A flat rotary grading screen for grain processing

Abstract

The present application relates to the technical field of screening equipment. In view of the fact that the screen of a traditional plane rotary grading screen is easily worn due to direct impact of grain raw materials, a plane rotary grading screen for grain processing is proposed, including a plane rotary grading screen body, the plane rotary grading screen body including a screen cover, the screen cover is connected with a feed pipe, the feed pipe is connected with the discharge end of the grain raw material feeding system used with the plane rotary grading screen body; a bracket is supported at the bottom of the screen cover, a material blocking barrel is supported on the bracket, the material blocking barrel is in the shape of a conical barrel with the tip facing upward, the material blocking barrel is arranged opposite to the feed pipe, and a rotary driving member is also provided on the bracket, the rotary driving member is drivingly connected to the material blocking barrel, and is used to drive the material blocking barrel to rotate around its own axis. The present application has the effect of reducing the wear of the plane rotary grading screen due to direct impact of materials.

Description

Technical Field

[0001] The present application relates to the field of screening equipment, and in particular to a flat rotary grading screen for grain processing. Background Art

[0002] In the process of grain product production and processing, before deep processing of grain raw materials, it is usually necessary to screen the grain raw materials first to remove the debris (mainly shells, branches and broken leaves, etc.) carried by the grain raw materials, so as to reduce the pollution of the debris to the subsequent deep processing. At present, the screening of grain raw materials is usually completed by a flat rotary grading screen.

[0003] In related technologies, such as Figure 1 The plane rotary grading screen 1 includes a base 11, a screen box 12, a screen cover 14 and an eccentric driving mechanism 13 and other components; wherein the screen box 12 is hung on the base 11 at a certain angle downward by a plurality of hanging ropes, and the offset driving mechanism is drivingly connected to the screen box 12; a plurality of layers of screens are supported in the screen box 12, and the plurality of screens divide the inner cavity of the screen box 12 into a plurality of screening cavities; a plurality of discharge pipes are connected to the bottom of the screen box 12, and the plurality of discharge pipes are respectively connected to the plurality of screening cavities; the screen cover 14 is installed on the screen box 12 through a plurality of locking fasteners, and a feed pipe 15 is connected to the screen cover 14, and the feed pipe 15 is connected to the discharge end of the grain raw material feeding system used in conjunction with the plane rotary grading screen 1.

[0004] When the grain raw materials are screened by the plane rotary grading screen 1, the screen box 12 performs a reciprocating plane elliptical rotation motion driven by the eccentric driving mechanism 13, and the grain raw materials are introduced into the feed pipe 15 through the discharge end of the grain raw material feeding system and then fall into the screen box 12 through the feed pipe 15, and the sundries and grain raw materials are screened and separated by a plurality of screens in the screen box 12.

[0005] With regard to the above-mentioned related technologies, when the flat rotary grading screen is screening grain raw materials, the screen at the top is directly opposite to the feed pipe on the screen cover, which makes it easy to wear due to the concentrated impact of the grain raw materials for a long time, causing the upper screen in the screen box to need to be replaced frequently. The screen replacement requires the screen cover to be removed from the screen box first. The screen cover is limited by its own volume and weight, and removal requires the cooperation of lifting equipment. The overall operation is extremely inconvenient, so there is room for improvement. Summary of the invention

[0006] In order to reduce the situation where the upper screen in the flat rotary grading screen is easily worn due to direct impact of grain raw materials, the present application provides a flat rotary grading screen for grain processing.

[0007] The present application provides a planar rotary grading screen for grain processing, which adopts the following technical solution:

[0008] A planar rotary grading screen for grain processing comprises a planar rotary grading screen body, the planar rotary grading screen body comprises a screen cover, the screen cover is connected with a feed pipe, the feed pipe is connected with the discharge end of a grain raw material feeding system used in conjunction with the planar rotary grading screen body; a bracket is supported at the bottom of the screen cover, a material blocking barrel is supported on the bracket, the material blocking barrel is in the shape of a conical barrel with the tip facing upward, the material blocking barrel is arranged opposite to the feed pipe, and a rotary driving member is also provided on the bracket, the rotary driving member is drivingly connected to the material blocking barrel, and is used to drive the material blocking barrel to rotate around its own axis.

[0009] By adopting the above technical scheme, when the grain raw materials are screened by the plane rotary grading screen, the rotating drive member drives the retaining barrel to rotate; the grain raw materials transmitted from the discharge end of the grain transport and feeding system pass into the screen box through the feed pipe on the screen cover and first contact with the retaining barrel before flowing into the screen box; the retaining barrel is used to limit the grain raw materials that fall into the screen box through the feed pipe from directly impacting the upper screen of the screen box, which is conducive to reducing the wear of the upper screen of the screen box due to the direct impact of the grain raw materials. Using the rotary drive member to drive the retaining barrel to rotate, on the one hand, it can alleviate the direct impact of the grain raw materials on the retaining barrel, thereby making the retaining barrel less susceptible to damage; on the other hand, the rotating retaining barrel can change the force and angle of the grain raw materials when they hit, so that some debris adhering to the grain raw materials is easier to separate from the grain raw materials. At the same time, the centrifugal force generated by the rotating retaining barrel can evenly scatter the grain raw materials outside the retaining barrel, reducing the situation where the grain raw materials are concentrated in a certain area of ​​the screen.

[0010] Preferably, the rotary drive member comprises a rotary motor supported on the bracket, the rotary motor is located at the bottom of the material blocking barrel, and the output shaft of the rotary motor is connected to the top of the material blocking barrel through a connecting assembly.

[0011] By adopting the above technical solution, while the rotary motor is used to drive the material blocking drum to rotate, the rotary motor can be shielded and protected by the material blocking drum to limit the subsequent grain raw materials entering the screen box from impacting and contacting the rotary motor.

[0012] Preferably, the bracket is vertically supported with a connecting rod, the top end of the connecting rod is passed through the sieve cover, the sieve cover is provided with a lifting drive member corresponding to the connecting rod, and the lifting drive member is drivingly connected to the corresponding connecting rod for driving the connecting rod to lift and lower vertically.

[0013] By adopting the above technical solution, the height position of the bracket can be adjusted. On the one hand, the bracket can be driven to lift the material blocking barrel through the lifting drive component to adjust the distance between the material blocking barrel and the bottom end of the feed pipe, thereby controlling the feeding speed of the grain raw materials at the feed pipe; on the other hand, after the subsequent material blocking barrel is worn, the lifting drive component can be used to first drive the bracket to drive the material blocking barrel to move up to the feed pipe, so that maintenance personnel can complete the disassembly, assembly and replacement of the material blocking barrel through the feed pipe fittings.

[0014] Preferably, the output shaft of the rotary motor is coaxially connected to the driving rod, and the connecting assembly includes a connecting sleeve passed through the top end of the material blocking barrel, the connecting sleeve is sleeved on the driving rod, and a plurality of top screws are threaded through the outer periphery of the connecting sleeve, and the top screws are tightly arranged against the outer periphery of the driving rod.

[0015] By adopting the above technical solution, a stable connection between the material blocking barrel and the output shaft of the rotary motor is achieved, so that the rotary motor can drive the material blocking barrel to rotate smoothly; at the same time, when the material blocking barrel needs to be replaced later, it is only necessary to loosen the top screw on the connecting sleeve to separate the material blocking barrel from the output shaft of the rotary motor, thereby facilitating the disassembly, assembly and replacement of the material blocking casing.

[0016] Preferably, an annular limiting plate is coaxially connected to the outer periphery of the driving rod, and the bottom end of the connecting sleeve abuts against the annular limiting plate.

[0017] By adopting the above technical scheme and setting the annular limit plate, on the one hand, the annular limit plate can be used to provide auxiliary support for the connecting sleeve and the material retaining barrel, which is beneficial to improving the stress condition between the top screw and the driving rod, so that the stud can limit the driving rod more stably; on the other hand, when installing the material retaining barrel, after the connecting sleeve is inserted into the driving rod and its bottom end is overlapped on the annular limit plate, the annular limit plate can be used to limit the connecting sleeve from moving downward, so as to realize the positioning of the connecting sleeve, and facilitate fixing the connecting sleeve to the driving rod through the top screw.

[0018] Preferably, a plurality of convex strips are provided on the outer periphery of the material stopping barrel, and the plurality of convex strips are evenly distributed axially around the material stopping barrel, and two ends of the convex strips extend to the top and bottom ends of the material stopping barrel respectively.

[0019] By adopting the above technical solution, by arranging a number of convex strips on the outer periphery of the material blocking barrel, on the one hand, it is beneficial to improve the overall strength of the material blocking barrel, so that the material blocking protective barrel is not easily damaged by the impact of the grain raw materials; on the other hand, when the subsequent rotary driving part drives the material blocking protective barrel to rotate, the material can be hit by the convex strips, so that some debris adhering to the grain raw materials can be better separated from the grain raw materials.

