We all know that bearings are used in a wide range of applications, ranging from heavy machinery to small toys. They all play a vital role. The speed of bearings is a headache for bearing developers. The higher the speed of precision bearings, the higher the friction. The smaller it is, the stronger the power will be when it is used in accessories such as engines. Aviation technology has higher requirements for precision bearings, because aviation instruments must be very powerful in order to reach the sky. Today, Huipu Bearings takes you to understand that precision bearings can increase speed and can be used in aviation technology.

Aviation bearings are one of the core components of aero engines, with high temperature, high speed, large load, complex force, harsh working environment and so on.

Theoretically speaking, the current direct method to improve the thrust and fuel rate of aero engines is still to increase the turbine inlet temperature and rotor speed, and the increase in speed has a greater impact on the speed limit performance, temperature resistance, lubrication performance and load carrying capacity of aviation bearings. Stern requirements.

Although my bearing industry has developed rapidly for many years, it has become the largest bearing in the world in terms of output and sales amount. However, the key technology domain needs to be strengthened. In particular, the gap between aviation bearing technology and the world’s strong bearings is obvious. Meet the requirements of the rapid development of our aviation equipment models and substantial performance improvement.

According to public information, the life of foreign advanced aviation bearing products is generally more than 8 times the calculated life (up to 30 times higher), and the reliability is more than 98%. The life of our aviation bearings is generally 3 to 5 times the calculated life. The reliability is about 96%.

For example, the life of the main shaft bearing of my turbine engine is generally about 500 to 1500 hours, the maximum temperature resistance does not exceed 200 ℃, and the emergency dry running capacity of the transmission device is not more than half an hour. The western developed companies can achieve the bearing life of 3000 to 3,000 hours. For 6000 hours, the temperature resistance value is 350℃, the dry running capacity is more than 1.5 hours, and the actual performance is better than the above indicators.

It is precisely because of our lack of high-speed bearing technology that the high-speed bearing areas such as internal aviation bearings, high-speed rail bearings, and robot bearings are basically imported bearings. These key areas are in urgent need of improvement.

Therefore, under the joint support of the 863 Program, the 973 Program, the Science and Technology Research Program, and the National Natural Science Foundation of China, Harbin Institute of Technology and Harbin Bearing Manufacturing Co., Ltd. jointly carried out the research and industrial application of Si3N4 silicon nitride ceramic hybrid bearings. jobs.

Hybrid ceramic bearings are composed of inner and outer ring bearing steel + silicon nitride ceramic balls + stainless steel retainer, etc. It combines the advantages of both metal and ceramic properties.

According to public information, silicon nitride ceramic balls are considered to have good comprehensive mechanical and physical properties in bearing applications requiring high performance. Bearing steel balls can easily lose their hardness and strength in high temperature environments, while silicon nitride ceramic balls can maintain their original hardness at 400°C. Only when it reaches 800°C, its hardness and strength begin to drop significantly. And even if the bearing is lost, it will happen in a way similar to the loss of the bearing steel ball, that is, local spalling, while other types of ceramic materials are damaged by catastrophic fragmentation. This is true in the aviation bearing industry. Allowed. And the ceramic ball in the bearing has oil-free and self-lubricating properties, the friction coefficient is very small, and it can reach a high speed, which is more than 1.5 times the speed of the ordinary metal bearing, which can meet the needs of the engine to increase the thrust and improve the combustion rate.

Since the ceramic ball can run normally even if the lubricating grease dries out, it avoids the premature damage of the bearing caused by the grease drying out in ordinary metal bearings, which is suitable for the operation of aero engines.

According to public information disclosure, it is speculated that hybrid ceramic bearings may have been initially applied in our new turbofan 15 aero engine and transmission domain. In order to improve the long-range strike capability of our navy ships, a certain submarine/ship-launched anti-ship missile proposed design requirements to increase the range and speed, and its missile turbine rotor must reach a rated speed of 120,000 rpm or more.

In the early stage of the project test, when a certain produced metal aviation bearing was used for engine operation test, when the test speed reached 40,000 rpm, the bearing quickly heated up and caused smoke to appear around it. After a few minutes of continuous operation, the bearing made a strong noise, and then the axle stopped, which seriously affected the progress of the missile development, and had to purchase foreign high-speed aviation bearings through special channels to meet the needs of the missile turbine engine rotor.

After switching to hybrid ceramic bearings developed by Harbin Institute of Technology in the later stage, the bearings passed the 5-hour continuous operating life assessment for the second time. During the test, the bearings had no abnormalities except for slight smoke. After the test, the bearing rotates flexibly without abnormality. With the continuous development of our helicopter engine transmission technology, ceramic rolling element bearings with their excellent performance have been gradually used in transmission systems for high-speed input, clutches, tail drive shafts and tail reducer pitch levers, and planetary gear trains. The dry running time of the main reducer has been increased from half an hour to one hour, which meets the requirements for installation.

The above is the content of the precision bearing that Huipu introduced to you to increase the speed, which can be used in aviation technology. As my bearing technology becomes more and more advanced, we can develop more advanced aviation equipment. The precision bearing products produced by Huipu are of good quality and reasonable price. Welcome to visit our factory!