Micro-tractor walk-behind tractor Malysh is the cheapest of the micro-tractors, since it is made mainly of scrap - assemblies and Parts produced by the industry for serial machines.
A two-wheeled car, driven by a person following it. A large set of interchangeable trailed and mounted implements makes the walk-behind tractor universal, allows you to use it for plowing, harrowing, cultivation, hilling and other operations for soil cultivation, plant care. And in a hitch with a single-axle bogie - and how vehicle for the transportation of various household goods. In the latter case, you become the driver and sit on the suspension seat in front of the cart.
The main units of the walk-behind tractor are the VP-150M engine, transmission, power take-off system, chassis, control system and hitch, arranged on a rectangular frame made of a channel.
Of the motors produced by the industry for equipment in personal use, the VP-150M engine from the "Electron" scooter with a capacity of 7.5 liters turned out to be the most suitable for the walk-behind tractor. with. (5.5 kW). It is single-cylinder, two-stroke, carburetor; has a compact built-in gearbox and clutch; him electronic ignition... Equally important is the fact that the motor is equipped with a centrifugal fan, while when using other motors, amateur designers have to handicraftly solve the issues of forced cooling.
Rice. 1. Motoblock "Kid":
1 - frame, 2 - muffler, 3 - engine, 4 - fuel tank, 5 - trapezoid lock, 6 - traverse, 7 - control trapezoid lock, 8 - tool bag, 9 - trapezium bar, 10 - clutch lever, II - wheel lock lever, 12 - gas lever, 13 - gear shift lever, 14 - differential reverse lever, 15 - transmission cover, 16 - power take-off shaft, 17 - winding pulley, 18 - final drive shaft, 19 - attachment (cultivator).
For the case of using other motors, let us give for comparison the basic data on the VP-150M engine. The transmission of torque to the gearbox is carried out by a helical pair of gears with a gear ratio of 3.045. The gearbox itself is three-speed, with constant mesh gears. Gear ratios in steps: in the first gear -4,883, in the second -2,888, in the third -1,800. Since the engine and gearbox are made in one monoblock, their description is not given. There are no special requirements for operation and maintenance engine complete with clutch and gearbox; they are regulated by the manufacturer's recommendations.
The transmission of the walk-behind tractor is mechanical, gear-chain. It consists of a serial differential with a reverse (from a cargo scooter "Ant"), an intermediate shaft, two final drives and a wheel locking mechanism. The intermediate shaft also serves as a power take-off for the attached implements. Torque is transmitted from the engine to the intermediate shaft by a chain with a pitch of 12.75; from it to the differential - with a chain with a pitch of 15.875 mm and then again with chains of final drives with a pitch of 15.875 mm - and the drive wheels. The Z1 sprocket belongs to the engine, the Z4 comes with a differential, and the Z2 and Z3 come from the Voskhod motorcycle.
Rice. 2. Transmission layout:
1 - Engine output shaft, 2 - intermediate shaft, 3 - differential, 4 - wheel axle shaft.
The intermediate shaft is made of 40 steel and is installed in two ball bearings No. 180205. Flanged housings for them can be used with standard ones from decommissioned agricultural machines; attachment to the side cheeks of the transmission cover. The diameters of the shaft seats are selected according to the dimensions of the sprocket hubs, and the length - depending on the width of the transmission casing, plus some margin so that a two-groove drive pulley with a diameter of 100-120 mm can be installed on it on the right side.
Rice. 3. Kinematic diagram of the walk-behind tractor:
I - engine, 2 - intermediate shaft, 3 - double-grooved power take-off pulley, 4 - differential, 5 - final gear, B - wheel, 7 - wheel locking mechanism.
The frame of the walk-behind tractor can be welded from suitable profiles available at hand; for its longitudinal side members, channel No. 6 was used, and for transverse ones - No. 8. From the bottom, the bearing housings of the axle shafts are bolted to the horizontal frame side members and to the brackets. Bearings No. 180207 are put here, two on the semiaxis; it is better to choose standard housings for them, from decommissioned agricultural machines. Their installation on the brackets should be done especially carefully: you should as accurately as possible maintain the alignment of the wheels and the perpendicularity of the axle shafts relative to the longitudinal axis of the frame.To mark the holes for fastening the housings with bearings, we put them on a solid axle-mandrel, which will subsequently be sawn into two axle shafts. An indicator of the correct installation of the housings will be the free rotation of the mandrel in the bearings of the axle shafts.
