How does the clutch work in a gasoline trimmer. Lawnmower repair: an overview of faults and effective solutions.
How does the clutch work in a gasoline trimmer
What are the functions of a car clutch?? First of all, this node is necessary for smoothly moving the car from a place, as we said at the beginning of the article. If the motor and gearbox are rigidly connected, the car jerks forwards violently after engaging a gear because all the power from the motor is immediately transmitted to the gearbox. Improper use of the clutch causes mechanical damage to components and also leads to frequent stopping of the engine when moving off.
Thanks to the work of the clutch, namely the sliding of the drive and slave discs, the torque increases gradually. The motive force is not increased immediately, so that the car moves very smoothly and gently.
The clutch box is also necessary for easy shifting of gears when the vehicle is in motion. When the car goes with a certain speed, which steadily increases or decreases, there is a need to switch to a higher or lower gear, which is facilitated by the timely separation of the shafts of the node between the transmission and the engine. Otherwise, higher forces would be required to shift gear, causing rapid wear on the gearbox and its other mechanisms in the future. In particular, forcing the speed increases the load on the gear teeth. Thus, the clutch also performs the function of reducing the load on the surface of the parts of the gearbox, which facilitates the transition from one gear to another. In this case, the gearbox (photo of this mechanism is presented below) suffers minimal loads from the engine. And this greatly increases the life of the gearbox parts, the price of which is sometimes too high.
In addition, the clutch is designed to reduce the level of stress on the gearbox during emergency braking of the car. When the car reduces speed sharply, the torque on its wheels is significantly reduced. But since the transmission is connected to the motor at this time, it has inertia of rotation and maintains the same speed. This can cause considerable damage to its parts. The overload protection itself is ensured by slipping on the idler and drive discs. In this case, the torque is stabilized as much as possible.
How the clutch works in a gasoline-powered trimmer
The driver gives commands for the clutch and flywheel drive and disengages by pressing the appropriate pedal, which is located under the left foot. The principle of the clutch pedal is that it moves the disc away from the flywheel through a system of mechanical actuators. When it is released, the disc is again in contact with the flywheel, transmitting torque to the transmission.
A complex mechanical assembly, the gearbox, is attached to the transmission’s primary shaft. It also can not work without a clutch, because to do shifts without its temporary disconnection from the engine is very difficult, and for beginners this task in general is unsolvable.
Torque is transmitted to the gears on the primary shaft which stop when the clutch pedal is depressed. It does not matter when the transmission is in neutral, because even if the primary shaft is moving, it is not engaged with the secondary shaft.
To transfer torque to the secondary shaft, the driver depresses the clutch so the primary shaft stops. Then he lever turns on the desired gear, connecting the pinion shafts, after releasing the pedal torque is transmitted from the primary to the secondary shaft.
When driving a car, you need to know some points that will allow you to avoid common mistakes:
- The design and operation of the clutch when the pedal is depressed causes torque to stop being transmitted to the drive wheels and the car, after driving for a while on inertia will stop, and the engine will run and never stall.
- If the transmission is in neutral, the vehicle will not move and the engine will not stall either.
The clutch pedal has three conditional positions in which the main phases of the system occur:
- upper position when the pedal is not depressed;
- middle or operating position. On different cars, this position may be higher or lower from the floor, so you need to find it when changing to a new car;
- lower position with the pedal fully depressed.
It is in the middle position that the disc comes into contact with the flywheel, to avoid unnecessary wear of the parts, it is necessary to connect them very smoothly. The main mistake for beginners who know that the clutch needs to be released gradually: after reaching the engagement of the disc and flywheel they sharply drop the pedal, the machine jerks several times and stalls.
To properly move off, you need to depress the clutch pedal, put it in first gear, quickly release the pedal to the middle position, and there the pedal is held for about three seconds. After the machine has traveled about one meter, the pedal is completely released.
When switching upshift clutch must be released quickly, and the higher the gear, the faster the pedal is released. All these skills are obtained gradually as a result of repeated training.
