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.

The clutch is an important part of the tractor. Only by mastering the correct installation skills can the working efficiency of the tractor be improved. At present, small four-wheeled tractors and three-wheeled transport vehicles mostly use double-plate dry friction clutches, which are easy to disassemble but troublesome to install. For this kind of tractor, the tractor clutch manufacturer has summarized some installation skills, let’s learn about it together!

(1) When installing the driven friction plate assembly, the shorter ends of the two driven disc hubs should face each other. If two long hubs or one long hub end is opposite to one short hub end by mistake, the moving plate will be suspended in the middle of the two driven discs, and the torque cannot be transmitted, causing the clutch to slip.

K series

(2) The inner and outer bearings of the clutch (60206 and 602024 bearings respectively) are single five-pointed star concentric ball bearings with an oil-proof cover on one side. When working, the grease in the bearing is thrown into the surface of the friction plate, causing the clutch to slip.

(3) When there is no special tool for assembly, the three small springs can be compressed by 20-22 mm and tied symmetrically with cotton threads, and then the bundled small spring dustproof rings can be placed on the three separate mechanical rods respectively; After the clutch is installed, remove the cotton thread.

(4) When tightening the 6 nuts on the cover of the casing, tighten them diagonally several times. After tightening, the end must not protrude from the side of the V-belt groove to avoid rubbing the belt.

13-Inch

(5) When installing the release bearing, the side with the thrust ring should face the release lever, otherwise it will aggravate the wear of the release lever.

(6) When installing the clutch release claw seat, care should be taken to make the oil collecting tank directly below to prevent the lubricating oil from being thrown into the clutch shell and causing the transmission belt to slip.

(7) After the clutch is installed, push the clutch housing along the axial direction by hand. At this time, there should be no obvious shaft problem, otherwise it should be disassembled for inspection.

I will share so much with you about the installation of small tractor clutches. I hope it can help you better. If you have any questions during the installation process, please feel free to contact us.

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

40-Type-18-Spline

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

1Z4A4280

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.

In modern agricultural production, tractor is a very important machine, and no other machine can replace the work of tractor. Therefore, tractor is widely used in agricultural production at home and abroad.

The use of the tractor clutch can ensure the smooth shifting and shifting of the tractor, and is one of the important accessories to ensure the normal operation of the tractor. With the development of society and the advancement of science and technology, knowledge such as electricity, heat, and information technology has been gradually applied to the machinery manufacturing industry, and the manufacturing technology of tractors has also improved, and has begun to gradually develop towards informatization, which has a great impact on the quality and performance of tractor clutches. Requirements have been further improved. Therefore, the research on the working principle of tractor clutch, how to use it and its maintenance and repair is also the work that tractor manufacturers and users have been doing all the time. Today, I will simply share with you how the tractor clutch works, precautions for use and how to overhaul.

How the tractor clutch works can be understood from its structure and working principle.

The composition and working principle of the tractor clutch

The tractor clutch is mainly composed of four parts, namely: the active part, the driven part, the pressing device and the operating mechanism. The clutch is mainly composed of a flywheel and a pressure plate of the clutch. The flywheel is directly connected to the crankshaft of the engine and is controlled by the crankshaft; the clutch pressure plate is connected to the gearbox, and the transmission force is transmitted to the gearbox through the combination of the flywheel and the clutch pressure plate. The gearbox performs shifting work. In the process of using the clutch, there are two states, namely the combined state and the disengaged state. When the clutch is in the engaged state, the pedal of the clutch is at the highest position, at this time, there is no contact between the release lever in the clutch and the release bearing, and the clutch pressure plate presses the driven plate, thereby transmitting the transmission force to the transmission; while in the disengaged state When the clutch pedal is stepped on, the gap between the release lever and the release bearing is eliminated. At this time, the pressure plate and the release lever move downward under pressure, causing the pressure on both sides of the driven plate to decrease and disappear. The transmission force is transmitted to the transmission, that is, the disengagement state of the clutch.

tractor clutch

Precautions for the use of tractor clutches

1. When starting, the clutch pedal should be lifted correctly

When the tractor is just starting, the clutch pedal should be stepped on correctly, and the clutch plate should not be lifted violently, which will make the clutch combination not stable enough and cause great damage to the friction plates. The correct starting method should be “fast, slow, slow”. When the tractor starts, quickly make it in a low gear, and pause to find the contact point at this time, and then change to a high gear to protect the safety of the tractor clutch. , to avoid unnecessary safety accidents caused by clutch damage when the tractor starts.