Rice. 4. Walk-behind tractor frame assembly:
1 - side members, 2 - semi-axle brackets, 3 - semi-axle bearing housing, 4 - transmission casing (in the top view, its right half is not shown), 5 - brackets for attaching the journal of the output shaft of the engine, in - front engine support, 7 - brackets for attaching the journal kickstarter.
Rice. 5. Intermediate shaft of the walk-behind tractor:
1 - shaft, 2 - pulley seat, 3 - circlip, 4 - bearing housing, 5 - JA 180205 bearing, 6 - spacer sleeve, 7 - Za sprocket, 8 - flange, 9 - Z2 sprocket, 10 - casing.
Rice. 6. Possible positions of the control beam
Then corners of 25X 25 mm are welded to the frame in its rear part, to which the transmission cover is screwed, made of steel sheet 5-6 mm thick. It serves as the basis for installing the intermediate shaft, differential and control mechanism. The rear side of the casing has a removable cover; front - a bracket for attaching a fuel tank.
Rice. 7. Half-axles with a wheel blocking clutch of the "Kid" walk-behind tractor:
1 - guide bushings, 2 - return spring, 3 - slide, 4 - fork, 5 - cable, c - half shaft, 7 - fixed half-coupling, 8 - movable iolum coupling.
In the front part of the frame, corners are welded from the inside - a bracket for a motor with a forced cooling fan.
The axle (or semi-axle) is made of high quality steel, its dimensions can be specified depending on the available bearings and the size of the wheel hubs. From the inside, two half-couplings are mounted on the semi-axle. The right one moves freely on the square and, with the help of a lever installed in the control head, is brought into engagement with the left coupling half, providing a rigid connection of the axle shafts - blocking the wheels.
Rice. 8. Final drive of the walk-behind tractor:
1 - transmission casing; 2 - final drive casing; 3 - bearing housing, 4 - drive shaft with a Zb sprocket, 5 - bearing М 180205, 6 - channel bar JI6,7 - bearing housing, 8 - bearing М 180207, 0 - wheel hub, 10 - key, 11 - semi-axle, 12 - the bolt that fixes the hub, 13 - bearing cover, 14 - sprocket / t, 15 - angle 25X 25 mm, 16 - differential, 17 - spacer sleeve.
The structure of the controls is clear from the figures. The handle bars are connected to the crosshead with a clamping hinge, which allows you to adjust the height of the handle, adjusting it to the height of the operator. In addition, the traverse itself can be rotated 180 ° or the required intermediate angle, which creates additional convenience when controlling the walk-behind tractor during operation.
The design was developed and tested in practice by students of the Kharkov Institute of Mechanization and Electrification of Agriculture.
In agrotechnical science, cultivation is loosening and leveling the surface layer of the soil without turning it over. And if in large fields this procedure is carried out by tractors with special devices attached to them - cultivators, then in summer cottages and household plots this procedure had to be carried out mainly by hand until relatively recently - three decades ago.
Mini cultivators - a new meaning of the old word
The situation began to change in the early 90s of the last century, when the first walk-behind tractors and motor-cultivators began to appear in the gardens and summer cottages. Then there were still few of them, and their quality left much to be desired. But today, not a single self-respecting owner can no longer imagine his work on the ground without a mechanical motorized assistant.
The next step in facilitating heavy work on the ground was the appearance of mini motor-cultivators. They got their name because of their small size and light weight. In the classification of motor-cultivators adopted today, all mini-cultivators belong to the class of ultra-light models. Such mechanized assistants - small, nimble - are able not only to loosen the soil in the garden, but also to perform this work in the garden space covered with branches or in a small enclosed greenhouse space.
Device and rules for choosing a mini-cultivator
A small cultivator has only one working function - to loosen the soil to a certain depth. But, unlike a walk-behind tractor and a heavy motor-cultivator, this "baby" is devoid of a running gear. In other words, a small cultivator does not have wheels, but moves along the ground due to the translational rotation of its working body - the cutter.
Mini-cultivators are of two types:
- Electrical;
- Gasoline.
Regardless of the type, such mechanisms weigh no more than 15 kg. The working grip in one pass is from 20 to 30 cm. The maximum soil loosening depth is 8 cm. The motor power for gasoline models is 1.5-2.5 hp, for electric analogs - up to 2000 watts.