[0020] Preferably, the feed pipe is connected to the discharge end of the grain raw material feeding system used in conjunction with the planar rotary grading screen body through a silicone sleeve; one end of the silicone sleeve close to the feed pipe is sleeved on the outer periphery of the feed pipe through a rubber ring.

[0021] By adopting the above technical scheme and setting the silicone sleeve, during the subsequent reciprocating planar motion of the screen box of the planar rotary grading screen body, the silicone sleeve can be extended and retracted accordingly, so that the feed pipe and the discharge end of the grain raw material feeding mechanism always maintain a sealed connection, thereby limiting the leakage of grain raw materials during the feeding process and reducing the entry of external debris into the feed pipe; by connecting the end of the silicone sleeve close to the feed pipe to the outer periphery of the feed pipe through a rubber ring, a detachable connection between the silicone tube and the feed pipe is achieved, and when the subsequent retaining barrel is worn, the silicone sleeve can be removed from the feed pipe to facilitate maintenance personnel to disassemble, assemble and replace the retaining barrel through the feed pipe.

[0022] Preferably, a silicone material blocking tube is further provided in the silicone sleeve, the outer periphery of the top end of the silicone material blocking tube is connected to the inner periphery of the silicone sleeve, and the bottom end of the silicone material blocking tube extends into the feed tube.

[0023] By adopting the above technical solution, when the grain raw materials of the feeding mechanism fall into the connecting tube through the flexible sleeve, some grain raw materials are easily accumulated in the annular gap between the inner circumference of the flexible sleeve and the feeding tube. By setting the silicone blocking tube, the annular gap between the inner circumference of the flexible sleeve and the feeding tube is blocked by the silicone blocking tube, so as to limit the accumulation of grain raw materials in the annular gap between the inner circumference of the flexible sleeve and the feeding tube, and reduce the grain raw materials accumulated in the annular gap between the inner circumference of the flexible sleeve and the feeding tube from becoming moldy and contaminating the grain raw materials in the subsequent passages.

[0024] In summary, the present application includes at least one of the following beneficial technical effects:

[0025] 1. A bracket is supported at the bottom of the feed pipe of the screen cover, and a material blocking barrel opposite to the feed pipe and a rotary driving member for driving the material blocking barrel to rotate are arranged on the bracket. The grain raw materials that subsequently enter the screen box through the feed pipe are put into contact with the material blocking barrel first, and then flow to the screen in the screen box through the material blocking barrel. The material blocking barrel is used to limit the grain raw materials that flow in through the feed pipe from directly impacting the screen, which is beneficial to reduce the wear of the upper screen inside the screen box due to the impact of the grain raw materials; the material blocking barrel is driven to rotate by the rotary driving member, which is beneficial to buffer the impact of the grain raw materials on the material blocking barrel; at the same time, the rotating material blocking barrel evenly throws out the grain raw materials and disperses them into the screen box, reducing the situation where the grain raw materials that enter the screen box through the feed pipe are concentrated and accumulated on the screen.

[0026] 2. The bracket is driven by the lifting drive to drive the material blocking barrel to rise and fall vertically. On the one hand, the falling speed of the grain raw materials at the mouth of the feed pipe can be controlled by adjusting the vertical position of the material blocking barrel; on the other hand, when the material blocking barrel needs to be replaced later, the lifting drive can drive the material blocking barrel to move up to the feed pipe, so that maintenance personnel can complete the disassembly and assembly of the material blocking barrel through the feed port.

[0027] 3. By setting the silicone material blocking tube in the silicone sleeve, the annular gap between the silicone sleeve and the feed pipe is blocked by the silicone material blocking tube, which is helpful to limit the subsequent accumulation of grain raw materials in the annular gap between the silicone sleeve and the feed pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This application is used to illustrate the overall structure of the existing flat rotary grading screen.

[0029] Figure 2 It is a schematic diagram of the overall structure of the plane rotary grading screen body used to illustrate the embodiment of the present application.

[0030] Figure 3 It is a schematic diagram of the local structure of the screen cover used in this application.

[0031] Figure 4 This is an exploded schematic diagram used in this application to illustrate the rotating motor of the material retaining barrel.

[0032] Figure 5 This is a schematic diagram used in this application to illustrate the state in which the lifting drive drives the bracket to drive the material blocking cylinder to move upward into the feed pipe.

