A differential self-cleaning double-roll crushing device

Abstract

The utility model relates to a differential self-cleaning double-roll crushing device, including a box body, and a double-roll crushing shaft assembly, a fixed knife assembly and a screen assembly arranged in the box body, wherein the double-roll crushing shaft assembly includes two groups of crushing rollers with different rotation speeds, and a moving knife installed on the crushing rollers, and the fixed knife assembly is provided with two groups corresponding to the double-roll crushing shaft assembly, and each group of fixed knife assemblies includes a central fixed knife and an inclined fixed knife respectively located on both sides of the same crushing roller, the central fixed knife is located in the middle area of ​​the box body, the inclined fixed knife is installed on the inner wall of the box body and tilted downward, and the screen assembly is located below the double-roll crushing shaft assembly, and is used to leak out material fragments crushed to a specified size specification. Compared with the prior art, the utility model can effectively solve the problems of low crushing efficiency of flexible plastics and winding of crushing shafts, and has a self-cleaning function, stable operation, and simple operation and maintenance.

Description

Technical Field

[0001] The utility model belongs to the technical field of environmental protection equipment and relates to a differential self-cleaning double-roller crushing device. Background Art

[0002] For most of the unclassified domestic waste in the county, comprehensive sorting technology is used within the factory to achieve resource utilization. While using dry anaerobic production of biogas for cogeneration of heat and power, it can also achieve the recycling of 8 types of renewable resource products and energy, including scrap metals, plastic particles, nutrient soil, finished sand, RDF products and reclaimed water.

[0003] At present, how to efficiently recycle high-value plastics in renewable resource products and produce high-quality plastic particles is the key to profitability in the waste recycling field. In order to improve the recycling rate of these flexible plastic wastes, they must first be crushed so that the size meets the feeding requirements of subsequent sorting equipment.

[0004] The principles of existing crushers on the market can be roughly divided into several categories, such as extrusion, splitting, breaking, shearing, impact or striking. Most of them use a mixture of two or more action modes to crush materials, but the above crushing mechanism is less applicable to flexible materials.

[0005] CN204974085U provides a household garbage fine crusher, which can effectively crush household garbage, but does not forcibly crush the unbreakable objects in the household garbage. Due to its single-axis structure, flexible plastic garbage is not forcibly crushed during operation and is prone to entanglement, affecting the operation of the equipment. Utility Model Content

[0006] The purpose of the utility model is to provide a differential self-cleaning double-roll crushing device to effectively solve the problems of low crushing efficiency of flexible plastic waste and entanglement during the crushing process.

[0007] The purpose of the utility model can be achieved through the following technical solutions:

[0008] A differential self-cleaning double-roll crushing device comprises a box body, and a double-roll crushing shaft assembly, a fixed knife assembly and a screen assembly arranged in the box body, wherein:

[0009] The double-roll crushing shaft assembly includes two groups of crushing roller shafts with different rotation speeds, and a moving cutter installed on the crushing roller shafts.

[0010] The fixed knife assembly is provided with two groups corresponding to the double-roll crushing shaft assembly, and each group of fixed knife assemblies includes a central fixed knife and an inclined fixed knife respectively located on both sides of the same crushing roller shaft, the central fixed knife is located in the middle area of ​​the box, and the inclined fixed knife is installed on the inner wall of the box and tilted downward.

[0011] The screen assembly is located below the double-roller crushing shaft assembly and is used to leak out material fragments crushed to a specified size specification.

[0012] Furthermore, the crushing roller shaft is divided into a first crushing roller shaft that runs at a high speed and a second crushing roller shaft that runs at a low speed, and the moving knife member includes a moving knife spacer sleeved on the crushing roller shaft, and a moving knife head fixed on the moving knife spacer sleeve, and the moving knife heads are arranged in several rows at equal intervals along the axial direction on the two groups of crushing roller shafts. Preferably, 3-6 rows can be arranged. In addition, the two groups of crushing roller shafts are driven to rotate by two different drive modules, and the speed difference between the two can be controlled to be about 100-300rpm. Specifically, the drive module is composed of a motor, a rotating base and a motor base, and the motor speed is adjustable. At the same time, a number of moving knife heads can be arranged at equal intervals on the moving knife spacer sleeve, and the number of their arrangements is equal to the number of columns of the moving knife heads.

