At present, rotary tillage machinery has been widely used in China and gradually developed into an important category of agricultural machinery. At present, agricultural machinery products driven by China include rotary cultivators and compound working machines, driven disc plows, plows, paddy field driven harrows and vertical toothed harrows. But the rotary tiller is the main model with relatively large output. At present, 3 series 145 products of 2.2-74.6 kw walking tractors and rotary tillers for riding tractors are the updated products in the late 1980s. Since 1990s, China has developed a number of new products of rotary tillage compound working machines and tools, and put them on the market gradually. At present, there are about 1.5 million large and medium-sized tractor rotary tillers in China, and there are 2 million walking tractors and small four-wheel rotary tillers. Rotary tillers have accounted for 80% in the mechanization application of rice production in the south, and they are also widely used in rice production, vegetable cultivation and dry land preparation in the north.

First, the characteristics of rotary cultivators

It has the following working characteristics:

1. Strong soil crushing performance, flat ground after operation. When working in dry land, the tractor power output shaft drives the rotary tiller to rotate, cutting soil, and the cut clods collide with each other and break. After the clods are broken, the covering will be even and flat, and there will be no furrows on the ground.

2. The longitudinal structure size and buried depth travel are shorter, the site is correspondingly reduced, and the productivity is higher.

3. It can give full play to the power of tractors. When working on cultivated land, the tractor driving wheel may slip, resulting in reduced traction. When the rotary tiller shaft rotates, the cutting direction of the blade is opposite to the forward direction of the tractor, so the cutting reaction force of the soil to the blade is consistent with the forward direction of the tractor. Therefore, when the tractor and the rotary tiller work together, the rotation of the rotary tiller itself will generate a force to push the machine forward, which can give full play to the tractor's power.

4. The plowing and harrowing operation is completed at one time, which reduces the number of operations, saves energy consumption and time, and can complete the production task in time in the summer harvest and summer sowing season without delaying the farming season.

Second, the correct use of rotary cultivators

1, correctly select the rotary tiller shaft speed and tractor speed. In order to ensure that the rotary tiller meets the agronomic requirements, the forward speed of dry farming is 2-3 km/h, and that of hydroponics or harrowing is 3-5 km/h. As for the spindle speed of the rotary tiller, the low speed gear is generally selected when plowing in dry land or soil with large specific resistance, and the high speed gear is generally selected when plowing in water, harrowing and plowing in soil with small specific resistance.

2, rotary tiller operation. Because the tractor has two structures: hydraulic suspension device and power output shaft, the lifting operation of rotary cultivator is also different. One is that the tractor hydraulic suspension mechanism is driven separately from the power output shaft (such as Taishan -50, Dongfeng -50, Shanghai -50 tractors, etc.). Whether the power output shaft rotates or not, the lifting of the rotary cultivator is not affected by the power output shaft. On the other hand, the hydraulic suspension mechanism of another tractor (such as Harvest -27 tractor) is linked with the power output shaft. In this mode, the rotary tiller can only be lifted when the PTO shaft rotates. When this tractor is working in the field, if the knife sinks into the mud, the knife shaft will not turn, and the tractor will stall because of heavy load, so the rotary tiller will not be lifted. At this time, the universal joint on the power take-off shaft should be removed, and the rotary cultivator can be lifted by idling the power take-off shaft to make the cutter shaft rotate out of gear.

Three. Adjustment and maintenance of rotary cultivator

1, chain adjustment. When adjusting the chain, pay attention to that the loose edge of the chain will lead to chain climbing, and too tight will aggravate the wear and tear. When adjusting, pay attention to that the force of the top tensioning slide rail should be within the range of 5- 10 kg, so as to compact the loose chain. If you can't press hard, the chain is too tight.

