Impeller for centrifugal pump and pump including the same

Abstract

A centrifugal pump impeller 11 includes an impeller body in which an inner channel 35 is formed, and a single centrifugal vane 37 provided in the impeller body so as to have a leading edge at an outlet and a trailing edge at a predetermined point of an outer periphery of the impeller body. The centrifugal vane 37 is designed so that the area of an outer channel 36 , which is defined by the centrifugal vane 37 , in an angle range of 270° in a peripheral direction from the trailing edge of the centrifugal vane 37 to the total area of the impeller body surrounded by the outer periphery of the impeller body is less than 0.3.

1 . A centrifugal pump impeller having a predetermined passage diameter, comprising:
 an impeller body in which a helical inner channel is formed, the inner channel turning about a rotational axis while extending in an axial direction so as to connect an inlet opening in one end surface to an outlet opening in a peripheral surface of the impeller body; and   a single centrifugal vane provided in the impeller body so as to have a leading edge at the outlet and a trailing edge at a predetermined point of an outer periphery of the impeller body, wherein   the centrifugal vane is formed to extend over an angle range of 270° or more in a peripheral direction about the rotational axis as a center, and defines an outer channel recessed from the peripheral surface of the impeller body, the outer channel continuing to the outlet and turning along the peripheral surface of the impeller body, and   in a transverse cross section of the outer channel at a center in the axial direction, a ratio of an area of the outer channel in an angle range of 270° in the peripheral direction from the trailing edge of the centrifugal vane to a total area of the impeller body surrounded by the outer periphery of the impeller body is less than 0.3.   
     
     
         2 . The centrifugal pump impeller of  claim 1 , wherein a ratio of the passage diameter to a bore diameter of the pump is 100%. 
     
     
         3 . A centrifugal pump, comprising:
 a centrifugal pump impeller;   a casing that houses the centrifugal pump impeller; and   a motor that drives and rotates the centrifugal pump impeller, wherein   the centrifugal pump impeller has a predetermined passage diameter, and includes
 an impeller body in which a helical inner channel is formed, the inner channel turning about a rotational axis while extending in an axial direction so as to connect an inlet opening in one end surface to an outlet opening in a peripheral surface of the impeller body, and 
 a single centrifugal vane provided in the impeller body so as to have a leading edge at the outlet and a trailing edge at a predetermined point of an outer periphery of the impeller body, 
   the centrifugal vane is formed to extend over an angle range of 270° or more in a peripheral direction about the rotational axis as a center, and defines an outer channel recessed from the peripheral surface of the impeller body, the outer channel continuing to the outlet and turning along the peripheral surface of the impeller body, and   in a transverse cross section of the outer channel at a center in the axial direction, a ratio of an area of the outer channel in an angle range of 270° in the peripheral direction from the trailing edge of the centrifugal vane to a total area of the impeller body surrounded by the outer periphery of the impeller body is less than 0.3.   
     
     
         4 . The centrifugal pump of  claim 3 , wherein
 a ratio of the passage diameter to a bore diameter of the pump is 100%.