Study on Cryogenic Hybrid Journal Bearings for Rocket Thrbopumps

火箭血栓泵低温混合轴颈轴承的研究

• 批准号: 13555266
• 负责人: OIKE Mamoru
• 金额: $ 8.51万
• 依托单位: Ishinomaki Senshu University (2002-2003)Tohoku University (2001)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13555266/
• 关键词: hybrid bearing; hydrostatic bearing; cryogenic fluid; rocket turbopump

A hybrid bearing is a fluid-film journal bearing with characteristics of both hydrostatic and hydrodynamic bearings. The main advantage of hybrid bearings are small design size, good load capacity, a quasi-unlimited life (no observed wear), and the use of the process fluid for lubrication. By replacement of the self-lubricating ball bearings in the cryogenic turbopumps by the hybrid bearings, a significantly higher lifetime can be obtained and the inherent limitation of the rotational speed of the turbopumps can be widely extended in cryogenic rocket engines for future reusable launch vehicles (RLVs), where the lifetime of mechanical components is a critical issue. Therefore, experimental study on cryogenic hybrid bearings was carried out to develop the high performance hybrid bearings forcryogenic turbopumps.Test hybrid bearings were designed to operate at a rotational speed of up to 120,000 rpm based on the analytical results obtained from the conventional calculation method. The tes … More t bearing has a 60 mm diameter with L/D = 0.42, clearance/radius = 0.001, and 9 recesses. Rotating tests were carried out using the journal bearing test apparatus in Kakuda propulsion research center of JAXA. Liquid nitrogen is supplied to the test bearing with a pressure of about 5 MPa. Test results for the bearing with a 0.51 mm orifice diameter show that the self-excited vibration having a several times larger amplitude than that of the synchronous vibration was induced by pneumatic hammer instability due to cavitating flow of liquid nitrogen. However, the bearing with a 0.80 mm orifice diameter can be operated at the rotational speed of up to 50,000 rpm without any self-excited vibration. Comparison between the test results and the numerical predictions of rotordynamic coefficients based on the test conditions shows that instability induced by large cross-coupled stiffness coefficients due to fluid rotation is considered to onset at the rotational speed over 50,000 rpm.Therefore, a new hybrid bearing with a higher rotordynamic performance has been designed and manufactured based on the numerical predictions described above. Less

混合轴承是一种兼具静、动两种特性的液膜轴颈轴承。混合轴承的主要优点是设计尺寸小，负载能力好，准无限寿命（无观察到的磨损），并使用工艺流体进行润滑。在未来可重复使用运载火箭（RLVs）的低温火箭发动机中，机械部件的寿命是一个关键问题，用混合轴承代替低温涡轮泵中的自润滑球轴承可以获得更高的寿命，并且可以广泛扩展涡轮泵固有的转速限制。为此，开展了低温混合轴承的实验研究，开发了用于低温涡轮泵的高性能混合轴承。根据传统计算方法的分析结果，设计了测试混合动力轴承，以高达120,000 rpm的转速运行。tes…More t轴承直径为60 mm， L/D = 0.42，间隙/半径= 0.001，有9个凹槽。在JAXA Kakuda推进研究中心的轴颈轴承试验装置上进行了旋转试验。液氮以约5mpa的压力供应给试验轴承。对孔径0.51 mm轴承的试验结果表明，液氮空化流引起的气锤失稳引起的自激振动幅值比同步振动幅值大几倍。然而，具有0.80 mm孔直径的轴承可以以高达50,000 rpm的转速运行，而没有任何自激振动。试验结果与基于试验条件的转子动力系数数值预测结果的对比表明，流体旋转引起的大交叉耦合刚度系数引起的失稳被认为始于转速超过50,000 rpm时。因此，基于上述数值预测，设计和制造了一种具有更高转子动力学性能的新型混合动力轴承。少

项目成果

菊池 正孝: "DN値300万における極低温ハイブリッドセラミック玉軸受の性能"日本航空宇宙学会北部支部2003年講演会および第4回再使用型宇宙推進系シンポジウム講演論文集. 35-40 (2003)

Masataka Kikuchi：“DN 值为 300 万的低温混合陶瓷球轴承的性能”日本航空学会北方分会 2003 年会议和第四届可重复使用空间推进系统研讨会论文集 35-40（2003 年）。

高田 仁志: "DN値300万における極低温ハイブリッドセラミック玉軸受の性能"日本航空宇宙学会北部支部2002年講演会および第3回再使用型宇宙推進系シンポジウム. 239-244 (2002)

高田仁：“DN 值为 300 万的低温混合陶瓷球轴承的性能”日本航空航天学会北方分会 2002 年讲座和第三届可重复使用空间推进系统研讨会 239-244（2002 年）。

三橋 克則: "軸受荷重測定システムの誤差評価"日本航空宇宙学会北部支部2003年講演会および第4回再使用型宇宙推進系シンポジウム講演論文集. 53-58 (2003)

Katsunori Mitsuhashi：“轴承载荷测量系统的误差评估”日本航空学会北方分会2003年会议暨第四届可重复使用空间推进系统研讨会论文集53-58（2003）。