Rotary lobe pumps

A pump comprising:

• a shaft extending through a rotor case before being connected to a rotor at a shaft/rotor connection, the rotor comprising an inside surface oppositely disposed to an outside surface of the shaft, the pump further comprising a seal assembly for providing a seal between the inside surface of the rotor and the outside surface of the shaft,
• the seal assembly comprising a sleeve support through which the shaft passes before the shaft is connected to the rotor, the sleeve support being connected to the rotor case, the sleeve support extending from the rotor case along the shaft towards the shaft/rotor connection, the sleeve support passing through an elongated seal,
• the elongated seal being accommodated in a seal housing and between the sleeve support and the seal housing, the seal housing being frictionally accommodated in the inside surface of the rotor and between the elongated seal and the inside surface of the rotor,
• the seal housing comprising an outer surface with at least one circumferential groove disposed therein for accommodating an O-ring, the O-ring being trapped between the seal housing and the inside surface of the rotor,
• the elongated seal being disposed between the shaft/rotor connection and the rotor case, the elongated seal being frictionally secured to an inner surface of the seal housing and extending radially inwardly to engage an outside surface of the sleeve support.