The Complete Guide to Correct Use and Safe Operation of Rotary Tillers

A rotary tiller is an agricultural machine matched with a tractor to complete plowing and harrowing operations. It is very commonly used in agricultural production, and the safe operation of the rotary tiller is very important. Using the rotary tiller correctly can make the work highly efficient while avoiding safety accidents, and it is very important for maintaining its good technical condition and ensuring the quality of tillage. Below, let us learn about the safety operation knowledge and precautions for rotary tillers.

I. Overview of the rotary tiller

(1) Composition of the rotary tiller

Rotary tillers are divided into many models according to the width of the land they till. Small ones are mounted on walking tractors, while medium and large ones are mounted on four-wheel tractors. A rotary tiller is generally composed of working parts, transmission parts and auxiliary parts: the working parts are composed of the blade shaft, blades and blade holders; the transmission parts are composed of the universal joint, transmission shaft and gearbox; the auxiliary parts are composed of the suspension frame, side plates, mudguard cover plate and land-leveling support plate.

(2) Working principle of the rotary tiller

The rotary tiller uses the power output by the tractor to drive the rotary tiller blades to cut and turn the soil, and throws the cut soil clods backward to collide with the mudguard, so that the soil clods are further broken up. Then the land-leveling support plate drags and scrapes the ground surface level, completing the plowing and harrowing operations in one pass.

II. Methods of using the rotary tiller

After knowing the structure and working process of the rotary tiller, it is relatively easy to understand the correct methods of using the rotary tiller.

(1) Inspection of a newly purchased rotary tiller

Before using a newly purchased rotary tiller, you must check whether all parts and fasteners were lost or loosened during transportation. If so, the relevant parts must be replenished or tightened.

(2) Power connection of the rotary tiller

The rotary tiller is connected to the tractor's output shaft through the transmission shaft to drive the rotary tiller blades. When making the suspension connection, install the universal joint and safety pin on the rotary tiller, and at the same time install the other universal joint on the tractor. When the tractor's lower suspension is raised to the same height as the rotary tiller's suspension pin, reverse the tractor. While reversing, install the transmission shaft, hook up the lower suspension, press in the locking pin, and attach the upper suspension.

Note: First, the openings of the adjacent universal joints at both ends should be in the same plane. The long end of the transmission shaft must match the tractor model, ensuring that when the rotary tiller is raised, the shaft and sleeve neither jam against each other nor lack sufficient matching length, and connect according to the standard three-point suspension.

Second, during the running-in period, first add gear oil up to 25 cm from the screw opening, then raise the rotary tiller, start the tractor and run it in place. After running for 2 hours, shut it down, drain the gear oil, add an appropriate amount of diesel to clean out the dirt at the bottom of the gearbox, then drain the diesel, tighten the oil drain bolt, and according to the provisions of the instruction manual, add qualified gear oil to the specified amount. Check whether the blades are loose or damaged during transportation. If they are loose or damaged, they should be reinforced or replaced.

(3) Adjustment of the rotary tiller

After the rotary tiller is connected and checked, adjustments must also be made so that its tillage depth, soil breaking and land leveling meet agricultural requirements.

1. Adjustment of tillage depth

Generally speaking, the working depth of the rotary tiller should not be less than 10 cm. For a rotary tiller matched with a walking tractor, the tillage depth is adjusted by changing the height of the tail wheel; during adjustment, simply turn the adjusting handle. For a rotary tiller matched with a wheeled tractor, the tillage depth is controlled by the hydraulic system. Before adjusting the tillage depth, first adjust the length of the tractor's upper pull rod until the rotary tiller and the transmission shaft are basically in one plane, then adjust the position release device on the hydraulic cylinder piston rod to set the soil entry depth of the rotary tiller.

2. Level adjustment

In order to ensure that the rotary tillage depth on the left and right sides is consistent, check whether the distance from the blade tips to the ground on both sides is the same. If the distances to the ground are not the same, adjust the pull rods on both sides of the tractor until the distance from the rotary tiller blades to the ground is consistent on both sides.

3. Adjustment of the transmission shaft angle

In order to make the transmission shaft and universal joint rotate smoothly, after the rotary tiller is connected, use a ruler to measure the distance between both sides of the rotary tiller and the rear wheels, and judge whether the angle between the transmission shaft and the forward direction is consistent. If the angle is not consistent, adjust the tractor's lower pull rods so that the rotary tiller is in the most favorable working state.

