1 Reciprocating introduction
The main working parts of the reciprocating power rake are two rows of nail teeth, driven by the tractor power output shaft for transverse reciprocating motion, two rows of nail teeth movement in the opposite direction. When working, the ability to break soil is strong, and the soil layer is not disrupted. Only one operation can achieve good results, and the ability to adapt to different soil conditions is strong. At the back of the machine can be connected with the crushing roller (roller harrow) to flatten and compact the topsoil.
The reciprocating power harrow is composed of damping device, frame, flywheel, eccentric swinging fork, central swinging arm, nail teeth (beam), depth limiting wheel and crushing roller (roller harrow), etc. The driving mechanism of the nail tooth (beam) adopts eccentric swing fork type, which is directly driven by the power output shaft of the tractor. There is no variable speed device, and the effect of crushing soil can be adjusted by changing the forward speed of the tractor. Because the reciprocating motion of the working parts produces strong vibration during operation. A spring damping device is provided on the suspension frame of the harrow to cushion the vibration and maintain the smooth operation.
2 Horizontal rotation introduction
The main working part of the horizontal rotary power (rotary tooth) harrow is a row of vertical shaft rotors, each rotor is equipped with two vertical harrow knives (nail teeth). When working, the rotor is driven by the power output shaft through the transmission system. While rotating, it advances, impinges on the soil clods, and makes the soil loose and broken in the plough layer. The rotor of the rake is a "gate" font, and the "gate" font planes of the two adjacent rotors are perpendicular to each other, so the operation area of any rotor is staggered and overlapping, without missing the rake area. The harrow blade (nail teeth) on the rotor is generally installed with a slight tilt back, so that too much wet soil is not thrown to the surface. The number of rotors is even and can be 4, 6, 8 or 10 depending on the width requirement. The rotor is driven by a power output shaft through a gear transmission, a pair of bevel gears and a horizontal cylindrical straight teeth meshing drive located in the box frame. Therefore, the rotation direction of adjacent rotors is opposite, which can offset the side force and make the unit work smoothly. The speed of the rotor can be realized by the shifting mechanism of the gearbox. The torsional roller harrow composed of round steel is connected behind the nail tooth beam, which can make the topsoil more finely broken and flat, and has the suppression effect. The working depth of harrow can be controlled by adjusting the height of crushing roller.
Generally, the plow depth of harrow is 20-25cm, the spacing of rotors is 250-300mm, and the tracks of adjacent rotors have several millimeters of overlap. The rotor speed is 131-450r/min. The horizontal rotary power rake is widely used in foreign countries, which is used for land preparation after tillage. The maximum depth of operation can reach 25-29cm.
3 Comparison
Both the driving harrow and the rotary tiller are the machinery of soil finishing by the rotary tiller teeth on the rotating shaft driven by the gear box. They are usually used after the soil is loosened and turned. By breaking and stirring the soil to create a suitable seed germination and growth bed. In general, there are many similarities and differences between them. Take the Zirkon power harrow and the Mascio rototiller.
Rakenchikan drives the harrow
In terms of type, power driven harrows can be divided into reciprocating power harrows, horizontal rotary power harrows and vertical rotary power harrows according to the motion mode of working parts. Among them, the horizontal rotation (rotary tooth) is more common. Rotary tooth harrow can be deeply turned over the soil to stir, break large clods, stubble and soil mix; After mixing with soil, the straw fiber of previous stubble can degrade gradually and increase the content of soil organic matter, so as to increase soil fertility. On the other hand, straw returning can increase soil moisture retention and reduce the damage caused by evaporation and wind. The power rake usually works with the suppression roller, which can break the soil and smooth the effect. After the finishing of two sets of devices, the soil forms an ideal seedbed with dense and sparse bottom. Power harrows usually operate in the 10-30 cm range, with most of them around 15cm. Compared with the rotary tiller, the power rake price is higher and the demand is larger supporting tractor power output.
Mascio rototiller
Rototiller is a kind of tillage machine which is matched with tractor to complete tillage and harrow operation. It can cut up the root stubble buried below the surface, which is convenient for planter operation and provides a good seed bed for later sowing. Rototiller is divided into horizontal axis type and vertical axis type, of which the former is widely used in China, the latter is mainly used in paddy fields, widely used in Japan. Rototillers operate at shallower depths than driven harrows, but they have more crushing power and require less power. From the blade structure, the horizontal rotary cultivator can be divided into fixed type and movable type. The former has better soil crushing effect, but the latter can effectively avoid overload damage caused by debris such as stones in the land to the machinery.
Soil condition, tractor power, previous crop and other factors should be fully considered when using drive rake or rototiller rake. Rotary tiller and power rake are gearbox driven, but their load levels are very different. In general, rototillers are light and low cost. In China, the popularity rate of rototiller is much higher than that of power rake. In addition to the factors of lower price and small power demand, rototiller operation can run faster and break soil better. But in the developed countries of Europe, the number of rototillers is declining year by year. This is mainly because there are serious defects in the operation effect of rototiller: after the soil is crushed by rototiller, it is very bad for soil moisture retention. The surface fine soil will gradually evaporate and float away with the wind, resulting in serious soil and water loss and land desertification. The impact is more obvious in the European region dominated by black clay. In addition, when soil is broken by the rototiller, in addition to the evaporation of water, the microbial community will also be seriously damaged. The activity of microorganisms was closely related to soil fertility. After years of continuous use of rototiller on the same piece of land, soil fertility will continue to decline. These are the main reasons why European farms are gradually abandoning the rotary cultivator.