[0013] Furthermore, each row of moving cutter heads located on the first crushing roller shaft is arranged in a W shape;

[0014] Each row of moving cutter heads located on the second crushing roller shaft is arranged in an M shape.

[0015] Furthermore, the arrangement positions of two axially adjacent movable cutter heads satisfy that: their projections along the axial direction overlap, so that the movable cutter heads in the same row are closely arranged in steps.

[0016] Furthermore, the movable knife spacer is welded to fix the movable knife seat, and the movable knife head is fixedly installed on the movable knife seat by means of threads.

[0017] Furthermore, the movable cutter head has a triangular cross-section along the axial direction and can be made of a material such as alloy.

[0018] Furthermore, a row of fixed blade teeth are respectively processed on the sides of the central fixed blade and the inclined fixed blade facing the crushing roller shaft, and in the same row of fixed blade teeth, the groove formed between two adjacent fixed blade teeth is sufficient for the moving blade member at the corresponding position during the working process to pass through, and the size and position of the groove are preferably such that the moving blade member (i.e., the moving blade head) can roughly pass through, and the size of the moving blade head can be slightly smaller than the groove.

[0019] Furthermore, the central fixed knives of the two groups of fixed knife assemblies are installed through the same central knife seat.

[0020] Furthermore, the height of the central fixed blade of the two groups of fixed blade assemblies is lower than the central axis of the crushing roller shaft.

[0021] Furthermore, the screen assembly is composed of several groups of screen units, each group of screen units includes a mounting base located in the box, a screen bracket fixed on the mounting base, and a screen body arranged on the screen bracket, and the screen body is arc-shaped.

[0022] Furthermore, the distance between the screen body and the moving blade on the double-roll crushing shaft assembly during operation is 12-18 mm, preferably 15 mm;

[0023] The screen body is provided with hexagonal mesh holes with an inscribed circle diameter of 20-60 mm.

[0024] Compared with the prior art, the utility model has the following advantages:

[0025] (1) When the device of the utility model is working, flexible plastic waste is put into the device to be processed, and the double-roll crushing roller shaft assembly is driven to perform differential rotation. In this way, after the flexible plastic is mounted on the movable blade, it cooperates with the fixed blade assembly to crush and tear the flexible plastic waste, thereby achieving the crushing purpose.

[0026] (2) By setting a screen assembly and optimizing its shape and position, after being crushed, the plastic waste material that reaches the crushed size will leak out from the screen assembly; if the specified size requirement is not reached after one crushing, the material will be repeatedly crushed to the specified size in the crusher under the drive of the crushing shaft and then leak out from the screen body, so that the flexible plastic waste can be crushed to the greatest extent, providing material fragments of stable size specifications for the subsequent flotation process, thereby improving the recycling rate of flexible plastic waste and maximizing the safety of flotation equipment operation.

[0027] (3) The double-roll crushing shaft assembly is driven by different motors and operates at differential speeds. In this way, due to the speed difference, different parts of the moving cutter head and the fixed cutter member (including the inclined fixed cutter and the central fixed cutter) engage during the differential rotation, so that the moving cutter head cuts the entangled material, thereby achieving the function of cleaning the entangled material on the shaft. The cutter head on the moving cutter member can remove the flexible plastic entangled material on the crushing roller shaft, reducing the failure of the equipment caused by the entanglement of flexible materials, thereby implementing the self-cleaning function of the crushing roller shaft.