2. Be quick and thorough when separating

The disengagement speed during the disengagement process of the tractor clutch is generally in the opposite state to that during the combination process. When disengaging the clutch, care should be taken to do it quickly and thoroughly to avoid slow disengagement, which will cause a lot of heat due to friction, which will cause serious burn damage to the friction plates, seriously affect the life of the clutch, and be extremely harmful to the clutch. big. Therefore, when disengaging the clutch pedal, attention should be paid to the speed and degree of disengagement to protect the clutch from damage.

Tractor clutch overhaul

For the tractor used for farming, there will be a situation of not using it for a long time. If there is no good machine maintenance habits, it is likely to cause some small parts of the clutch to fail.

For example, the clutch will rust due to long-term non-use. At this time, the clutch should be removed in time and the rust should be cleaned up.

Or there will be clutch slippage, and this kind of failure is mainly caused by the following factors: such as oil on the surface of the friction plate; too small or no free clearance of the clutch; wear of the friction plate; broken or weakened elastic force of the pressure spring; driven disc Warping and deformation, the unevenness of the flywheel and the pressure plate plane is too large; the return spring is loose or broken, etc. At this time, we should take an appropriate maintenance plan according to the cause of the clutch failure.

I believe that through this article, you have a better understanding of the working principle, use precautions and maintenance of tractor clutches. As a manufacturer and trader specializing in the research and development and production of tractor clutch assemblies and clutch plates, our products are all It meets international quality standards and is well-received in a variety of different markets around the world.

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.

tractor clutch

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.

Most of the steering mechanisms of crawler tractors are steering clutches. When the tractor is performing deep soil preparation or sowing operations, failures such as slippage of the steering clutch, incomplete separation or inability to separate the locomotive often occur, resulting in difficulty in steering and deviation of the locomotive, which not only affects the work, but also wastes power and increases operating costs. In this case, it is necessary to find out the reasons in time to eliminate them, so as not to affect the normal operation of the locomotive. The common tractor steering clutch failures mainly include the following.

Clutch slip

The clutch slips and the forward speed of the tractor is reduced. When the steering lever on one side is pulled to control the steering, the steering clutch on the other side is swept away, the tractor cannot be steered, and makes a “click, click” sound, the operation is difficult, the work efficiency is reduced, and the steering clutch is burned.

Reason

(1) Cultivated land is often a partial traction operation. In order to prevent the right crawler from falling into the furrow, the driver often turns the left steering rod, which causes the early wear of the left friction plate, the wear of the friction plate becomes thinner, and the passive plate Exposed rivets.

(2) The foot brake is used before the steering clutch is completely separated, or the steering clutch is engaged before the brake is released, resulting in an increase in the strength of the inner and outer springs of the steering clutch and insufficient spring compression force.

(3) The clutch enters the oil, leaks into the gear oil from the central drive or the final drive, and leaks into the grease and diesel oil from the oil tank.

(4) The joystick has no free travel, the tractor is operated unreasonably, and the locomotive is overloaded for a long time.

Method of exclusion

Check the joystick and check it every 50-60 hours. Don’t use too much force when pulling the steering lever, and release it quickly and steadily.

If oil is found to stick to the driving piece and the driven piece, it should be cleaned with a metal cleaner. The cleaning work is best done immediately after the work is finished, because the driving piece and the driven piece are very hot at this time, and the oil is easy to wash off.

