STV-12 seeders - separate seed disc for each crop

Seeder STV-12

This seeder was created by engineers of the design bureau of the Belarusian enterprise Gomelselmash. The design bureau was founded back in 1947 specifically for the creation of new and modernization of outdated agricultural equipment. The end of the twentieth century turned out to be very fruitful for developers - it was then that the model of the STV-12 precision seeding seeder was released. Her original pneumatic sowing device turned out to be more successful than the mechanical one - it did not damage the seeds at all.

Purpose

A unit was developed for sowing beet seeds, which it does quite well. However, it can be used to sow the field with other crops. The main thing is that the grain size should not be less than two and a half millimeters. In particular, groundnuts, large peas and beans, corn, sunflower seeds, rapeseed, soybeans and even cabbage are suitable for this.

Distinctive features

In addition to the already mentioned pneumatic device for sowing, the following features of this seeder can be noted:

• For different crops, there are different replaceable sowing discs that come included.
• Following the coulter, a press wheel moves, which presses on the groove with the seeds, and then they germinate more easily.
• The finishing wheel, which completes the work, allows the soil above the buried grains to remain soft and loose, but on the sides, on the contrary, compacts it.

The seed is transferred into the coulter trough evenly and accurately. This is facilitated by special devices: a vacuum cutter and a mechanical type ejector comb.

Photo of the STV-12 seeder

Advantages of the model

The equipment was developed and assembled in Belarus at the Gomselmash enterprise. The oldest design bureau, founded in 1947, worked on the model.

The seeder is based on an outdated model, which has been improved. The uniqueness of the model is in its precise pneumatic device, which not only distributes seeds with an accuracy of mm, but also does not damage them. Germination after seeder is 35% higher than that of other similar models. The technique was developed for planting beets, but is suitable for other crops with seeds of at least 2 mm: peas, beans, sunflowers, corn, cabbage, rapeseed and soybeans.

Unlike mechanical ones, the seeder carefully distributes seeds in the soil, regardless of its type. The seeder has excellent performance when working on sandy and loamy soil, with high humidity. Subsequently, Moldova released a similar seeder Todak STVT twelve. The models do not have significant differences, so spare parts from one fit the other.

The main advantages of the STV 12 seeder include:

• The STV package includes several seed discs, which are used for planting material of various sizes.
• Directly behind the coulter, the rows are compacted using compaction wheels, so the germination rate of crops increases by 35–45%.
• Special wheels for closing complete the work. They are designed so that the top layer of soil remains light and a crust does not form on the surface, and the sides of the rows are compacted and leveled. This increases the directional permeability of moisture and oxygen into the soil.
• Due to the special device of the vacuum cutter in the grooves of the coulter, the seeds move smoothly inside the seeder and are not damaged.
• The ejector comb ensures precision sowing. The rows have an even shape, the seeds are buried evenly.

Device

On a welded frame made of a metal rectangular beam, there are sowing, transport and working mechanisms, a fan, and disc markers. A special lock is used for the automatic coupler. Two drive wheels with a transmission mechanism transmit movement to the drive shaft of the sowing mechanisms (there are six of them). From it, rotation is transmitted to the seed discs through a chain transmission. If the unit needs to be transported, the wheels are moved to special transport supports.

Depending on the type of seeds, different numbers of sowing sections are placed, thereby changing the distance between individual rows. So, if beet seeds are planted, then there should be twelve sections, and the distance between the rows should be 45 centimeters.

Corn seeds require eight devices for sowing, the row spacing is 70 centimeters. The main element of the section is the sowing apparatus. In addition, there is a seed hopper, a coulter, as well as support, press and closing wheels.

The sowing device contains a drum that rotates simultaneously with a replaceable sowing disc. Thanks to the fan rotating due to the tractor PTO, the air is rarefied, and the seeds are sucked into this disk in a certain order. To ensure that they stick one at a time and not two at a time, there are two ejectors, adjustable according to the caliber of the seeds. The breaker serves to cut off individual seeds, ensuring their precise planting. When working, beet coulters are used for all seeds; only for corn there is a special corn coulter.

Correspondence table between replacement discs and seed crops:

Pneumatic precision seeders STV

Description

Today, three models of precision seeders are produced: STV-6, STV-8K, STV-12.
Precision seeders are universal pneumatic seeders for dotted seeding of the following crops: corn, large beans, low bush beans, peas, groundnuts, sunflowers, soybeans, calibrated and pelleted beet seeds, rapeseed, onions, spinach, cabbage, fava beans and other seeds with minimal size 2.5 mm. A fundamentally important structural element of a precision seeder is the sowing center, consisting of a narrow sowing drum 1

, which rotates with the sowing disc
2
.
The fan creates a vacuum through the hollow axis 3
, which ensures the suction of seeds
4
to the sowing disc.
Two ejectors of different designs 5
,
7
correct possible double sticking.
The toothed ejector is set steplessly on a scale of 6
depending on the size of the seeds.
Through a sufficiently large viewing window, you can monitor the filling of the disk holes. The separated seeds are cut off at a precisely defined location by a breaker 8
located behind the disk. This cutting point is a prerequisite for high precision seed placement and increased sowing speed.

The precision seeder is a unified machine designed for sowing seeds of the following crops: corn, faba beans, large beans, peas, lupine, sunflower, soybeans, pelleted beet seeds and other seeds with a minimum size of 2.5 mm. Such possibilities are realized by replacing replaceable sowing discs, coulters, and adjustable seeder parameters (seed placement depth, row spacing, system pressure, etc.). The model range of precision seeding machines includes: - STV-8K (eight seeding units);
— STV-8KU (eight sowing units + fertilizer application); — STV-12 (twelve sowing units).
At the customer's request, intermediate discs can be manufactured for sowing other crops.
Important!
Since the seeder can sow seeds of various crops, the appropriate sowing disc is selected for each type of seed.

* The capacity of one fertilizer bunker for the STV-8KU seeder is indicated in brackets

Parameters of seeding discs for various crops

The ratio of the row spacing of the sowing elements and the tractor track

Specifications

Technical characteristics of the STV-12 seeder:

Design features

The basis of the seeder design is a rectangular frame made of hardened heavy-duty steel. The model can be seen in more detail in the photo.

The following mechanisms are located on the frame:

• sowing;
• transport;
• worker;
• disc markers.

The coupling of the mechanisms is a lock, which is designed specifically for this model of mower. The drive wheels, when working, transmit movement to the shaft of the seeding part of the seeder and six mechanisms with disks are launched. When transporting the seeder, the wheels are easily folded using a special moving support.

The number of sowing sections is set in an amount that depends on the size of the planting material. By changing the number of sections, the row spacing during planting also changes. For example, for planting beets, 12 sections are placed, the row spacing is 45 cm. Corn is sown using eight compartments, the row spacing is 70 cm. Each section consists of a sowing apparatus, which has a spare hopper, support and press wheels and a coulter.

The seed sowing apparatus consists of a rotating drum that operates simultaneously with the disk. Under the influence of the tractor's PTO, a vacuum is created in the drum and the seeds are sucked to the disk. To ensure that one seed at a time sticks to the disk, the design includes a double ejector that adjusts the material in size. And the mechanism—the cutter—makes sure that only one seed gets into the ground when planting. The seeder can process twelve rows at the same time.

The coulter installed in the seeder is suitable for all types of crops; it is only changed for corn grains. Adjustment for different soils is carried out directly on the field before work. The ratio of seed discs to various planting materials is presented in the table below:

The seeder is set up immediately before work. The required disk is selected and installed in the drum. If corn is supposed to be sowed, the opener is changed.

Not available: