Two-stage cleaning device for grain combine harvester

Abstract

The invention relates to the technical field of agricultural cleaning, in particular to a two-stage cleaning device for a grain combine harvester, the two-stage cleaning device comprises a pre-cleaning device and a main cleaning device which are sequentially arranged along the conveying direction, the pre-cleaning device comprises an air supply device and an auger conveying mechanism, the auger conveying mechanism comprises an auger shaft, and the main cleaning device is arranged on the auger shaft. The auger shaft is of a pipeline type structure, one end of the auger shaft is closed, the other end of the auger shaft is communicated with an air supply device through a fan pipeline, and the surface of the auger shaft is provided with a plurality of ventilation holes and fixedly sleeved with spiral blades. According to the device, the synergistic effect of mechanical scattering and airflow scattering is achieved in the material conveying and scattering process, adhesion between grains and stems and leaves is remarkably reduced, the material looseness and layering uniformity are improved, and a stable material flow foundation is provided for follow-up cleaning.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, specifically to a cleaning device for a grain combine harvester, and more particularly to a two-stage cleaning device that achieves material pre-separation through the synergistic effect of airflow and mechanical conveying, belonging to the field of combine harvester cleaning technology. Background Technology

[0002] After a combine harvester threshes crops, the threshed material typically consists of grains, short stalks, husks, and some light impurities, which need to be separated by a cleaning device. Currently, most combine harvesters use an air-screen cleaning device, which separates grains from impurities through the combined action of a vibrating screen and airflow.

[0003] However, during the harvesting of small-grain crops such as millet, the grains often enter the cleaning device in an agglomerated state due to entanglement and adhesion between the grains, stems, and husks. Traditional cleaning devices lack effective pretreatment structures, resulting in insufficient loosening of the material before it enters the main cleaning stage. This makes it difficult for the airflow to effectively act on individual particles, leading to problems such as decreased cleaning efficiency, increased impurity content, and increased cleaning losses.

[0004] Furthermore, when materials enter the main cleaning screen in an agglomerated state, the airflow has difficulty penetrating the material layer, making it difficult to separate some impurities in a timely manner, further affecting the cleaning effect. Therefore, it is necessary to set up a pre-cleaning mechanism before the main cleaning device to ensure that the materials are sufficiently loosened and preliminarily separated before entering the main cleaning device, thereby improving the cleaning efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a two-stage cleaning device for grain combine harvesters to solve the problems of severe material agglomeration, difficulty in effectively applying airflow to the material, and low cleaning efficiency in existing cleaning devices.

[0006] This invention is achieved through the following technical solution: A two-stage cleaning device for a grain combine harvester includes a pre-cleaning device and a main cleaning device arranged sequentially along the conveying direction. The pre-cleaning device includes an air supply device and an auger conveying mechanism. The auger conveying mechanism includes an auger shaft, which is a pipe-type structure with one end closed and the other end connected to the air supply device through a fan pipe. The surface of the auger shaft is provided with several ventilation holes and helical blades are fixedly sleeved on the surface.

[0007] In use, this application first performs pre-cleaning, followed by main cleaning, achieving two-stage cleaning. During pre-cleaning, the grains, along with stalks and leaves, enter the auger conveyor mechanism. The auger shaft, a tubular structure, rotates continuously and is continuously supplied with air by a blower, causing the airflow to be ejected through ventilation holes. During this conveying process, the material undergoes "mechanical dispersal," while the airflow from the centrifugal fan, ejected through the ventilation holes, forms an "airflow spiral," achieving loosening of the material layer and laminar flow grading. This combination of dispersal and blowing effectively breaks down the adhesion between millet grains, stalks, and leaves, achieving uniform material distribution and initial separation, while avoiding uneven material distribution and excessive screen load caused by adhesion.

[0008] Preferably, the main cleaning device includes an air supply device and a linear vibrating screen connected to the discharge end of the auger conveyor mechanism. The upper screen surface of the linear vibrating screen has large square holes. The air supply device delivers air to the area between the upper screen surface and the auger conveyor mechanism, and to the lower screen area, through upper and lower air ducts. The air supply device delivers air through the upper air duct to the area between the upper screen surface and the auger conveyor mechanism. During the free fall of the material, the directional airflow from the upper air duct quickly blows away light impurities, causing them to form a backward flow field along the top of the screen body. This promotes the early separation of light impurities from the main material flow and discharges them outside the screen, thereby achieving rapid migration and efficient separation of light impurities and improving the overall cleaning effect. The air blown from the lower air duct makes the airflow distribution on the screen surface more uniform, avoiding local dead zones and turbulence, and improving the gas-solid stratification stability and cleaning accuracy of the material on the screen surface.