At the end of each shift, the oil drain plug of the isolation room should be opened, the leaked gear oil should be released, and the cause of the oil leakage should be checked.

12 Inch 26 Spline

Steering clutch not fully disengaged

The effective stroke of the joystick is too small. Although the joystick is pulled hard when turning, it still cannot reach the full stroke, which makes it difficult for the tractor to turn.

Reason

(1) The total thickness of the steering clutch friction plate (the size from the active drum to the pressure plate after assembly) is too large, and the pressure plate and the release bearing are close to the partition. When the steering clutch is disengaged, the disengaging bearing dial quickly touches the partition plate, the control lever cannot be pulled, the effective stroke becomes smaller, and the disengagement is not complete.

(2) Where the steering clutch release fork rod and the two lugs of the release bearing sleeve cooperate, the release fork rod and the fork rod seat are worn. When the joystick is pulled, the fork arm is quickly pressed against the active drum pressure plate (even the pressure plate is ground with groove marks), which makes the joystick stroke smaller and cannot be completely separated.

(3) The installation inclination of the steering clutch release lever is incorrect. When the joystick is pulled to turn, the joystick cannot reach the full stroke, and when the clutch is not completely separated, the spherical groove of the separation lever and the ball head of the separation push rod are stuck, and the steering clutch is not completely separated.

(4) The missing support washer or the assembled support washer is too thin and damaged, which makes the steering clutch assembly have a free movement on the rear axle shaft. When the lever is pulled, the steering clutch does not disengage, but leans against the partition. The steering clutch also doesn’t fully disengage when the lever is pulled to full travel.

(5) There is too much sediment and dirt in the shaft of the joystick and the shaft sleeve, the shaft is too tight or stuck in the sleeve, the stroke of the joystick is too small, and the separation is not complete.

(6) The frame along the beam, the bracket is deformed or broken, the front fulcrum bolts of the gearbox or the connecting bolts between the gearbox and the rear axle housing are loose, and the fixing bolts of the joystick shaft bracket are loose or broken, etc., which will increase the free travel of the joystick. , the effective stroke becomes smaller, and the steering clutch is not completely separated.

Method of exclusion

(1) If the total thickness of the steering clutch friction plate is too large, it should be re-checked to find out the cause of the excessive thickness. If the newly riveted friction plate does not meet the requirements (too thick), the friction plate of the standard thickness should be riveted again. piece. Ensure that the total thickness is within the technically allowable range.

(2) If it is caused by the wear of the separation fork rod, etc., the wear parts can be repaired or replaced to restore the normal positional relationship between the separation fork rod and the separation bearing sleeve, the separation rod and the fork rod seat.

(3) If the installation inclination of the steering clutch release lever is incorrect, reinstall the release lever so that the installation inclination is within the standard range.

(4) If the support washer is missing or the assembled support washer is too thin or damaged, a qualified support washer should be re-installed to eliminate the free gap of the assembly on the rear axle shaft.

(5) After inspection, if the frame is deformed or broken along the beam or bracket, it should be corrected and repaired or replaced with new parts; if the bolts at each point are loose, they should be tightened as required, and new bolts should be replaced if the bolts are broken.
In summary, it can be seen that the incomplete separation of the steering clutch is caused by the fact that the effective stroke of the joystick is too small and the free stroke is too large. In use, the frequency of use of the steering clutch is the highest.

High-frequency engagement and separation will naturally accelerate wear. Therefore, in order to ensure its technical performance, attention should be paid to frequently check and adjust the effective stroke and free stroke of the joystick to keep it within the standard range.

12 Inch

Steering clutch does not disengage

The tractor cannot steer to one side.

Cause of issue

(1) The separation fork is broken or the end is severely worn out and the dial is pulled out.

(2) The pressure plate nut lock ring is broken, and the nut is loose or damaged.

(3) The supporting gasket is missing.

