Conical mixing apparatus having support structure for the mixing screw provided below the bottom of the mixing vessel

Mixing apparatus comprising at least one mixing vessel mounted on a supporting housing, said mixing vessel having a side wall, a bottom wall having a central aperture and a vertical axis, a mixing screw located in said vessel having a central shaft connected to a dirve and support mechanism at its upper end for simultaneously rotating said screw around the axis of its shaft and revolving said screw around the axis of the vessel, the lower end of the mixing screw shaft extending through said aperture and being supported below said vessel in a bearing located in said housing, said bearing comprising a universal joint as well as radial and axial force receiving bearings, said universal joint having a first tiltable member supported by means of pivot pins extending from said housing and a second tiltable member supported by means of pivot pins extending from said first tiltable member, the radial and axial force receiving bearings being mounted in a bearing support in said second tiltable member perpendicular to the pins thereof, a cover secured over said bearing support and around the mixing screw shaft extending through the aperture in the bottom of the mixing vessel, said cover having its upper surface shaped as a segment of a sphere around the centre of the universal joint and means for sealing the spherical surface of the cover with respect to the aperture in the bottom wall of said mixing vessel.