Abstract: The application relates to a pump apparatus for pumping liquid, and more particularly to a technique for removing foreign matters contained in the liquid when an impeller catches on the foreign matters. The pump apparatus includes: an impeller (1); an electric motor (7) configured to rotate the impeller (1); an inverter (14) configured to drive the electric motor (7); a current measuring device (15) configured to measure a current supplied to the electric motor (7); and an operation controller (17) configured to instruct the inverter (14) to cause the impeller (1) to perform a foreign-matter removing operation including at least two of: an intermittent operation that intermittently rotates the impeller (1) in a forward direction; a reverse-rotating operation that rotates the impeller (1) in a reverse direction; and a forward and reverse inching operation that rotates the impeller (1) in the reverse direction and the forward direction alternately and repeatedly.

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).

Abstract: The present invention relates to a volute pump and particularly provides a volute pump for delivering a liquid containing fibrous substances and solid substances, while preventing these substances from obstructing the pump. The volute pump includes a pump casing (10) having a protrusion (14) projecting into a flow passage (11) and separating a starting end of a volute from a terminal end of a volute. The protrusion (14) faces a liquid outlet (23) of an impeller (20). A radius of curvature (Rb) of a cross section of a distal edge of the protrusion (14) at its one side end (14b) is larger than a radius of curvature (Ra) of the cross section of the distal edge of the protrusion (14) at other side end (14a). The other side end (14a) faces a main plate (20a), while the one side end (14b) is located opposite to the main plate (20a).

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 casing liner used for a sewage pump includes a surface to face an edge of a blade of an impeller when the casing liner is assembled with the impeller into the sewage pump. At least one groove with given width is formed in at least a part of the surface. The groove includes a first section with given depth, which is located on the side close to a rotational center of the impeller, a second section smaller in depth than the first section, which is located on the side far from the rotational center of the impeller, and a third section that is an inclined face connecting the first and second sections, the first to third sections being arranged in a width direction of the groove.

Abstract: A pump impeller for a submerged pump capable of removing or reducing the radial load is provided. A non-clogging submerged pump is provided, which includes a substantially cylindrical body, an intake port provided in a center of a lower end surface of the body, a discharge port that is open in a side surface of the body, and a flow channel passing from the intake port to the discharge port within the body. The flow channel includes a plurality of flow channels, and the flow channels have their size, shape, and position defined such that fluid unbalance is reduced with respect to an axis of rotation.

Abstract: The present invention relates to a volute pump and particularly provides a volute pump for delivering a liquid containing fibrous substances and solid substances, while preventing these substances from obstructing the pump. The volute pump includes a pump casing (10) having a protrusion (14) projecting into a flow passage (11) and separating a starting end of a volute from a terminal end of a volute. The protrusion (14) faces a liquid outlet (23) of an impeller (20). A radius of curvature (Rb) of a cross section of a distal edge of the protrusion (14) at its one side end (14b) is larger than a radius of curvature (Ra) of the cross section of the distal edge of the protrusion (14) at other side end (14a). The other side end (14a) faces a main plate (20a), while the one side end (14b) is located opposite to the main plate (20a).

Abstract: A casing liner used for a sewage pump includes a surface to face an edge of a blade of an impeller when the casing liner is assembled with the impeller into the sewage pump. At least one groove with given width is formed in at least a part of the surface. The groove includes a first section with given depth, which is located on the side close to a rotational center of the impeller, a second section smaller in depth than the first section, which is located on the side far from the rotational center of the impeller, and a third section that is an inclined face connecting the first and second sections, the first to third sections being arranged in a width direction of the groove.