Method of exclusion

(1) Check whether the release fork is out of the dial ring. If it is separated, it proves that the release fork and other parts are seriously worn; if it is a newly replaced release fork, the release fork may be a substandard product.

(2) Check whether the clutch pressure plate nut is loose or damaged. If it is loose, it should be tightened. If it is damaged, replace it with a new one. If the lock ring is broken, it must be replaced.

(3) Pay attention to the following issues when assembling the steering clutch:

a. When installing the main and driven pieces, the first piece close to the cutting groove of the driving drum must be installed with the driven piece.

b. Install 10 pieces of main and driven pieces each, and the total thickness is within the specified range. When it is super thick, the super thick driven piece should be ground under the surface grinder or use the old piece that meets the requirements. It is not allowed to reduce the driving piece or the driven piece. Because reducing the driven plate will reduce the maximum transmission torque of the steering clutch, the torque will be reduced by about 1/10 for every reduction of one plate.

c. Periodically check and adjust the free travel of the joystick.

d. Periodically drain the oil accumulated in the steering clutch chamber.

The above is the relevant content about the common faults of the tractor steering clutch. If you encounter problems during the operation, you must first find the root of the problem, and then make targeted improvements according to the problem, so as to improve the working efficiency of the tractor clutch to a certain extent.

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.

The clutch generally exists in the gearbox of the tractor and plays the role of power separation. In a fuel vehicle, the heart of the power is the engine. When the power output from the engine is to be transmitted to the wheels, it must pass through the gearbox and the drive shaft in the middle. We can call this transmission chain the power transmission system. Then the clutch is located at the head end of the gearbox, and when it is engaged, it allows the transmission system to transmit power smoothly; when the clutch disengages, it cuts off the power transmission from the engine to the wheel end.

So why do you need to cut off the power from the engine to the wheel end? This is mainly related to the working characteristics of the engine. Like a normal engine, there will be a minimum speed requirement, that is, the lowest crankshaft rotation speed for the engine to work smoothly. For example, the minimum speed of the four-cylinder engine is about 500 rpm or more, and the three-cylinder engine is about seven or eight hundred rpm. Below this value, the engine is likely to stall. Therefore, when our car is stationary, the engine should also be kept above this minimum speed. At this time, it is necessary to have a power separation device to realize the connection and separation of power.

On the whole vehicle, the tractor clutch system can be roughly divided into two parts: the control system and the clutch. The control system is the clutch pedal that we operate with our feet, plus a set of transmission devices to transmit the action of the clutch pedal to the clutch. The clutch is a device used to realize the transmission and interruption of engine power.

K series

Let’s talk about several forms of the clutch system. Among them, the control system generally has three forms, rod-type control system, zipper-type control system and hydraulic control system.

Like the rod system, which can be seen on previous tractors and old heavy trucks, the transmission device in their middle is composed of connecting rods. The transmission efficiency of this system is relatively low, the arrangement of the connecting rod is also relatively difficult, the space required is relatively large, and the stroke of the entire pedal will be relatively large. Therefore, the application of the stick control system is relatively limited.

The second type is the zipper control system. It transmits the operation of the pedal to the clutch through a zipper in the middle. This is a similar principle to the handbrake braking mentioned in the previous explanation of the braking system. Although the zipper system is more flexible in terms of spatial arrangement, its transmission efficiency is not high, and its service life is relatively short.

The transmission device of the hydraulic control system is mainly composed of the clutch master cylinder, the clutch sub-pump, and the hydraulic pipeline. The specific transmission principle is similar to the working principle of the braking system. Interested friends can click on my homepage to watch the video explaining the braking system. The hydraulic system is more efficient and can make the clutch engagement softer. If you want to continue to subdivide, there are semi-hydraulic structures and full-hydraulic structures. The main difference between them is in the driving mode of the release bearing, which is a semi-hydraulic structure. The release fork is pushed by the clutch wheel pump, and then the release bearing is pushed by the release fork. The fully hydraulic structure integrates the release bearing and the clutch sub-pump, and cancels the separation fork. This structure generally installs the sub-pump inside the gearbox.

