Abstract: A pump is disclosed that comprises: (1) a support structure including a body having an annular end in which an opening is defined, and a volute connected to the said end of the body so as to define a pumping chamber therewith; (2) a bladed rotor disposed in the chamber and connected to a shaft which is mounted rotatably in the body and extends through the opening; and (3) a first and a second annular sealing member which are carried by the structure and which encircle the shaft in a leaktight manner. A lubrication chamber containing a lubricating grease is defined between the sealing members and the shaft. A first sealing ring, closer to the rotor, has an inner portion which forms at least one sealing lip which bears on the shaft, and a circular portion disposed outside the lip and having a substantially U-shaped cross-section with its convex side facing the rotor.

Abstract: A pump is disclosed that comprises: (1) a support structure including a body having an annular end in which an opening is defined, and a volute connected to the said end of the body so as to define a pumping chamber therewith; (2) a bladed rotor disposed in the chamber and connected to a shaft which is mounted rotatably in the body and extends through the opening; and (3) a first and a second annular sealing member which are carried by the structure and which encircle the shaft in a leaktight manner. A lubrication chamber containing a lubricating grease is defined between the sealing members and the shaft. A first sealing ring, closer to the rotor, has an inner portion which forms at least one sealing lip which bears on the shaft, and a circular portion disposed outside the lip and having a substantially U-shaped cross-section with its convex side facing the rotor.