The most important part of the walk-behind tractor is the drive. It is the main of all the elements presented in the walk-behind tractor. Therefore, when it becomes necessary to purchase a gearbox, all of it further work, and even the functionality of the walk-behind tractor depends on the quality.
The gearbox for a walk-behind tractor is a certain type of device capable of transmitting, appropriately converting torque, for which mechanical transmissions are conductors. Accordingly, agricultural machinery will work more productively.
How to make a gearbox for a walk-behind tractor with your own hands
Gearboxes of two types, which are called: worm gear, as well as chain, have several small, but quite important differences. They are contained in the characteristics that are inherent in two types, but gearboxes work with different ones: efficiency, angular speed, number of gears, as well as shafts, ratio between gears.
Gearboxes for motoblock what they are
When you have walk-behind tractors that are relatively cheap, they often have simplified assembly gearboxes that are not collapsible.
In this case, the service life is significantly reduced. Any additional features, among which: repair, and, accordingly, assembly, replacement of parts, or disassembly, to check the condition of the unit.
This means that the material from which the gearbox itself is made is of very poor quality. Most of the parts presented in the assembly will not be sleeved. The gearbox diagram will allow you to present not only the principle of its operation, but also determine the service life.
Expensive motoblocks have gearboxes with a more complex structure, the possibility of further assembly and disassembly. Maintenance can be carried out by correcting all malfunctions in the operation of the gearbox. Repairs must be carried out in order to extend the service life. It is important to replace faulty parts with other, more expensive items. Gearbox lubrication also prolongs its life.
In most cases, the gearbox serves as a converter for speeds. That is, the angular velocity, qualitatively and quickly switches to low. The input shaft will show a high angular velocity, the output will already be low.
Unforeseen breakdowns are prevented by constant and high-quality maintenance. With a stepwise variation in speed, the gearbox is called a conventional gearbox. In the case when it does not work on a stepped system, it is called a variator.
Homemade angular gearbox for walk-behind tractor
In principle, the gearbox does not have a too intricate structure; it is quite possible to assemble it yourself. First make the correct calculation in rated power (Pn); Pn=Re(hp)xFS. This will allow you to make a choice in favor of the correct angle, which must be determined at the bevel gear. According to this principle, not only the number of possible revolutions per minute will be calculated, but also the torque will be calculated.
A do-it-yourself gearbox needs to determine the conditions for its operation. Among them, there is a radial load, or axial load that the shafts have at their ends. Its operation will be optimal if the temperature and type of lubricant are correctly selected.
After completing all the above steps, you can proceed to the assembly. The case can be selected from the factory. The diameter of the housing will tell you what the housing of the bearings for the shaft will be like. A caliper and a good quality drill will help. Next, we take two bearings under the shaft itself.
It is important to install a steel flange on the front of the gearbox. Accordingly, inside: a bearing, necessarily a flanged one and a washer. The flange is attached to the generator itself with screws. The steel key, together with the drive gear and the driven gear shaft, must be selected in advance. All nodes connected to the gear mechanism are connected to the rotary generator. It has a pulley that provides a V-belt drive. It should be fixed to the driven shaft using a nut with a spring washer.
Angular gearbox for walk-behind tractor
In the automotive industry, angular gearboxes are often used. Efficient work is achieved by installing such a unit.
A similar kind of gearbox is needed to ensure that the transmission is docked with the engine itself. You can take a ready-made gearbox, simply modifying it.
The main elements of the design of the angular gearbox
There are several main elements in the gearbox, including: a flange, a housing from the generator itself, a pulley with a V-belt type of transmission, a steel washer, a pulley mount, a steel key, a rotor shaft, a flange mount, a flange bearing and others.
Motoblocks with a gear reducer and a reduction gear for a motoblock
Motoblocks with modern characteristics, are quite acceptable for installation of a reducer with step-down characteristics. After all, they are equipped with special cooling with the help of air.
Even heavy soil when plowing potatoes is not terrible for a machine with such an aggregate. You can provide quick wheel slip, and other additional features.
Motoblocks with gear reducer
The gear reducer is quite easy to figure out if you look at its transmission. It is the transmitter between the wheels and the engine. The direction in the walk-behind tractor changes.
The gearbox, together with the clutch, is called the transmission. In heavy walk-behind tractors, it is often used.
Motoblock and reverse gear for it
The coupling is located strictly between the bevel gears, freely located on the main shaft. This is how the reversing circuit in the gearbox is presented, which, if you look at it, is not too complicated.
It clings only to the splines in the gears. This is what allows her to change the direction of the gear, made in the form of a spiral. The cam, or the fork, is represented by the clutch itself.
Talking about the benefits of the gearbox, I think there is no special need. Everyone understands everything perfectly. 🙂 With it, you can change the number of revolutions of the motor shaft or change the amount of torque. The article describes in detail how and from what you can make a gearbox with your own hands. Articles How to make a pulley with your own hands and Educational Bez Belt drive will help you understand the material below in more detail.
Location: Simferopol
The subject of the E + M channel: Making mechanisms and electronic devices from improvised means, with minimal cost! The channel presents lessons in physics, mechanics and electronics, which will be needed for self-design and understanding of the principle of operation of home-made devices.
Materials:
- bicycle spoke
- hub motor
- wooden lath
- tin
- CD boxes
- linoleum
- sheet plastic
- rubber band for money
- Super glue
- hot glue
- screwdriver;
- telescopic antenna;
- square;
- compass;
- awl;
Gearbox drawings
How to make a gearbox for a walk-behind tractor with your own hands?
The design of modern motor-cultivators assumes the presence of only a few main parts, allowing the walk-behind tractor to be as easy to use as possible.
And if there are no questions about details such as cutters or a plow, then the gearbox for a motor cultivator is an interesting topic for discussion among users of motor cultivators.
Owners often ask questions about what kind of oil to fill in the walk-behind tractor gearbox or even how to make the gearbox yourself.
The attention that is paid to aspects in the use of the walk-behind tractor does not cease to subside even for a second.
What is a gearbox (regulator, converter)?
The gearbox is a mechanism that is used to convert torque and then transfer it to the shafts of the machine. The means of controlling this process are mechanical transmissions. In fact, the gearbox is that part of the walk-behind tractor, the quality of which depends on how long the walk-behind cultivator will serve you.
Types of converters for walk-behind tractor
As gardening equipment became widespread, there was a need to optimize different kinds mechanisms for different purposes. This trend could not but affect the regulator.
In the assembly of motoblocks of the budget segment, as a rule, non-separable gearboxes are installed.
Naturally, such units are cheap for the manufacturer, because the materials from which they are made are of low quality.
