Patent ID: 8087915

Claim:
A rotary pump of the type comprising: a stator ( 1 ), in this stator a chamber (V) delimited by a peripheral wall ( 110 ), formed in said stator an inlet connection ( 31 ) and an exit passageway, an inlet passageway ( 32 ) formed in said stator ( 1 ) and extending from said inlet connection ( 31 ) to said chamber (V), within said chamber a rotor ( 2 ), mounted revolving around an axis (X) eccentric with respect to said chamber (V), said rotor having a support portion ( 2 ′), a vane supporting portion ( 2 ) and mechanical coupling means ( 24 , 25 ) intended for driving the rotor in rotation, said vane supporting portion ( 2 ) of the rotor being tangent (β) to a region of the peripheral wall ( 110 ) of said chamber (V), said vane supporting portion ( 2 ) of the rotor having two parallel walls ( 5 , 5 a ) that delimit a diametrical space and divide the vane supporting portion ( 2 ) in two half shells ( 4 , 4 a ), and at least one vane ( 3 ), mounted sliding in said diametrical space of the vane supporting portion ( 2 ) and tangent at its end portions to the peripheral wall ( 110 ) of said chamber, wherein: every half shell ( 4 , 4 a ) of the vane supporting portion ( 2 ) of the rotor is hollow; every half shell ( 4 , 4 a ) has at each end in the circumferential direction a radial inlet passage opening ( 7 , 8 , 9 , 10 ) opening at the surface of the vane supporting portion ( 2 ) and communicating with the hollow space of the half shell ( 4 , 4 a ); each said inlet passage ( 7 , 8 , 9 , 10 ) of the half shells is controlled by a one-way valve ( 6 , 6 a ; 41 ) so arranged as to allow a flow from the outside of the vane supporting portion ( 2 ) towards said hollow space of the half shell ( 4 , 4 a ); and each half shell ( 4 , 4 a ) has, at the end portion of the vane supporting portion ( 2 ) facing said support portion ( 2 ′), a discharge opening ( 12 , 13 ).