After talking about the form of the operating mechanism, let’s look at the clutch. The clutch assembly mainly includes the clutch driven plate assembly and the clutch cover assembly. The most important thing in the driven disc assembly is the friction plate, and the most important thing in the clutch cover is the diaphragm spring. Diaphragm springs are different from coil springs on general shock absorbers. When we released the clutch pedal, there was no pressure in the master cylinder to push the wheel cylinder.

The diaphragm spring will press the friction disc of the clutch against the flywheel of the engine because of its own elasticity. In this way, the power of the engine is transmitted to the friction plate through the friction disc of the flywheel. The friction plate is connected with the input shaft of the gearbox through splines, and finally the power of the engine is transmitted to the wheels through the clutch and the gearbox.

When we step on the clutch pedal, through the hydraulic transmission device, the release bearing presses the diaphragm spring “in”. During the pressing process, the position of the diaphragm spring near the center of the circle will go inward, and the place around the circle will be It will be mentioned that since the circumferential position of the diaphragm spring is fixedly connected with the friction disc, the friction disc and the flywheel will be separated, thus realizing a cut-off of power from the engine to the gearbox.

When we are driving a tractor, if we are not skilled, it will often start to stall. The main reason is that when the car is about to start at idle speed, the power output by the engine needs to overcome the sum of all the resistance of the vehicle. The output characteristics of the engine at idle speed are smooth and continuous. If the time to release the clutch is too fast, the load on the engine will increase instantaneously, causing its speed to be too low, thereby stalling.

The overhaul of the tractor is inseparable from the overhaul of the clutch components. In order to improve the maintenance quality of the tractor, the overhaul methods and standards of the main components of the tractor clutch are introduced in detail.

The tractor clutch is composed of four parts: the active part, the driven part, the pressing mechanism and the operating mechanism. The main component of the active part is the driving disc; the main component of the driven part refers to the driven disc with friction linings riveted on both sides; the main components of the pressing mechanism are the pressing spring, pressing lever, and pressing rod bracket; The main components are separation lever, separation bearing, etc. The following tractor clutch manufacturers talk about the maintenance of the main components of the tractor clutch based on actual experience.

Overhaul of drive and driven discs

The main damage of the active disk is wear, scratches, burns and cracks on the friction surface; warpage and deformation of the friction surface. When the thickness of the active disc is 18±0.1 mm, the surface groove depth exceeds 0.50 mm, the arch deformation exceeds 0.30 mm, and the flatness tolerance exceeds 0.12 mm, it should be ground or flat. However, after polishing, its thickness is not less than 16±0.40 mm. If the active disk is cracked or too thin, it should be replaced with a new one.

The driven disc is the most vulnerable part of the clutch. The main damage is 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, loose riveting between the steel plate and the disc, spline holes wear, etc. It can be determined by measuring the depth of the rivet head with a vernier caliper. The burial depth of the rivet head shall not be less than 0.3 mm, otherwise, use a new friction plate. If the friction plate is seriously worn or there are more than two cracks and fall off, and the burnt surface is large and deep, the new plate should be riveted again. If there is a slight oil stain on the friction plate, it can be burned off with the flame of a blowtorch, or cleaned with gasoline, and the slight burnt surface can be polished with sandpaper.

When replacing the new piece to remove the old piece, use a drill bit 0.40-0.50 mm smaller than the diameter of the old rivet to drill out the rivet head, and then gently punch out the old rivet and remove the old piece. Use a wire brush to remove dust and rust from the driven disc, and check other parts of the driven disc. The warpage of the driven disc steel plate will cause the clutch to vibrate and wear unevenly when starting, so its warpage should be checked. The warpage of the driven disc steel sheet is also called circular runout or yaw. It can be installed on the inspection frame and measured at the outermost edge of the driven disc with a dial indicator. The circular runout limit is 0.80 mm. If it exceeds the limit, it can be calibrated by cold pressing with a special clamp;

13-Inch-(2)

Repair of elastic push rods

The main damage of the elastic push rod is the weakening of the elastic force, the reduction of the hole center distance, the wear of the support hole, and the breakage of the elastic push rod. After the elastic force of the elastic push rod is reduced, it is heated to 780 ~ 810 ° C, quenched in oil, and then heated to 450 ~ 475 ° C for tempering.

