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

基本信息

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

项目摘要

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

杂化轴承是具有静液压和流体动力轴承的特征的流体膜期刊。混合轴承的主要优点是设计尺寸小，良好的负载能力，准空间寿命（未观察到的磨损）以及使用工艺液进行润滑。通过通过混合轴承更换低温涡轮机中的自润滑球轴承，可以获得明显更高的寿命，并且可以在未来可重复使用的发射车（RLVS）中广泛散布涡轮机的旋转速度的继承限制，而机械组合的生命是重要的问题。因此，对低温杂种轴承进行了实验研究，以开发高性能杂种轴承的强制性涡轮机。测试杂交轴承旨在根据从常规计算方法中获得的分析结果以高达120,000 rpm的旋转速度运行。 TES…更多的T轴承的直径为60 mm，L/d = 0.42，间隙/半径= 0.001和9个凹槽。使用Jaxa Kakuda推进研究中心的轴承测试设备进行旋转测试。将液氮提供给测试轴承的压力约为5 MPa。用0.51 mM孔口直径的轴承的测试结果表明，由于液氮的液体流动，气动锤不稳定性引起了比同步振动大几倍的振动。但是，具有0.80 mm孔口直径的轴承可以以高达50,000 rpm的旋转速度操作，而无需进行任何自激发振动。根据测试条件，测试结果与转型系数的数值预测之间的比较表明，由于流体旋转而引起的大型交叉耦合刚度系数诱导的不稳定性被认为是在50,000 rpm上以超过50,000 rpm的速度开始的，因此，具有更高的转型性能的新混合轴承是基于较高的旋转性能的新型混合轴承。较少的