Grain cleaning machines: device, technical characteristics, adjustment. Repair of grain cleaning machines

Post-harvest processing includes cleaning, sorting, drying, storage. It also includes loading and transport works. In the grain part of the crop there are, besides the grain of the main crop itself, seeds of weeds, chaff, individual ears, scraps of straw and the like. Such impurities negatively affect the quality of the product, complicate its storage. Grain cleaning machines are used to eliminate these problems. Let us consider what they are.

Necessity of the equipment

Grain acts as the main agricultural product. From it are produced: flour, pasta and bread products, cereals. In addition, grain is an important element in the development of poultry and livestock. It is used in feed mixtures. Its quality influences the increase in the production of oil, milk, meat and other food products. Cereals serve as raw materials for the production of alcohol, starch, molasses and so on. In agriculture, much attention is paid to increasing the volume of such crops. At the same time, measures are constantly being taken to improve the quality of the product. To effectively solve the tasks, it is necessary to improve agricultural technology, the introduction of high-yielding varieties, the structure of sown areas. Equally important is the condition of the equipment. At present, improved grain cleaning machines are being introduced everywhere. Comments of agricultural workers indicate a high efficiency of functioning of modern technology, ample opportunities for use.

Classification

In agricultural activities, stationary and mobile grain cleaning machines are used. The latter are used in open areas, in vaults, under canopies. Stationary grain cleaning machines are designed for operation on complexes and aggregates. Depending on the purpose, the equipment can be general and special. The common is used in the initial treatment. To it carry air-trellised, air, приводные and other installations. Special grain cleaning machines are used for separation of seeds from impurities left after processing on aggregates of general purpose. These include sorting pneumatic tables, electromagnetic installations and so on. The technical characteristics of grain cleaning machines must meet the established requirements. In particular, the units are calculated for high productivity. During processing, the content of impurities is no more than 0.5-1%. The purity of seeds for sowing should be 98-99%.

Mobile OVS-25

These grain cleaning machines are used in open currents to treat a heap after harvesting by a combine. OVS-25 refers to air-lattice type installations. The device for grain cleaning machines is as follows:

• Loading conveyor.
• Receiving chamber with an air part.
• Two latticework camps.
• Shipping conveyor.
• Mechanisms of drive and self-movement.
• Automatic boot device.

Technological process

A self-propelled grain cleaner follows along the shoulder. In the process of moving the scraper conveyor collects the heap and transfers it to the distribution auger of the receiving chamber. At the output from it, the product is divided into two identical parts. They pass through air channels. Here, light impurities are separated from the grain and carried away by a pneumotransporter. Heavier elements settle in the settling chamber. Both parts of the cleaned grain are sent through different channels to the lower and upper sieve banks. Seed processing is carried out in the same way. The grain freed from light elements falls on the sieve. On it it is divided approximately in half. Fine grain and impurities pass through the holes. The remaining part and large elements fall on another sieve, then on the next, and after - on the bottom. Through the holes in the upper elements pass the seeds of weeds, small admixtures, frail and crushed grain. The main raw material, passed through the upper sieve, is sent to a sloping board. On it, it slides into the receiver, where the grain accumulates from the lower elements. From here, the raw materials are sent to the shipping conveyor, from where - into the car body. Separated from the grain waste, impurities from the sedimentation tank go to the auger forage waste.

Features of elements

In the feed conveyor there is an inclined scraper mechanism and two feeders. The latter are articulated with hinges with a lower head. Feeders are raised and lowered by means of a winch. On the frame there are boxes, in which there are two pairs of bevel gears. With their help the feeders are given traffic. The upper drive head of the conveyor is operated by an electric motor. It transmits motion through a V-belt transmission.

Receiving chamber

It is made in the form of a space between vertical channels. The upper part includes a feeder. It contains:

1. Receiving tray.
2. Feeder valve.
3. Distribution screw.
4. Flow divider.

By means of the feeding device, the heap is spread out along the width of the unit and its separation into equal parts.

Air system

It contains:

1. Two vertical channels.
2. Sedimentation chamber.
3. Air duct.
4. Inertial dust separator.
5. Fan.
6. Pneumatic conveyor.

Channels are connected to the fan. Light impurities, together with air, enter the dust separator and pneumatic conveyor. Heavy elements settle in the corresponding chamber. The lower part of it is equipped with a complex of easily movable valves. Under the influence of the gravity of the accumulating impurities they open. In the side wall of the air casing there is a window with a retractable flap. It moves by means of a rack and a gear wheel. The strength of the air flow is regulated by the size of the opening of the damper. The dust separator has a louver type. The pneumatic conveyor is made of sheet steel in the form of an air duct with a circular cross-section.

Lattice mills

Each of them includes:

1. The brush mechanism.
2. Frame.
3. Siege.
4. Vibrational shaft.

The sieves are installed in two rows. The upper one is equipped with dividing and grain constructions, the lower one is under-sowing and sorting. The grinding mills are attached to the frame by means of wooden springing vertical suspensions. The elements receive movement from the eccentric from the main shaft. Brushes are supplied from below to the sieves. They are driven back and forth by means of connecting rods. In the work of great importance is the regulation of grain cleaning machines. When installing brushes, their bristles should protrude 1-2 mm above the sieves. This ensures a complete clearing of the holes from the stuck in them grains. The frame rests on rubber wheels. There are only three of them. The hubs in the rear wheels are equipped with a chain sprocket for the drive. The axis in the front wheel is mounted on the turntable. Its upper part is vertical. This axis is included in the frame bushing. A drawbar is attached to the fork by means of a hinge. With its help, the whole unit is connected to the tractor.

Moving

The universal grain cleaner is moved by an appropriate mechanism. It includes:

1. Electric motor.
2. V-belt transmission.
3. Two-speed reducer.
4. Chain drives.
5. Cam clutches.

The electric motor has a power of 1.1 kW. It is started by the button that is on the control panel. By means of the reverse mechanism, the grain cleaning machines can be moved back and forth. The gear is attached to the frame. Its switching is carried out with a fork with a lock. The latter is located on the cover of the reducer. With the help of cam clutches the output shaft is articulated with two semiaxes. Their ends are equipped with asterisks. By means of cam clutches, the unit is rotated and the gearbox is disconnected during transportation by the tractor.

Conclusion

Some craftsmen collect grain-cleaning machines with their own hands. This process is somewhat complicated. The main problems are associated with a sufficiently large number of parts and components of the unit. Nevertheless, having certain knowledge and skills, it is possible to collect simple grain-cleaning machines with your own hands. Most of the subjects engaged in agricultural activities prefer to purchase factory-made units. The instructions provide information on the arrangements for preparing the device for operation. Repair of grain cleaning machines is carried out by the appropriate specialists. Simple replacement parts can be made and yourself.