With the increase in the number of times of use or improper use of the tractor clutch, the friction plates and transmission mechanism of the clutch will inevitably wear out, causing the clutch to slip, incomplete separation, and shaking during work, affecting the normal use of the vehicle. Therefore, timely inspection and adjustment of the clutch in use is essential. The following introduces the inspection and adjustment techniques of clutches used on several common models.

Adjustment of the clutch of Benno 350, 480 tractor

Benno 350, 480 tractor clutches are single acting clutches. In order to ensure reliable transmission of power, the active part must be pressed against the driven part so that the clutch does not slip. There should be a gap of 2.5 ±0.5 mm between the release bearing and the end faces of the three release levers. When the clutch is released, a little force is applied to the clutch pedal to eliminate this gap. The pedal stroke is called “free stroke”, which is converted to the separation The rocker arm is about 5 to 8 mm.

From this point on, continue to exert force on the clutch pedal, so that the separation rocker arm continues to swing forward until it hits the limit screw. 35mm. In the process of use, due to the wear of the driven plate, the pressure plate moves forward, and the free stroke is gradually reduced accordingly. Therefore, it must be checked and adjusted regularly. The methods are as follows:

(1) Adjustment of free stroke. It can be solved by turning the adjusting fork to shorten or lengthen the push rod, and the adjustment of the working stroke can be solved by screwing in or out the limit screw. After the adjustment is completed, the nuts on the push rod and limit screw should be tightened.

(2) Adjustment when the clutch is not completely disengaged. First adjust the working stroke to the maximum value, if it is invalid, open the peep window on the right side of the rear axle housing, first loosen the lock nut and tighten the three adjusting nuts at the same time, the rotation angles must be equal, and the operation of the separation clutch should be used. The test confirms whether the adjustment is effective. After the adjustment is completed, tighten the lock nut.

(3) Adjustment when the clutch slips. When the clutch slips, first check whether the free stroke is within the specified range. If the free stroke disappears or the 3 release levers have been compressed, the free stroke must be adjusted to the specified range. If the free stroke is within the specified range and the clutch slips, the three adjusting nuts must be adjusted, and the same rotation angle must be rotated outwards. After adjustment, tighten the nut again.

Adjustment of clutch of SH-500 tractor

The SH-500/504/650/654 tractor clutch is a single-plate, dry-type, double-acting clutch. The adjustment method is as follows:

(1) Adjustment of the free stroke of the clutch pedal. Remove the pin on the control rod, rotate the connecting fork, change the length of the rod, and adjust the free stroke of the clutch pedal to 25-35 mm.

(2) Adjustment of the main clutch release stroke. Loosen the locking nut on the main pressure plate, and turn the adjusting screw, so that the gap between the adjusting screw on the main pressure plate and the three lugs of the auxiliary friction plate pressure plate is 1. 8 mm.

(3) Another adjustment method for the separation stroke of the main clutch. Open the observation hole cover on the left side of the transmission, turn the clutch, align the adjusting screw on the main pressure plate and the three lugs of the auxiliary friction plate pressure plate with the observation hole, and then adjust one by one.

(4) Adjustment of the distance between the head of the three separation levers and the end face of the rear cylinder block of the diesel engine. Separate the diesel engine from the transmission, loosen the nut, and turn the adjusting screw on the release lever with a screwdriver, so that the distance between the heads of the three release levers and the end face of the rear cylinder block of the diesel engine is (158.5 ± 0.15) mm.

Adjustment of Dongfeng-504 Tractor Clutch

Dongfeng-504 tractor is a double-acting clutch, the adjustment method is as follows:

(1) Adjustment of the position of the clutch release lever. This adjustment is made when the clutch is installed. The adjustment method is: Loosen the lock nut on the release lever, and rotate the adjusting screw with an Allen wrench, so that the distance between the end face of the ball head of the release lever and the outer end face of the flywheel is 89-90 mm, and the adjustment values ​​of the three release levers should be the same. Must not exceed 0.2 mm. After meeting the requirements, tighten the adjusting screw.

