Adjusting the clutch cable: sequence of actions

Clutch classifications

Clutch designs vary. They differ in how to manage it, in structure.

Classification by control method:

• with a mechanical drive;
• with hydraulic drive;
• with electric drive;
• with combined drive (eg hydromechanical drive).

Classification by type of friction:

• dry friction is when friction linings (discs) operate in air;
• wet friction is when the discs run in an oil bath.

Classification by type and location of pressure springs:

• several pressure springs of a cylindrical mold are located around the perimeter;
• the diaphragm pressure spring is located in the center.

2.1. Clutch upgrade

Thus, since the principle of the device provides severe friction between parts, natural wear cannot be avoided. It is possible to make the clutch on the engine block yourself, but owners of motorized vehicles who do not have experience in plumbing are not advised to perform this operation.

Consider an example of creating a mechanism for heavy walk-behind tractor
... The basis is the flywheel and the input shaft of the "Moskvich" car box, a steering knuckle with a hub from Tavria, profile B, a driven pulley in two streams and a steel billet as a crankshaft (suitable for GAZ-69). The home product starts by turning a steel billet on a lathe to fit the hub onto the resulting falshval. After the pulley is seated on the honed shaft, the seat along the diameter on the pulley inner ring under the bearing should be punctured to fit perfectly.

If the hub moves without clearance, and the pulley scrolls, this is a sign of a correctly completed task. Flip the piece over and do the same on the back. In the next step, use a drill and drill bit (5mm) in the pulley to make 6 holes equidistant from each other. Since the bolts will be 10 mm, the holes of the wheel driving the drive belt must be drilled from the rear with a 12 mm drill.

Crankshaft CR-M12

The pulley is mounted on the flywheel, the same drill must be made with the hole and tighten both parts with the bolt to secure. While the pulley is on the flywheel, place marks on the flywheel through the holes made on it. Remove the pulley and drill all 6 holes.

Using bolts (10 mm), remove the structure, the thread without a cap should be 60 mm. A crankshaft inside a proto-hit pig. To make sure the flywheel does not hit, its surface must also be punctured and then centered along the bore.

smooth the inner plane of the flywheel together with the pulley on a lathe. The metal layer is removed by no more than 1 m. Pre-install the flywheel for shipment, check the beating of the planes, it should not exceed 0.1 mm. Ultimately, the basket remains attached to the flywheel. to the menu

Motoblocks greatly facilitate the work of farmers and owners of their own backyard plots

This article will focus on such an important structural element of this unit as the clutch.

Signs of a faulty clutch

The clutch on any car wears out over time and starts to work with degraded performance. So, the clutch system must be additionally diagnosed when the following symptoms appear:

• On machines with a manual transmission, the clutch is “sufficient” when the corresponding pedal is up. And the higher, the more worn out the clutch. In particular, it is easy to check when the machine is moving from a standstill.
• Decrease in dynamic performance. When the clutch discs slip between each other, the power from the engine is not fully transmitted to the gearbox and wheels.In this case, you can often hear the unpleasant smell of burnt rubber emanating from the clutch disc.
• Reduced dynamics when towing a trailer. Here the situation is similar to the previous one, when the disk can turn and not transfer energy to the wheels.
• The vehicle jerks when moving from a standstill. This is due to the fact that the driven disc has a damaged plane, that is, it is warped. This usually happens due to overheating. And overheating is caused by a significant effort on the clutch elements of the car.
• The clutch "leads". This situation is the opposite of slippage, that is, when the drive and driven discs do not separate completely when the clutch pedal is depressed. This is expressed in the difficulty of changing gears to the point that some (and even all) gears are simply impossible to include. Also, during the switching process, unpleasant sounds usually appear.

The clutch wears out not only for natural reasons, but also if the machine is misused. Do not overload the car, tow very heavy trailers, especially when driving uphill, do not start with slipping. In this mode, the clutch operates in a critical mode, which can lead to its partial or complete failure.

If at least one of the above signs is detected, it makes sense to perform an adhesion test. Driving with a faulty clutch not only causes discomfort during the operation of the car, but also aggravates its condition, which is reflected in expensive repairs.

How to do it yourself?

The clutch for a walk-behind tractor can be made or changed on your own, if you have experience in locksmith work. For the manufacture or replacement of a homemade mechanism, you can use spare parts from cars or from a scooter:

• flywheel and shaft from the Moskvich gearbox;
• hub and rotary cam from Tavria;
• pulley with two handles for the driven part;
• crankshaft from "GAZ-69";
• B-profile.

