Two stage belt drive for combine harvester - uses rollers on rocking levers coupled by spring to tension belts adjacent intermediate pulley at thresher drum

摘要

The two-stage belt transmission for combined harvester, transmits rotation from a drive shaft (2) to those of the thresher and straw shakers. The system incorporates two outer pulley wheels and an intermediate pulley wheel on parallel horizontal spindles, a trapezoidal section belt extending from each of the outer wheels to converge on the intermediate wheel. Tensioning of the active runs of the respective belts is effected by two rollers (6, 7) which straddle the two-stage intermediate pulley (3), each roller being mounted on a pivotable cranked lever (8, 9). The levers are coupled by a tension accumulator e.g. a compression spring (10). The spring may be combined with a shock absorber, the levers being symmetrical about the vertical axis through the intermediate pulley.