As a very important form of mechanical transmission, gear transmission system has the characteristics of strong bearing capacity, stable transmission, accurate movement and high reliability. Therefore, bevel gear transmission is widely used in aviation engineering and aerospace engineering. The reliability of bevel gear has a vital impact on the operation of the whole mechanical system. With the development of modern industry, bevel gear transmission system with outstanding performance has been widely used. As an important mechanical component, the dynamics of bevel gear system has been concerned by scholars at home and abroad.
As the Pearl on the crown of modern industry, aeroengine works in the environment of high temperature, high pressure and high load. Because the aeroengine directly provides power for the aircraft, the aeroengine is the most critical part of the aircraft. As the “heart” of aircraft, the reliability of aeroengine directly determines the reliability of aircraft. Therefore, improving the strength and reliability of engine parts is of great significance to ensure aircraft flight safety.
In the aeroengine, there are not only the main components such as compressor, combustion chamber, turbine, afterburner and tail nozzle, but also various auxiliary systems to ensure the normal operation of the engine, such as starting system, fuel system, lubricating oil system, cooling system, etc. In these auxiliary systems, some engine accessories (such as lubricating oil system, fuel pump, etc.) have certain speed, power and Steering requirements, which need to be driven by the engine rotor. On the other hand, since most of these accessories can only be installed outside the engine gearbox, some transmission parts are required to transmit the power of the engine to the accessories according to a certain speed and steering. At this time, the bevel gear transmission system comes in handy and plays an irreplaceable role.
In aeroengines, there are usually one or more accessory drives. The central bevel gear, which transmits the engine spindle speed and power to the accessory device, is one of the most important parts of the aeroengine. At the same time, because the central bevel gear is an important part to match the engine and accessory mechanism, the manufacturing and installation accuracy of the central bevel gear is very high, which is also the key part and weak link of the whole engine transmission system. Moreover, due to the high working speed and strong speed fluctuation of the aeroengine, the dynamic load of the engine transmission system will be large and the working state will be very bad. Not only the working conditions and temperature are changeable, but also accompanied by the external excitation caused by the prime mover and load. When the bevel gear works, there will be internal excitation caused by time-varying meshing stiffness, transmission error, tooth side clearance and other factors. Therefore, the service life and strength of central bevel gear will be greatly tested in aeroengine.
Major accidents caused by bevel gear failure are also common. As far as China is concerned, there are many emergencies of transmission system bevel gear jamming when air force aircraft are on duty. With the rapid development of aeroengine technology in the world, the requirements of aeroengine with high thrust weight ratio, high reliability and low fuel consumption for transmission system become more and more stringent. Therefore, in order to meet the requirements of aeroengine bevel gear with high speed, heavy load, light weight and high reliability, the research on the strength and dynamics of bevel gear becomes particularly important.