Autor: |
Li, Shengbo, Luo, Yuan, Shutin, Denis, Kazakov, Yuri, Sytin, Anton, Liu, Yifan, Zeng, Zexiang, Chen, Zhaobo, Savin, Leonid |
Předmět: |
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Zdroj: |
Journal of Vibration Engineering & Technologies; 2024 Suppl 1, Vol. 12, p1119-1143, 25p |
Abstrakt: |
Purpose: This paper aims to examine the impact of oil lubrication in foil bearings, as well as various aspects of their design and manufacturing methods, on the vibration behavior of thin rotors. The study aims to combine the advantages of oil-lubricated journal bearings with foil bearings traditionally lubricated with gas, mutually eliminating their disadvantages and creating a superior compliant bearing design. Methods: The study is primarily experimental. Initially, several variations of oil-lubricated foil bearings were designed, with varying aspects of design (bearing length, presence of bump foils, presence of lubrication orifices) and foil manufacturing methods. Then the geometric characteristics of the bearings were experimentally verified, and the data on the vibration behavior of a slender rotor weighing 13 kg and rotating speed up to 15,000 rpm was collected for all bearing samples. Various aspects of the performance of the tested bearings were analyzed in detail using frequency analysis. Finally, conclusions are drawn about the capabilities and limitations of the solutions considered, and recommendations for the design of oil-lubricated foil bearings are given. Results: The results demonstrate that appropriately designed oil-lubricated foil bearings have excellent damping capabilities even in the presence of liquid oil in the bearing structure. The best bearing samples entirely eradicated both oil whip and oil spin instability over the entire testing speed range up to 15,000 revolutions per minute. Nevertheless, design faults, encompassing inadequate manufacturing techniques, may dramatically diminish the stability margin of a rotor system. Consequently, top foils of identical dimensions but produced by distinct methods displayed diverse behavior in various aspects. Finally, a dimensionless parameter was proposed that reflects the ability of a bearing to provide rotor stability and can be useful in bearings' designing and optimization. Conclusion: It can be inferred from the findings of this research that oil-lubrication is applicable also for foil bearings that are usually lubricated with gas. Properly designed oil-lubricated foil bearings have some advantages and lack a number of disadvantages of gas foil bearings, providing stable dynamic rotor behavior, higher load capacity and potentially superior thermal performance owing to the superior cooling capacity of the liquid lubricant. The primary benefits over conventional rigid oil-lubricated bearings include greater damping and stability margins, while also restricting the radial dimensions and weight of the bearing, all without the need for any supplementary dampers. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
Externí odkaz: |
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