| 摘要 |
PROBLEM TO BE SOLVED: To provide a centrifugal pump which has a pump casing applicable in common for different shapes of impeller and can exhibit required performance.SOLUTION: A double suction centrifugal pump includes: an impeller 2a which ejects actuation fluid Liq sucked from a lateral surface, from an ejection side 2c of a peripheral part in a pump casing 3; a channel 5b which guides the actuation fluid Liq ejected from the impeller 2a to an ejection port while circulating the actuation fluid in a spiral form and allows a cross-section formed by cutting the channel with a plane containing a center line CL of a main shaft 2 to be gradually increased in the rotation direction of the impeller 2a; and a housing part 5c which is formed so as to be communicated with the channel 5b and houses the impeller 2a. Therein, an interval in the shaft direction of the pump casing 3 on the channel 5b is gradually reduced along the radial direction around the main shaft 2 from the boundary with the housing part 5c and, on the top on which the interval gets to minimum, a narrow path part 51 on which the interval is gradually increased is formed along the radial direction. |