The service life of such devices tends to approximately one season, after which the regulator can be sent for scrap.
This is not surprising, because they are not collapsible, because they have a closed structure that cannot be repaired, and each breakdown leads to the replacement of the mechanism completely. In turn, collapsible converters are installed on medium and premium class cultivators.
Homemade gearbox for walk-behind tractor
Of course, the materials from which their mechanisms are made are much more resistant to various kinds of deformations, they are also able to withstand aggressive environments without reacting with them, as a result, they are not subject to corrosion.
But the main advantage of collapsible converters is their constant readiness for repair in the event of failure of one or more parts of the walk-behind tractor gearbox.
Needless to say, gear oil is used according to its type and quality.
In the bottom line, we distinguish the following types of converters:
- angular;
- lowering;
- gear;
- reverse
Motor-block reducer Neva MB-2
The angle converter is used in mechanical engineering, it can be found in some cars or even industrial equipment, for example, in factories. Its presence in the design of the walk-behind tractor makes possible use equipment under heavy load.
This converter is suitable for those types of cultivators where the transmission with the engine is joined with the expectation of a chain.
A buck converter is sometimes called a creeper (colloquial form). Its main purpose is to add power when, for example, while plowing potatoes, the wheels begin to slip. It is used in construction with motor-blocks of gasoline and diesel type, the engines of which are cooled by air currents.
Gear converters are used in the system of heavy walk-behind tractors or even cars. Since the transmission is made up of a box, differentials and the regulator itself, and its nodes are presented in the form of gears, belts, etc., the gear transmission uses this converter, based precisely on the features of its structure.
Motoblock reducer chains
The reverse got its name due to the reversal scheme, with the help of which converters of this type got their main trump card over other types, namely, the ability to use reverse gear in a walk-behind tractor. By the way, the reverse is not very productive and will not be able to provide your cultivator with high speeds.
Do-it-yourself gearbox for a walk-behind tractor
Enthusiast farmers are wondering: how to make a gear walk-behind tractor with your own hands? The question is relevant, since it is sometimes easier and cheaper to make such a miracle from the materials and parts available on the farm than to purchase a regulator assembled by the manufacturer at the factory.
Indeed, in the “invention” of the converter there are no super-complex manipulations, and a tool made on a walk-behind tractor with your own hands always serves correctly, however, first of all, you should acquire some tools:
- screwdrivers (straight and oblique type);
- hacksaw (for metal);
- pliers or pliers;
- vise;
- some other tools and consumables, the presence of which one way or another may be needed during the assembly process.
The assembly, or rather, the preparation of the converter begins with the cooking of the case. It can be made of metal plates. Sometimes they use a body from the Ural shaft with its subsequent refinement.
Do-it-yourself motoblock gearbox
For gears, you can turn to the Druzhba chainsaw (4).
At the same time, a tip is cut off in one of the shafts and a hole of the required diameter is drilled, while a second shaft is installed on the opposite side of the future gearbox, and with it - bearings, a cage. The output shaft must be fastened to the pulley.
Oil in the motoblock gearbox
Just like any mechanism, the filled-in lubricator individually fits the geared walk-behind tractor. Its quality directly affects the work of the cultivator. Depending on the conditions of use, oil should be chosen individually, but fortunately, universal brands like Motul save, when buying which the user will not make a mistake.
Prices
Of course, not all people are enthusiastic about building a converter at home. Therefore, for those for whom buying a gearbox will be more profitable than self-designing, there are online stores selling these mechanisms.
The average price for them is from 12 to 15 thousand rubles.
However, there are also much more expensive models. What matters is how pricing is built. And, above all, the price depends on the number of functions that the converter is equipped with. You can not ignore the quality of its assembly - it also greatly affects the cost. And also important is the power and the ability to use reverse gear.
These are the general characteristics of the gearbox, but there are many more. From which it follows that the gearbox on the walk-behind tractor - complex mechanism, in the choice of which you should not be mistaken.
Do-it-yourself step-down gearbox for a walk-behind tractor
One of the most important elements of the walk-behind tractor is the drive. If you need to purchase a gearbox for a walk-behind tractor, then you should know that the service life of the entire unit will depend on its reliability. The gearbox for a walk-behind tractor, (made by oneself), is designed to convert and transmit the torque that it receives from mechanical gears and makes agricultural machinery work.
How to make a gearbox for a walk-behind tractor with your own hands
There are several differences between the worm and chain gearboxes for a walk-behind tractor important features: gear ratio, efficiency, number of shafts and gears, angular speeds and power.
What are the gearboxes for a walk-behind tractor
Non-collapsible gearboxes are usually installed on cheap walk-behind tractors. The design of such a unit is not particularly reliable. It also has a short lifespan. In addition, it is impossible to carry out repairs or disassembly-assembly. In the manufacture of such units, low-quality metal and non-sleeved parts are used. To understand why it's impossible long time to use a reducer, you need to familiarize yourself with its diagram.
It is customary to install collapsible gearboxes on expensive walk-behind tractors. Thanks to this, it is possible to disassemble the walk-behind tractor gearbox and carry out maintenance. They repair the gearbox of the walk-behind tractor to increase its service life, if high-quality spare parts are used when replacing faulty elements.
It is imperative to regularly diagnose the gearbox in order to repair the necessary unit in time. Regular lubrication of the gearbox should also be carried out, which will allow the unit to be used much longer. Most often, a gearbox for a walk-behind tractor is used so that a high angular velocity is converted into a low one. The input shaft has a high speed and the output shaft has a low speed.
To avoid unexpected breakdowns, it is necessary to carry out regular maintenance, which will allow you to work successfully on an agricultural machine. If the change in angular velocity occurs in steps, the gearbox is called a gearbox, but if the change occurs steplessly, it is called a variator.
Homemade angular gearbox for walk-behind tractor
You can make a walk-behind tractor yourself. To do this, it will be necessary to calculate the rated power (Pn); Pn \u003d Pe (hp) xFS, as a result of which the correct type of angle is determined for the bevel gear. Torque and RPM are also calculated.
You also need to determine the operating conditions of a home-made gearbox for a walk-behind tractor, which includes: radial and axial load on the ends of the shafts, minimum and maximum temperatures, determination of environmental conditions, intermittent or non-intermittent operating cycle, type of lubricant.
After determining the technical parameters, you can start collecting angle gearbox. To do this, it is necessary for the angle gearbox to select a housing.
For example, you can use the factory one, from the Ural or Dnepr motorcycle. Then, based on the diameter of the gearbox housing, we make the gear shaft bearing housing from steel. Here we use the appropriate size drill and caliper. Then, in accordance with the intended dimensions, we select the gear shaft bearings (2 pcs).