Before you start the process of installing the clutch, carefully study the drawings of the mechanism. The diagrams clearly show the relative position of the elements and the step-by-step instructions for assembling them into a single structure. The first step is to sharpen the crankshaft so that it does not have contact with other parts of the system. Then place the motoblock hub on the shaft. Then prepare a groove on the shaft for the release bearing. Try to do everything carefully and accurately so that the hub sits tightly on the shaft, and the pulley with handles rotates freely. Repeat the same operation with the other end of the crankshaft.

Insert a 5 mm drill into the drill and carefully drill 6 holes in the pulley, at an equal distance from each other. On the inside of the wheel connected to the drive cable (belt), you also need to prepare the corresponding holes. Place the prepared pulley on the flywheel and fix it with the bolt. Mark the locations corresponding to the pulley holes. Twist the bolt and separate the parts. Now carefully drill holes in the flywheel. Reconnect the parts and tighten the locking bolts. The flywheel and crankshaft must be sharpened from the inside - to exclude the possibility of clinging and beating parts against each other. The system is ready. Place it in its proper place in your machine. Connect the cables, while pulling them away from rubbing parts.

If you have a small unit, the belt option may also suit you.
Take two sturdy V-shaped belts with a length of about 140 cm. The B-profile is ideal. Open the gearbox and install a pulley on its main shaft. Install the tandem roller on the spring loaded bracket. Note that a minimum of 8 bracket links must be associated with the clutch start pedal. And a double roller is needed to ensure the necessary tension on the belts during operation and to loosen them in the event of slipping / idling.To minimize the wear of elements, provide block-stops in the design for idle operation of the motor.

Consider another way to independently design a clutch system. Attach a flywheel to the engine. Then connect the clutch system removed from the car using an adapter that can be made from the crankshaft from the Volga. Secure the flywheel to the engine crankshaft. Place the clutch basket with the pallet facing up. Check that the dimensions of the shaft flange mountings and the basket plates are identical.

If necessary, increase the required clearances with a file. The gearbox and gearbox can be removed from the old unnecessary car (check the serviceability and general condition). Assemble the entire structure and test its operation.

You can find out more about how the overhaul of the clutch of a heavy walk-behind tractor takes place.

The clutch is tightly interconnected with the gearbox. It performs quite important functions. Namely, it transfers torque from the crankshaft to the gearbox located in the transmission, disconnects the gearbox and the crankshaft (this is done when shifting gears). And this mechanism also ensures the smooth running of the walk-behind tractor from a place. Thanks to him, it is possible to stop equipment without turning off the engine (this is possible through the clutch lever, cable and the entire system as a whole).

Soil type

When answering the question of how to choose a walk-behind tractor, the first step is to pay attention to the density of the soil that you have to process. The heavier the ground, the more powerful and heavy mechanism will be required.

A walk-behind tractor weighing up to 70 kg will pull the hiller or plow only on light ground without slipping. For virgin lands and heavy soils, its weight should start from 95 kg.

Speaking about the power plant of a walk-behind tractor, it should be noted that a diesel engine is better than a gasoline engine for cultivating heavy soil. It has higher tractive effort, longer service life and lower fuel consumption. The disadvantage of such a motor is the difficulty in starting at an air temperature below + 2C.

Motoblocks weighing less than 150 kg when working with a hiller, plow or potato digger must be equipped with lugs - metal wheels.

Clutch for walk-behind tractor - design and principle of operation

The clutch of absolutely any agricultural machine consists of a number of elements. The design of the mechanism includes:

• Permanent control device;
• Leading node;
• Driven components.

The design of the control mechanism includes a release lever, which is connected to a push-action disc by means of a pedal deflector and rods. When the implement clutch is locked, a signal is generated which is received by the release levers. They, in turn, disconnect the driven disc from the pressure body, as a result of which the mechanism is turned off.

The bearing in the clutch unit of a modern walk-behind tractor serves to reduce friction, while excluding the contact of the levers rotating around their axis and a completely stationary layering. The spring is responsible for returning the control mechanisms to their original position. The branch, in this case, is repelled from the levers at the distance required for the final shutdown.

Device and types of mechanisms

All clutches consist of similar elements: leading, driven and a control unit for engaging and disengaging the clutch.

Based on the characteristics of the machine, the following types of clutch mechanisms are distinguished:

Centrifugal - tightly coupled to the differential, providing agility around corners. However, it consists of parts subject to high friction and slippage under heavy loads.

