大型立式水泵机组推力瓦性能分析及改进设计

Performance analysis and design improvement of thrust bearing bush in a large vertical pump unit

分析了大型立式水泵机组中主电动机推力瓦的性能,以此来阐明江都水利枢纽第四泵站主电动机巴氏合金推力瓦的烧损故障原因.结合机组本身的实际情况,采用弹性金属塑料瓦替代巴氏合金瓦,对电机推力瓦进行改进设计.根据弹性金属塑料瓦的实际应用情况,通过与巴氏合金瓦进行比较分析,提出了弹性金属塑料瓦的优点及其使用注意事项.实践证明:改进设计后,在瓦面质量合格的情况下,机组运行稳定,瓦温保持在30℃左右(此时冷却水温度为20℃左右);该站首台使用塑料瓦的7号机组已安全运行20 000 h以上,瓦面平均磨损量小于0.05 mm,基本上消除了出现烧瓦故障的可能性.

The performance of the thrust bearing bush of the main motor in a large vertical pump unit was studied, and the cause of burnout malfunction of the main motor thrust bush in No. 4 Pumping Station of Jiangdu Hydro-junction was analyzed. A thrust bearing bush with elastically metallic plastics as a substitute for babbit alloy was used for the structure imrovement in the main motor. According to the application of the elastically metallic plastic thrust bush, and by comparison with the babbit thrust bush, the special attention for the application of the elastically metallic plastic thrust bush was introduced. Through 20 000 hours safe operation, wear extent of the plastic bush was less than 0.05 mm. At the same time, the main pump unit operated steadily; its plastic bush temperature was held at about 30 ℃ and its cooling water temperature kept around 20 %. Therefore, the design improvement adopting the plastic bush could ultimately decrease the probability of the burnout trouble.