Advantages and disadvantages of homemade mini-tractors
The mini-tractor, made by hand, is much cheaper than the factory models, and in terms of functionality can sometimes give up more powerful tractors. This self-made machine can be used in vegetable and orchard gardens, for cultivation of sown areas (not exceeding 10 hectares), for transportation of small-sized cargo and for harvesting work.
The cash cost of such machines is paid back literally in one season, because the main components and mechanisms are usually taken off of scrap equipment or purchased at bargain prices. Some farmers convert other equipment into a mini-tractor. In this case, the process of making machinery is greatly simplified.
The disadvantages are the difficulty in selecting the right parts. In addition, in case of failure of some nodes, there may be problems with replacement or repair. After all, no matter how you look at it, but the tractor is going to get out of old stuff, so some parts are impossible to find.
To make drawings, you need to have technical skills and knowledge. After all, the mini-tractor must work with attached and trailed equipment, for this it is necessary to calculate the pulling power of the engine.
There is also the so-called wet type of coupling. How does it differ from the first option? It contains the hydraulic transformer oil between the two discs. Also, the “wet” unit does not have as hard of a grip between the driven disc and the driven disc.
Compared with its counterparts, it has a number of advantages. Among them, it is necessary to note the good protection of the vehicle from overheating, as well as high reliability of the mechanisms. However, the “wet” element also has its own disadvantages. Its main disadvantage is the high cost, so most budget cars do not use such a system.
Possible malfunctions of the grass trimmer gearbox, lawnmower gearbox, brushcutter gearbox
Cordless grass trimmers
Less common type of garden tool. This is a trimmer for grass, which operates from an electric motor, but from a battery. It allows you to cut the grass evenly quietly, but does not depend on the duration of wear.
Because of time constraints, these models are purchased for maintenance of vacation homes where there is no electricity, or for landscaping in kindergartens and similar facilities.
- Keep it quiet
- Setting up different cutting systems;
- There are no area limitations;
- Light models;
- Power reserve lasts for 30-45 minutes;
- Fast charging;
- Powerful models available.
What a clutch consists of
In order not to break the clutch, you need to know not only how it works superficially and what its functions are, but also what parts it consists of. The main components are the clutch master and slave parts, the release mechanism and the clutch system.
The engine torque is transmitted from the flywheel to the drive end, which in turn transmits the torque to the drive shaft. The friction torque is provided by the pressure mechanism, which, thanks to the tight coupling of the driven and driven parts, gives the long-awaited result of movement.
Clutch disengagement is not unimportant. So one disk, on which springs are located peripherally, is located in the cast-iron crankcase, which, in turn, is located in the motor block crankcase.
The driving part includes the clutch housing and flywheel, the latter in turn is mounted to the crankshaft flywheel by six special bolts. The pressure plate is located in the middle section of the housing. The drive torque of the pressure plate is transmitted from the flywheel through three gaps in the plate that fit through the shell windows. The drive disc, hub, and drive shaft are the main and obligatory components of the clutch slave part.
The friction plates on either side of the friction disc are made from copper asbestos (or another asbestos metal composition) that can withstand extremely high temperatures and are known for their frictional properties. The drive disc is connected to the hub by rivets or by springs. These springs form part of the anti-rotation damper (i.e. dampener)
The clutch mechanism is a device in which there is a transfer of torque through the work of frictional forces. The clutch mechanism allows for brief disengagement of the engine and gearbox and then smooth connection. The components are enclosed in the clutch housing, which is secured to the engine housing.
- crankcase and shroud,
- of the drive disc (which is the engine flywheel),
- pressure plate with springs,
- pressure plate with wear plates.
The driven disc is permanently pressed against the flywheel by the pressure plate under the influence of the strong springs. the great frictional forces between the flywheel, slave and pressure plates cause this to rotate together when the engine is running. But only when the driver does not move the clutch pedal, regardless of whether the vehicle is moving or standing still.
to start moving the machine, it is necessary to press the slave disc connected to the driving wheels against the rotating flywheel, i.e to engage the clutch. And this is a difficult task, because the angular velocity of the flywheel is 20. 25 revolutions per second, and the speed of the drive wheels is zero.