[0033] Figure 6 yes Figure 3 Enlarged schematic diagram of part A in the middle.

[0034] Description of reference numerals:

[0035] 1. Plane rotary grading screen; 11. Base; 12. Screen box; 13. Eccentric drive mechanism; 14. Screen cover; 15. Feed pipe; 151. Annular limit groove; 2. Bracket; 20. Connecting rod; 21. Stopper barrel; 210. Annular protrusion; 211. Raised strip; 22. Rotary motor; 221. Motor support; 222. Coupling; 223. Drive rod; 224. Annular limit plate; 23. Connecting sleeve; 231. Top screw; 3. Lifting cylinder; 31. Connecting block; 4. Silicone sleeve; 41. Silicone stopper tube; 5. Rubber ring. DETAILED DESCRIPTION

[0036] The following is combined with Figure 2-6 This application is described in further detail.

[0037] The present application embodiment discloses a planar rotary grading screen for grain processing, referring to Figure 2 and Figure 3 , including a plane rotary grading screen 1 body, the plane rotary grading screen 1 body includes a screen cover 14, the screen cover 14 is vertically connected to a feed pipe 15, the feed pipe 15 is connected to the discharge end of the grain raw material feeding mechanism used in conjunction with the plane rotary grading screen 1 body through a silicone sleeve 4. A bracket 2 is supported at the bottom of the screen cover 14, and a material blocking cylinder 21 is supported on the bracket 2. The material blocking cylinder 21 is in the shape of a conical cylinder with the tip facing upward; the material blocking cylinder 21 is arranged opposite to the feed pipe 15.

[0038] Subsequently, the grain raw materials fall into the screen box 12 through the feed pipe 15, first contact with the material blocking cylinder 21, and then flow into the screen inside the screen box 12. The material blocking cylinder 21 is used to limit the grain raw materials from directly impacting the upper screen in the screen box 12, which helps to reduce the wear of the screen due to direct impact of the material.

[0039] The bracket 2 is also provided with a rotary driving component, which includes a rotary motor 22 arranged on the bracket 2. The rotary motor 22 is fixed to the bottom of the bracket 2 through a motor support 221, and the rotary motor 22 is arranged vertically upward; and the output shaft of the rotary motor 22 is passed through the bracket 2, and the output shaft of the rotary motor 22 is connected to the top of the material blocking barrel 21 through a connecting assembly, thereby realizing the driving connection between the rotary driving component and the material blocking barrel 21.

[0040] Through the above arrangement, when the main body of the subsequent plane rotary grading screen 1 is in operation, the material blocking barrel 21 is driven to rotate by the rotary motor 22. On the one hand, the rotating material blocking barrel 21 is conducive to buffering the impact of the grain raw materials on the material blocking barrel 21, thereby reducing the wear of the material blocking barrel 21 due to the long-term concentrated impact of the grain raw materials; on the other hand, the grain raw materials contacting the material blocking barrel 21 can be evenly dispersed to the outer periphery of the material blocking barrel 21 through the rotating material blocking barrel 21, so as to achieve uniform arrangement of the materials on the screen net in the screen box 12. At the same time, when the falling material contacts the rotating material blocking barrel 21, the rotating material blocking barrel 21 can cause some debris adhering to the grain transport material to be separated from the grain raw materials.

[0041] Reference Figure 3 and Figure 4 , the output shaft of the rotary motor 22 is coaxially connected to the driving rod 223 through the coupling 222; the connecting assembly includes a connecting sleeve 23 coaxially penetrated and fixed on the top of the material blocking barrel 21. The connecting sleeve 23 is coaxially sleeved on the driving rod 223, and a plurality of top screws 231 are threaded through the outer circumference of the connecting sleeve 23, and the top screws 231 are all pressed against the outer circumference of the driving rod 223. Through the above arrangement, on the one hand, a stable connection between the material blocking barrel 21 and the output shaft of the rotary driving member is achieved; on the other hand, when the subsequent material blocking barrel 21 is worn and needs to be disassembled and replaced, the top screws 231 on the connecting sleeve 23 are loosened, so that the material blocking barrel 21 can be separated from the output shaft of the rotary motor 22, which is convenient for the disassembly and replacement of the material blocking barrel 21.

