| 摘要 |
PROBLEM TO BE SOLVED: To provide a cascade pump capable of suppressing the inclination of a rotary shaft of an impeller generated by pressure difference between an inlet part and an outlet part of a boosting channel.SOLUTION: A cascade pump 1 is equipped with a generally disc-shaped impeller 30 which has a blade portion 35 installed with a large number of blades 37; and a housing 10 which rotatably stores the impeller 30. The impeller 30 has a thin plate portion 34 formed with an annular recessed groove on the inner side in a radial direction of the blade portion 35, and the housing 10 has an annular projecting portion 19 fitted in the annular recessed groove. A seal portion 45 for preventing the leakage of fluid in a boosting channel 15 has a stepped seal portion 48 extending in a direction orthogonal to a radial direction of the impeller 30, by level difference between the blade portion 35 and the thin plate portion 34 of the impeller 30. On an inner peripheral surface 35b facing the stepped seal portion 48 of the blade portion 35, pressure Papplying from a fluid positioned in the stepped seal portion 48 toward the outer side in the radial direction is acted.SELECTED DRAWING: Figure 3 |