[0009] Preferably, the air supply device includes a cross-flow fan and two centrifugal fans. The cross-flow fan is connected to the upper air duct, and the two centrifugal fans are connected to the lower air duct. A guide plate is installed in the lower air duct. The cross-flow fan forms a stable transverse airflow field, which laterally blows the material falling from the pre-cleaning device, causing light impurities to be carried out by the airflow and heavy particles to fall down, achieving a function similar to winnowing.

[0010] Preferably, multiple auger shafts are arranged side-by-side within the auger conveying mechanism. Each auger shaft has a first driven bevel gear fixedly sleeved at its end. Each driven bevel gear meshes with a first driving bevel gear. The first driving bevel gears are fixedly connected to each other via the same rotating shaft and rotate synchronously. The rotating shaft is driven by a rotational drive mechanism to rotate along its axis. Having multiple auger shafts achieves better transmission and dispersion effects.

[0011] Preferably, the bottom shell of the auger conveyor is composed of several concave screens connected together. Each auger shaft corresponds to a concave screen below it. A guide chute is fixedly installed at the bottom of the concave screen. The bottom surface of the guide chute is inclined downward in the direction away from the linear vibrating screen. The concave screen plate can play a screening role, thereby screening out the already threshed grains in advance, thus reducing the subsequent load.

[0012] As a preferred option, a receiving box with small squares is provided at the discharge end of the guide channel and below the lower screening area of ​​the linear vibrating screen. The receiving box with squares can intuitively reflect the distribution pattern and sorting effect of the material.

[0013] Preferably, the auger shaft is rotatably connected to a sealed bearing and has an air intake pipe. The air intake pipe is connected to a fan duct. The fan duct is closed at both ends and connected to an air supply device through a connecting pipe. The air intake pipe and the auger shaft are rotatably connected through a sealed bearing, which can ensure the rotation of the auger shaft and air intake.

[0014] Preferably, a rotating shaft is vertically and rotatably connected to the air intake pipe via a sealed bearing. A second driven bevel gear is fixedly sleeved on the rotating shaft, and a second driving bevel gear meshing with the second driven bevel gear is fixedly sleeved on the auger shaft. A rotating disk is provided below the second driven bevel gear, and the rotating disk is coaxial and vertically connected to the rotating shaft. The rotation of the auger shaft can drive the rotation of the second driving bevel gear, which in turn drives the rotation of the second driven bevel gear, thereby driving the rotation of the rotating disk. The grain mixture falling from the pre-cleaning device falls onto the rotating disk and is thrown out by the rotating disk, thus increasing the area of ​​dispersion and achieving a better grain winnowing and screening effect.

[0015] Preferably, the rotating disc has a circular structure that is narrow at the top and wide at the bottom. Several guide grooves are evenly arranged along the circumference of the outer edge of the top surface of the rotating disc, so as to achieve more uniform discharge and better screening effect.

[0016] Preferably, the rotating disk is a hollow disk, the rotating shaft is a tubular structure and is connected to the air inlet pipe and the rotating disk. The top surface of the rotating disk is provided with spray holes, which can blow off the grain mixture falling on the rotating disk, preventing grains with a certain degree of adhesion from adhering to the rotating disk, and at the same time blowing away the broken particles from the rotating disk. Combined with the cross-flow fan, better grain screening effect is achieved.

[0017] The beneficial effects of this invention are threefold: 1. Pre-cleaning and air-assisted auger co-separation structure This invention introduces a spiral auger structure with ventilation holes in the pre-cleaning stage. The through holes in the shaft form a directional airflow, achieving a synergistic effect of "mechanical dispersing + airflow dispersion" during material conveying and scattering. This significantly reduces the adhesion between grains and stems and leaves, improves the looseness and stratification uniformity of the material, and provides a stable material flow basis for subsequent cleaning.