[0042] Reference Figure 3 and Figure 4 , the outer periphery of the driving rod 223 is also coaxially connected to an annular limiting plate 224, and the bottom end of the connecting sleeve 23 overlaps the annular limiting plate 224. On the one hand, the connecting sleeve 23 can be auxiliary supported by the annular limiting plate 224 to improve the stress condition of the connection between the top screw 231 and the driving rod 223, so as to facilitate more stable contact with the outer periphery of the driving rod 223. On the other hand, when installing the material blocking barrel 21, the connecting sleeve 23 at the top of the material blocking barrel 21 is inserted into the driving rod 223 and its bottom end is overlapped on the annular limiting plate 224. The annular limiting plate 224 can be used to limit the downward movement of the connecting sleeve 23, so as to tighten the top screw 231 on the outer periphery of the connecting sleeve 23 until it is tightly contacted with the outer periphery of the driving rod 223.

[0043] Reference Figure 3 and Figure 5 , both ends of the bracket 2 are vertically connected to the connecting rod 20, and the end of the connecting rod 20 away from the bracket 2 is penetrated through the screen cover 14. Two lifting driving members are supported on the screen cover 14 corresponding to the two connecting rods 20. Specifically, the lifting driving ribs include a lifting cylinder 3 supported vertically upward. The bottom end of the lifting cylinder 3 is fixed to the screen cover 14 through a support, and the top end of the lifting cylinder 3 is connected to the top end of the corresponding connecting rod 20 through a connecting block 31, so that the lifting driving member is driven and connected to the corresponding connecting rod 20. Through the above arrangement, the lifting drive member is used to drive the bracket 2 to drive the material blocking barrel 21 to rise and fall vertically, so as to adjust the distance between the material blocking barrel 21 and the bottom end of the feed pipe 15, thereby realizing the adjustment and control of the falling speed of the grain raw materials at the feed pipe 15; at the same time, when it is necessary to disassemble and replace the worn material blocking barrel 21 in the future, the lifting drive member can be used to drive the bracket 2 to move upward until the material blocking barrel 21 on the bracket 2 moves up into the feed pipe 15, so as to facilitate the maintenance personnel to remove the material blocking barrel 21 from the feed pipe 15.

[0044] The outer periphery of the bottom end of the material retaining cylinder 21 is coaxially connected with an annular protrusion 210, and the outer periphery of the annular protrusion 210 is adapted to the inner periphery of the feed pipe 15. The provision of the annular protrusion 210 is, on the one hand, conducive to improving the overall strength of the outer periphery of the bottom end of the material retaining cylinder 21; on the other hand, when the material retaining cylinder 21 is subsequently removed from the feed pipe 15, the annular protrusion 210 can be used to remove some debris adhering to the wall of the feed pipe 15 to the outside of the feed pipe 15.

[0045] A plurality of convex strips 211 are also provided on the outer periphery of the blocking sleeve, and the plurality of convex strips 211 are evenly distributed around the axial direction of the blocking barrel 21, and the two ends of the convex strips 211 extend to the top and bottom ends of the blocking barrel 21. The provision of the plurality of convex strips 211 is, on the one hand, conducive to improving the overall strength of the blocking barrel 21; on the other hand, after the subsequent grain raw materials dropped from the feed pipe 15 come into contact with the rotating blocking barrel 21, the grain raw materials can be further struck by the plurality of convex strips 211, thereby facilitating better separation of some of the debris adhering to the grain raw materials from the grain raw materials.

[0046] The feed pipe 15 is connected to the discharge end of the grain raw material feeding mechanism through the silicone sleeve 4; during the subsequent operation of the flat rotary screen grading screen, the silicone sleeve 4 can be stretched and deformed accordingly, which is conducive to maintaining a sealed connection between the discharge end of the feeding mechanism and the feed roller at all times, reducing the subsequent overflow of grain raw materials and limiting the entry of external debris into the feed pipe 15.

[0047] The bottom end of the silicone sleeve 4 is fixed on the outer periphery of the feed pipe 15 by the rubber ring 5, so that the silicone sleeve 4 can be detachably sleeved on the feed pipe 15. When the material blocking barrel 21 needs to be repaired and replaced later, the silicone sleeve 4 can be removed from the feed pipe 15, so that the maintenance personnel can disassemble and replace the material blocking barrel 21 through the feed pipe 15. An annular limiting groove 151 is provided on the outer periphery of the feed pipe 15 corresponding to the rubber ring 5, and the inner periphery of the rubber ring 5 is embedded in the annular limiting groove 151, which is conducive to reducing the situation that the rubber ring 5 is separated from the outer periphery of the feed pipe 15 during the operation of the subsequent plane rotary grading screen 1, so that the silicone sleeve 4 can be more firmly sleeved on the feed pipe 15.

