power input is by means of the drive shaft 1 , which is connected at one end to an electric motor , for example , and carries a bevel gear at its other end . the drive motor has not been shown here . the drive shaft 1 is installed with a complete bearing unit in an insert in the housing 16 . by means of tooth engagement with a horizontal bevel gear , the driving power is transmitted to the vertical bevel - gear shaft 2 of the angular transmission . to support the axial and radial forces , the vertical bevel - gear shaft 2 is held above and below the bevel gear by bearings , which are secured on the housing . the shaft end projecting above the upper bearing is connected in a rotationally fixed manner to a sun gear 4 by a coupling 3 . the coupling 3 is preferably a toothed coupling . the sun gear 4 is centered in an overhung manner ( i . e ., without radial support ) between the planet gears 5 . the revolving planet gears 5 are rotatably mounted in the planet carrier 6 . the planet carrier 6 is guided in the radial direction by means of the planet gears 5 meshing with the annulus 17 and its entire weight hangs from a tie bar 7 which is secured on a tie - bar holder ( 8 ) mounted rotatably in the planet carrier 12 of the upper epicyclic stage . mounted at the end of a cylindrical extension of the planet carrier 12 is a toothed coupling 9 which transmits the torque to the sun pinion 10 of the upper epicyclic transmission stage . the planet gears 11 meshing with the sun pinion 10 centered in an overhung manner ( i . e ., without radial support ) roll within the fixed annulus 18 . the planet carrier 12 , on which the planet gears 11 are rotatably mounted , revolves and with it the thrust ring 14 , on which it is directly secured in a rigid manner . the thrust ring 14 takes the form of a circular disc which projects only slightly in the radial direction beyond the thrust bearings 15 , which are arranged in a ring pattern , and is significantly thinner than a thrust plate which is customarily installed . the thrust ring 14 bears the weight of the upper output planet carrier 12 and of the transmission elements of the lower stage which are suspended on the carrier . the thrust ring 14 transmits the weight - associated forces acting on it and the axial forces resulting from the grinding process in the bowl mill 20 secured on it into the housing 16 via the thrust bearings 15 . these very large axial forces are introduced into the foundation by the housing 16 via direct force transmission . the thrust bearings 15 are embodied as hydrodynamic or hydrostatic bearings or as a combination of the two types of bearing , depending on the overall size of the mill and the grinding pressure which occurs . the thrust ring 14 is supported radially via the planet carrier 12 , which is guided at its lower end in a bearing 13 . in the vertical direction , the bearing 13 is mounted between the annuluses 17 , 18 in the interior of the annulus holder 19 and is preferably embodied as a sliding - contact bearing . the one - piece annulus holder 19 represents a compact unit which is inserted complete into the housing 16 and connected in a rotationally fixed manner together with the annuluses 17 , 18 , which are preferably shrunk in and additionally secured in a form - fitting manner , e . g . by means of keys . the annuluses 17 , 18 are of the same diameter , thereby ensuring that the annulus holder 19 has a simple configuration . if different annulus diameters are desired , the smaller annulus must be produced from a hollow cylinder with a greater wall thickness to maintain the shape of the annulus holder 19 . the epicyclic stages running in the annuluses 17 , 18 are likewise compact units which are each installed as complete units . in another embodiment shown in fig2 the bevel - gear transmission stage 1 , 2 is provided as a complete module with its own vertical housing 21 . a complete module of this kind can be inserted through a tunnel leading radially into the housing 16 and positioned under the raised sun gear 4 . the sun gear 4 is connected to the bevelgear shaft 2 by means of the coupling 3 by lowering the sun gear 4 , this being performed , like the raising process , from above by means of lifting gear . in another design configuration shown in fig3 a module of this kind belonging to the bevel - gear transmission stage 1 , 2 is embodied with a flanged housing 22 . by means of flanges 23 , the flanged housing 22 is flanged as a compact unit to the annulus holder 19 , and the coupling 3 connects the bevel - gear shaft 2 to the sun gear 4 . to simplify assembly , both the vertical housing 21 and the flanged housing 22 can be embodied in several parts . it is thereby possible to partially disassemble these units , even after they have been installed . this allows maintenance or repair work to be carried out easily . thus , while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof , it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated , and in their operation , may be made by those skilled in the art without departing from the spirit of the invention . for example , it is expressly intended that all combinations of those elements and / or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention . moreover , it should be recognized that structures and / or elements and / or method steps shown and / or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice . it is the intention , therefore , to be limited only as indicated by the scope of the claims appended hereto .