A device for branching a fluidic partial flow off a main flow by a hydraulic pump (10) includes individual main chambers (12, 14, 16, 18, 20) sealed from each other and divided into functional groups, and operates according to the displacement principle. The chambers enable fluid from at least one main flow inlet (22) to be transported from an inlet or suction side to an outlet or pressure side of the hydraulic pump (10) and then via at least one main flow outlet. At least one independent partial chamber (26) is provided for the transport of the partial flow in addition to the main chambers (12, 14, 16, 18, 20). The partial chamber forms part of the pressure side of the hydraulic pump (10) and is connected to an independent partial current outlet (42) separate from the main flow inlet (22) and the main flow outlet (24).