We install a steel flange on the reverse side of the gearbox. It will have a steel washer and a flanged bearing inside. Using several screws, we fasten the steel flange to the generator housing. Before that, we select the driven gear shaft, steel key and drive gear. All nodes are connected to the transmission mechanism and the shaft of the rotary generator. The V-belt pulley is located on the transmission mechanism and is attached to the driven gear shaft with a nut and spring washer. To assemble a homemade angle gearbox, you will need the following tools: a caliper and a ruler, a straight and Phillips screwdriver, metal drills, files and metal files, wire cutters and pliers, rubber gaskets, a vice and a hammer.
Angle gearbox for walk-behind tractor
The angular gearbox is widely used in motorcycle technology: in the automotive industry, modified cultivators, industry.
How can I make a walk-behind tractor from a cultivator
When installing an angular reduction gear on walk-behind tractors, under heavy loads, they achieve more effective work.
This type of gearbox is usually used to connect the engine to a transmission designed for a chain. The angular gearbox for a walk-behind tractor is made from existing samples, similar ones are installed on Dnepr or Ural motorcycles. Then you will need to modify the gearbox.
The main elements of the angular gearbox
The components of the bevel gear are: generator housing, flange bearing, rotary shaft, steel washer, steel flange, bevel drive gear, bevel gear housing, steel key, gear shaft bearings (2 pcs), driven gear shaft, bearing steel housing pinion shaft, pulley mount, V-belt pulley, flange mount.
Motoblocks with a gear reducer and a reduction gear for a motoblock
A reduction gear for a walk-behind tractor, in common people a creeper, is installed on modern diesel and gasoline air-cooled walk-behind tractors. Thanks to this, the user can use the walk-behind tractor on especially heavy soils for plowing and digging potatoes. The reduction gear helps with wheel slip when there is not enough own power.
Motoblocks with gear reducer
To understand what a gear reducer is, consider the structure of the transmission. It transmits torque from the engine to the wheels, and changes the speed and direction of the walk-behind tractor. The transmission consists of a gearbox, differential, gearbox and clutch. Transmission units are gear, chain, belt, or a combination of one or the other. Gear transmission consists of bevel and cylindrical gears (gear reducer). It is used on some models of machines and heavy walk-behind tractors. The figure shows the gear transmission of the Ugra NMB-1 walk-behind tractor, which uses a gear reducer.
Reverse gear for walk-behind tractor
In the reverse gear, reversing is carried out according to the following scheme: between the opposite bevel gears, which sit freely on the drive shaft, there is a clutch.
She, being in extreme positions, clings to the splines on these gears. Therefore, when the clutch engages, the direction of rotation of the gear changes. The gears must be of the helical type. The clutch drive mechanism is a traditional fork or cam.
motoblok-cultivator.com
Do-it-yourself angle gearbox
The angular gearbox has found wide application in motorcycle technology, especially modified cultivators, in the automotive industry, in industry, for example, on valves, etc. The installed angular reduction gear on walk-behind tractors helps to achieve efficient operation under heavy loads.
This type of gearbox, as a rule, is used to dock an engine with a longitudinal crankshaft, with a transmission that is designed for a chain. Do-it-yourself angular gearbox can be made from existing samples, say, like on a Soviet Ural or Dnepr motorcycle. In this case, you will need to make a number of improvements that would suit your purposes for the further use of the gearbox.
There are also available samples of angular type gearboxes on sale, but they do not always fit the stated criteria of each buyer, then the gearbox greatly reduces speed, has a low gear ratio, or does not fit at all in dimensions for articulation with other mechanisms.
The second option is to independently make an angular gearbox (angular gear motor). In this case, let's figure out what basic elements the reducer consists of.
To work on the assembly of the angular gearbox, you will need:
Phillips and straight screwdriver;
Ruler and caliper;
A set of drills for metal;
Files and files for metal;
Pliers and wire cutters;
Rubber gaskets;
Hammer and vise;
And other tools, depending on the size and type of bevel gear selected.
Homemade angle gearbox with your own hands - a step-by-step assembly process
The definition of operating conditions includes a number of factors such as type of operating cycle (intermittent, continuous), radial and axial loads on shaft ends, maximum and minimum temperatures, ambient conditions (eg dust and dirt levels) and type of lubricant. After you have determined which technical specifications you need, proceed to the assembly of the angular gearbox.
Angular gearbox diagram
Angular gearbox diagram compulsory system air cooling
1 - housing (used from a generator from a Ural motorcycle);
2- rotary generator shaft without winding (used from the Ural motorcycle);
3 - flange bearing;
4 - flange (steel);
5 - washer (steel);
6-hull of the angular gearbox (2″ fitting water elbow);
7- bevel drive gear (used from the gearbox of the Druzhba-4 chainsaw);
8-key (steel);
9- driven gear shaft;
10-bearing shaft-gear (2 pcs.);
11-housing for two bearings of the pinion shaft (steel);
12-pulley for V-belt transmission of forced air cooling system;
13-pulley fastening (spring washer with nut);
14-mounting the flange to the body (screw 3 pcs.)
Let's start assembling
As an example, let's take detailed description manufacture of an angular gearbox for a homemade mini-tractor with a "hinged" frame. IN this case bevel gear is used for forced air cooling system.
The cylinders of the power unit are equipped with an air cooling system. At the first stage, cooling was carried out using a common fan, but it was not effective. After that, the cooling system was modernized - each cylinder was equipped with its own impeller.
In this case, a 2″-inch fitting-plumbing elbow is used as the bevel gear housing. You can also make a housing for the angular gearbox yourself by welding from metal plates or choose the appropriate size. Since the drive is connected through an angle gearbox (in our case, going to the fan), it can be made from a modified factory shaft of the Ural generator. The gears used in the angular gearbox can be taken from the corresponding unit in the Druzhba 4 chainsaw. They just need to be improved. In one gear-shaft, it is necessary to cut off the end switch, after that we drill and machine holes in it to the appropriate diameter of the rotor-generator shaft we need. Next, we put it on and weld it.
The second gear shaft, complete with a cage and bearings, is installed in the bevel gear housing from the opposite side. On the output shaft of our bevel gearbox, a pulley will be mounted that transmits rotation directly through the V-belt drive (as shown in the diagram above), on each pulley of two fans that are located above each cylinder of the engine. We weld the holders of the fan bearings to the hood ramp. The pulleys are taken from the washing machine, the fans in this case were used from heating radiator car UAZ-469.
