BIDIRECTIONALLY OPERABLE, UNIDIRECTIONALLY FEEDING PUMP

摘要

The invention concerns a gear pump comprising a housing (12) provided with an inlet (17) and an outlet (19), an internally toothed ring (3) and an externally toothed gear wheel (2) which is arranged inside and meshing with the toothed ring. A cylindrical bore (7) is provided in the gear wheel, and a bearing unit (6) is arranged in the cylindrical bore for rotatable bedding of the gear wheel with respect to a rotation axis (A) arranged eccentrically in relation to the ring axis (C) and with the bearing unit being pivotable around the gear wheel axis. The gear ring is fixed to the housing, and means is provided for driving the gear wheel into an orbiting movement within and in relation to the gear ring to create a number of expanding chambers (16) and a number of contracting chambers (18) between the gear wheel and the gear ring. A commutator plate (20) is arranged next to the gear wheel and the gear ring in a space in the housing, and connected to the driving means in a way to rotate at the speed of the orbiting motion around the gear ring axis. The commutator plate has channels (32, 33) connecting the expanding channels and the contracting channels with the inlet and outlet respectively.