Apparatus for measuring a mass flow of flowable bulk materials, according to the Coriolis measuring principle, having - an outer, stationary housing; - - in which a vane wheel is rotatably supported; - and a drive - - which comprises a torque measuring device and a drive motor for powering the vane wheel with constant speed of rotation, - - - with which a drive shaft connected to the vane wheel is powered; - - - - which is routed in a vertical orientation through the top side of the housing, such, that the rotational axis of the vane wheel extends along a central axis of the apparatus, - wherein the vane wheel is fastened in the housing below the rotatably supported drive shaft, - and wherein below the vane wheel, an outlet funnel is provided on the housing, - - which with the housing encloses a bulk material chamber and - - contains a discharge opening at a lower end, - wherein the apparatus substantially extends rotationally symmetrical around the central axis and - wherein with the vane wheel, a mass flow fed in the axial direction can be radially deflected and the drive torque required for deflection can be detected in the torque measuring device, characterized in that the drive shaft is configured as a two-sided open hollow shaft, which is aligned with a first opening at a feed opening and is open with a second opening towards the vane wheel through which the mass flow to be measured can be fed in the vertical direction to the vane wheel. - an outer, stationary housing; - - in which a vane wheel is rotatably supported; - - in which a vane wheel is rotatably supported; - and a drive - - which comprises a torque measuring device and a drive motor for powering the vane wheel with constant speed of rotation, - - - with which a drive shaft connected to the vane wheel is powered; - - - - which is routed in a vertical orientation through the top side of the housing, such, that the rotational axis of the vane wheel extends along a central axis of the apparatus, - - which comprises a torque measuring device and a drive motor for powering the vane wheel with constant speed of rotation, - - - with which a drive shaft connected to the vane wheel is powered; - - - - which is routed in a vertical orientation through the top side of the housing, such, that the rotational axis of the vane wheel extends along a central axis of the apparatus, - - - with which a drive shaft connected to the vane wheel is powered; - - - - which is routed in a vertical orientation through the top side of the housing, such, that the rotational axis of the vane wheel extends along a central axis of the apparatus, - wherein the vane wheel is fastened in the housing below the rotatably supported drive shaft, - and wherein below the vane wheel, an outlet funnel is provided on the housing, - - which with the housing encloses a bulk material chamber and - - contains a discharge opening at a lower end, - - which with the housing encloses a bulk material chamber and - - contains a discharge opening at a lower end, - wherein the apparatus substantially extends rotationally symmetrical around the central axis and - wherein with the vane wheel, a mass flow fed in the axial direction can be radially deflected and the drive torque required for deflection can be detected in the torque measuring device,