Cottage and cottage
Choosing a cultivator for a summer residence
There are many tips and recommendations regarding the criteria for choosing a cultivator, related to its technical characteristics (power, engine type, ability to install additional equipment, weight, etc.) or the size of the land that needs to be processed. But, these are not the only criteria that should be considered when buying a cultivator in order not to face the unpleasant consequences of making the wrong choice. We are talking about the specifics of the soil to be cultivated, since its different types require a different approach to processing. In addition, the power and model of the cultivator required to work on it will largely depend on what type of soil prevails on your land plot.
So, the first type of soil is sandy. These are light and nutrient-poor soils that are easy to work with. Their advantage is that the processing does not require much effort. Thus, if you are cultivating a plot with a sandy type of soil, then you will not need to fork out for a very powerful cultivator, but it will be quite possible to get by with buying a medium or even light model. The last option would be appropriate if you have small plot, the area of which does not exceed ten acres.
If its size is larger, then you should pay attention to models with medium power.
The second type of soil is clay. It is very heavy, dense, poorly permeable to moisture, has low air permeability, as a result of which it requires frequent loosening or aeration. This type of soil is quite difficult to cultivate, and taking into account the fact that it needs it more often than other types of soil, it follows that its cultivation requires a cultivator with high power ratings. Thus, if on your land plot heavy clay or loamy soil types predominate, you cannot do without the help of a heavy or medium cultivator model with enough power to cope with the difficult and frequent work of cultivating it.
Special attention is required to work with virgin soil. If you are planning to study new plot, which has not been processed for a long time before, and use a gasoline cultivator for this, then consider the fact that the unit must have high engine power and have a lot of weight (from 60 kg). Such a technique can cope not only with virgin soil, but also with other types of difficult-to-cultivate soils (stony, clay).
Also watch the video - How to work on a cultivator with a rototiller.
All by myself and with my own hands
For several years now, I have been using homemade when hilling and weeding row spacings in a potato field. cultivator. Despite the fact that the grip weight (hence, the developed traction) is clearly less than that of a mini-tractor, he is satisfied with his motor assistant. Although sometimes you have to put extra effort pushing the machine forward when working on heavy soils. In general, it turned out to be a reliable and compact car.
And I consider the possibility of quickly transferring it to an even more compact state (during transportation and storage) an additional advantage. After all, the actual operating conditions of mini-tillage equipment we have are such that it is more often idle than it works. Winter is long, and garden plots, land plots are located far from garages and storerooms, where this equipment is usually stored.
The cultivator is assembled on a welded frame, where an engine with an air cooling system, a silencer, an air filter and a starter from the Druzhba chainsaw, a fuel tank, an intermediate shaft of a two-stage chain drive, a drive wheel, and a bracket for mounted implements are installed. There are no problems with storage and transportation, because cultivator folding. It is necessary first of all to unscrew the upper bolt M10 (see the layout of components and parts) and fold the control knobs along the top rack.
Then, unscrewing a couple of nuts and removing the corresponding bolt from the mounting bracket of the main rack with the frame, turn the bracket and, tilting the rack forward until it stops in the channel bar of the frame, proceed to the following two elementary operations: detaching the mounting bracket for attachments (unscrew three bolts from below) and removing the drive wheel. By loosening the tension, you can also remove the chain connecting the drive wheel to the intermediate shaft of the two-stage transmission, and then, slightly unscrewing the nuts securing the drive wheel axle, release it from the grooves.
Transfer of the cultivator to working condition - in the reverse order. Other design features include a chain tension adjustment system. In the first stage, the adjustment is made by moving the intermediate shaft assembly along the frame guide beam. First, loosen the two nuts of the coupling collar securing the intermediate shaft.
Do it yourself: the simplest models of an electric cultivator
Then move the shaft along with the clamping collar along the guide.
And having found the optimal position, firmly fix it. Only then tension the second stage of the chain drive using a special sprocket. The intermediate shaft ball bearings are axially fixed by spacers that are fitted between the respective sprocket hubs and the bearings. The z2=48 sprocket was taken from an "adult" bike (only the pedal levers were cut off). Together with the hub, it is fixed to the intermediate shaft with a wedge.
Asterisk z3=10 - from an old bike motor (after preliminary riveting, it is welded to a self-made hub and fixed on the axle with the same wedge). Chains - bicycle, but if possible, it is better to replace them with more durable ones. For example, from a moped or motorcycles "Minsk", "Voskhod" (the pitch of these chains is the same). Now about the drive wheel assembly. The sprocket z4 = 48 available here is also a bicycle one.
It is attached to the outer flange of the hub with six M6 bolts. And to the inner flange of the hub with M8 bolts, a drive wheel disk made of steel sheet 15 mm thick. The drive wheel has eleven welded lugs with a "helmet" profile. They are made of steel plates with a thickness of 3 ... 5 mm. The height of each is 38 mm, the angle at the top is 110°. The ends of the lugs are cut 18 mm into the wheel disc and welded to it.
Capron (fluoroplastic) bushings are inserted into the hub on both sides, acting as plain bearings. The fuel tank is taken from an old motor bike. It is very convenient, as it has a decent volume - 2.5 liters, a good fastening and a neck with a lid that ensures tightness during transportation. One filling of such a tank with fuel is enough to process three plots of land of 6 acres each. To control the clutch, a factory handle with a “squeezed” state lock is used, which is necessary for starting and warming up the engine. "Gas" is regulated by a shifter from the decompressor of an old motorcycle.
As a power plant cultivator and the D4 engine of a motor bike is used. It has been modified, equipped with start-up systems and forced air cooling. The essence of the refinement is that under the bolt that secures the drive gear on the crankshaft (with right side engine), a ratchet fan drive pulley for the starting system is installed. Everything is approximately the same as in the technical solutions, the description of which can be found in the "Model Designer" (No.
A pulley with a rubber belt transmits rotation to the impeller axial fan attached to the engine head. The gear ratio of such a drive is i=0.5. The diameter of the fan impeller is 110 mm, the number of blades is 6. A fan is installed on two bearings 200. A 2-mm steel plate with a centering (relative to the drive gear) belt is screwed to the clutch cover, and a coil with two mounting flanges is screwed to the plate.
One of them serves to mount the starter from the Druzhba chainsaw. In addition, the modified engine has a clutch lever replaced. It is made curly, because the intermediate shaft drive chain goes up from the engine, and not down, as on mopeds. For the same reason, the upper partition of the cover covering the drive sprocket was also sawn out. The exhaust pipe is shortened and rotated 180°. As a hiller, a manual cultivator (purchased in a store) with extended sidewalls was used.
According to the publications of the "Model Designer" a small plow was also made, but it has not yet been possible to test its performance. He cultivated the land with what he had already thoroughly got used to. And he tried to help his hard worker - cultivator y move forward with the greatest depth of the hiller.
However, the latter is not necessary: you can walk twice over the treated area, but already spending minimal effort. After all, a modified and well-groomed engine develops quite a lot of torque. And if something happens - the wheel will simply slip without overloading the power unit. And one more piece of advice. During operation cultivator and flush the air filter every five hours of operation - you will not lose.
Kinematic scheme cultivator A.
The layout of the cultivator (protective covers are removed): 1,2 - control handles, 3 - Ml0 bolt with a nut (installed in the working condition of the cultivator, 10 pairs), 4 - main stand, 5 - attachment mounting bar (2 pcs.), 6 - main rack mounting bracket, 7 - frame, 8 - second stage chain tensioner, 9 - intermediate shaft assembly, 10 - fuel tank, 11 - fan, 12 - muffler, 13 - air filter, 14 - D4 engine, 15 - drive unit wheels, 16 - mounting bracket for mounted implements, 17 - working body (cultivator or small plow).
Intermediate shaft assembly: 1 - a hub with a pressed-in sprocket from a bicycle, 2-mounting wedge (2 pcs.), 3 - intermediate shaft (steel 45), 4 - body (steel 20), 5 - clamp to the frame (spring steel) , 6 - ball bearing 80203 (2 pcs.), 7 - spacer sleeve (steel pipe, L12, 2 pcs.), 8 - hub (steel 45), 9 - sprocket from D6 engine, 10 - frame beam.
Frame: 1 - rear cross member, 2 - bushing (StZ, 2 pcs.), 3 - rear stand, 4 - frame guide beam (channel 33 × 23.5 × 3 bent steel), 5 - gas tank support, 6 - middle stand , 7 - front strut, 8 - front cross member, 9 - spars, 10 - brackets for the drive wheel axle (StZ); det. 1, 3, 5, 6, 7, 8 and 9 - steel pipe 26.8 × 2.5.
Rack main: 1 - spar (steel pipe 21.3 × 2.5 1.690, 2 pcs.). 2 — bracket for side handles (St3.sheet.s3, 4 pcs). 3 - M10 nut, 4 - central bracket (St3 sheet s3), 5 - cross member (steel pipe 21.3 × 2.5, L200).
Drive wheel assembly: 1 - drive wheel axle (steel 45), 2 - M12 nut (2 pcs.), 3 - Grover's washer (2 pcs.), 4 - left frame side member bracket, 5 - bushing (nylon or fluoroplastic, 2 pcs.), 6 - double hub (steel 45), 7 - M8 bolt (6 pcs.), 8 - drive wheel disk (StZ), 9 - grouser (St5, 11 pcs.), 10 - M6 bolt (6 pcs. .), 11 - an asterisk from a bicycle, 12 - a frame side member, right.
Left control handle: 1 - handle (from a motorcycle). 2 - clutch lever with a latch (for the right handle - throttle control lever), 3 - rod (steel pipe), 4 - tip (StZ).
Bracket for mounting the main rack (StZ, strip 22×3).
The axis of the chain tensioner (steel 45).
Attachment bracket for mounted implements: 1 - cross member (corner 40 × 40), 2, 3 - traction left and right (corner 40 × 40), 4 - plate (St3, sheet, s5).
Details of the chain tension mechanism: a - lever (StZ, strip 22×4, 2 pcs.), b - latch (StZ, strip 20×1.5, 2 pcs.).
A cultivator is an essential piece of equipment for any farmer. It allows you to cultivate the soil without turning large layers of earth, without disturbing its fertile layer.
But he has one important disadvantage- its cost. Therefore, quite often in the vastness of our country you can find a hand-made or electric cultivator made by yourself.
What materials are needed
Making a do-it-yourself cultivator for a tractor, mini-tractor or walk-behind tractor is an extremely simple matter, the only thing that matters is the desire and necessary tool. For assembly you will need:
- compact grinder;
- discs for metal;
- welding machine and electrodes to it;
- emery with two discs that have different abrasive values;
- drill and a set of various drills for it.
The materials from which the cultivator will be made are also needed:
- metal square plates, the size of which depends on the specific model of the walk-behind tractor (most often 15 × 15 cm plates are enough);
- flat rectangular plates, which will act as cutters. Their length and width also depend on the specific model of the walk-behind tractor. The optimal size is 25 in length and 4 cm in width;
- bolts and nuts in the amount of 16 pieces (in pairs);
- long tube from solid steel.
When selecting materials, it is important to consider the following factor: they must not only be very durable, but also resistant to corrosion.
This is important because during cultivation, moisture will be present on the working surfaces, which is a strong oxidizing agent.
After everything you need is prepared, you can start assembling. Using a drill for metal, a hole should be made in each square and rectangular plate.
After that, you need to combine them in such a way that there is one cutter on each side of the square. They are fastened to the bases with bolts of a suitable size.
In the absence of such fasteners, welding can be used. But in this case, the connection will not be very strong, so a do-it-yourself disc cultivator will only be able to process loose black soil.
A mounted cultivator, which is necessary for processing difficult soils, must be as durable as possible, since when working on rocky or clay soil the working part (milling cutters and their base) bears the maximum load.
It is cut in half and a platform with cutters is “put on” on each part. It can be fastened with both bolts and contact welding.
Upon completion of the above operation, it is necessary to attach both parts of the homemade cultivator to the walk-behind tractor shaft. This is best done with a drill for metal and bolts of the appropriate diameter.
The tube with cutters and the shaft of the walk-behind tractor are drilled through.
After the assembly is completed, you should check the reliability of all connections, and then you can safely proceed to testing the cultivator.
What you need to make a chainsaw cultivator with your own hands
This type of technology is quite expensive. With a lack of funds, a way out of the situation may be homemade unit, made from the engine of a conventional Druzhba chainsaw.
To make such a simple device with your own hands, you only need time, patience and some details:
- engine from the Druzhba chainsaw;
- muffler;
- starter;
- fuel tank (can be used from an old motor bike);
- chain with a Z4 pitch (suitable from a regular bike, but best option- from a light motorcycle "Minsk" or "Voskhod");
- shaft, which acts as an intermediate;
- wheel for support on the ground;
- metal corners from which the supporting frame will be assembled;
- wheels, the diameter of which will depend on the design of the frame and other features of a home-made cultivator.
You will also need a tool with which the metal will be processed:
- angle grinder;
- welding;
- a set of open-end wrenches;
- pliers.
First of all, the frame is assembled.
It can be connected with bolts or contact welding.
Of course, a bolted connection is much more reliable, but it can not always be used. Also, if necessary, instead of the corners for the construction of the frame, you can use a tube made of thick steel.
The frame itself is a complex shape. It looks like a trapezoid with both sides tilted in the same direction. Between two identical forms, the crossbars that hold them together are welded.