Belt - suitable for low-power gasoline walk-behind tractors and cultivators, does not differ in durability and performance.

Hydraulic - transmits torque by changing the pressure force of the working fluid in the piston by squeezing.

Frictional - better than all other systems reacts to speed changes, has a long repair life and high efficiency.

Disk is the most reliable option for diesel motoblocks. Allows you to get under way without unnecessary jolts and develop a high speed of movement.

According to the type of friction and the presence of lubricant, a distinction is made between dry and wet clutches, that is, in an oil bath.

Purpose and varieties

The clutch carries out an inertial transfer of torque from the crankshaft to the transmission gearbox, provides a smooth start of movement and gear shifting, regulates the contact of the gearbox with the motor of the walk-behind tractor. If we consider the design features, then the clutch mechanisms can be divided into:

• friction;
• hydraulic;
• electromagnetic;
• centrifugal;
• single, double or multi-disc;
• belt.

According to the operating environment, a distinction is made between wet (in an oil bath) and dry mechanisms. According to the switching mode, a permanently closed and non-permanently closed device is divided. According to the way in which torque is transmitted - in one stream or in two, one- and two-stream systems are distinguished. The design of any clutch mechanism includes the following elements:

• control node;
• leading details;
• driven components.

The friction clutch is the most popular among farmers-owners of motoblock equipment, because it is easy to maintain, high efficiency and long continuous operation. The principle of operation is the use of friction forces that arise between the contacting faces of the driven and driving parts. The leading components work in a rigid connection with the engine crankshaft, and the driven ones - with the main shaft of the gearbox or (in its absence) with the next transmission unit. The elements of the friction system are usually flat discs, but in some models of walk-behind tractors a different shape is implemented - shoe or conical.

In a hydraulic system, the moment of movement is transmitted through a fluid, the pressure on which is provided by a piston. The piston is returned to its original position by means of springs. In the electromagnetic form of clutch, a different principle is implemented - the movement of the elements of the system occurs under the action of the forces of electromagnetism.

This type refers to permanently open. The centrifugal type of clutch is used in automatic gearboxes. Not very common due to rapid wear of parts and long slip times. The disk type, regardless of the number of disks, is based on the same principle. Differs in reliability and provides smooth start / stop of the unit.

The belt clutch is characterized by low reliability, low efficiency and rapid wear, especially when operating with high-power motors.

Clutch device

With all the variety of brands of motoblocks, their classes and modifications, the clutch device always includes several necessary parts:

• control unit;
• leading component;
• driven components.

The control unit includes direct control squeeze levers connected to the pressure disk by means of rods and a deflector equipped with a pedal. At the moment the device is turned off by the operator, reinforcement is transmitted from the pedal to the levers using a branch equipped with a bearing. During the compression of the springs, the levers associated with the pressure plate move it away from the driven one, which leads to the disengagement of the clutch.

The presence of a bearing in the design is designed to minimize the friction factor, since the baffle and the levers do not touch. The standard design has three arms that are set at 120 degrees relative to each other. The presence of springs ensures the return of device parts to their original position

The deflection is displaced by the distance necessary to disengage the mechanism, and its observance is very important: if the desired distance cannot be reached, this leads to the clutch slipping, and the friction pads are exposed to increased stress and premature wear. Moreover, if the distance, on the contrary, is exceeded, the clutch is not completely disengaged.

In this video, you will learn how to change the clutch:

The driving component consists of the end of the engine flywheel and the pressure plate rotating with it at the same time. In this case, the disk also moves axially relative to it. Between these two components is another disc, the hub of which is located on the splined shaft. This is the slave part of the device. Around the drive disc there are springs of a cylindrical shape, which have a preliminary compression and are necessary for pressing the pressure disc. This is achieved due to the fact that one end they abut against the disk, and the other is located on the casing located on the driven surface. It is this design that ensures that the device is in a constantly on mode, even in the absence of movement with the motor not muffled.

Enabling the stop of the device generates a signal transmission to the release levers and the simultaneous disengagement of the driven part, due to which the clutch is disengaged.

Typically, the clutch design of small agricultural machinery has a bearing that is necessary to reduce friction. Its presence provides a smooth movement of the levers with the exclusion of their contact with each other. There is also a spring in the device that allows the control element to return to its original position after switching speeds.

