It has strong ability of breaking soil, and is mostly used for cultivation of shrub land, marshland and grass wasteland. The working parts (see figure) include a rotary tillage knife roller and a number of earth-cutting blades evenly arranged according to the multi-head spiral, which are driven by the tractor power output shaft through the transmission device, and the common speed is 190 ~ 280 RPM. The direction of rotation of the cutter roller is usually the same as the direction of rotation of the tractor wheels. The cutter cuts the soil from front to back and throws the soil blocks back and up onto the housing and dragging plate to further break them. When the knife roller is cutting and throwing the soil, the reaction force of the soil on the knife roller is helpful to push the unit forward, so the traction force required in the operation of the horizontal rotary tiller is very small, and sometimes the knife roller can even push the unit forward.
The earth cutting blade can be divided into chisel knife, curved knife, right Angle knife and arc knife. The front end of the chisel knife is narrow, it has good soil entry capacity, low energy consumption, but it is easy to wind up grass, so it is mostly used in the vegetable garden and courtyard where there are few weeds. The curved edge of the scimitar has the effect of sliding cutting, and it is easy to cut off the grass root instead of winding the grass, so it is suitable for paddy farming. Right-angle knives have vertical and horizontal cutting edges, wide body, good rigidity, easy to manufacture, but poor performance in soil. The arc knife has high strength, good rigidity, good sliding cutting effect, and is usually used on heavy rotary tiller. When matching with tractors below 15 kilowatts, direct connection is generally adopted, without universal joint transmission; When matching with tractors above 15 kilowatts, three-point suspension type and universal joint drive are adopted. Heavy - duty rotary tiller generally adopts traction type.
The tillage depth is controlled and adjusted by a drag plate or a depth limit wheel. The drag plate is arranged behind the knife roller, and plays the role of soil crushing and leveling; The depth limiting wheel is located in front of the knife roller. The configuration of the last stage drive device of the cutter roller has two kinds: side drive and central drive. Side drive is mostly used for offset rotary tiller with smaller tillage. The central drive is used for the rotary tiller with large tillage amplitude. The machine has good symmetry and the whole machine has uniform force. However, a zone under the transmission box can not be reached by the soil cutter, so it is necessary to set up another device to eliminate the leakage tillage.