John Deere Lawn Tractor Fuel Pump Oil Leak Diagnosis & Repair Solution
The first step in the clutch engagement procedure is to release the pedal, i.e.е. let the pressure plate springs move the friction disc up to the flywheel until they just touch each other. At the expense of frictional forces, the disk, slipping for a while relative to the flywheel, will also start to rotate, and the car will slowly creep.
In the second step, hold the oil-pressure plate firmly to prevent movement of the oil-pressure plate.е. hold the clutch pedal in the middle position for two to three seconds to allow the rotation speed of the flywheel and disc to equalize. The car will then increase its speed.
At the third stage. flywheel together with pressure and slave discs already rotate together without slippage and with identical speed, giving 100% transmitting torque to a gearbox and further to driving wheels of the car. This corresponds to the state of the clutch mechanism. it is on, the car is moving. Now all that’s left to do is completely release the clutch pedal and take your foot off the.
If the clutch pedal is suddenly released when beginning to move, the vehicle “jumps” forward and the engine stalls.
To disengage the clutch, the driver presses the pedal and the pressure plate moves away from the flywheel and releases the friction plate, interrupting the transmission of torque from the engine to the transmission. If the brake pedal is depressed quickly, but not suddenly, press the clutch pedal all the way to the end of its travel.
master the operation of the clutch pedal in three steps
The clutch is not properly engaged
All vehicle components and systems periodically need to be diagnosed and inspected. Clutch is not an exception, whose components often break down because of intensive use, aggressive driving style and improper adjustment of the mechanism.
To inspect the clutch, inspect it for damage or wear, and replace the parts at the proper time. At the same time, there are a number of visible signs that indicate problems with shifting in the vehicle.
Therefore, every car owner should have an idea of how to determine clutch failure, What you should pay special attention to and when to seek help from the service center.
Basic symptoms of a fault
The symptoms of traction failures on each vehicle differ in detail and depend on which mechanism is installed on that vehicle.
Therefore, the unit may differ in the type of working medium (“dry” / “wet”), the type of drive (hydraulic / mechanical / electric / combined), the operating principle (single disc / multi-disc).
And common to all types are the following symptoms of clutch failure:
- The pedal falls to the floor with little or no resistance.
- Clutch compression creates a “soft ride”.
- Traces of working fluid leakage are visible on the saw cover of the master cylinder or near the clutch pedal.
- Traces of fluid are visible on the slave cylinder.
- The clutch does not disengage (incomplete disengagement).
- Sliding clutch (partial engagement).
- When depressing the pedal, there is vibration (violent reaction of the device).
- Static noise when shifting gears while driving.
- When the pedal is depressed and released, it does not return to its original position.
- Much effort is required to depress the pedal.
It should be noted that each type of malfunction has characteristic causes, as well as visible signs by which they can be identified.
How to determine if the system is malfunctioning while driving?
Any car owner should contact a service center to diagnose the clutch if:
- When you engage the transmission, the car begins to move very slowly or does not move at all;
- When driving “uphill” the traction is very weak or absent;
- The car picks up speed unevenly (jerking);
- Starting from a place, the car begins to move with a noticeable bump;
- There is no change in speed when the pedal is depressed;
- I can hear some noises during shifting. knocking, rattling, squeaking.
If they appear the first signs of clutch failure, the car owner better not hesitate to visit a car service. Timely diagnosis and troubleshooting will avoid further costly repairs.
Main clutch failures
If the clutch “drives” (t.Е. Does not switch off completely), this indicates a defect in the transmission or pressure plate of the basket. A similar sign can also occur due to friction damage of the gasket, misalignment of one or both discs, inaccurate adjustment of the exhaust bearing and clutch fork.
If there is engine speed, but the speed of the car does not increase, the reasons for this may be:
- Heavy wear of friction linings;
- Weakening of the diaphragm spring;
- Oil contamination of the friction gaskets due to its leakage through the crankshaft oil seal;
- Overheating of the mechanism drive disc.