(2) Inspection and adjustment of the main clutch release stroke. During inspection, remove the clutch inspection port cover and measure with a feeler gauge. The clearance between the end faces of the three limit nuts and the main clutch pressure plate should be within the range of 2 to 2.05 mm. If it does not meet the requirements, it should be adjusted. The method is: loosen the lock nut, turn the adjustment nut, and tighten the lock nut after meeting the requirements.

(3) Adjustment of the free stroke of the clutch pedal. The adjustment method of the free stroke of the clutch pedal: Loosen the lock nut on the clutch lever, turn the lever, and change its length, so that the free stroke of the pedal is between 22 and 24 mm (equivalent to a clearance between the release lever and the release bearing of 2 mm).

JDT724, JDT7501 tractor

JDT724, JDT7501 tractors are normally engaged, single-plate, dry-type, double-acting clutches. The adjustment methods are as follows:

(1) Adjustment of the free stroke of the clutch pedal. Loosen the lock nut on the clutch lever, remove the connecting pin, and unscrew (or screw in) the adjusting fork to adjust the free stroke of the pedal to 20-30 mm. Finally reassemble the parts and tighten the lock nut. For models JDT7501, JDT754l and JDT8241, the free stroke of the pedal should be 30-50 mm.

(2) Adjustment of the clearance between the release lever and the end face of the release bearing. Remove the cotter pin on the adjusting nut from the front inspection hole on the left side of the clutch housing, and unscrew (or screw in) the adjusting nut so that the clearance between the end of the release lever and the end face of the release sleeve thrust bearing reaches (2.5 ± 0.5) mm, then insert a new cotter pin and lock it.

(3) Adjustment of the main clutch release stroke. When adjusting, screw the three support bolts until they stand against the end faces of the corresponding three stop pins, and then return the support bolts to 9 slots (you can hear 9 sounds), so that the end faces of the three stop pins The gap between it and the end faces of the three support bolts is (2.25±0.5)mm.

(4) Adjustment of the distance between the head of the three separation levers and the rear surface of the rear driven disc. When repairing, replacing parts and reinstalling the clutch assembly, the adjustment nut should be unscrewed (or screwed in) so that the distance between the three separating lever heads and the rear face of the rear driven plate meets the requirements. The total length of the clutch equipped with the coil spring is 39.7-40 mm; the total length of the clutch equipped with the disc spring is 42.5 mm.

The above is about the adjustment methods of different types of clutches, but it is worth noting that when adjusting the clutches of various models, please refer to the instruction manual provided with the car by the manufacturer.

Tractor clutch friction discs are divided into inner friction discs and outer friction discs, which are usually installed inside the tractor clutch. The clutch of the tractor is mainly composed of clutch piston, end plate, drum, disc drum, outer friction plate, inner friction plate, pressure plate and spring, etc. There are three wet shift clutches in total (two for shifting, one for for reversing), which are hydraulically engaged.

Tractor clutch friction plate

1. Transmission of rotational torque. The tractor engine flywheel is the driving part of the clutch, and the driven disc and driven hub with friction discs are connected with the driven shaft (ie, the driving shaft of the transmission) by sliding splines. The compression spring presses the driven disc against the end face of the flywheel.

2. The torque of the tractor engine is transmitted to the driven disc by the friction between the flywheel and the contact surface of the driven disc, and then transmitted to the driving wheel through the driven shaft and a series of components in the drive train. The greater the compression force of the compression spring, the greater the torque that the clutch can transmit.

Precautions for the replacement of tractor clutch friction discs

1. The driven disc assembly should be kept clean, and the tractor clutch friction plate must be dust-proof, anti-fouling and oil-proof. Before assembling on the engine, the surface of the pressure plate and flywheel should be wiped clean to remove oil stains to prevent the clutch from slipping.

2. The tractor clutch has been adjusted before leaving the factory under normal circumstances, and it does not need to be adjusted during installation.

3. In order to ensure the smooth operation of the clutch, the clutch pressure plate assembly and the driven plate assembly have been balanced before leaving the factory. Do not replace the spare parts at will during use. When the tractor clutch must be disassembled for repair, mark it first, then assemble and rebalance according to the original mark after repair.

4. When assembling or disassembling the clutch on the tractor engine, you must alternately tighten or loosen the bolts or nuts that fix the clutch on the flywheel.

