摘要 |
A pump impeller which includes: a back shroud having an inner main face with an outer peripheral edge and a central axis, the impeller in use being rotatable about the central axis in a direction of rotation, a plurality of pumping vanes extending from the inner main face of the back shroud, the pumping vanes being disposed in spaced apart relation, and each pumping vane including: opposed first and second side faces, a leading edge in the region of the central axis and a trailing edge in the region of the outer peripheral edge of the back shroud, and with a passageway between adjacent pumping vanes, wherein the first side face at the leading edge is in a plane which is at an acute angle with respect to a plane of the inner main face of the back shroud, and the first side face at the trailing edge is in a plane which is at an obtuse angle with respect to the plane of the inner main face of the back shroud. |