2. Adjustment of bearing clearance. There are two ways to adjust: one is to add or reduce gaskets. When the position of the inner ring is fixed and the outer ring is adjustable, the axial clearance can be adjusted by increasing or decreasing the washers on the bearing cover. This method is mainly used to adjust the bearing clearance: 1m the first shaft of the rotary tiller, 1.25- 1.75m the side drives the conical bearings on the first and second shafts of the rotary tiller, and the middle drives the cylindrical gear wheel shaft and the conical bearings on the spline shaft of the rotary tiller. Check the adjusted bearing clearance. If there are no measuring instruments and special tools, you can rotate the shaft by hand by experience. There should be no obvious axial movement and flexible rotation. If it is too tight to rotate, add shims. If it is too loose, you should remove the gasket. The second is to adjust the nut. For bearings with fixed outer ring and adjustable inner ring, axial clearance can be adjusted in this way. This method is mainly used to adjust the second shaft of 1m rotary tiller intermediate gear box, the conical bearing on the third shaft of 1.25- 1.75m side-driven rotary tiller intermediate gear box, and the bevel gear of the bevel gear shaft (the first shaft) of rotary tiller gear box driven by intermediate gear. The adjustment method is (taking 1m rotary cultivator as an example): firstly, tighten the round nut at one end of the big bevel gear and lock the thrust washer, then tighten the round nut at the other end, and rotate the bearing by hand until it can no longer be rotated by inertia force, then knock the shaft with a wooden hammer to make the inner and outer rings of the bearing abut against each other, then check the pre-tightening condition of the bearing, and lock the round nut with a locking plate after adjustment.

3. Maintenance of main working parts

① machete. The curved knife with blunt edge should be sharpened again, and the deformed curved knife should be padded and corrected, and then quenched (the handle part is not quenched). The hardness of the quenching machete shall be HRC50-55. If it is damaged, it should be replaced with a new one.

(2) Cutter seat. Most tool holder damages are desoldering, cracking or hexagonal hole deformation. Covered electrode welding can be used to repair the partially damaged tool handle, and the severely damaged tool handle should be replaced. But pay attention to the deformation of the cutter shaft when welding the cutter seat.

(3) Knife shaft tube. A section of round steel with good weldability can be put in the broken pipe of the cutter shaft. After welding, artificial aging and straightening should be carried out, and then the bearing seats at both ends should be inspected. If the out-of-tolerance is too large, the shaft head at one end without spline should be replaced, and a new shaft head should be machined according to the outer diameter of the original spline end to ensure the flexible and balanced rotation of the cutter shaft.

Four, rotary tiller out of gear failure

1, common reasons

Rotary cultivator (1) uses claw clutch. Due to the long service time, the meshing surface of the jaw teeth is seriously worn, which makes the top of the meshing teeth bald into an arc, loses the self-locking ability after meshing, and is easy to slip when running.

(2) The elastic force of the positioning spring of the meshing sleeve is too small or broken, and the meshing teeth are stressed or the unit vibrates, so that the meshing sleeve slides axially and comes out.

(3) The axial wear of the directional steel ball groove of the meshing sleeve is large, and the steel ball moves axially during the working process of the unit, so that the meshing teeth are disengaged.

2, rotary cultivator out of gear fault elimination method

(1) When the meshing teeth of the clutch are worn and exposed, they should be repaired or replaced in time. When repairing, carbon-copper covered electrode can be used for surfacing the meshing teeth, and then the standard tooth indentation is used for post-welding dressing, and heat treatment is carried out according to regulations.

(2) Replace the spring that is too small or broken with the standard spring to ensure that the meshing sleeve has sufficient positioning stability and reliability.

(3) If the groove of the positioning steel ball of the engagement sleeve is excessively worn, it should be repaired or replaced with a new one.

(4) When the pull-out groove and the joystick ball head are excessively worn, they can be repaired by welding, and then heat treated after artificial trimming. Replace the unrepairable parts with new ones.

Five, the correct maintenance of rotary tiller

"Prevention is more important than cure, and maintenance is more important than maintenance" is the principle of using and maintaining rotary cultivators. Rotary tiller maintenance is divided into shift maintenance and quarterly maintenance. Under normal circumstances, shift maintenance should be carried out after each shift, and the maintenance contents include:

1, check and tighten the connecting bolts;

2. Check whether there are any defects in wearing parts such as bolts and cotter pins, and replace them if necessary;

3. Check whether the transmission box, ten bytes and bearings are short of oil, and replenish them immediately if necessary.

4. When it is not used for a long time, the rotary cultivator supporting the wheeled tractor should be placed on the level ground, and it should not be hung on the tractor.