Patent ID: 6224331
Filing Date: 2001-05-01
Classification: F04D

Abstract:
A centrifugal chopper pump comprising:a pump casing having a frontal intake port and a pump outlet in a side thereof;a rotatable drive shaft extending into said casing from a rear side of the casing, said drive shaft rotating about an axis of rotation in a preselected direction of rotation;an impeller mounted on said drive shaft for rotation therewith, said impeller having a set of radially extending vanes and a generally radial back shroud joined to an elongate side edge of each vane, said vanes each having a sharpened leading edge that extends generally radially in relation to said axis of rotation, each vane projecting forwardly from said back shroud and sweeping backwardly from said leading edge relative to said direction of rotation to a trailing edge, wherein narrow, elongate, cross-sections of each vane taken in a series of consecutive axial planes as defined by said axis of rotation are rotated relative to one another from an initial cross-section near said leading edge that extends generally radially to a trailing cross-section adjacent said trailing edge which extends to a substantial angle to said initial cross-section;at least one cutter member rigidly mounted on said pump casing, located in said intake port, and having an inner edge that extends generally radially in relation to said axis of rotation,wherein, during operation of said pump, the leading edges of said vanes rotate closely past said inner edge of said at least one cutter member to cut incoming solid material caught between the leading edges of said vanes and said at least one cutter member.