A unit from the Druzhba chainsaw is already being installed on them. At the bottom of the frame is a shaft, on which there are two wheels for a future do-it-yourself cultivator, and an asterisk. On it, through a chain drive, the engine transmits torque.
The working part is a shaft on which cutters are located, fixed with square sheets of metal. The rotation is transmitted to the shaft using the same bicycle sprockets (Z4).
Attention!
It is only important to remember that the angle between the plane of the shaft and the sprocket must be exactly 90 degrees in order to avoid frequent chain jumps.
How to make a cultivator from a trimmer with your own hands
If necessary, you can easily construct a mini-cultivator with your own hands from an ordinary garden petrol trimmer. To carry out this simple operation, you will need:
- working trimmer;
- tool for metal processing (grinder, welding and hand tools);
- ordinary garden pitchfork;
- a steel tube, the diameter of which will allow it to be connected to the trimmer shaft.
As a working part, you can use specially curved rods from ordinary garden pitchforks. Their optimal length is approximately 10-15 cm. It is to this depth that the soil is most often loosened.
First of all, you should make the working part. It will be a flattened fork tines, their width should be approximately 1 cm.
With the help of emery, on which a disk with a small abrasive number is installed, the resulting cutters are sharpened. After that, it is necessary to make a round penny, the diameter of which will be approximately 10 cm.
He must be perfect shape to place cutters at an equal distance from each other, the optimal number of which is 3 pieces.
You can use more, but in this case, the load on the device will be extremely high.
The optimum engine power for use as a cultivator unit is 2 horsepower or more. These trimmers are produced by Husqvarna, their cost is 9,550 rubles.
The DDE GB 32 RD model is somewhat cheaper.
Assembling a homemade cultivator
Its power is 1.4 liters. With. It is also suitable for use as a cultivator unit.
One of the most milestones work - connecting the base with cutters to the trimmer.
This operation is greatly simplified if the end of the shaft has a reverse thread, to which the tooling is simply screwed. This model is the trimmer DDE GB 32 RD.
In such a case, a nut of the desired diameter is welded onto the steel tube. Also there are trimmers, inside the shaft of which there is a thread.
How to make a cultivator from a drill with your own hands
If in the garden it is required to perform work with a cultivator, but this must be done with great accuracy, you can make the tool in question from a conventional drill. This will require quite a bit:
- working drill;
- a steel rod that can compress the cartridge of an existing drill;
- cutters.
It is also necessary to have a tool for processing metal surfaces:
- Bulgarian;
- emery;
- welding.
Preliminary drawing up of drawings for a do-it-yourself cultivator is not required.
A steel rod, the optimal diameter of which is 10 mm, will act as a shaft that transmits rotation from the drill motor through the chuck to the cutters.
Any sheet metal can act as cutters, if its thickness and hardness allow working with problematic soils.
You can also use ordinary metal corners, which have a width of 10 mm and a length of 100-150 mm. Of these, with the help of a grinder, ordinary flat rectangles are made.
After that, you can safely insert the resulting structure into the drill chuck and carry out work on processing the garden, personal plot.
One of the main parts of the motoblock engine is the gearbox. If you understand its device and master the elementary skills of a locksmith, then this block can be built independently.
What it is?
First you need to understand what a reducer is. It is a mechanism that ensures the movement of a cultivator. The gearbox for a walk-behind tractor converts torque into driving force. Sometimes the device is called a transducer. The operational life of motoblocks depends on it, therefore it is very important to pay attention to the quality of parts when choosing.
The dimensions of the gearbox depend on the dimensions of mechanized motor vehicles.
Equipment
The converter can be collapsible and non-collapsible. As a rule, the last option is equipped with budget modifications of walk-behind tractors. Their difference is in less expensive parts that cannot be replaced. In the event of a breakdown, the entire gearbox will have to be replaced. Manufacturers determine the service life of such models from one to two seasons, no more, provided correct use apparatus.
More expensive equipment is equipped with a collapsible gearbox, which can be repaired by replacing failed components. Therefore, the service life is increased significantly.
The following items are included with the converter.
- Frame. Depending on the type of gearbox, it may or may not be collapsible.
- Rotor shaft which provides torque.
- Gears different sizes.
- Chain or belt depending on the type of gearbox.
- With chain transmission, movement is carried out using sprockets - toothed discs.
- With a belt drive, the mechanism is equipped pulleys on which the belt is put on.
- Bearings. Since all parts rotate, it is necessary to reduce friction and ensure that the elements rotate freely. The bearing is designed to cope with this task.
All parts are inside the case. In addition to the standard set of components, elements for bearing lubrication, for example, an oil pump or a cooling apparatus, can be added inside the device.
Kinds
Depending on the type of transmission used in the gearbox, the converters are divided into several types. Miscellaneous devices used in machinery different areas activities.
Chain
The name is due to the design of the gearbox, which is based on a chain as a transmitting element. In one device, it may not be alone. The movement is provided by asterisks, small - leading, large - driven. The principle is similar to the operation of the system on a bicycle. Performance and reliability are highly dependent on the quality of the materials used to manufacture the main moving parts.
Among the negative points, the need for regular maintenance should be highlighted: chain tightening, lubrication. Unlike a belt drive, a chain drive does not allow slippage and lasts longer.
with reverse
The reversing mechanism provides equipment with the possibility of reverse. In this case, the reverse rotation clutch is installed between the bevel gears, which are placed on the main shaft.
Unfortunately, the reverse gear is not designed to reproduce high speed.
belt
The simplest gearbox available on the market is of the belt type. As a rule, budget models of gearboxes use just such a device. The belt serves as a transmission element that is attached to the pulleys. Under heavy loads, the belt slips or breaks.
Slippage can be eliminated by installing toothed pulleys and a similar belt.
Belt converters reduce the aggressive effect on the power plant, reducing jerks. In addition, their device is simple, and repair is easy.
Among the minuses, unfortunately, there are more factors.
- At high temperatures the belt is stretched. This is what reduces grip.
- Rapid wear (wearing out).
- Rupture of the belt drive due to kinks or twists.
- As the rpm increases, the belt begins to slip.
- The pulleys must be in the same plane.
gear
Gear reducers are most often used in engines of heavy equipment. The transmission in this case consists of a gearbox, differentials and a regulator, gears and belts. The design of the device is simple.
Gear transmission contains bevel or cylindrical gears. Due to the fact that several of them can be placed on one shaft at once, the dimensions of the converter are reduced.
Inside the gear box, the gears work in pairs, so the ratio of the number of teeth on the driving and driven parts should be observed. Since freedom of rotational elements is necessary, the gear reducer requires regular lubrication and the presence of oil.
