Aeroengine mechanical system is an extremely complex system, which is produced under the joint action of various conditions. As the most important part of the entire aircraft, the operation of the engine's overall mechanical system has a considerable impact on the development of the air transport industry.
1. Air transport
As the most important way people choose to travel, aviation is favored by many people because of its own advantages. Air transportation is rarely restricted by natural conditions, and it is the fastest among all transportation in terms of transportation speed, and its charging standard is determined according to the distance of transportation, so the economic value is relatively high. The mechanical system of an aero-engine is mainly composed of four parts: transmission, lubrication, sealing and bearings, and the entire transportation system is relatively complicated. Domestic research in this area is relatively weak, so there are many problems in the installation, use and maintenance of mechanical equipment. In order to further solve this problem, we will analyze these four operating systems one by one.
2. Aeroengine mechanical system
(1) Transmission system
The research on the transmission system has always been the key to the further development of aero-engines. The overall development trend of the current domestic transmission system is to reduce the volume and weight of the transmission system as much as possible on the basis of ensuring high speed and heavy load. Increase service life and reduce operating costs. The development of foreign transmission systems is relatively rapid, and the noise and vibration of transmission systems have been studied under the development of gear rotation technology. And through the experiment, the service life of the gear can be accurately predicted, and the requirements of various uses can be met on the basis of ensuring the economic performance as much as possible. Driven by the 11th Five-Year Plan, the country also has more advanced design analysis software, and has formulated different operation plans and design criteria according to different models.
(2) Lubrication system
The design of lubrication system involves many marginal and difficult subjects, and there are few authoritative theories. However, with the development of the aviation industry, there is a higher pursuit of the lubrication system, so foreign airlines took the lead in research, and after decades of research, some results have been obtained. Regarding the fire prevention and driving of the engine lubrication system, it is gradually applied to the aero-engine. Of course, in-depth research has also been carried out in China. Regarding the improvement of the ventilator separation and the efficiency of the lubricating oil pump through the new design, by reducing the volume of the fuel accessories, the number of gears in the transmission of the accessory casing is further reduced, thereby reducing the engine casing. The size of the outer contour is used to achieve high-speed operation of the engine and to reduce the weight of various components of the lubrication system.
(3) Sealing technology
Sealing is equally important for both military aviation and civil aviation engines. Under the current sealing technology, it can basically meet the current military and civil aviation engines. But the new generation of aero-engine sealing technology is facing new challenges, in order to achieve the rapid development of the aviation industry. To combine the sealing and lubricating engine air system, especially pay attention to the research of the infrastructure, to achieve the best matching between different seals. In terms of engine performance improvement, with the extensive application of contact air seals such as brush seals, the efficiency of the engine has been greatly improved. At present, there are already professional companies producing it in China, and it has begun to take shape. Therefore, it is necessary to promote the brush seal to continuously improve the performance of the aero-engine.
(4) Main bearing shaft
In the design of bearings, most of them use special bearings integrated with the supporting structure, and design the bearings and the engine together to reduce the weight of the engine while ensuring the basic functions of the bearings. Through the analysis of a large number of experimental data, the service life of bearings of different materials is compared, and the most suitable material is selected for the production of bearings. Usually, the operating life of bearings is higher than that of other designs. In the application of bearings, the design of the engine combined with the research and development of the bearings jointly formulated a relatively complete bearing use specification and established a corresponding database for the engine bearings of the entire aviation industry. The technologies of the two parties are constantly merging, and the rationality of the working environment is fully considered in the design process to reduce the damage to the bearing caused by the operation of other systems. When designing and installing the bearing, it is necessary to actively communicate according to the initial conditions given by the designer, and to design the bearing more reasonably on the basis of a win-win situation for both parties. In the basic research of bearings, a large number of experiments have been carried out according to the damage of bearings in operation and the surface residual stress of re-working, and the theory of bearing application has been further enriched through the fatigue service limit of various materials. And by strengthening the surface of the material, the service strength of the bearing is increased, which is convenient for the bearing to prolong its service life under the condition of serious lubricating oil pollution.
(5) Methods in the development of mechanical systems
1. Design that pays attention to details Standardize the settings of chamfering, luminosity, tightening strength, etc. in the sample preparation one by one. During the construction process, the construction is carried out in strict accordance with the design schematic diagram, all unscientific operations are eliminated, and the operation of the aero-engine is further improved. 2. The application of basic experiments In the oil supply of bearings and gears, the anti-pollution degree of bearings, and sealing friction experiments, it is necessary to pay more attention to the experimental data, and continuously accumulate data to achieve a more scientific engine system. design. 3. Professional design All aspects of the mechanical system are operated by a professional team. Facing the different actual conditions of different aero-engines, a corresponding research group is established to deal with the problems in the operation of the engine in a unified way, so as to better Realize the rationalization of engine operation. 4. The dominant design will carry out in-depth implementation of requirements such as light weight and simplification, and the design department should take all the conditions into consideration when designing. In the production of parts, the specific requirements should be provided to the manufacturer, which will greatly improve the efficiency of the engine accessories produced. 5. Integrated development There is a connection between the lubrication system and multiple components, and an integrated design must be gradually realized. Concentrate more functions into a smaller space, reduce the weight of the entire engine, and improve the stability of engine operation. 6. Integration of multiple technologies Experts in air transportation research are also kings in other fields. Generally, new research projects start from aviation and are continuously refined to various fields. This requires that in today's development of aviation technology, more technologies in related fields should be introduced into aviation development, and the professionalism of aero-engine technology should be continuously improved.
3. Summary
The mechanical system of an aero-generator consists of many subsystems, and the scope involved is relatively complicated. Under the current technological development, we are facing both opportunities and challenges. We must start from reality and use data to speak, so as to raise the development of aviation industry to a new stage. To sum up, the design of the aero-engine mechanical system should pay more attention to the design of the basic aspects, and at the same time actively learn from other industries, and continuously apply technologies suitable for aviation development to achieve better development of the aviation industry.
Author: Gao Qi Unit: Eastern Aviation Technology Co., Ltd.
references:
[1] Kang Shanshan, Tang Xiaoqiang, Tong Hao, Shao Zhufeng. The teaching practice of the whole process of mechanical system model manufacturing [J]. Laboratory Research and Exploration, 2017, (02): 235-238+243.
[2] Chen Junwei. Research on Airworthiness Compliance of Aeroengine Over-rotation Protection System [J]. Gas Turbine Test and Research, 2016, (06): 56-60.
