A rotary tiller, which is also known as a rototiller, power tiller, rotavator, rotary hoe, or rotary plow, is a motorized cultivator. It works the soil by means of rotating tines or blades, and is either self-propelled or drawn as an attachment behind either a two-wheel tractor or four-wheel tractor. A rotary tiller is an implement that utilizes its set of curved tines that are attached to a rotating shaft to dig into soil and turn it into a seedbed that’s ready for planting.
According to the way they are configured, the rotary cutter shafts are divided into three categories: horizontal shaft, vertical shaft and tilting type. Correct use and adjustment of the rotary tiller is important to maintain its good technical condition and ensure the quality of tillage.The rotary tiller has the function of breaking the bottom layer of the plough, restoring the soil tillage structure, improving the soil’s ability to store water and moisture, eliminating some weeds, reducing pests and diseases, levelling the surface and improving the standard of agricultural mechanisation.
Soil tillage machines with rotating tines as working parts, also known as rotary cultivators. According to the configuration of the rotating tines, they are divided into two types: horizontal and vertical. The horizontal axis rotary tiller with horizontal axle is more commonly used. The classification has a strong ability to break up the soil, an operation that can make the soil fine, soil and fertilizer mixed evenly, the ground is flat, to achieve the requirements of dryland sowing or paddy planting, is conducive to strive for farming time, improve work efficiency, and can make full use of the power of the tractor. However, the mulching ability of the stubble and weeds is poor, the ploughing depth is shallow (12-16 cm for dry ploughing; 14-18 cm for hydroponic ploughing) and the energy consumption is high. Mainly used in rice fields and vegetable fields, also used in orchard ploughing. The heavy-duty rotary tiller can plough to a depth of 20-25 cm and is mostly used to reclaim shrublands, swamps and grassy wastelands.
Horizontal Shaft Type
Strong soil breaking ability, mostly used for cultivating shrublands, swamps and grassy wastelands. The working parts (see diagram) include a rotating tillage roller and a number of cutting blades evenly configured according to a multi-headed screw line, driven by the tractor’s power output shaft through a transmission device, with a common speed of 190 to 280 rpm. The direction of rotation of the cutter roller is usually the same as the direction of rotation of the tractor wheel. The cutting blade cuts the soil from the front to the back and throws the soil backwards and upwards to the hood and towing plate to break it up further. When the cutter roller cuts and throws the soil, the reaction force of the soil on the cutter roller helps to push the unit forward, thus the traction force required for horizontal rotary tiller operation is minimal and sometimes the unit can even be pushed forward by the cutter roller.
Soil cutting blades can be divided into chisel, curved, right-angle and curved knives. The chisel blade has a narrow front end, good soil penetration and low energy consumption, but it is easy to tangle with weeds and is used in vegetable gardens and yards with few weeds. The curved blade of the curved knife has a sliding cutting effect, which is easy to cut the grass roots without tangling the grass, and is suitable for rice field cultivation. The right-angle knife has vertical and horizontal cutting edges, with a wide blade, good rigidity and easy manufacturing, but the performance of entering the soil is poor. Curved knives are strong, rigid and have good slip-cutting action and are usually used on heavy rotary tillers.
When matching with tractors below 15 kW, it is usually directly connected without universal joint drive; when matching with tractors above 15 kW, it is three-point suspension and universal joint drive; heavy-duty rototillers generally use traction type. The ploughing depth is controlled and adjusted by the dragging plate or the depth limiting wheel. The dragging plate is located behind the knife roller, and plays the role of soil breaking and levelling; the depth limiting wheel is located in front of the knife roller. The last drive of the knife roller is configured in two ways: side drive and central drive. The side drive is mostly used for the smaller offset rotary tiller. The central drive is used for larger rotary tiller, the symmetry of the machine is good, the whole machine is evenly stressed; but the transmission box below a strip of soil cutting blades can not reach the formation of leakage, need to set up another device to eliminate leakage.
Vertical Shaft Type
The working part is a rotary tiller with 2 to 3 spiral cutters. The rotator rotates around the vertical axis and the cutters cut up the soil. It is suitable for hydroponics in rice fields and has a strong soil breaking and pulping effect, but the mulching performance is poor. It is used more often in Japan. To enhance the tillage effect of the rotary tiller, in some countries various additional devices are added to the rotary tiller. For example, a spike-tooth harrow is attached to the back of the tiller to enhance the soil breaking effect, and a loosening shovel is added to deepen the tillage layer.
