可倾瓦轴承全尺寸试验及润滑与振动性能研究

针对某在役百万千瓦级核能发电机用可倾瓦轴承瓦温过高的问题,给出了优化的轴承结构参数,并对两个不同参数的全尺寸三瓦可倾瓦轴承在动平衡试验机上同时进行了瓦块温度、油膜厚度、瓦块摆角等润滑性能及轴系振动性能试验,提出了基于瓦块自适应摆动特性的油膜厚度测试方法和瓦块摆角识别方法。结果表明:1号轴承相比2号轴承具有更好的润滑性能;利用瓦块随转子自适应摆动特性识别的油膜厚度相比理论结果具有较高的识别精度,同时依据试验膜厚信息识别的瓦块摆角相比理论结果具有较好的一致性;在振动性能方面,依据转子振动数据识别了转子的一阶临界转速及临界时轴承的综合刚度k_X、k_Y,其与理论综合刚度keq相比平均误差约50%。

Experimental Study of Full-Size Tilting-Pad Bearings and Research of the Lubrication and Vibration Performance

For the failure damage of local melting caused by high temperature rise of a tilting-pad journal bearing, which is used to support an in-service megawatt nuclear power generator, the structural parameters of the bearing were redesigned, and an experimental study was performed to investigate the lubrication performances of pad temperatures, film thicknesses, pad tilting angle and the rotor-bearing system vibration performance of the redesigned bearing and the in-service bearing on a dynamic balancing machine. While, an oil-film thickness test method based on self-adaptive wobble characteristic of the main-pad and a pad tilting angle recognition method are performed. The results show that the No.1 bearing has better lubrication performances than No.2 bearing, the tested film thicknesses of the two bearings based on self-adaptive wobble characteristic of the main-pads have a high recognition accuracy compared with the theoretical results, and the pad tilting angle of No.1 bearing recognized by the tested film thickness information has a good agreement with the theoretical results. In the vibration performance, the first order critical speed and the integrated stiffness kX and kY at the critical speed were calculated from the vibration data, and the average error of the test stiffness is 50% to the theoretical integrated stiffness keq.