VOLUTE PUMP

PROBLEM TO BE SOLVED: To facilitate the manufacture of a volute pump and make it compact by partitioning the inside of a cylindrical vessel having a circular or elliptical cross section by an inclined plate and forming a chamber on one side which is partitioned by the inclined plate into a volute discharge casing of which cross sectional area of a flow passage is changed gradually and a chamber on the other side into a suction casing. SOLUTION: An inclined plate 2 is mounted in the inside of a cylindrical vessel 1 having circular or elliptical cross section, and a chamber on one side which is partitioned by the inclined plate 2 is used as a discharge casing and the other chamber 6 is used as a suction casing. A discharge nozzle 7 is connected to a section where cross sectional area of a flow passage is large in the discharge casing 5, and a suction nozzle 8 is connected to the suction casing chamber 6. Moreover, a watershed 10 for guiding water from an impeller 3 into the nozzle 7 efficiently is provided, and the watershed 10 and the inside of the vessel 1 are connected by a guide plate 11. The guide plate 11 is formed in such a manner that it becomes apart from a shaft core 0 gradually in the radial direction when advancing on the downstream side and that cross sectional area of the flow passage is increased gradually in the direction of flow.