Tilting Type
The tilting working parts of the tiller are placed diagonally in the horizontal plane, the rotary plane of the tiller blade is at a certain angle to the forward direction of the machine – the tilting angle. The arrangement of the rotary tillage blades in a single row on the knife shaft is related to the forward speed of the machine, the rotation speed of the knife roller and the width of the knife blade. There is a certain phase difference between two adjacent rotating blades on the same spiral. The tilting rotary tiller works without re-tillage, relieving the soil constraints and thus reducing power consumption and tillage resistance.
Rotary tiller development direction
1. to the development of wide high-speed rotary tiller. With the development of rice intensive, large-scale production, paddy cultivation with a wide high-speed rotary tiller will become the direction of development.
2. to the direction of the joint operation unit development. Large and medium-sized tractors with strong power output system, traction and suspension capacity, for supporting the dryland joint tillage machinery to provide the conditions. Rotary tiller as a driving tillage machine, easy to replace or additional working parts, can complete the stubble, deep pine, crushed soil, border, monopoly, furrowing, precision or semi-perfect sowing, deep fertilizer, laying film, suppression and spraying and other joint operations, can significantly improve production efficiency, reduce operating costs. Foreign developed countries have promoted the use of a combination of work process arrangement, rotary tiller as the main unit of joint operations, such as Canada’s universal rotary tiller, Japan’s joint plow and harrow plow and rotary seeder, etc..
3. To sustainable development strategy type development. Reduce pollution and reuse of resources has become the ultimate purpose of the current agricultural mechanization design, can complete the straw back to the field operations such as reverse stubble rototiller new models will become an important research direction of future rotary tillage machinery. In addition, with the rapid development of modern science and technology, some new technologies will also be widely used in the rotary tiller, such as signal systems.
4, small rotary tiller demand increased. With the development of China’s greenhouse technology, rural greenhouse cultivation area is increasing, due to market demand, small suitable for the operation of rotary tillage machinery in the greenhouse has become a new focus of research.
Machinery use
1, the operation began, the tiller should be in the lifting state, first combined with the power output shaft, so that the knife shaft speed to the rated speed, and then down the tiller, so that the blade gradually into the soil to the required depth. It is strictly forbidden to combine the power output shaft or drop the tiller sharply after the blade has entered the soil to avoid bending or breaking the blade and increasing the load on the tractor.
2. In the operation, should try to travel slowly at low speed, so as to ensure the quality of work, so that the soil is fine, but also to reduce the wear and tear of the machine parts. Pay attention to listen to the rotary tiller whether there are noises or metal knocking sound, and observe the broken soil, plowing deep situation. If there are any abnormalities, stop the machine immediately for inspection and continue to work only after elimination.
3. In the head of the turn, the work is prohibited, the tiller should be raised, so that the blades leave the ground, and reduce the tractor throttle, so as not to damage the blades. When lifting the tiller, the tilt angle of the universal joint should be less than 30 degrees, too large will produce impact noise, premature wear or damage.
4. In reverse, over the ridge and transfer of plots, the tiller should be lifted to the highest position, and cut off the power to avoid damage to the machine. If moving to a distant location, use a locking device to secure the tiller in place.
5. After each shift, the tiller should be maintained. Remove the mud and weeds from the blades, check the tightness of the connections, fill the lubricating oil points and grease the universal joints to prevent increased wear.
Machinery adjustment
1. Left and right level adjustment. With the rotary tiller tractor first parked on the flat ground, lower the rotary tiller, so that the blade from the ground 5 cm, observe the left and right knife tip from the ground height is consistent, to ensure that the operation of the knife shaft level consistent, plowing depth uniform.
2. Front and rear level adjustment. Lower the tiller to the required ploughing depth, observe the gimbal angle and the tiller an axis is close to the horizontal position. If the universal joint angle is too large, you can adjust the upper tie rod, so that the tiller is in a horizontal position.
3. Lift height adjustment. Rotary operation, the universal joint angle is not allowed to be greater than 10 degrees, the head of the turn is not allowed to be greater than 30 degrees. Therefore, the rotary tiller lifting, for the use of bit adjustment screws in the appropriate position in the handle screw limit; use the height adjustment, lifting to pay special attention, such as the need to raise the rotary tiller, should be removed from the universal joint power.