If vibration occurs when the transmission shifts or the car begins to jerk, it indicates the following abnormalities:
- Flywheel or pressure plate is damaged or deformed;
- The pins on the driveshaft hub or the transmission input shaft are worn;
- Burned friction gaskets;
- The mount is not fixed or the engine bracket is worn out.
Avoiding Clutch Failure There are a few simple rules to follow when driving a vehicle. First, perform routine inspections in a timely manner, and check the condition of components and mechanisms before each trip.
Second, follow all of the vehicle’s operating procedures, ensuring proper maintenance. Third, when replacing clutch parts, install only original parts.
It would seem that why a chainsaw for an elderly resident who grows vegetables and fruits, or the owner of a country house who has a small garden and a few flower beds? The issue disappears when the desire arises to build a bathhouse, repair a greenhouse, tear down an old business, or simply make a bench to rest on. Unfortunately, any mechanism must be periodically prevented and parts replaced, and for this you need to understand the construction of the device, in addition, the repair of chainsaws with their own hands will save time and money.
Constructive elements of chainsaws
All chainsaws are similar in structure, whether they are made in Europe (Echo, STIHL, Husqvarna) or at home (Cedar, Urals) The main elements are located inside the body. the fuel tank and engine, and outside. the starter, handle, part of the saw (bar) with the chain. A sharp jerk of the cable starts the engine, and it is the blade of the saw.
To begin with, we suggest you read the video clips, which show how a chainsaw is designed and how it works:
Lawnmower Only Starts With Starting Fluid! Step By Step Repair!
From time to time malfunctions occur in saws that require disassembly. What can happen to something as simple as a chain saw? At least the following:
Most problems are related to engine failures (fuel system, exhaust system, ignition, part of the cylinder with a piston) or malfunctions of other systems and components (clutch, chain brake, tire, lubrication system). Let’s consider the most common faults and ways to fix them.
A working chainsaw starts with one jerk and doesn’t cut
Checking the ignition system
The first thing to do when the chainsaw breaks down is to check the spark plug by disconnecting the wire and carefully twisting it with a special wrench.
If everything is alright with the electrical system, let’s check the carburettor.
There are vacuum carburetors on grass trimmers. During its disassembly, cleaning or washing you need to be extremely careful. in no case disassemble the lower part of the carburetor, where the primer is. The air filter (it is visible if you remove the protective casing from the carburetor) should be washed with detergents. Best for washing dishes. After drying we put it back. Flush the carburetor with clean gasoline and blow out all the holes with a pump. We also wash the gas line filter, then dry and reassemble everything. Usually after all the manipulation, the grass trimmer starts to work.
Thin rope instead of a fishing line. is it worth using it on a brushcutter??
The idea has crossed the mind of just about everyone who has ever had to mow ten acres of overgrown grass. At first glance, it seems like a good idea. Cable is stronger than fishing line, it does not wear out as much. But it is not that simple.
Maintaining the cutting attachments on the lawnmower
Dull or worn out saw attachments over time. The work with the equipment becomes more strenuous, the load increases, and the quality of mowing is made worse. Iron saw blades are sharpened, plastic ones are replaced.
If the cutting attachment is a trimmer line, it wears out evenly and a new one is put in the spool. The mechanism of operation of the line trimmer consists in the gradual unwinding of the spool under the action of centrifugal force. When in contact with grass, the line for the trimmer is abraded, from the spool is fed evenly. A special winding is needed if you set the goal of two cutting elements coming out at once not to tangle with each other.
The illustration shows how to correctly wind the line for the trimmer on the lawnmower reel. Before winding the newest line for the trimmer you need:
- The spool is equipped with the spool guide and the spool cap is located on the spool;
- Remove pieces of the old line from the spool;
- Measure 5 meters of new string and fold it in half
- there are guides in the coil under 3.5 end, hook the middle part behind the notch and wind up in the direction of the arrows for each half of the string;
- the remaining 20 cm through the special notches on the opposite ends of the reel;
- install the spring and washers, lead the line ends outwards, close the reel with the lid.
For a better opportunity to learn how to change the line for the trimmer on the chain saw, see video.
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