[0018] 2. Directional blowing from the upwind duct accelerates the migration of light debris. By utilizing the height difference between the pre-cleaning device and the upper screen surface, a directional airflow ejected from the upper air duct rapidly blows away light impurities during the free fall of the material. This creates a backward flow field along the top of the screen, prompting the light impurities to detach from the main material flow and be discharged outside the screen in advance. This achieves rapid migration and efficient separation of light impurities, improving the overall cleaning efficiency. 3. Multi-fan tiered air supply and uniform flow field control By combining centrifugal fans and cross-flow fans, a composite airflow system with upper and lower layered air supply is formed. With the help of guide plates, the wind speed and flow direction can be adjusted and controlled, making the airflow distribution on the screen surface more uniform, avoiding local dead zones and turbulence, and improving the gas-solid stratification stability and cleaning accuracy of the screen material. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the present invention in Embodiment 1; Figure 2 This is a schematic diagram of the rotating disk installation in Example 2; Figure 3 This is a top view of the rotating disk.

[0021] As shown in the figure: 1. Screw shaft; 2. Ventilation hole; 3. Spiral blade; 4. Linear vibrating screen; 5. Upper air duct; 6. Lower air duct; 7. Cross-flow fan; 8. Double centrifugal fan; 9. First driving bevel gear; 10. First driven bevel gear; 11. Concave plate screen; 12. Receiving box; 13. Rotary disc; 14. Second driving bevel gear; 15. Second driven bevel gear; 16. Guide channel; 17. Blowing hole. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] A two-stage cleaning device for a grain combine harvester, such as Figure 1As shown, it includes a pre-cleaning device and a main cleaning device arranged sequentially along the conveying direction. The pre-cleaning device includes an air supply device and an auger conveying mechanism. The auger conveying mechanism includes an auger shaft 1, which is a pipe-type structure with one end closed and the other end connected to the air supply device through a fan pipe. The surface of the auger shaft 1 is provided with several ventilation holes 2 and spiral blades 3 are fixedly sleeved on the surface. The diameter of the ventilation holes 2 is 1.5-2 times the diameter of the grain to prevent straw and larger debris from entering the holes and causing blockage.

[0024] The main cleaning device includes an air supply device and a linear vibrating screen 4 connected to the discharge end of the auger conveyor mechanism. The upper screen surface of the linear vibrating screen 4 has large square holes. The air supply device delivers air to the area between the upper screen surface and the auger conveyor mechanism and the lower screen area through the upper air duct 5 and the lower air duct 6 respectively. The air supply device includes a cross-flow fan 7 and a double centrifugal fan 8. The cross-flow fan 7 is connected to the upper air duct 5, and the double centrifugal fan 8 is connected to the lower air duct 6. A guide plate is installed in the lower air duct 6.

[0025] A corresponding concave screen 11 is installed below each auger shaft 1. The concave screen 11 pre-cleans the dispersed material: the material on the screen enters the main cleaning device for secondary cleaning, and the material under-screened directly enters the grain bin. At the same time, this structure can separate a portion of the grains in advance, reducing the load on the main cleaning device and improving the overall cleaning efficiency and operational stability.

[0026] In use, this application first performs pre-cleaning, followed by main cleaning, achieving two-stage cleaning. During pre-cleaning, the grains, along with stalks and leaves, enter the auger conveyor mechanism. The auger shaft 1, a tubular structure, rotates continuously and is continuously supplied with air by a blower, causing the airflow to exit through ventilation holes 2. During conveying, the material undergoes mechanical dispersal, while the airflow from the centrifugal fan exits through ventilation holes 2, forming an airflow spiral, achieving loosening of the material layer and laminar flow grading. This combination of dispersal and blowing effectively breaks down the adhesion between millet grains, stalks, and leaves, achieving uniform material distribution and initial separation, while avoiding uneven material distribution and excessive screen load caused by adhesion.

[0027] The air supply device delivers air through the upper air duct 5 to the area between the upper screen surface and the auger conveyor mechanism. During the free fall of the material, the directional airflow from the upper air duct can quickly blow away light impurities, causing them to form a backward flow field along the top of the screen body. This promotes the light impurities to leave the main material flow in advance and be discharged outside the screen, thereby achieving rapid migration and efficient separation of light impurities and improving the overall cleaning effect. Meanwhile, the air blown out by the lower air duct 6 makes the airflow distribution on the screen surface more uniform, avoiding local dead zones and turbulence, and improving the gas-solid stratification stability and cleaning accuracy of the material on the screen surface.