[0048] A silicone blocking tube 41 is coaxially connected to the inner circumference of the silicone sleeve 4, and the bottom end of the silicone blocking tube 41 extends into the feed roller to block the annular gap between the silicone sleeve 4 and the feed tube 15. When the subsequent grain raw materials fall into the feed tube 15 through the silicone sleeve 4, the silicone blocking tube 41 is used to block the annular gap between the silicone sleeve 4 and the feed tube 15 to limit the accumulation of grain raw materials in the annular gap between the silicone sleeve 4 and the feed tube 15, which is beneficial to reduce the situation where the grain raw materials become mildewed due to accumulation in the silicone sleeve 4, thereby contaminating the subsequent grain raw materials that fall into the feed tube 15.

[0049] The implementation principle of the embodiment of the present application is: while the plane rotary grading screen 1 is running, the material blocking drum 21 is driven to rotate by the rotary motor 22; the grain raw materials output from the discharge end of the grain raw material feeding mechanism fall into the feed pipe 15 through the silicone sleeve 4, and then fall into the material blocking drum 21 through the feed pipe 15, and the rotating material blocking drum 21 is used to evenly disperse the grain to the outer periphery of the material blocking drum 21, and finally fall onto the screen in the screen box 12, thereby limiting the direct impact of the grain entering the screen box 12 through the feed pipe 15 on the screen, which is beneficial to reduce the wear of the upper screen of the screen box 12 due to the direct impact of the grain raw materials.

[0050] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A planar rotary grading screen for grain processing, comprising a planar rotary grading screen (1) body, the planar rotary grading screen (1) body comprising a screen cover (14), the screen cover (14) being connected with a feed pipe (15), the feed pipe (15) being connected with a discharge end of a grain raw material feeding system used in conjunction with the planar rotary grading screen (1) body; characterized in that: The bottom of the screen cover (14) is supported by a bracket (2), and a material blocking cylinder (21) is supported on the bracket (2). The material blocking cylinder (21) is in the shape of a conical cylinder with the tip facing upwards. The material blocking cylinder (21) is arranged opposite to the feed pipe (15). A rotary drive member is also arranged on the bracket (2), and the rotary drive member is drivingly connected to the material blocking cylinder (21) for driving the material blocking cylinder (21) to rotate around its own axis. The rotary drive member comprises a rotary motor (22) supported on the bracket (2), the rotary motor (22) is located at the bottom of the material blocking barrel (21), and the output shaft of the rotary motor (22) is connected to the top of the material blocking barrel (21) through a connecting assembly; The bracket (2) is vertically supported with a connecting rod (20), the top end of the connecting rod (20) is passed through the sieve cover (14), and the sieve cover (14) is provided with a lifting drive member corresponding to the connecting rod (20), and the lifting drive member is drivingly connected to the corresponding connecting rod (20) and is used to drive the connecting rod (20) to rise and fall vertically; The output shaft of the rotary motor (22) is coaxially connected to a driving rod (223); the connecting assembly comprises a connecting sleeve (23) penetrating the top end of the material blocking barrel (21); the connecting sleeve (23) is sleeved on the driving rod (223); a plurality of top screws (231) are threadedly passed through the outer circumference of the connecting sleeve (23); and the top screws (231) are tightly arranged against the outer circumference of the driving rod (223); An annular limiting plate (224) is coaxially connected to the outer periphery of the driving rod (223), and the bottom end of the connecting sleeve (23) abuts against the annular limiting plate (224); The outer circumference of the material blocking barrel (21) is provided with a plurality of convex strips (211), the plurality of convex strips (211) are evenly distributed axially around the material blocking barrel (21), and the two ends of the convex strips (211) extend to the top and bottom ends of the material blocking barrel (21) respectively; The feed pipe (15) is connected to the discharge end of the grain raw material feeding system used in conjunction with the plane rotary grading screen (1) body through a silicone sleeve (4); one end of the silicone sleeve (4) close to the feed pipe (15) is sleeved on the outer periphery of the feed pipe (15) through a rubber ring (5); A silicone material blocking tube (41) is also provided in the silicone sleeve (4), the outer periphery of the top end of the silicone material blocking tube (41) is connected to the inner periphery of the silicone sleeve (4), and the bottom end of the silicone material blocking tube (41) extends into the feed tube (15).

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