impeller
/ɪmˈpelə(r)/(亦作impellor)
noun
1- the rotating part of a centrifugal pump, compressor, or other machine designed to move a fluid by rotation（离心泵、压缩机等的）叶轮, 转子。
1.1
- a similar device turned by the flow of water past a ship's hull, used to measure speed or distance travelled（船只的）记速叶轮, 记程叶轮。