To simplify the shape of a flow passage, enable the manufacture of a volute pump casing by using a steel plate, and reduce manufacturing cost by attaching a plate to a circular or elliptical cylinder by tilting it to change cross sectional area of the flow passage gradually in the volute pump casing constituted in such a manner that the cross sectional area of the flow passage is changed gradually in the direction of flow.
A volute pump is provided with a volute pump casing C, an impeller 12 stored in the casing C, and a pump main shaft 13 which supports the impeller 12. The casing C is attached to a circular or elliptical cylinder 1 made of steel plate by tilting an inclined plate 2 for a shaft core a suction port 9 is connected with the inclined plate 2 in opposition to an inlet of the impeller 12, and a discharge port 4 is connected to a section where cross sectional area of a flow passage is large. Moreover, a watershed 5 is provided in the casing C, and the watershed 5 is connected with the inside of the cylinder 1 by a guide plate 6. Consequently, the cross sectional area of the flow passage is gradually increased in the direction of flow by forming the guide plate 6 in such a manner that it becomes away from the shaft core 0 gradually in the radial direction when advancing toward the downstream of the flow.
KATO HIROYUKI
INOUE HIROBUMI
KURIO SHOTARO
NABE SHIRO
TAKAHASHI TAKAHIRO
MIYAWAKI TAKASHI
