Aluminum castings are lightweight and able to withstand the highest operating temperatures of all die cast alloys.
Aluminum Alloy Characteristics:
Aluminum's strength, corrosion resistance, and heat dissipating properties offer mechanical designers significant advantages. And our proprietary Thin Wall Aluminum Technology has made aluminum die casting an option for even more applications.
Aluminum Alloy Casting,Aluminum Precision Casting,Aluminum Alloy Die Casting Parts,Aluminum Alloy Die Casting HSI INDUSTRIEL LTD , http://www.hsiindustriel.com
The modified gear structure is characterized by six relief holes on the N2's web, a reduced N2 hub diameter, and an increased N3 rim thickness. In the calculation analysis, a three-dimensional finite element model is established for the improved intermediate gear structure. The pseudo-wavefront subspace iteration method is used to calculate the first 50 natural frequencies and modes of the three gear structures. According to the vibration mode superposition method, the steady state, dynamic response and dynamic stress response of the three gear structures are calculated. Through calculation and analysis, the following conclusions are drawn: the improved gear structure has a lower natural frequency, and the first-order frequency (1808.4 Hz) is lower than the frequency of the improved front gear structure by about 14. Due to a turboshaft engine deceleration The working frequency of the first stage gear drive is 20099.9 Hz, which is much higher than the low order natural frequency of the structure. Therefore, the reduction in the frequency of the improved gear structure does not affect the dynamic characteristics of the system.
The first seven modes of the improved front and rear gears are the same, but the subsequent modes vary depending on the size and form of the structure. The maximum displacement response in the three directions of the improved gear has increased, which may be mainly due to the reduction in the hub diameter of the wheel 2. The maximum stress value in the improved gear structure is reduced, and the maximum stress values ​​at the roots of the N2 and N3 hubs are relatively close. Through the research of this project, the improved gears did not find rotor dynamics. In contrast, the improved dynamic gear value distribution of the gear is more uniform.
The intermediate gear of the test piece installed and improved is installed on the No. 050 engine. With the sand control test, the engine is tested under various working conditions. A total of six stages of tests are carried out, with a total of 30 hours and a total of 100 starts. The speed reducer works stably and normally, and all the gear tooth surfaces of the speed reducer are well engaged, and there is no abnormality in the non-destructive inspection. The improved intermediate gear was installed in No. 202 engine and carried out 2000 times/5@40 cycle test test. A total of 2087 times were started, and the total working time was 223h17min. During the assessment, the reducer was running normally. After the decomposition check, all the gears meshed well and not damaged. No abnormalities were found in the flaw detection.