4. Adjustment of lifting height  

If the upward inclination angle of the universal joint exceeds 30°, it will increase the power loss of the universal joint and easily damage the universal joint. When turning at the headland, if the power to the rotary tiller is cut off first and then it is raised, work efficiency will be affected, so the rotary tiller needs to be raised while transmitting power, but the lifting height must be limited. Generally, raising it until the blade tips are 15 cm-20 cm above the ground is best.

5. Adjustment of blades

According to different tillage requirements, there are three methods for installing and adjusting the blades:

(1) Staggered method

When leaving the factory, the blades are generally installed in the most commonly used staggered method or spiral method. In the staggered method, one left and one right curved blade are installed on the same plane. The blades at both outer ends of the blade shaft both bend inward, so that soil clods are not thrown to both sides, and after tillage the land is leveled and harrowed flat.

(2) Outward method

The blades at both outer ends of the blade shaft bend inward, while the middle blades all bend outward; this is called the outward method. After tillage with the outward method, soil clods are thrown to both sides to form a shallow furrow, which is suitable for ridge finishing operations.

(3) Inward method

The blades all bend toward the middle of the blade shaft. After tillage, a ridge is formed in the middle, which is suitable for tillage before ridge forming. It can also allow the unit to work across furrows, playing the role of making a field ditch. Note: when rearranging the blades, the blade edges should be consistent with the rotation direction of the blade shaft; otherwise, the rotary tiller will vibrate during operation, and in serious cases damage the machine parts.

(4) Operation of the rotary tiller

After checking and adjusting the rotary tiller, we can operate it.

1. Starting off

When the tractor starts off, the rotary tiller should be in the raised state, with the blade tips 20 cm above the ground; it does not need to be higher. When engaging the power output shaft to run, observe whether there are any abnormal phenomena in each transmission part. After the rotary tiller reaches the predetermined speed, gently release the clutch, and the tractor slowly starts off. At the same time, operate the hydraulic lifting adjustment handle to slowly lower the rotary tiller, gradually entering the soil, until the tillage depth is reached.

Note: It is strictly prohibited to start off directly with the rotary tiller blades in the soil, and it is strictly prohibited to lower the rotary tiller suddenly, so as to avoid damage to parts or breaking the transmission shaft.

2. Running

For the forward speed during tillage, 2-3 km per hour is suitable for dry fields, and 7 km per hour is suitable in land that has already been plowed or harrowed. The forward speed must not be too fast, to prevent overloading the tractor and damaging the power output shaft. When the rotary tiller is working, the universal joint inclination angle should not be greater than 15°. The tractor wheels should be within the working width of the rotary tiller wheels, walking on unplowed land, so as to avoid compacting already tilled land. During operation, if too much grass is tangled on the blade shaft, stop the machine in time and clean it, so as to avoid increasing the load on the machine. While moving forward, if obstacles such as stones or water pipes are encountered, take care to avoid them so as not to damage the machine. During rotary tillage operations, it is strictly prohibited for people to ride on the tractor or the suspended part, to prevent accidental injury by the rotary tiller. When using a walking tractor rotary tillage unit for operations, the auxiliary gearshift lever must be placed in the low position before the rotary tiller can be used.

3. Turning

After the rotary tiller has entered the soil, it is strictly prohibited to turn midway. When turning at the headland, the rotary tiller should be raised out of the soil, 20 cm above the ground being sufficient, to avoid blade deformation and breakage, and the engine speed should be appropriately reduced. The power does not need to be cut off, but care should be taken that the rotary tiller should not be raised too high, and the universal joint transmission angle should not exceed 30°. Note that when turning at the field headland, even if the rotary tiller is in the raised state, sharp turns in place by the tractor are also prohibited, to avoid damage to the connection part of the gearbox. When transferring between plots or traveling long distances, the power to the rotary tiller should be cut off, and it should be raised to the highest position and locked. When using a walking tractor rotary tillage unit for operations, try not to use the steering clutch during rotary tillage; use the pushing and pulling of the handle frame to correct the direction. When turning at the headland, lift the handle frame, then twist the steering clutch, and do not make dead turns, so as to prevent damage to parts.

4. Reversing

After the rotary tiller blades have entered the soil, reversing is strictly prohibited. If the machine needs to reverse during work, the rotary tiller must be raised, to avoid the support plate being rolled backward into the soil and colliding with the blades, causing damage.

5. Rotary tillage methods

Commonly used rotary tillage methods include the shuttle method, the skip method and the return method. Shuttle method: one row immediately follows another, working back and forth. This method is not likely to leave untilled strips, and there are many turns at the headland, so it is suitable for small tractors or walking tractors; skip method: after tilling one pass, leave a width and till the second pass, and after finishing, till the intervals on the way back. This method has fewer headland turns, but easily misses strips, and is suitable for large tractors; return method: in paddy field tillage, the return method is often used in order to make the ground level and reduce missed strips.

