Introduction
The agricultural market is very competitive today. Have you thought about how to increase crop yields while lowering costs? Combine harvesters are important tools because they are efficient and require less labor. This article will explain how combine harvester work, the different types available, and what to consider when buying one. I hope this helps you!
combine harvester
What is Combine Harvester
A combine harvesting machine, also known as a grain combine, is a machine that can harvest, thresh, separate, clean, and collect grain all at once. It helps turn your field crops into grains. Using a combine harvesting machine can reduce losses by 5% to 8% compared to traditional manual harvesting. It also saves you labor when bundling, moving, and feeding during threshing, greatly easing your workload.
combine harvester
Components of Combine Harvester
Different types of combine harvesters have different designs. Here, we’ll take the fully-fed combine harvesting machine as an example to explain its main parts.
Grain Divider
The grain divider is installed on both sides of the combine harvesting machine. When it contacts the crops, it separates the crops ready for harvest from those that are not, guiding the crops into the cutter bar.
Reel
The reel is located above the cutter bar and has a pentagon shape. It supports the uncut crops and lays the cut crops onto the cutting platform. The speed and position of the reel need to be adjusted based on the growth of your crops to ensure effective handling and transport.
Cutter Bar
The cutter bar is at the front of the machine. It usually consists of a series of alternating blade-like cutters. These blades move back and forth quickly, driven by a high-speed shaft, effectively cutting the grain stalks without damaging the grains.
Conveyor
The auger is located at the back of the cutter bar. It moves the cut crops, which are laid out on the platform, toward the conveyor entrance using spiral blades. Then, a telescoping arm feeds the crops into the conveyor channel.
Threshing Cylinder
The threshing cylinder is the main threshing part of the combine harvesting machine. It rotates to hit and rub the crops using structures like bars or spikes. The speed of the cylinder needs to be adjusted based on the type of crop and its moisture level.
Concave Plate Sieves
The concave plate sieves have holes that allow the grains to pass through while trapping larger impurities, like stems. To ensure the grains can separate easily, the gap in the concave plate sieves should also be adjusted based on the type of crop.
Clear Selection Sieve
The clean selection sieve includes upper and lower screens, which mainly use vibrations to further remove impurities from the grains, like chaff and broken straw. Different sizes and shapes of holes can filter out different impurities. By adjusting the screen’s angle and vibration frequency, you can improve the cleaning process.
Fan
The fan provides airflow for cleaning. By adjusting the fan’s speed and direction, light impurities on the cleaning screen can be blown away, leaving clean grains on the screen.
Auger
The auger lifts the cleaned grains to the storage bin for stacking.
Grain Tank
The storage bin is used to temporarily hold the cleaned grains.
How Does Combine Harvester Work?
To clearly explain how a combine harvester works, I will break down its steps into cutting, threshing, separating, storing, and straw handling. I will use a fully-fed combine harvester as an example.
Cutting
When the combine harvester enters the field, the divider separates the unharvested crops from those ready to be harvested. The feeding auger helps guide the crops to the cutter bar, where the crops are cut. After cutting, the feeding auger lays the crops flat on the platform.
Threshing
The spiral guide fins on both sides of the auger transport the crops to the middle of the cutter bar. The telescoping teeth in the middle push the crops onto the inclined conveyor bridge, which then carries the crops to the drum.
Inside the cylinder, metal rods hit and rub the incoming crops, causing the grains to fall off the heads, while the straw is expelled from the back of the cylinder.
Grains, broken straw, chaff, and other debris fall through the concave plate sieves into the vibrating screen. The shaking sieve separates larger impurities, while the rotor and sieve further separate the grains from the straw. The sieve sorts the grains and larger impurities by size, and the fan uses airflow to blow away the lightweight chaff. The rotor spins quickly, creating centrifugal force to further separate the grains from the impurities.
Winnowing
The clean grains reach the cleaning system, where the fan and vibrating screen play important roles. The fan blows away the lighter impurities, while the vibrating screen further sorts the grains, ensuring that only clean grains go into the storage bin. The grain mixture moves onto a slide and enters the re-threshing and cleaning device for further processing.