[0028] Among them, the cross-flow fan 7 forms a stable transverse airflow field, which blows the material falling from the pre-cleaning device laterally, so that light impurities are carried out with the wind and heavy particles fall down, achieving a similar effect to winnowing.

[0029] Multiple auger shafts 1 are arranged side-by-side within the auger conveying mechanism. Each auger shaft 1 has a first driven bevel gear 10 fixedly sleeved at its end. Each first driven bevel gear 10 meshes with a first driving bevel gear 9. The first driving bevel gears 9 are fixedly connected to each other via the same rotating shaft and rotate synchronously. The rotary drive mechanism includes a driven wheel fixedly sleeved on the rotating shaft and a fixedly mounted drive motor. The drive motor shaft is equipped with a driving wheel, and the driving wheel and driven wheel are driven by a transmission belt. The use of multiple auger shafts 1 achieves better transmission and dispersion effects.

[0030] Both the discharge end of the guide channel 16 and the lower screening area of ​​the linear vibrating screen 4 are equipped with receiving boxes 12 with small squares. The receiving boxes 12 with squares can intuitively reflect the distribution pattern and sorting effect of the materials.

[0031] The auger shaft 1 is rotatably connected to the air intake pipe via a sealed bearing. The air intake pipe is connected to the fan duct. The fan duct is sealed at both ends and connected to the air supply device via a connecting pipe. The air intake pipe and the auger shaft 1 are rotatably connected via the sealed bearing, which can ensure the rotation of the auger shaft 1 and the intake of air.

[0032] The beneficial effects of this invention are threefold: 1. Pre-cleaning and air-assisted auger co-separation structure This invention introduces a spiral auger structure with ventilation holes 2 in the pre-cleaning stage. The through holes in the shaft form a directional airflow, achieving a synergistic effect of "mechanical dispersing + airflow dispersion" during material conveying and scattering. This significantly reduces the adhesion between grains and stems and leaves, improves the looseness and stratification uniformity of the material, and provides a stable material flow basis for subsequent cleaning.

[0033] 2. Directional blowing from the upwind duct accelerates the migration of light debris. By utilizing the height difference between the pre-cleaning device and the upper screen surface, the directional airflow ejected from the upper air duct rapidly blows away light impurities during the free fall of the material, causing them to form a backward flow field along the upper part of the screen body. This prompts the light impurities to leave the main material flow in advance and be discharged outside the screen, thereby achieving rapid migration and efficient separation of light impurities and improving the overall cleaning efficiency.

[0034] 3. Multi-fan tiered air supply and uniform flow field control By combining centrifugal fans and cross-flow fans 7, a composite airflow system with upper and lower layered air supply is formed. With the help of guide plates, the wind speed and flow direction can be adjusted and controlled, making the airflow distribution on the screen surface more uniform, avoiding local dead zones and turbulence, and improving the gas-solid stratification stability and cleaning accuracy of the screen material.

[0035] Example 2, as Figure 2 and Figure 3 As shown: A rotating shaft is vertically and rotatably connected to the air intake pipe via a sealed bearing. A second driven bevel gear 15 is fixedly sleeved on the rotating shaft. A second driving bevel gear 14, which meshes with the second driven bevel gear 15, is fixedly sleeved on the auger shaft 1. A rotating disk 13 is provided below the second driven bevel gear 15. The area thrown out by the rotating disk 13 is located within the screen surface of the linear vibrating screen 4. The rotating disk 13 is coaxial with and vertically connected to the rotating shaft. The rotation of the auger shaft 1 drives the rotation of the second driving bevel gear 14, which in turn drives the rotation of the second driven bevel gear 15, thereby driving the rotation of the rotating disk 13. The grain mixture falling from the pre-cleaning device lands on the rotating disk 13 and is thrown out by the rotating disk 13, thus increasing the area of ​​dispersion and achieving a better grain winnowing and air separation effect, resulting in better screening.