When choosing a mini-cultivator, you need to consider a number of factors. First of all, this is the area of the land plot. Babies are babies because they are designed to work in small areas of 3-5 acres. To work on large areas, you need to purchase more powerful and heavy mechanisms.
Second important point, which can tip the scales in the direction of one or another option - the location of the land. If the area where the mechanism is to work is near the source electrical energy then it is better to choose the electric model. But its capabilities are severely limited by the length of the electric cable or the charge of the batteries. Therefore, if the land plot is located at a considerable distance from housing or other buildings to which electricity is supplied, then it is better to opt for a gasoline mini-cultivator, as it is more mobile and independent of external sources.
Popular brands
Today, many well-known trade brands are provided on the domestic mini-equipment market. The most popular brands of mini-cultivators that are purchased for a summer residence or a small garden are:
- Productions of the French brands Pubert and Cayman;
- Italian production - Benassi, Bertolini;
- German trade marks - MTD, Wolf, Garden;
- Danish Texas;
- American - Kraftsman, Partner, Champion, Parton;
- Japanese Honda;
- South Korean Hyundai;
- Russian-made - Mole, Favorite, Leader, Master, Neva.
A quick glance at this list is enough to make sure there is plenty to choose from. And armed with such a little helper, you will save yourself from heavy monotonous work, saving your strength and health for more important and enjoyable things.
From the family of microtractors developed by students of the Kharkov Institute of Mechanization and Electrification of Agriculture, the simplest and most affordable for self-made- Walk-behind tractor "Malysh" (KhIMESH-2): it makes the most of the units and parts of the equipment produced by the industry. It is a small two-wheeled vehicle driven by an operator following it. A large set of interchangeable trailed and mounted implements makes the walk-behind tractor universal, allows it to be used for plowing, harrowing, cultivation, hilling and other operations for soil cultivation, plant care, and when coupled with a uniaxial trolley, it can also be used as a vehicle for transporting various household goods. In the latter case, the operator becomes the driver and sits on a suspension seat in front of the bogie. Due to the listed properties, the walk-behind tractor can be used not only in personal farming, but also can serve for the mechanization of labor-intensive processes in crop production, especially in vegetable growing and experimental plots of selection stations, as well as in animal husbandry and greenhouse farming.
The main units of the "Malysh" design are the VP-150M engine, transmission, power take-off system, chassis, control system and hitch, arranged on a rectangular frame made of a channel.
Of the motors produced by the industry for equipment in personal use, the VP-150M engine from the "Electron" scooter with a capacity of 7.5 hp turned out to be the most suitable for the walk-behind tractor. (5.5 kW). It is single-cylinder, two-stroke, carburetor; has a compact built-in gearbox and clutch; it has electronic ignition. Equally important is the fact that the motor is equipped with a centrifugal fan, while when using other motors, amateur designers have to handicraftly solve the issues of forced cooling.
In case of using other motors, we will give for comparison the basic data on the VP-150M engine. The transmission of torque to the gearbox is carried out by a helical pair of gears with a gear ratio of 3.045. The gearbox itself is three-speed, with constant mesh gears. Gear ratios: first gear - 4.883, second - 2.888, third - 1.800. Since the engine and gearbox are made in one monoblock, their description is not given. There are also no special requirements for the operation and maintenance of the engine complete with the clutch and gearbox: they are regulated by the manufacturer's recommendations.
1 - frame; 2 - muffler; 3 - engine; 4 - fuel tank; 5 - traverse clamp; 6 - traverse; 7 - control trapezoid lock; 8 - tool bag; 9 - trapezium transverse bar; 10 - clutch lever; 11 - wheel locking lever; 12 - throttle lever; 13 - gear shift lever; 14 - differential reverse lever; 15 - transmission casing; 16 - power take-off shaft; 17 - winding pulley; 18 - final drive shaft; 19 - mounted implement (cultivator)
1 - motor output shaft; 2 - intermediate shaft; 3 - differential; 4 - a semi-axle of a wheel
1 - engine; 2 - intermediate shaft; 3 - double-ribbed power take-off pulley; 4 - differential; 5 - final transfer; 6 - wheel; 7 - wheel locking mechanism
1 - spars; 2 - semiaxis brackets; 3 - semi-axle bearing housing; 4 - transmission casing (its right half is not shown in the top view); 5 - brackets for fastening the journal of the output shaft of the engine; 6 - front engine support; 7 - brackets for fastening the neck of the kickstarter
The transmission of the walk-behind tractor is mechanical, gear-chain. It consists of a serial differential with a reverse (from a cargo scooter "Ant"), an intermediate shaft, two final drives and a wheel locking mechanism. The intermediate shaft also serves as a power take-off for the attached implements.