5. When installing the clutch, lubricate the spline of the driven disc and the spline of the first shaft of the gearbox with temperature-resistant and pressure-resistant grease properly to ensure that the driven disc can move freely on the spline of the first shaft of the gearbox. It should be noted that excessive lubrication will cause the tractor clutch friction plate to slip.

6. Great care must be taken during installation, not to damage the splines of the driven disc, and to prevent the axial movement of the driven disc from being stuck and unable to separate due to burrs.

7. It must be ensured that the tractor clutch release stroke meets the requirements. If the separation stroke is too large, it is easy for the release lever to hit the driven disc, which will bring danger; if the separation stroke is too small, the tractor clutch will not be completely separated.

8. When the clutch is in the engaged state, there should be a gap of 2-3mm between the release bearing and the release ring, so as to prevent the pressure plate from pressing the friction plate when the tractor clutch friction plate is worn, so as to ensure reliable transmission. engine torque.

9. The release bearing must be able to slide freely on the first shaft sleeve of the gearbox, so the sliding surface should be kept fully lubricated, and the sleeve must be positioned correctly.

10. When the tractor clutch friction plate is worn to the specified wear limit, the driven disc assembly should be replaced in time. To prevent the clutch from slipping and scratching the surface of the pressure plate and flywheel.

11. Be careful when handling the tractor clutch, do not drop it. During transportation, do not lift the separation ring to avoid deformation of the torsion spring.

12. Use it correctly to avoid slippage of the tractor clutch caused by improper operation. The tractor driver is strictly prohibited from stepping on the clutch pedal all the time. In principle, it is required that the clutch should be opened quickly, and the pedal should be pressed to the bottom. occur for a long time.

It is not allowed to start with a large accelerator and a high gear; when shifting from a low gear to a high gear, the accelerator is engaged before the vehicle speed is high enough; starting on a steep slope several times in a row; the vehicle slips or the wheels sag on a muddy road Under such circumstances, the driver uses the method of increasing the accelerator and half-clutch to force the rush, etc. In this way, the clutch will generate high temperature due to continuous severe friction, resulting in burnout of the friction plate, deformation of the pressure plate and even thermal cracking, resulting in serious consequences.

13. In the daily maintenance of the tractor, attention should be paid to the inspection of the clutch release operating mechanism of the tractor, and the leakage of the pump and pipeline should be eliminated in time to ensure the normal operation of the tractor clutch.

The above is all the introduction to the precautions for tractor clutch friction plate replacement. I hope that through our sharing this time, everyone will have a deeper understanding of its replacement, which can effectively improve the work efficiency of the tractor.

During the use of the tractor, as the workload increases, the technical conditions of the tractor will gradually deteriorate. Over time, the tractor assembly, mechanism, system and other parts and components will partially or completely lose their working ability, which will eventually make the tractor work. The power of the tractor is reduced, the economy is deteriorated, the reliability is reduced, and various appearance symptoms will appear one after another, and the clutch is one of the most frequently faulty components. Being able to grasp the common failure phenomena of tractor clutches and analyze the causes of failures is of great significance for the correct maintenance and use of tractors.

Common symptoms of tractor failure

Clutch slip

1. If there is oil stain on the friction plate and pressure plate, clean it with gasoline to remove the fault;

2. If the friction plate is too worn or burned, the clutch plate should be replaced in time;

3. The pressure of the disc spring is reduced, and the disc spring should be replaced;

4. The free stroke of the pedal is too small, or there is no free stroke, re-adjust the free stroke of the pedal as required;

5. The clutch driven plate is seriously deformed, replace the clutch driven plate.

The clutch is not completely separated, and there is a noise in the gear shift

1. The free stroke of the pedal is too large and the working stroke is too small. Adjust the free stroke of the springboard to 25-30mm;

2. The clutch driven disc is seriously warped, and the driven disc should be replaced immediately;

3. There is oil on the friction plate and the driven disc, and the friction plate and the driven disc should be cleaned;

4. The heads of the three separation levers are not in the same plane and should be adjusted to the same plane as required.

 The tractor shakes when starting

1. The heads of the three separation levers are not in the same plane, adjust as required;

2. There is oil on the friction plate and the driven disc, and the friction plate and the driven disc should be cleaned;

3. The clutch driven disc is seriously warped, and the driven disc should be replaced immediately;

4. If the fixing screws of the flywheel and the clutch housing are loose, stop the machine immediately to check and troubleshoot.

