摘要 |
Mechanism for keeping clean the narrow gaps between the impeller of a pump, especially a sewage pump, and an object placed against the impeller in the direction of the rotational axis of the impeller, for example a pump casing. Keeping the gaps clean of solids contained in the wastewater has been found to be a very difficult problem. According to the invention, this problem has been solved by providing at least the side of the impeller facing the pump casing and the corresponding side of the pump casing with projections arranged eccentrically with respect to the axis of rotation of the impeller in such a way, that the mutually overlapping proportions of said projections alternately increase and decrease during the rotation of the impeller. |