Among the advantages, one can also single out the noiselessness of the engine on the specified type of gearbox.
Worm
The worm gear converter is characterized by a long service life and a high degree of reliability. The design is considered not very complex, requiring qualified maintenance. The worm mechanism is already angular. In addition, it has a reverse, which makes it possible for the equipment to move not only forward, but also backward.
The gearbox got its name by the presence in its composition of a special worm gear, which moves along a screw having a trapezoidal four or two-start thread. By varying the number of teeth, you can change the rotational speed. All components are made of anti-friction steel, which is characterized by increased strength.
The converter consists of only two main components. In addition, it is quiet and smooth running.
Users appreciate it for its efficiency, long operating period. Worm gear has a unique ability, characteristic only for him, not to transfer rotation from the execution device to the engine.
Angular
One of the most efficient and reliable gearboxes. Therefore, it is used to equip industrial machines and equipment operating under heavy loads. This type of converter is also actively used in the automotive industry.
The angle gearbox provides a connection between the engine and the transmission, which is designed for a chain drive. It should be noted that the magnitude of the load will depend on the quality of the lubricants and the temperature regime.
step down
The task of a reduction gear is to reduce the number of revolutions, while increasing power. This is achieved by using a gear system. As a rule, modern converters of this type are equipped with an air cooling system.
Engines based on them are reliable, multifunctional and withstand significant loads. Therefore, they are installed on walk-behind tractors used to work on heavy soils.
How to choose?
You can make a converter for a walk-behind tractor with your own hands, but if you do not have the necessary experience, then it is better to purchase it in specialized outlets. Today, a huge range of high-quality modifications is presented on the market, the cost of which varies depending on various technical and quality characteristics.
The following factors may affect the price.
- The quality of the materials from which the components are made.
- The number of functions performed by the converter.
- manufacturer status.
- Reversing mechanism (its presence or absence).
- Reproducible power. When choosing, you should not chase for more power, but focus on the technical characteristics of the vehicle. Since the capabilities of the gearbox and the motor must match.
- Type of construction (collapsible or non-collapsible).
- Design features. For example, the type of transmission or the type of clutch.
- Life time. As practice shows, a well-chosen converter can last from 7 to 15 years, depending on the type of transmission.
For small vehicles, a centrifugal clutch is often used in the transmission. Its mission is to ensure that when the engine is started and warmed up, the movement does not start. This is convenient, since in winter regions it is impossible to move off or start work without preparation. Engines without centrifugal clutch are cheaper, so it should be guided by personal preference.
When buying a converter, do not forget about the dimensions of the motor. It would be a shame to spend money on something that will not be included in the case later. When choosing a gearbox, you must also take care of the oil that is poured into it. It plays an important role, being the key to the efficient and uninterrupted operation of the mechanism.
There are several factors to consider when choosing.
- Climatic conditions. If the vehicle will be operated in the northern regions, then give preference to those vehicles that do not freeze at sub-zero temperatures. In the southern regions, you should not spend money on buying such options.
- Loads. In the presence of heavy or virgin soil, the walk-behind tractor will work at increased loads, which means that the friction between the parts will increase, the torque will increase. To increase the service life of spare parts, you should select a lubricant that takes these features into account.
Be sure to pay attention to the seals when choosing a gearbox. If they are of poor quality, the oil will begin to leak. Gradually, its level will decrease. If this is not noticed in time, then the remains may boil from heating, the parts will jam.
When choosing a gearbox from a particular manufacturer, remember that when repairing, it is necessary to replace the failed components with similar ones. Therefore, you should choose a supplier that has its own representative offices in your area.
How to do?
Enthusiasts-masters assure that a simple gearbox for a walk-behind tractor can be straightened with your own hands in a home workshop. To do this, you need to have a certain set of tools and more or less skills in working with them.
You will need:
- ruler and caliper;
- a set of different screwdrivers;
- hacksaw;
- pliers and wire cutters;
- vise;
- hammer;
- welding machine if necessary;
- spare parts and Consumables(seal, rubber gasket, bolts, gears, chain or belt, bearing, shafts).
A lot has been said about the benefits of a walk-behind tractor in the subsidiary farm. If funds allow, they buy it. If you want to save money, make your own.
At first glance, this is a complex technical device that can only be made in the factory. In fact, a home-made walk-behind tractor with a gearbox from Ant is quite common in the yards of homegrown farmers.
If you understand the design, and have an elementary set of a locksmith in the house:
- welding machine;
- Bulgarian;
- drilling tool.
then you can build a self-propelled iron horse literally from pasture materials. To do this, you need to understand how the design works.
Motoblock device. Basic structural elements
However, most the best option there will be a homemade gearbox. It does not need to be paired with the power plant, since the calculation is made for specific tasks, and you are not limited to ready-made technical solution.
How to make a gearbox for a walk-behind tractor with your own hands
First you need to decide on the parameters of the power plant. IN specifications ax indicates the number of revolutions of the crankshaft. This is the first value that is needed for calculations. This figure is not constant, with the addition of "gas" the speed increases. Idle speed + 10% is taken as the base value.
For example, your engine idle speed + 10% is 600 rpm. The required wheel axle revolutions for a speed of 3 km/h are 200 rpm. Accordingly, your gearbox for a walk-behind tractor must have a gear ratio of 3: 1.
The speed of rotation of the axis is reduced by 3 times, in relation to the speed of the motor shaft. Accordingly, the torque is tripled.
Determine the type of gearbox:
Important! Whatever design you choose, you must remember the following rules:
Any gearbox, except for a belt one, needs constant lubrication. Therefore, it must be placed in a box. The tightness of the case will protect against the ingress of dirt and dust, inevitable during field work. Shafts must be fitted with seals. An example to follow are factory gearboxes from Soviet-made agricultural machinery.
The chain drive is not as sensitive to lubrication, but the chain must be regularly maintained - cleaned and lubricated.
Manufacturing or selection of finished structures
With access to a wide range of components: a junkyard of old equipment or ownerless property of a repair shop, it is possible to manufacture a gearbox with an accurate selection of the gear ratio.
However, such a complex structural element requires serious metal processing equipment. You can choose a housing of a suitable size, drill holes for the shafts on the bearings, and assemble the design no worse than the factory one.
However, experience shows that the selection of finished structures with minor modifications is much more effective. As an example, consider a home-made walk-behind tractor based on a motor from an IZH motorcycle.
Used its own gearbox, with the ability to switch gears. The stock gear ratio is not enough, although the small sprocket on the output shaft of the gearbox, complete with a large star from the drive wheel, already provides a good reduction in speed.