When the center-to-center distance of the elastic push rod becomes smaller, the original center-to-center distance can be restored by thermal deformation method. between the mouth. Increase the center distance of the holes, and then perform quenching and tempering according to the above method. When the center distance of the pin holes is enlarged, care should be taken to make the center lines of the two pin holes parallel. When the fitting clearance of the pin hole of the elastic push rod is greater than 0.50 mm, it can be repaired by the maintenance dimension method. The maintenance size can be increased by 1 mm, and the fitting clearance between the pin and the hole is 0.12 mm.

Repair of the compression lever

The pressing lever is also called pressing claw, pressing rod, cam, and releasing claw. It is commonly made of 45Cr or 40Cr; the arc hardness is HRC43-48, and the quenching depth is 1-3 mm. The main damage of the pressure rod is the wear of the pressure bearing arc surface and the pin hole. After the arc surface is worn, the distance from the bearing surface to the front hole will be shortened. The pin hole wear has a unilateral nature, the front hole is ground below, and the rear hole is ground above, which is determined by the force during compression. When the pressure rod wears less, the arc surface can be trimmed with whetstone to remove wear scars and unevenness; when the wear exceeds 1 mm, it should be repaired by surfacing welding.

Wear-resistant alloy electrodes can be used during surfacing to increase its wear resistance; after welding, use a grinding wheel to trim and form, and use a template to check the positional accuracy of the arc surface relative to the two holes, that is, use two pins to insert into the template hole and the pressure rod hole, See if the arc surfaces of the two coincide. After repair, the arc surface should be smooth and its busbar should be parallel to the center line of the two holes.

When the clearance between the pin hole of the pressure rod and the pin exceeds 0.4 mm, it should be repaired. The repair method is the same as that of the elastic push rod and carried out at the same time. It can also be repaired by inserts: the inserts are made of No. 45 steel, the wall thickness is 2-3 mm, and the interference is 0.04-0.08 mm. In addition, the pin hole can also be reprocessed after surfacing (annealing before welding), and the quality difference of each pressure rod on the same machine after repair should not exceed 15g.

12 Inch

Maintenance of release bearing and release sleeve

When checking the release bearing, fix the outer ring and rotate the inner ring. If there is blockage or obvious clearance, it is because the balls and raceways are worn and should be replaced; if the rotation is flexible, but there is a slight “rustling” sound, it is due to lack of lubrication, if necessary Melt it in grease, cool it and remove it for use. The release bearing should rotate flexibly without sharp noise or jamming, its axial clearance should not exceed 0.60 mm, and the wear of the inner race should not exceed 0.30 mm. The separation bearing is closed and cannot be disassembled for cleaning or lubricant. Before loading, the bearing should be soaked in molten lubricating oil (a mixture of calcium-based grease and gear oil in half), and it can be condensed before it can be used. fitted. If it is damaged, replace it with a new one.

The main damage of the release sleeve is: the pin hole supporting the elastic push rod is worn, the front end face is worn, the hole matching the clutch bearing is worn, the interference with the release bearing disappears, and the fit with the oil seal is worn, etc. When the inner hole is worn and the fitting clearance is greater than 0.50 mm, the inner hole or journal of the sliding sleeve should be repaired according to the maintenance dimension method. When the matching parts are repaired by the insert method, the hole can be enlarged by 7 mm. In order to facilitate processing, high temperature annealing should be performed before boring.

