Abstract: The present invention relates to a volute pump for delivering a liquid containing fibrous substances. The volute pump includes an impeller (1) having a vane (2), and an impeller casing (5) which houses the impeller (1) therein. The impeller casing (5) includes a volute chamber (7), a suction port (3) and a discharge port (4) which communicate with the volute chamber (7), and a tongue portion (10) which forms a starting portion of the volute chamber (7). A groove (18), extending from the suction port (3) to the volute chamber (7), is formed in an inner surface of the impeller casing (5). An intersection point (B), where a terminal end of the vane (2) passes across the groove (18) as viewed from an axial direction of the impeller (1), is located at an opposite side from the tongue portion (10) with respect to a central point of the impeller (1).

Abstract: A volute pump for delivering a liquid containing fibrous substances. The volute pump includes an impeller (1) rotatable together with a rotational shaft (11), and an impeller casing (5) having a suction port (3) and a volute chamber (7). A groove (18), extending from the suction port (3) to the volute chamber (7), is formed in an inner surface of the impeller casing (5). The impeller (1) includes a hub (13) to which the rotational shaft (11) is fixed, and a sweep-back vane (2) extending helically from the hub (13). The sweep-back vane (2) includes a leading edge portion (2a) extending helically from the hub (13), and a trailing edge portion (2b) extending helically from the leading edge portion (2a). The leading edge portion (2a) has a front-side curved surface (2e) extending from an inner end (2c) to an outer end (2d) of the leading edge portion (2a).

Abstract: A volute pump for delivering a liquid containing fibrous substances. The volute pump includes an impeller (1) rotatable together with a rotational shaft (11), and an impeller casing (5) having a suction port (3) and a volute chamber (7). A groove (18), extending from the suction port (3) to the volute chamber (7), is formed in an inner surface of the impeller casing (5). The impeller (1) includes a hub (13) to which the rotational shaft (11) is fixed, and a sweep-back vane (2) extending helically from the hub (13). The sweep-back vane (2) includes a leading edge portion (2a) extending helically from the hub (13), and a trailing edge portion (2b) extending helically from the leading edge portion (2a). The leading edge portion (2a) has a front-side curved surface (2e) extending from an inner end (2c) to an outer end (2d) of the leading edge portion (2a).

Abstract: The present invention relates to a volute pump for delivering a liquid containing fibrous substances. The volute pump includes an impeller (1) having a vane (2), and an impeller casing (5) which houses the impeller (1) therein. The impeller casing (5) includes a volute chamber (7), a suction port (3) and a discharge port (4) which communicate with the volute chamber (7), and a tongue portion (10) which forms a starting portion of the volute chamber (7). A groove (18), extending from the suction port (3) to the volute chamber (7), is formed in an inner surface of the impeller casing (5). An intersection point (B), where a terminal end of the vane (2) passes across the groove (18) as viewed from an axial direction of the impeller (1), is located at an opposite side from the tongue portion (10) with respect to a central point of the impeller (1).