On the shaft, installed in the bearing podium, there is another small sprocket, which, with the help of a second chain, transmits torque to the wheels. In turn, a large-diameter star is installed on the drive axle.
The result is a design with a two-stage reduction in speed and solid torque. Using the gearbox from the motorcycle, you can choose the desired speed, with little or no use of the throttle. The engine almost always runs at idle, which prolongs its life.
No less popular is the use of a ready-made gearbox from the Ant scooter.
It is not necessary to use the entire wheeled platform, it is enough to install your rollers on the bridge. By applying a gearbox from the selected power plant, you will get the optimal ratio of power and speed.
Video: finalization of the Neva walk-behind tractor gearbox.
Making a gearbox for a walk-behind tractor with your own hands is a difficult and at the same time interesting task. This is one of the important mechanisms, without which the work of garden equipment using a walk-behind tractor is unthinkable. Its main task is to reduce the speed of the drive shaft and at the same time increase or decrease the torque on the drive.
You can buy a transmission mechanism for your walk-behind tractor in a specialized store, but it is more reasonable to assemble the gearbox with your own hands, taking into account all the technical characteristics of the engine. This would be the best option, since when designing a mechanism for a specific power plant, an individual calculation is made, which will simplify the task of pairing it with the engine.
When starting to manufacture a gearbox, it is necessary to clarify which type of mechanism is preferable for your walk-behind tractor. It depends not only on the power of the engine, but also on its layout, as well as on the level of complexity of the tasks.
Gearbox types
The design of any converting device for a walk-behind tractor (reducer) consists of a set of motion-transmitting shafts or gears of different diameters, enclosed in a durable housing.
Converting devices are divided into several types according to the type of transmission:
- chain;
- belt;
- gear;
- worm (gear-worm);
- combined systems.
For chain-type gearboxes, rotation is transmitted using a chain and sprockets of different sizes, which are mounted on rotational shafts. The principle of operation of the belt mechanism is similar to the chain mechanism, but instead of sprockets and chain, pulleys and a belt are used.
Inside the housing of the gear reducer, shafts are placed with gears mounted on them, having straight or oblique teeth. Gears transmit rotation from the engine to moving parts. Bevel gears are used in corner mechanisms for heavy motoblocks.
Mechanism types
According to the method of operation and action, all converting mechanisms for walk-behind tractors are divided into several types:
- angular;
- lowering;
- reversible with reverse speed (reverse gear);
To redirect rotational energy from the vertical drive to horizontal plane an angle gearbox using bevel gears (bevel gear) is used.
Reducing the number of revolutions and increasing the power of the drive mechanism is provided by reduction gear reducers, or. They are considered the most reliable for the operation of a diesel or gasoline walk-behind tractor with air cooling. This allows them to be used for particularly heavy work, such as plowing heavy soil or harvesting potatoes with a potato digger.
Buy a hitch and trailed to a walk-behind tractor in online stores
How to make a homemade gearbox for a walk-behind tractor
For self-assembly of a converting device on a walk-behind tractor, you must stock up on the following tools:
- caliper and metal ruler;
- Screwdriver Set different sizes, including oblique;
- pliers and wire cutters;
- saw for metal;
- electric drill with a set of drills for metal;
- vise;
- hammers - large and small;
- rubber pads.
If you decide to independently assemble the gearbox for your walk-behind tractor, be sure to make an approximate calculation. This will help determine, at a minimum, the gear ratio and type of conversion device you need.
Also using preliminary calculations you will be able to estimate the dimensions of the future transmission device.
To make the correct calculation, decide on the parameters of your engine. For calculations, it is necessary to clarify several data:
- The number of revolutions of the engine crankshaft. However, this value is not constant: it is worth "adding gas", and it will increase significantly. Therefore, the calculations are based on the base - the number of idle revolutions plus 10%.
- Estimated number of revolutions for the suspension axle. It is calculated taking into account the diameter of the wheels to determine the coast for one complete revolution. Based on this, it is possible to calculate at what speed the axle should rotate in order to ensure the most comfortable speed of the walk-behind tractor. This is an average of 3 to 5 km / h.
Let's consider a simple example: the engine power at idle, considering the increase by 10%, is 600 rpm, and for a speed of 3 km/h, a rotation speed of 200 rpm is required. Therefore, the calculated reduction gear ratio is 3:1. In other words, to reduce the speed of rotation of the axle by a factor of three, in order to ensure a speed of movement of 3 km per hour, the torque is increased by a factor of three.
Step-by-step instructions for assembling a chain reducer
If you have certain skills, you can make a gearbox of any type with your own hands, but the easiest way is to assemble small-sized mechanism with chain drive. Materials for it are easier to find, they are reliable in operation.
To make a homemade chain mechanism, stock up on the following spare parts and materials:
- asterisks with necessary quantity teeth;
- driven shaft;
- cylindrical and eccentric bearings;
- protective cover;
- fasteners for connecting parts of the casing;
- chains with the required number of links.
When assembling a gearbox of any design, bearings must not be replaced with bushings. Distortions between the leading and driven parts are unacceptable.
An old gearbox housing of a suitable size can be used as a protective cover by drilling holes in it for fastening.
- The manufacture of a home-made gearbox for a walk-behind tractor begins with fixing a drive sprocket on the output shaft of the engine. To fix it, you can use a key or flange. Depending on the design of the output shaft, even spot welding can be applied.
- The driven shaft should be machined on the machine. The asterisk is fixed on it in the same way as on the drive shaft.
- More reliable way- make a shaft from two semi-axes, at the ends of which flanges are machined. The driven sprocket is fixed between them, fastening the entire structure with bolts. In this embodiment, the second stage sprocket will be fixed more accurately and securely.
- To protect the gear mechanism from dirt and mechanical damage, it is placed in a protective case, which also serves as a reservoir containing liquid lubricant for moving parts.
- Sockets are drilled in the protective housing (crankcase) for the installation of thrust bearings. The driven shaft is mounted on cylindrical bearings, and the drive shaft is mounted on eccentrics. Changing, by virtue of their design features, the position in the seat within a radius of 15 °, the eccentric bearing also changes the position of the drive shaft, thus adjusting the chain tension.
It is necessary that the teeth of the sprocket mounted on the driven shaft be immersed in lubricating oil. When the shaft rotates, uniform lubrication of all components of the chain gearbox occurs.
- To ensure the tightness of the crankcase, oil seals and sealing gaskets are installed along the parting line and at the bearing seats. If standard gaskets do not fit, then a special low-resistant sealant can be used.
If the calculation of the gear ratio is done correctly, then the gearbox, carefully assembled taking into account all the design features of your walk-behind tractor, will ensure the smooth operation of the mechanisms no worse than its industrial counterparts.
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