The maintenance of the hole supporting the elastic push rod after wear is the same as the pin hole on the elastic push rod, and it is often repaired simultaneously; the treatment of the worn front end face is the same as the end face of the pressure rod bracket, and it is also repaired by the surfacing method; and the separation bearing and oil seal After the mating part is worn, it can be repaired by brush plating. The normally engaged clutch release sleeve is also known as the release bearing seat. When the trunnion fitting clearance is greater than 1.50 mm, it can be repaired by surfacing welding and brush plating, or the old trunnion can be cut off and drilled at the old trunnion. Tapping, screwing a new trunnion, and welding it firmly at the root. After repair, the coaxiality error of the left and right trunnions and the vertical error of the left and right trunnions and the sliding hole should not exceed 0.30 mm. When there is wear scar on the working surface of the ear arm of the separating bearing seat, it can be repaired with oil stone, and it can be repaired by welding when the wear is serious.

Repair of release housing and release ring

The main damage of the very engaging clutch release bearing and bearing seat is the loose fit with the bearing, and the increased fit between the two pins of the release ring. When the clearance of the former is greater than 0.05 mm, brush plating should be used to repair the mating surface and restore the fit; when the clearance of the latter is greater than 0.50 mm, the hole should be trimmed and then the oversized pin should be replaced to restore the fit (the standard clearance is 0.50 mm). 07 to 0.31 mm). After the ball head of the release ring is worn out, it can be replaced with a new ball head. The clearance between the ball head and the release ring is 0.10 to 0.42 mm, and the clearance between the ball head and the fixed seat cover is 0.14 to 0.42 mm. After wear, the pins matched with the split inner lever can be repaired by brushing or inserting.

The above is all about the maintenance of the main components of the tractor clutch. As long as the main components are regularly repaired, the service life of the clutch can be improved.

The friction disc is the main component of the tractor clutch, and the physical properties and mechanical properties of its working surface material directly affect the working performance of the clutch. So what are the materials of the clutch friction disc?

The effect of clutch friction disc

13-Inch-10-Spline-PTO-Disc-Asbestos-free

1. Transmission of rotational torque

The engine flywheel is the active part of the clutch, and the driven disc and the driven hub containing the friction plate are connected with the driven shaft by the rolling spline shaft. If the spring is clamped, the driven disc is clamped on the end surface of the flywheel of the water pump.

2. Engine torque

That is, it is transmitted to the driven disk by the friction effect between the water pump flywheel and the surface of the driven disk, and then sent to the driving wheel through the driven shaft and a series of components in the transmission system. The greater the clamping force of the spring, the greater the torque that the clutch can transmit.

Material of clutch friction disc

Friction parts are the key components of friction clutches, and the chemical properties and physical properties of the surface materials during their work immediately endanger the working characteristics of the clutch.

Common friction surface materials include powder metallurgy materials, asbestos-based materials, and rock-based materials.

1. Powder metallurgy materials

The surface allowable temperature, allowable working pressure, friction index at high temperature and service life are all high.

2. Copper base powder is not metallurgical

The key is to wet test the friction surface. The friction index and allowable working pressure of iron-based powder unmetallurgical materials are higher than those of copper-based materials, but the wear resistance is lower, and it is mostly used to dry test the friction surface.

3. Asbestos-based materials

It is made of asbestos plus binder and filler, and the soil is on a steel or iron base plate, and the allowable operating temperature is low.

4. Paper-based materials

It is made of asbestos, fibrous materials or compounds of the two to complement each other, and then bonded by epoxy resin after adding fillers. This type of material has a porous structure, good friction characteristics, similar dynamic and static friction indices, and low cost.

The main requirements for the material are: the coefficient of friction is large and stable, and the coefficient of dynamic friction should be as close to the coefficient of static friction as possible; high strength, can withstand impact, not easy to crack and peel at high speed; wear resistance, high temperature resistance, corrosion resistance and thermal conductivity. Small deformation; long-term standing should not cause adhesion. In addition, long service life, easy processing and low cost are also required.