Power transmission applicable in a combine harvester

A combine harvester comprising:

• a grain cleaning system including a support frame and a sieve assembly comprising a number of components including one or more sieves mounted on the support frame by a plurality of rocking arms enabling a fore-aft shaking movement of one or more of said components;
• a tailings return system for returning tailings issued from the sieve assembly back to the cleaning system or to a threshing system of the combine harvester, wherein the tailings return system includes a transversal tailings return auger and an inclined tailings elevating auger, wherein the transversal tailings return auger and the inclined tailings elevating auger each comprises a central rotation axle, wherein the transversal return auger is configured to feed tailings to the inclined tailings elevating auger;
• and
• a power transmission assembly for transmitting power from a transversal drive shaft of the harvester to the transversal tailings return auger and the inclined tailings elevating auger, wherein said power transmission assembly includes:
• (i) a first belt transmission coupling the transversal drive shaft to the transversal tailings return auger,
• (ii) a first gear transmission having an input axle and an output axle, wherein the input axle is either integral with or fixed to the central rotation axle of the transversal tailings return auger, wherein said first gear transmission is a planar gear transmission, and
• (iii) a second gear transmission coupling the output axle of the first gear transmission to the central rotation axle of the inclined tailings return auger.