[0028] (4) The differential self-cleaning double-roll crusher of the utility model has a compact overall structure, is safe and reliable, operates smoothly, and has a good crushing effect on flexible plastic waste. It can greatly improve the current situation where flexible waste is entangled in the crushing shaft, resulting in high equipment failure rate and low production efficiency, and reduce the production and operation and maintenance costs of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the crushing device of the utility model;

[0030] Figure 2A schematic top view of a crushing device;

[0031] Figure 3 It is a side view schematic diagram of the crushing device of the utility model;

[0032] Figure 4 It is a schematic diagram of the main view of the crushing device of the utility model;

[0033] Figure 5 It is a structural schematic diagram of a double-roll crushing shaft assembly;

[0034] Figure 6 It is a structural schematic diagram of the movable knife;

[0035] Figure 7 It is a schematic diagram of the front view of the double-roll crushing shaft assembly;

[0036] Figure 8 The figure is a schematic diagram of the installation of the screen assembly;

[0037] Fig. 9 is a schematic diagram of a screen assembly;

[0038] Fig.10 It is a schematic diagram of the arrangement of the double-roll crushing shaft assembly and the fixed knife assembly;

[0039] Fig.11 It is a side view of the double-roll crushing shaft assembly and the fixed knife assembly;

[0040] Fig.12 is a schematic diagram of a fixed knife assembly;

[0041] Fig.13 It is a radial cross-sectional schematic diagram of a double-roll crushing shaft assembly;

[0042] Description of the markings in the figure:

[0043] 1-high-speed motor, 2-high-speed crushing shaft assembly, 3-low-speed crushing shaft assembly, 31-first sealing end plate, 32-moving knife, 33-second sealing end plate, 35-spherical roller bearing, 321-moving knife spacer, 322-moving knife head, 4-first inclined fixed knife, 5-second inclined fixed knife, 6-feeding port, 7-box, 8-crushing shaft sealing cover, 9-low-speed motor, 10-sealing plate, 11-frame, 12-motor base, 13-V-belt transmission system, 14-second center fixed knife, 15-center knife seat, 16-first center fixed knife, 17-screen assembly, 171-screen bracket, 172-screen body, 173-mounting base, 18-rotating base. DETAILED DESCRIPTION

[0044] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the following implementation manners or examples, unless otherwise specified, functional components or structures are conventional components or conventional structures used in the art to achieve corresponding functions.

[0047] In order to effectively solve the problems of low crushing efficiency and entanglement in the crushing process of flexible plastic waste, the utility model provides a differential self-cleaning double-roll crushing device, the structure of which can be seen in Figures 1 to 4 Etc., including a box body 7, and a double-roller crushing shaft assembly, a fixed knife assembly and a screen assembly 17 arranged in the box body 7, wherein:

[0048] The double-roll crushing shaft assembly includes two sets of crushing roller shafts with different rotation speeds, and a moving blade 32 installed on the crushing roller shafts.

[0049] The fixed knife assembly is provided with two groups corresponding to the double-roll crushing shaft assembly, and each group of fixed knife assemblies includes a central fixed knife and an inclined fixed knife respectively located on both sides of the same crushing roller shaft, the central fixed knife is located in the middle area of ​​the box body 7, and the inclined fixed knife is installed on the inner wall of the box body 7 and tilted downward.

[0050] The screen assembly 17 is located below the double-roller crushing shaft assembly and is used to filter out material fragments crushed to a specified size.

[0051] In some specific embodiments, a material guide port 6 is further provided on the top of the box body 7, and is used to guide the material into the double-roll crushing shaft assembly and the fixed knife assembly for crushing.

[0052] In some specific implementations, please refer to Figures 5 to 7As shown in the figure, the crushing roller shaft is divided into a first crushing roller shaft running at a high speed and a second crushing roller shaft running at a low speed. The moving knife member 32 includes a moving knife spacer 321 sleeved on the crushing roller shaft, and a moving knife head 322 fixed on the moving knife spacer 321. The moving knife heads 322 are arranged in several rows at equal intervals along the axial direction on the two groups of crushing roller shafts. Preferably, 3-6 rows can be arranged. In addition, the double-roll crushing shaft assembly is driven to rotate by a drive module, and the speed difference between the two can be controlled to be about 100-300rpm. Specifically, the drive module is composed of two motors of different powers, a rotating base 18 and a motor base 12, and the motor speed is adjustable. At the same time, a number of moving knife heads 322 can be arranged at equal intervals on the moving knife spacer 321, and the number of their arrangements is equal to the number of columns of the moving knife heads 322.