Deep soil loosening is a new soil tillage method promoted in recent years. In dry farming areas, it has the effects of deep tillage and soil improvement, raising soil fertility and increasing yield. On new-type rotary tillers, deep loosening shovels can be optionally installed to complete deep loosening operations while rotary tilling. Deep soil loosening, without disturbing the topsoil layer, loosens the 5-15 cm hardpan isolation layer below the topsoil, thickening the topsoil layer, greatly enhancing the speed and amount of precipitation infiltration, reducing water evaporation caused by exposed plowing, and creating suitable soil conditions for crop growth and development.

III. Precautions for operating the rotary tiller

1. Be careful when using it

When the unit starts off, first engage the power output shaft, then shift into the working gear, slowly engage the clutch, and at the same time operate the hydraulic lifting handle or lifting device so that the rotary tiller blades gradually enter the soil, then increase the throttle until normal tillage depth is reached. It is absolutely prohibited to lower the rotary tiller onto the ground and suddenly engage the ground drive, or to lower the rotary tiller suddenly into the soil; otherwise, the blades and blade shaft will be subjected to impact loads, causing damage to the transmission parts of the rotary tiller and tractor.

During operation, pay attention to listening for any abnormal noise or metal knocking sound from each working part. If there is any, stop immediately and check; only continue operation after troubleshooting.

When the rotary tillage is too deep, the soil is sticky and heavy or too hard, or the tractor emits black smoke and slips, appropriately reduce the tillage depth or reduce the tillage width, or shift into a low gear. When turning, reduce the throttle; the tail wheel and steering clutch should cooperate with each other and proceed slowly. Sharp turns are strictly prohibited, to prevent damage to related parts. When a wheeled tractor turns or reverses, the rotary tiller should be raised, to prevent breaking the blades or damaging the blade shaft.

When crossing ditches or field ridges, the rotary tiller operating handle should be placed in the disengaged position, to prevent the rear of the tractor from suddenly tipping up and the blades injuring people.

Promptly remove tangled grass on the blade shaft and blades, to avoid damaging the blade shaft and affecting tillage depth. When removing tangled grass, be sure to shut off the engine.

When the universal joint is working, both ends should be close to horizontal, and the included angle must not be greater than 10 degrees; when raised in the working state, the included angle must not be greater than 30 degrees, and at the same time reduce the speed, to prevent damage to the universal joint transmission shaft assembly.

During operation, standing behind or on the rotary tiller is strictly prohibited, to prevent danger. After every 3—4 hours of work, stop the machine and check whether the blades are loose or deformed. If any abnormality is found, tighten or replace them in time. When checking and troubleshooting, the engine must be shut off to ensure personal safety.

When transferring in the field, raise the rotary tiller and cut off the power output shaft. If the transfer distance is relatively large, use the locking device to fix the rotary tiller in a certain position, or remove the universal joint before transferring.

When parking, the rotary tiller should be placed on the ground; parking while suspended is strictly prohibited. After the maintenance work following use is completed and the machine needs to be stored for a long time, remove and wash away the soil and tangled grass on the exterior of the rotary tiller, replace the gear oil in the transmission case, and lubricate each lubrication point; remove the blades and universal joint, coat them with oil and store them indoors; coat other exposed working parts with oil to prevent rust, repair or replace damaged parts in time, then prop up the rotary tiller and store it in a place away from light and rain, ventilated and dry.

2. Be meticulous when operating

The rotary tiller should not be raised too high. Because raising it too high will damage the universal joint, and the tension chain of the lower suspension pull rod may also collide with the universal joint transmission shaft and cause damage to parts.

When engaging the tractor's power output shaft, the rotary tiller must not be raised too high, that is, the inclination angle of the universal joint shaft must not be too large, and it must be engaged after the clutch is completely disengaged.

For a split-type hydraulic system, the rotary tillage depth should be controlled by the positioning valve and positioning clamp of the oil cylinder. During tillage, the distributor handle should be placed in the floating position, not in the neutral position.

During operation, if the rotary tiller stops because of tangled grass, do not step on it with your foot to force it to rotate; otherwise, your foot may easily be mangled. When the rotary tiller is working, standing behind or on top of the machine is prohibited, to prevent accidents.

With the increase in the number of rotary tillers, mechanical failures and personal injury and fatality accidents involving rotary tillers have shown an upward trend. It is hoped that the above complete guide to safe operation knowledge for rotary tillers can help farmer friends master the methods of correctly using rotary tillers.