| 摘要 |
PROBLEM TO BE SOLVED: To enable a sound pressure level of paddling sound to be reduced even in a low lift range, the paddling sound being caused by a pump rotor.SOLUTION: A pump rotor 11 comprises an annular porous body 20 and a support 12 supporting the annular porous body 20. The porous body 20 confines bubbles inside during rotating, the bubbles generating in a fluid in a rotor housing chamber, and imparts a centrifugal force to the fluid. |