[0053] In addition, the driving module is connected to the double-roll crushing shaft assembly through a transmission system (a V-belt transmission system 13 commonly used in the art may be used), and specifically, the motor center shaft of the driving module is connected to the crushing roller shaft through the transmission system.

[0054] In a more specific embodiment, each row of movable cutter heads 322 located on the first crushing roller shaft is arranged in a W shape;

[0055] Each row of movable cutter heads 322 located on the second crushing roller shaft is arranged in an M shape.

[0056] In a more specific embodiment, the arrangement positions of two axially adjacent movable cutter heads 322 satisfy that: their axially projected portions overlap, so that the movable cutter heads 322 in the same row are closely arranged in steps.

[0057] In a more specific implementation, the movable knife spacer 321 is welded to fix the movable knife seat, and the movable knife head 322 is fixedly installed on the movable knife seat by means of threads.

[0058] In a more specific implementation, the movable cutter head 322 has a triangular shape in the axial section and can be made of alloy or other materials.

[0059] In some specific implementations, please refer to Figure 2 As shown in the figures, the central fixed knife and the inclined fixed knife are respectively processed with a row of fixed knife teeth on the sides facing the crushing roller shaft, and in the same row of fixed knife teeth, the groove formed between two adjacent fixed knife teeth is sufficient for the moving knife member 32 at the corresponding position during the working process to pass through.

[0060] In a more specific embodiment, the central fixed knives of the two fixed knife assemblies are installed through the same central knife seat 15. The central fixed knives can be fixed to both sides of the central knife seat 15 by bolts and other structures, and the direction is horizontal. At the same time, the angle between the inclined fixed knife and the horizontal direction can be set to about 10 to 25 degrees.

[0061] In some specific embodiments, the height of the central fixed blade of the two groups of fixed blade assemblies is lower than the central axis of the crushing roller shaft.

[0062] In some specific implementations, please refer to Figure 8 and Fig. 9 As shown, the screen assembly 17 is composed of several groups of screen units, each group of screen units includes a mounting base 173 located in the housing 7, a screen bracket 171 fixed on the mounting base 173, and a screen body 172 arranged on the screen bracket 171, and the screen body 172 is in an arc shape. The shape of the area enclosed by the screen assembly 17 is roughly similar to the lower part of the double-shaft crushing double-roller crushing shaft assembly. In addition, one end of the screen unit is connected to the housing 7 through the screen bracket 171, and the other end is connected to the middle bottom of the housing 7 through the mounting base 173. In order to simplify the structure of the middle area of ​​the housing 7, the mounting base 173 is preferably installed on the same center knife seat 15 as the center fixed knife of the above-mentioned fixed knife assembly, the difference being that the center fixed knife is installed on the upper part of the center knife seat 15, and the mounting base 173 is connected to the lower part of the center knife seat 15.

[0063] In a more specific embodiment, the distance between the screen body 172 and the moving blade (actually the moving blade head 322) on the double-roll crushing shaft assembly during operation is 12-18 mm, preferably 15 mm;

[0064] The screen body 172 is provided with hexagonal meshes with an inscribed circle diameter of 20-60 mm.

[0065] In some specific embodiments, the box body 7 can be set on a frame 11, and the frame 11 is provided with sealing plates 10 on three sides, and one side is hollow and used as an outlet for conveying crushed materials. The outlet can just receive the crushed garbage leaked from the screen assembly. At the same time, drive modules can be welded on both sides of the frame 11.

[0066] The above embodiments may be implemented individually or in any combination of two or more.

[0067] The above implementation is described in more detail below in conjunction with specific examples.

[0068] Embodiment 1:

[0069] This embodiment is a differential self-cleaning double-roll crushing device, the structure of which can be seen in Figures 1 to 4 Etc., including a box body 7, and a double-roller crushing shaft assembly, a fixed knife assembly and a screen assembly 17 arranged in the box body 7, wherein:

[0070] The double-roll crushing shaft assembly (consisting of a high-speed crushing shaft assembly 2 and a low-speed crushing shaft assembly 3 corresponding to different rotation speeds) includes two groups of crushing roller shafts with different rotation speeds, and a moving blade 32 installed on the crushing roller shafts.

