precision, high efficiency and personalized manufacturing of bearings. At the same time, through Internet of Things technology and big data analytics, realize intelligent management and quality control of bearing production process.

The development of new lubrication and sealing technologies: As the requirements for environmental protection and reliability continue to increase, new types of lubrication and sealing technologies will continue to be developed in the future. For example, biodegradable lubricants and environmentally friendly sealing materials will be developed to reduce pollution to the environment. At the same time, new types of self-lubricating materials and intelligent sealing technologies will be studied to improve the lubrication performance and sealing effect of bearings. New sealing technologies such as magnetic fluid sealing technology and dry gas sealing technology will be more widely used in the aerospace field. These technologies have the advantages of good sealing performance, high reliability and long service life, and can meet the requirements of use in harsh environments such as high speed, high temperature and high pressure.

Miniaturization and integrated design: With the development trend of miniaturization and integration of aerospace equipment, bearings will also develop in the direction of miniaturization and integration. For example, the development of micro-bearings and ultra-thin bearings to meet the application needs in small equipment such as micro-satellites, drones and micro aircraft. At the same time, the integrated design of bearings with other components, such as the integration of bearings with sensors, actuators and controllers, forms an intelligent bearing system, realizes real-time monitoring and control of bearings, and improves the performance and reliability of equipment.