Storage
The cleaned grains slide down the chute to the grain auger and are finally lifted to the storage bin by a scraper elevator. However, the storage bin is only for temporary storage. To improve efficiency, I recommend using a trailer to unload the clean grains while you are harvesting.
Straw management
A fully-fed combine harvesting machine uses cutting and throwing devices to handle the straw. After the straw separates from the grains, the machine moves it to the back of the drum, where it chops and evenly spreads it back onto the field. This allows the straw to return to the soil and serve as fertilizer.
Types of Combine Harvester
When classifying combine harvesters, we often use the harvesting method and the walking type as criteria. Next, I will explain these different types of harvesting machines to you.
Reaping Method
Based on the feeding method, combine harvesting machines can be divided into fully-fed and half-fed types.
Half-fed Combine Harvester
A half-fed combine harvester means only the heads of the crops enter the threshing drum. This design allows for higher efficiency and lower loss rates, with lower power consumption. It also helps keep the straw intact, resulting in a total grain loss rate of less than 2.5% and an impurity rate of less than 0.5%.
The structure for conveying and cutting crops in a half-fed combine harvesting machine includes a feeding finger and a straw-holding chain. This design is more complex, which makes the production cost higher.
combine harvester
Full-fed Combine Harvester
When using a fully-fed combine harvester for harvesting, all the cut straw and grain heads go into the cylinder for threshing. Because it needs to process the straw, it consumes more power. However, the total grain loss rate can be as low as 3.5%, and the impurity rate is less than 2%.
A fully-fed combine harvesting machine has a relatively simple structure, featuring a reel and an auger. Additionally, driving a fully-fed combine harvesting machine doesn’t require lining up, making it faster and more versatile.
Walking Type
Based on the walking type, combine harvesting machines can be divided into wheeled and crawler types.
Wheeled self-propelled Combine Harvester
Wheeled combine harvesting machines move using wheels, which keeps transportation costs low. However, they are not suitable for special road conditions. Wheeled harvesting machines have a stronger load capacity, a longer lifespan, and are easier and cheaper to repair. However since they have a smaller contact area with the ground, they may impact the soil.
Tracked Self-propelled Combine Harvester
Tracked combine harvesting machines move using tracks and need a trailer for transportation, which makes costs higher. However, they can operate smoothly on hilly terrain, terraced fields, and muddy ground. They have a weaker load capacity, and maintenance costs are higher due to the complexity of the tracks.
Key Considerations When Choosing a Combine Harvester
When you want to buy a combine harvesting machine, you might feel overwhelmed by the many types available in the market. You can consider the following factors to help you make a decision.
Crop Type
This article discusses rice and wheat combine harvesting machines. As the name suggests, you can use these harvesting machines to harvest rice and wheat. However, they can also use fully-fed combine harvesting machines for barley, canola, and soybeans, which have shorter stems. If you grow these crops, you might want to choose a fully-fed model.
Feed Rate
The feed rate of a combine harvesting machine directly affects its work efficiency and performance. If you need to complete more work in a shorter time, you should choose a combine harvesting machine with a higher feed rate.
small self-propelled combine harvester
Field Size and Terrain
If you are working in hard soil, you can choose a wheeled combine harvesting machine. If the land is muddy, I recommend using a crawler combine harvesting machine to avoid getting stuck.
Not all combine harvesting machines are large. If your fields are not very big or if you are working in hilly or mountainous areas where big machines can’t go, you can choose a small self-propelled combine harvesting machine. It perfectly solves this problem.
Grain Tank Capacity
Moreover, the capacity of the grain bin is also an important factor to consider. A larger grain bin allows for longer working time and fewer unloading trips, helping you reduce fuel consumption.
Wrap Up
In sum up, I have shared a lot of information about combine harvesting machines, and I hope you understand them better now than before reading this article. If you need help with purchasing, feel free to contact us at ANON. We are happy to provide you with professional assistance!
FAQ
What are the advantages of a combine harvester?
- Save labor
- Save time
- Higher efficiency
- Can complete multiple tasks at once
- Reduce harvesting costs