Common causes of clutch damage

1. User problems. The main reasons are the bad habit of half-stepping the clutch pedal or using the half-step clutch to control the speed of the vehicle; the free travel of the clutch pedal is too small, disappears and cannot be adjusted in time; the agricultural tools are too large and the ploughing depth is too deep and the load is too heavy.

2. Design problems. The maximum torque capacity transmitted by the clutch is insufficient, causing the clutch to slip and burn. Especially in the popular small chassis and high-horsepower tractors, the engine horsepower has increased, and some models have the original clutch, such as 1604 and 1804 tractors still use 13-inch tractors. The clutch is very prone to burning chips during use. The reason for the insufficient capacity of the clutch to transmit the maximum torque is that the compression force of the disc spring is insufficient, the size of the friction surface is small, and the friction coefficient of the friction plate cannot be reached.

3. Parts quality problems. It is mainly caused by the quality problem of the clutch itself. The tractor clutches produced in the early days were too heavy. In order to reduce the clutch pedal force, the method of reducing the pressing force of the disc spring and increasing the friction coefficient of the friction plate was adopted. The original intention was that the ability of the clutch to transmit the maximum torque remained unchanged. The compression force of the disc spring of the clutch manufacturer has been reduced, but the friction coefficient of the friction plate has not been effectively improved, resulting in a large number of clutches burned on the tractors sold on the market as soon as they work in autumn farming, which has a very bad impact.

4. Improper assembly adjustment and backward production process. The clutch assembly and adjustment technical requirements of high-horsepower tractors are relatively high. Some tractors have the situation that the clutch assembly is not in place and the factory technical state adjustment is not in place, which causes the clutch to burn out as soon as the user goes to work in the field after purchasing the machine.

By analyzing the failure phenomenon of the tractor, the driver can easily find out whether the tractor has a failure during the operation process, analyze the cause of the failure, and lay a good foundation for further repair and maintenance, which can reduce the damage of the tractor and reduce accidents. occurrence has a positive effect.

Between the tractor’s engine and the gearbox, there is a key component that can be used to separate the power from the engine crankshaft to realize the tractor’s parking and shifting. This is the protagonist of our article today: the tractor clutch, the overload protection function of the tractor clutch, can Make the starting of the tractor more stable.

As we all know, the clutch transmits torque by friction. The longer it is used, the more serious the friction damage will be. However, in the normal use of the tractor, the use of the tractor clutch is very frequent. If you do not pay attention to the tractor clutch repair, once the parts are worn out , resulting in the inability to transmit torque reliably, which will affect the normal use of the tractor. Therefore, we need to regularly troubleshoot the tractor clutch and deal with possible problems in a timely manner. Here, we will briefly talk about the tractor. When the clutch is repaired, the maintenance points of each component.

1. Maintenance of tractor clutch drive plate

The active disc of the tractor clutch, including the clutch pressure plate and the intermediate pressure plate, many manufacturers will use high-quality gray cast iron or ductile iron as the main raw material for these parts. The main damages of the active disc are mostly wear, scratches, burns and cracks on the friction surface; warpage and deformation of the friction surface; breakage of the lugs of the very engaging clutch, and increase of the bearing clearance due to wear; The pin fit gap is loose due to wear, the clutch cover is deformed or cracked, and the window hole is worn.

When the tractor clutch is repaired, the detection of the damage of the active disc is mainly based on visual inspection. The maintenance of the active disc mainly includes the following two points:

(1) If the clutch pressure plate has cracks, defects, or the thickness after grinding is smaller than the limit size, it should be replaced with new parts in time. If there are problems such as ablation, cracking or wear groove depth exceeding 0.5 mm on the surface, or when the plane tolerance exceeds the service limit, the clutch pressure plate can still be used after being smoothed by polishing.

(2) When the matching clearance between the driving disc and the transmission pin is greater than 1.00-1.50 mm, it should be repaired in time.

2.the maintenance of the tractor clutch driven plate

When it comes to the parts that are more prone to damage in the tractor clutch, we have to mention the driven disc. The main damages of the driven disc are: wear, hardening, burns, cracks on the surface of the friction plate, oil stains on the surface (dry type), loose friction plate, warping and deformation of the driven disc, fracture of the steel plate, riveting between the steel plate and the hub Looseness, spline hole wear, etc.

When the tractor clutch is repaired, the main content of the driven disc repair is the correction of the steel plate and the replacement of the friction lining. When the wear of the spline hub exceeds the limit, it is recommended to replace the new parts directly, and there is no need to repair it. When the driven disc steel sheet is warped and deformed, it can be repaired by cold pressing. After calibration, the perpendicularity between the plane of the driven disc steel sheet and its axis shall meet the requirements. When the steel sheet is broken, it should be replaced with a new one. After the steel sheet is overhauled, replace the friction lining with a new one.

3. Maintenance of tractor clutch cover

The failure of the clutch cover is mainly reflected in that the clutch cover is deformed or cracked due to the uneven strength of the pressure plate spring, or improper installation, loose bolts in use, etc. Once the clutch cover has cracks, it should be welded and repaired in time; if it is deformed, the clutch cover can be placed on a flat plate for inspection. When the flatness error exceeds 0.5 mm, it should be repaired.

4. Damage and maintenance of tractor clutch shaft

The main failure of the clutch shaft is reflected in the damage of the spline, the wear of the sliding journal and the journal wear of the bearing, and the bending of the shaft. After the splines are worn, check the backlash on the spline shaft with a standard spline sleeve or a new driven disc hub. When the backlash is greater than 0.8 mm, a new shaft should generally be replaced.

The above content is an introduction to the relevant points of tractor clutch repair. If you need to know more about tractor clutch repair, you are welcome to log in to our official website to browse, or contact our customer service.

The tractor clutch is through the operating mechanism, relying on the friction between the main and driven components, to temporarily separate or gradually connect the engine and the transmission to transmit power, facilitate shifting, ensure a smooth start of the tractor, and prevent damage to parts caused by overloading. During the use of the tractor, many drivers cannot use and maintain the clutch properly, and do not realize the importance of correct adjustment of the clutch. Often due to improper adjustment of the use and operation, the early wear of the clutch and the damage of the transmission parts are caused, which reduces the service life. In order to reduce the failure of the clutch and prolong its service life, it must be used and adjusted correctly.

Correct use and maintenance

(1) When using the clutch, do it quickly and completely when disengaging, and slowly release the pedal when engaging. When the tractor starts, release the pedals quickly. Obstacles and rough terrain cannot be overcome by slamming the clutch pedal.

(2) The time for stepping on the clutch pedal to separate should not be too long, generally not more than 15 to 20 s. If you need to stop for a long time, the gear lever should be in the neutral position and the pedal should be released.

(3) Do not habitually press your feet on the pedals. When driving, do not step on the clutch pedal at all times except for starting, shifting and braking at low speeds. Otherwise, the clutch is often engaged, disengaged or semi-slipped, which will accelerate the wear of the clutch friction plate and pressure plate.

(4) Try to avoid starting with a heavy load. When the tractor starts with a heavy load, the clutch is prone to serious slippage, which generates frictional heat and burns, cracks, warps and deforms the pressure plate and driven plate of the clutch, and the compression spring is annealed. The asbestos friction plate is generally within the working temperature of 400 ℃, and the friction coefficient above this temperature decreases with the increase of temperature. Therefore, during heavy-load operations, if the ploughed land encounters local resistance changes, it is necessary to shift gears in time, and the plow should be slightly lifted before starting to reduce the starting resistance.

(5) When stopping normally, the accelerator should be closed first, then the clutch should be disengaged, and the brake should be properly used to make the locomotive stop smoothly; when stopping in an emergency, the accelerator should be quickly closed, and the brake pedal should be quickly pressed, and then the clutch should be disengaged. The double-acting clutch can operate the PTO handle only after the second-stage friction plate is disengaged.

