What are the faults of tractor clutch? Here are the solutions summarized by the old driver

The clutch is arranged between the diesel engine and the gearbox. Its function:
Ensure that the power transmitted by the engine to the gearbox is separated or engaged under the working state of the engine, so as to realize speed change and shutdown;
Smoothly connect the power to ensure a smooth start of the tractor;
In case of overload during operation, the clutch will slip automatically to prevent overload of transmission parts.
In the process of use, the common faults of the clutch are incomplete separation and slipping, which affect the normal use of the tractor.
1. The clutch is not fully disengaged
Start the engine, step on the clutch pedal, it is difficult to shift, and there is gear impact sound. In serious cases, it is forced to shift into gear, and the vehicle rushes forward and stalls. Generally, the clutch is not completely separated; Alternatively, without starting the engine, one person can shift the gear lever into neutral and press the clutch pedal, and the other person can use a slotted screwdriver to move the driven plate under the vehicle. If the driven plate can rotate, it proves that the clutch can be separated;
If it cannot rotate, the clutch cannot be disengaged or disengaged completely. The clutch of walking tractor is not completely separated. In addition to the common reasons such as the clearance between the release bearing and the head of the release lever and the excessive free stroke of the clutch handle, there are the following seven uncommon reasons.
(1) In use, due to excessive release of the clutch handle or sudden increase of load, the contact between the driving plate and the pulley groove is impacted into a pit. When the clutch works, the driving plate is stuck in the groove and is not easy to come out, but is pressed on the friction plate (but not tightly), resulting in incomplete separation. At this time, after the impact and wear pits are fully welded by electric welding, file and restore the original shape.
(2) The raceways and balls of the front and rear bearings of the clutch are worn, and the bottom surface of its bearing seat is worn. When the axial clearance caused by these wear is large, so that the clutch assembly has obvious axial movement relative to the clutch shaft, the separation lever cannot play the role of lever in the separation process, and incomplete separation will occur. At this time, replace the bearing and bearing seat.
(3) The clutch shaft is on one side of the transmission case and is fixed by a claw bearing seat and another bearing seat. A bearing is installed in the claw bearing seat, and there is a 2mm thick gasket between the right side of the bearing and the sprocket end face. Due to long-term use, the sprocket end face is worn, the bearing is worn, and the gasket is thinner, which increases the axial clearance of the clutch shaft. At this time, even if the separation clearance is adjusted correctly, the clutch will not be completely separated. At this time, replace the bearing or add shims to make the clutch shaft no longer move.
(4) The direction of the friction plate is wrong during assembly, resulting in incomplete separation. Because one side of the spline sleeve in the center of the friction plate is flat and the other side is convex, the planes of the two spline sleeves should be opposite during assembly. If they are installed incorrectly, or the plane is opposite to the convex surface, or the convex surface is opposite to the convex surface, the total thickness of the two friction plates will increase. After assembly, the friction plate will be blocked by the pressure plate or clutch cover. During the separation process, the pressure plate cannot move, resulting in incomplete separation. At this time, it shall be removed and reassembled as required.
(5) When welding and repairing the release lever, the size of the release lever after surfacing is inconsistent. In this way, the force of the three adjusting pull rods to pull the pressure plate is uneven, resulting in the deflection of the pressure plate in the clutch. One part of the pressure plate is separated from the driven plate, and the other part also presses the driven plate, so that the clutch is not completely separated. At this time, the separation lever shall be removed and reprocessed to make the three separation levers have the same size.
(6) Wrong orientation of bearing pedestal with claw. The position of the two "claws" on the end face of the bearing seat with claws relative to the three fixed bolt holes: one claw is just between the two bolt holes, and the midpoint of the other claw is just opposite to the third bolt hole. During assembly, the claw between the two bolt holes should be above and the other claw should be below. Because the three bolt holes are evenly distributed, if you don't pay attention, you will get the orientation wrong, which destroys the relative position between the seat and the release claw, reduces the effective stroke of the release bearing, and causes incomplete separation. At this time, it should be disassembled and reinstalled.
(7) If the tractor is stored in the open air for a long time, the friction plate of the driven plate is warped, deformed or corroded by water, so that the spline sleeve and the spline of the clutch shaft are rusted together, resulting in incomplete clutch separation. At this time, remove the rust, clean or replace the friction plate.
2 clutch slipping
When the clutch is in the engaged state, when the locomotive is running normally or the load is increased, the clutch has obvious heating phenomenon and emits coke smell, which is the external manifestation of clutch slip. Clutch slip is one of the common faults in clutch use.
If the maximum torque transmitted by the clutch is smaller than the rated value, the clutch is easy to slip during operation. The maximum torque that can be transmitted by the clutch depends on the maximum torque that can be generated between the friction plate surfaces. Its size is affected by the total area of the friction surface (the size and number of driven plates), the action radius of the friction force (the average radius of the annular friction surface), the compression force between the friction surfaces and the friction coefficient. The causes and troubleshooting of clutch slip are as follows:
(1) There is oil stain on the friction plate, such as the failure of crankshaft oil seal and the engine oil channeling to the clutch chamber. It must be disassembled, washed with gasoline and dried.
(2) The clutch release clearance is too small, or the three ball joints are uneven, so that the pressure bearing end face of some release levers is still in contact with the thrust surface of the release bearing when the clutch is engaged, so the pressure of the pressure plate is reduced and the clutch slips. At this time, the separation clearance shall be adjusted as required.
(3) The elastic force of 6 springs in the clutch is too weak or the elastic force of each spring is too different. Check or replace.
(4) The surface of the friction plate is not flat, or the surface is curved due to poor riveting, and the actual contact area of the friction surface is reduced, resulting in sliding. The working surface of flywheel and pressure plate is uneven due to wear, or the surface is ablated, resulting in hardened layer and pull mark. At this time, the friction plate shall be riveted again or replaced.
(5) When the friction surface is seriously worn, the clutch will reduce the working stroke of the separation sliding sleeve and the pressing force due to the increase of the separation clearance. When the friction plate is worn until the rivet is exposed, the friction between the friction surfaces will be reduced due to poor contact. If it is used for a long time, check whether the friction plate is excessively worn. If the wear is too large and the rivet head protrudes out of the friction plane, the friction plate shall be replaced.
(6) The rear bearing seat hole of the clutch is not concentric with the front bearing seat hole, so that the clutch shaft is skewed relative to the centerline of the crankshaft. When the clutch is separated, the driven plate is not parallel to the working surface of the flywheel and pressure plate, or even the separation is unclear, resulting in eccentric wear. After eccentric wear, the contact area of the friction surface is reduced, and the clutch is easy to slip during operation.