Checking the clutch DSG 7

Among robotic gearboxes DSG, the most popular clutch is currently the DSG-7. Signs of its partial failure are usually the following:

• jerks of the car when starting to move from a place;
• vibration, both during the start and simply while driving, in particular, when the car is moving in second gear;
• loss of dynamic characteristics, namely, when accelerating, moving the car uphill, towing a trailer;
• unpleasant crunching sounds when changing gears.

DSG clutches are also subject to wear and should be checked periodically. However, this is done a little differently than in the classical "mechanics". In particular, the DSG grip check must be performed according to the following algorithm:

• Park the machine on a level road or surface.
• Depress the brake and alternately move the gear (mode) shift knob to different positions. Ideally, the switching process should take place without the expenditure of significant efforts, easily and smoothly, without grinding and extraneous sounds. In the event that when shifting there are extraneous "unhealthy" sounds, vibrations, gears are shifted with considerable effort - it is necessary to perform an additional check of the DSG clutch.
• Set drive mode D, then release the brake pedal. Ideally, the car should start moving even without the driver pressing the accelerator pedal. Otherwise, we can talk about strong wear of the clutch elements. However, in this case, the machine may not move due to engine wear. Therefore, additional verification is needed.
• Acceleration should not be accompanied by extraneous rattling sounds, grinding, jerking, failures (sudden reset of the acceleration dynamics). Otherwise, there is a high probability of significant clutch wear.
• With a sharp acceleration, the readings of the speedometer and tachometer should increase synchronously. If the tachometer needle goes up sharply (the engine speed increases), but there is no speedometer needle (the speed does not increase), this is a clear sign of wear of the clutch or the friction multi-plate clutch.
• When braking, that is, when lowering gears, their shifting should also occur smoothly, without clicks, jerks, rattles and other "troubles".

However, the best check of the DSG-7 clutch is performed using electronic autoscanners and special programs. The most common of them is "Vasya diagnostician".

How to adjust the grip of the walk-behind tractor

For the smooth operation of the clutch system and the entire walk-behind tractor as a whole, it is important to follow the care recommendations and regularly maintain the unit. This will avoid premature breakdowns and extend the life of the agricultural machine.

1. The clutch lever must be pressed and released smoothly, without jerking, otherwise a sharp force transmitting to the crankshaft may cause the engine to stop during operation.
2. If the walk-behind tractor begins to accelerate sharply when the clutch is depressed, it is necessary to adjust by tightening the adjustment screw. To do this, you need 2 wrenches: 10 and 12. It is necessary to loosen the lock nut and unscrew the adjusting screw. After adjustment, you need to see if there is a gap, and, if there is, the screw is clamped and fixed with a locknut.
3. If the machine travels very slowly or stops when the clutch is released, the screw is slightly loosened, after which the cultivator's stroke is tested.
4. In the event of extraneous noise from the agricultural machinery gearbox, you must immediately stop the engine and check the oil level in the gearbox housing. If there is not enough transmission oil, add it, then start the walk-behind tractor. If noises persist, disassemble the mechanism and replace worn or damaged elements.
5. In case of problems with shifting gears, you must first adjust the clutch. If this does not help, you need to inspect the gearbox and check the shafts - the splines may have worn out. Worn parts must be replaced.

Principle of operation

The centrifugal clutch offers undeniable advantages such as reliability and long service life. This design is used in automatic transmissions. This device consists of a standard set of components:

• flywheel;
• pulley;
• a hub equipped with a stopper groove and a key;
• flange;
• sleeve;
• casing;
• bearing;
• retaining ring.

Due to the connection of the differential with the centrifugal clutch, the control of the unit is facilitated, its maneuverability and smoothness of turns are improved. In addition, the differential regulates the speed of rotation of the wheels and participates in their blocking. In some models of walk-behind tractors, special blockers are used, which allow stopping one wheel autonomously from the other.

Modern units can be equipped with mechanisms of various designs. There are several types of these mechanisms:

• frictional - easy to maintain and capable of working for a long time without pauses with high efficiency;
• centrifugal - has the disadvantage of rapid wear of parts of industrial mechanisms;
• belt - does not differ in high reliability and performance, quickly breaks down on powerful power plants;
• hydraulic - by pressing the pedal, it sets in motion the piston, the rotation of which gives the movement of the lubricating fluid; from the piston, the force is transmitted to the connecting rod, and the springs return it to its original position;
• disk - is distinguished by high reliability of parts and smooth start-up; there are single-disk and multi-disk mechanisms that work on the same principle.