(6) In use, the friction plate adheres to oil, which will cause the clutch to slip; the clutch will be immersed in muddy water, which will cause the parts to rust. At this time, the clutch must be disassembled, the muddy water should be wiped off with cotton yarn, the oil stains and rust spots should be cleaned with gasoline, and the friction plates should be reassembled after drying in the shade or drying (no drying is allowed). When the clutch assembly is installed on the flywheel of the engine, it is best to use a mandrel for positioning, which can ensure the concentricity of the center of the clutch friction plate and the first shaft, and make the gearbox and the engine assemble smoothly.

Timely adjustment

During the use of the clutch, due to the wear and tear of the parts, the clutch will slip or the clutch will not be completely separated. Therefore, it should be adjusted in time. In order to make the clutch work normally, it is necessary to ensure that there is a clearance of 2 to 3 mm between the release bearing and the inner end faces of the three release levers, which is called the release clearance. When the clutch pedal is depressed until the clearance is eliminated, the travel required by the lower end of the separating rocker arm along the axis of the limit screw is called the free travel.

During use, due to the wear of the friction plate and the advance of the pressure plate, the free stroke will gradually decrease accordingly. Therefore, the free stroke of the clutch pedal and the separation gap of the clutch must be regularly checked and adjusted.

(1) Adjustment of the free stroke of the clutch pedal. Free travel is an important parameter to ensure the normal operation of the clutch. If the free travel of the clutch pedal is too small or there is no clearance, the clutch will slip, and it will not be able to start under load, but the engine will still run, resulting in wear and damage to the clutch. If the free stroke of the clutch pedal is too large, it is easy to cause the clutch to be incompletely disengaged, in a semi-disengaged and semi-engaged state, and it is difficult to beat the teeth or shift gears when shifting.

When the inspection finds that the free travel of the clutch pedal is too large or too small, it should be adjusted. Different models have different clutch pedal free strokes. For example, the normal value of the clutch pedal free stroke of Dongfanghong-X754 tractor is 15-25 mm, and the normal value of Dongfeng-50 tractor clutch pedal free stroke is 22-24 mm. Therefore, it should be adjusted according to the model structure and specific values.

(2) The gap between the end face of the clutch release bearing and the ball head of the release lever is the separation gap. The separation gap of the clutch is directly related to the free stroke of the pedal. The increase of the separation gap increases the free stroke of the pedal; the reduction of the separation gap reduces the free stroke of the pedal. The separation gap should also be adjusted properly. If the gap is too small, the separation will be incomplete. When shifting gears, it will be more serious when the friction surface is warped or not parallel. If the separation gap is too large, the control force will increase, that is, the driver labor intensity.

Some tractors use double-acting clutches, and the separation gap of the main and auxiliary clutches should also be checked and adjusted in time. For example, for Dongfeng-50 tractor clutch, the normal value of the gap between the end face of the release bearing and the ball head of the release lever is 2 mm. The clearance between the adjusting nut end face and the main clutch pressure plate should be (2 ±0.05) mm. When it is difficult to adjust the free stroke of the clutch pedal, the separation gap between the end face of the clutch release bearing and the ball head of the release lever can be adjusted so that both the free stroke of the clutch pedal and the clutch separation gap meet the technical requirements.

(3) When adjusting the clutch separation clearance, it is necessary to check and measure whether the heights of the three separation lever balls are consistent, so that the clearance deviation between the three separation lever balls and the end face of the separation bearing is within the range of technical requirements, that is, the three separation levers The ball heads are almost in the same plane of rotation.

For example, in the Dongfeng-50 tractor clutch, the distance between the end faces of the three release levers and the outer end surface of the flywheel is 89-90 mm, and the difference between the distances between the end faces of the three release levers is not more than 0.2 mm. If the heights of the two release lever balls are inconsistent and unsatisfactory, the normal operation of the clutch cannot be guaranteed. When the two release levers are disengaged or engaged, the forces of the two release levers are unequal, so that the main and driven elements of the clutch cannot be on the clutch shaft. The horizontal movement causes the clutch driven friction plate to tilt, which accelerates the wear of the friction plate.

(4) Check and adjust in time and eliminate the excessive axial clearance of the engine crankshaft and the excessive axial movement of the clutch shaft (the first shaft of the transmission) to achieve the best technical state.

The above is about the method of prolonging the service life of the tractor clutch. Only correct use and timely adjustment in case of failure can extend the service life to a large extent and improve the efficiency of the tractor.