[0036] The rotating disk 13 has a circular structure that is narrow at the top and wide at the bottom. Several guide grooves 16 are evenly arranged along the circumference of the outer edge of the top surface of the rotating disk 13, so as to achieve more uniform discharge and better screening effect.

[0037] The rotating disk 13 is a hollow disk, and the rotating shaft is a tubular structure that is connected to the air inlet pipe and the rotating disk 13. The top surface of the rotating disk 13 is provided with a blow hole 17. The blow hole 17 can blow off the grain mixture that falls on the rotating disk 13, preventing grains with a certain degree of adhesion from adhering to the rotating disk 13. At the same time, it can blow away the broken pieces from the rotating disk 13. Combined with the cross-flow fan 7, it can achieve a better grain screening effect.

[0038] Example 2 demonstrates that the grains can be better dispersed during the falling process, thereby ensuring a better cleaning effect.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A two-stage cleaning device for a grain combine harvester, characterized in that: It includes a pre-cleaning device and a main cleaning device arranged sequentially along the conveying direction. The pre-cleaning device includes an air supply device and an auger conveying mechanism. The auger conveying mechanism includes an auger shaft, which is a pipe-type structure with one end closed and the other end connected to the air supply device through a fan pipe. The surface of the auger shaft is provided with several ventilation holes and a spiral blade is fixedly sleeved on the surface.

2. The two-stage cleaning device for a grain combine harvester according to claim 1, characterized in that: The main cleaning device includes an air supply device and a linear vibrating screen connected to the discharge end of the auger conveyor mechanism. The upper screen surface of the linear vibrating screen has large square holes. The air supply device delivers air to the area between the upper screen surface and the auger conveyor mechanism and the lower screen area through the upper air duct and the lower air duct, respectively.

3. The two-stage cleaning device for a grain combine harvester according to claim 2, characterized in that: The air supply device includes a cross-flow fan and a dual centrifugal fan. The cross-flow fan is connected to the upper air duct, and the dual centrifugal fan is connected to the lower air duct. A guide plate is installed in the lower air duct.

4. The two-stage cleaning device for a grain combine harvester according to claim 3, characterized in that: Multiple auger shafts are arranged side by side in the auger conveying mechanism. Each auger shaft is fixedly sleeved with a first driven bevel gear at its end. The first driven bevel gears mesh with a first driving bevel gear. The first driving bevel gears are fixedly connected to each other via the same rotating shaft and rotate synchronously. The rotating shaft is driven by a rotation drive mechanism to rotate along its axis.

5. The two-stage cleaning device for a grain combine harvester according to claim 4, characterized in that: The bottom shell of the auger conveyor mechanism is composed of several concave screens connected together. Each auger shaft corresponds to a concave screen below it. A guide chute is fixedly installed at the bottom of the concave screen, and the bottom surface of the guide chute is inclined downward in the direction away from the linear vibrating screen.

6. The two-stage cleaning device for a grain combine harvester according to claim 5, characterized in that: The discharge end of the guide channel and the lower screen area of ​​the linear vibrating screen are both equipped with receiving boxes with small squares.

7. The two-stage cleaning device for a grain combine harvester according to claim 6, characterized in that: The auger shaft is rotatably connected via a sealed bearing and is connected to an air inlet pipe. The air inlet pipe is connected to a fan duct. The fan duct is sealed at both ends and connected to an air supply device via a connecting pipe.

8. The two-stage cleaning device for a grain combine harvester according to claim 7, characterized in that: The intake pipe is vertically and rotatably connected to a rotating shaft via a sealed bearing. A second driven bevel gear is fixedly sleeved on the rotating shaft. A second driving bevel gear that meshes with the second driven bevel gear is fixedly sleeved on the auger shaft. A rotating disk is provided below the second driven bevel gear. The rotating disk is coaxial with and vertically connected to the rotating shaft.

9. The two-stage cleaning device for a grain combine harvester according to claim 8, characterized in that: The rotating disk has a circular structure that is narrower at the top and wider at the bottom, and several guide grooves are evenly arranged along its circumference at the outer edge of the top surface of the rotating disk.

10. The two-stage cleaning device for a grain combine harvester according to claim 9, characterized in that: The rotating disk is a hollow disk, and the rotating shaft is a tubular structure that is connected to both the air intake pipe and the rotating disk. The top surface of the rotating disk has blow holes.

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