Torque is transmitted from the engine to the intermediate shaft by a chain with a pitch of 12.75 mm; from it to the differential - with a chain with a pitch of 15.875 mm and then again with chains of final drives with a pitch of 15.875 mm - onto the drive wheels. The Z1 sprocket is from the engine, the Z4 is included in the differential kit, and the Z2 and Z3 are borrowed from the Voskhod motorcycle.
The intermediate shaft is made of 40 steel and is installed in two ball bearings No. 180205. The flanged housings for them can be used from decommissioned agricultural machines; fastening - to the side cheeks of the transmission casing. The diameters of the shaft seats are selected according to the dimensions of the sprocket hubs, and the length - depending on the width of the transmission casing, plus a certain margin so that a two-groove drive pulley with a diameter of 100 - 120 mm can be installed on it on the right side.
The frame of the walk-behind tractor is welded from suitable profiles at hand; in "Malysh" channel # 6 is used for its longitudinal spars, and # 8 for transverse spars. Semi-axle bearing housings are bolted to the bottom of the horizontal frame spars and to the brackets. Bearings No. 180207 are put here - two on the semi-axle; hulls for them are also better to pick up from decommissioned agricultural machines. Their installation on the brackets should be done especially carefully: the alignment of the wheels and the perpendicularity of the axle shafts relative to the longitudinal axis of the frame should be maintained as accurately as possible. To mark the holes for fastening housings with bearings, we put them on a solid axle-mandrel, which should subsequently be cut into two axle shafts. The indicator of the correct installation of the housings is the free rotation of the mandrel in the bearings of the axle shafts.
1 - shaft; 2 - the place of the pulley landing; 3 - retaining ring; 4 - bearing housing; 5 - bearing No. 180205; 6 - spacer sleeve; 7 - asterisk Z3; 8 - flange; 9 - asterisk Z2; 10 - casing
1 - guide bushings; 2 - returnable spring; 3 - slider; 4 - plug; 5 - cable; 6 - half-shafts; 7 - fixed half-coupling; 8 - movable half-coupling
Then corners of 25 × 25 mm are welded to the frame in its rear part, to which the transmission cover is screwed, made of steel sheet 5-6 mm thick.
It serves as the basis for installing the intermediate shaft, differential and control mechanism. The back of the casing has a removable cover; front - a bracket for fastening a fuel tank.
In the front part of the frame, corners are welded from the inside - an engine bracket with a forced cooling fan.
1 - transmission casing; 2 - final drive casing; 3 - bearing housing; 4 - drive shaft with an asterisk 25; 5 - bearing No. 180205; 6 - channel No. 6; 7 - bearing housing; 8 - bearing No. 180207; 9 - wheel hub; 10 - key; 11 - semiaxis; 12 - bolt fixing the hub; 13 - bearing cover; 14 - asterisk 7.6; 15 - corner 25 × 25 mm; 16 - differential; 17 - spacer sleeve
The axle (or semiaxis) is made of high quality steel, its dimensions can be specified depending on the bearings available and the size of the wheel hubs. From the inside, two half-couplings are mounted on the semi-axle. The right one moves freely on a square and, with the help of a lever installed on the control bar, is brought into engagement with the left coupling half, providing a rigid connection of the axle shafts - locking the wheels.
History is replete with examples when a new direction brings success to an enterprise that previously made a name for itself in a completely different field. Legendary Nokia, which engaged in electronics and mobile communications in the 80s of the twentieth century, until then a hundred years ascetic in the pulp and paper industry, the production of cables, auto and bicycle tires, as well as a number of other activities.
Related materials:
Excavator hydraulic shears, what types are there and what they are for. Attachments for hydraulic excavator necessary for the demolition of buildings and ...
The concept of "measurement" has become a kind of foundation for such a definition as analog-to-digital conversion. To compare certain values with reference values, ...
Attachments are special devices, when changing them, you can significantly expand the capabilities of special equipment. If your company has a limited fleet of vehicles, ...
