Analysis Of Dynamic Characteristics Of Rotor-Bearing System Of Hydropower Unit And Study On Measurement Method Of Axis Precision

The key equipment of modern hydropower, hydro generator, trends large-scale, complication, high-speed, and high-output. The structure is more complex, integration is higher, the mutual relationship and couple among different devices are more close, which require more for unit management, maintenance, monitoring, diagnose. The vibration and steady are the key issue to solve, which had been noticed greatly. As a special rotation mechanism, the work medium of hydropower unit is water, the vibration characteristics are different from the general mechanism vibration for its unique operation condition. Therefore, the research on hydropower unit has high value both in engineering and theory.For the practical unit, based on modeling unit dynamic model, the transverse dynamic characteristic of large unit rotor-bearing system and vibration signal extraction are researched in depth. For guaranteeing steady and decreasing transverse vibration of rotor bearing, the high precise line measurement datum method in the installation process is proposed. The main contents are as follows:1. Research on free vibration characteristics of hydropower unit. For the large scale rotor-bearing system such as hydropower unit, a method of partition length for shaft segment is proposed. According to the configuration characteristics of vertical shaft units, the character of center movement trajectory of guide bearing journal is analyzed. The numerical results show that the horizontal sliding bearing design theory is not applicable. The applicable method for oil film force computation model is proposed. Based on the method, the relationship between guide bearing rigidity and eccentricity is calculated, influences of variation of guide bearing rigidity on three order critical speed and modal vibration mode of transverse vibration are analyzed. Therefore, the rigidity of the three guide bearings is obtained during installation. The influence on critical speed by negative rigidity of unbalanced magnetic pull force is analyzed.2. Research on transverse dynamic characteristic of hydropower unit. The unit rotor-bearing dynamic model with local nonlinear characteristic is established by analyzing the forces on the rotor-bearing of unit,...