A ROTARY DISPLACEMENT PUMP WITH VANES, SUITABLE FOR OPERATING WITH SCARCE OR ABSENT LUBRICATION

摘要

A rotary displacement pump with vanes, which comprises a body (2), a pumping chamber defined within the body (2) by a peripheral wall (3) having a cylindrical shape with a circular cross section, and comprises a rotor (4) that carries vanes (5) and can be put in eccentric rotation within the pumping chamber, wherein a freely rotatable annular member (11) is installed inside the cylindrical peripheral wall (3) and defines a pump operating space (C) wherein rotates the vanes carrying rotor (4), the end portions of the vanes (5) being put in radial slipping contact against the inner surface of the rotatable annular member (11). Preferably, between the pumping chamber wall (3) of the pump and the outer surface of the freely rotatable annular member (11) there is left free a cavity (12), and this cavity (12) is put in communication with a delivery connection (10) of the pump. A freely rotatable disc (14) may be placed between at least an axial end of the vane carrying rotor (4) and the corresponding end wall of the pumping chamber, forming a cavity (15) which is put in communication with a delivery connection (10) of the pump. Preferably, the pump is coupled with an own electric motor (16) for driving the same.