[0071] The fixed knife assembly is provided with two groups corresponding to the double-roll crushing shaft assembly, and each group of fixed knife assemblies includes a central fixed knife (a first central fixed knife 16 located on the right side and a second central fixed knife 14 located on the left side) and an inclined fixed knife (a first inclined fixed knife 4 located on the right side and a second inclined fixed knife 5 located on the left side) respectively located on both sides of the same crushing roller shaft, the central fixed knife is located in the middle area of ​​the box body 7, and the inclined fixed knife is installed on the inner wall of the box body 7 and tilted downward.

[0072] The screen assembly 17 is located below the double-roller crushing shaft assembly and is used to filter out material fragments crushed to a specified size.

[0073] A material guide port 6 is also provided on the top of the box body 7, and is used to guide the material into the double-roll crushing shaft assembly and the fixed knife assembly for crushing.

[0074] Please see again Figures 5 to 7 As shown in the figure, the crushing roller shaft is divided into a first crushing roller shaft running at a high speed and a second crushing roller shaft running at a low speed. The moving knife member 32 includes a moving knife spacer 321 sleeved on the crushing roller shaft, and a moving knife head 322 fixed on the moving knife spacer 321. The moving knife heads 322 are arranged in several rows at equal intervals along the axial direction on the two groups of crushing roller shafts. In this embodiment, 4 rows are arranged, that is, 4 moving knife heads 322 can be arranged axially at equal intervals of 90° on the same moving knife spacer 321. In addition, the double-roll crushing shaft assembly is driven to rotate by a drive module, and the speed difference between the two can be controlled to be about 100-300rpm. Specifically, the drive module is composed of two motors of different powers (respectively, a high-speed motor 1 that can run at a higher speed, and a low-speed motor 9 that runs at a lower speed), a rotating base 18 and a motor base 12, and the motor speed is adjustable. At the same time, a number of moving knife heads 322 can be arranged at equal intervals on the moving knife spacer 321, and the number of their arrangements is equal to the number of rows of moving knife heads 322. Specifically, during operation, the rotation speed of the high-speed motor 1 can be controlled to be 800 rpm, and the rotation speed of the low-speed motor 9 can be controlled to be 600 rpm. In this way, the rotation speed difference between the two can be controlled to be 200 rpm.

[0075] At the same time, the movable blade members 32 of this embodiment are provided with 16 groups as required, and the central angle of each movable blade head 322 on each group of movable blade members 32 is about 10°, and the interval between two adjacent movable blade members 32 is 10°, that is, the movable blade heads 322 on two adjacent movable blade members 32 are exactly 10° apart in the circumferential direction. Fig.13As shown, a sealing end plate (i.e., a first sealing end plate 31 and a second sealing end plate 33) is also provided on the crushing roller shaft to seal the outermost moving blade 32. The crushing roller shaft passes through the box body 7 through a self-aligning roller bearing 35, and both ends of the crushing roller shaft are sealed with a crushing shaft sealing cover 8.

[0076] In addition, the driving module is connected to the double-roll crushing shaft assembly through a transmission system (a V-belt transmission system 13 commonly used in the art may be used), and specifically, the motor center shaft of the driving module is connected to the crushing roller shaft through the transmission system.

[0077] Each row of movable cutter heads 322 located on the first crushing roller shaft is arranged in a W shape; each row of movable cutter heads 322 located on the second crushing roller shaft is arranged in an M shape.

[0078] The arrangement positions of two axially adjacent movable cutter heads 322 satisfy that: their projections along the axial direction overlap, so that the movable cutter heads 322 in the same row are closely arranged in stages. Specifically,.

[0079] The movable knife spacer 321 is welded to fix the movable knife seat, and the movable knife head 322 is fixedly installed on the movable knife seat by means of threads.

[0080] The movable cutter head 322 has a triangular cross-section along the axial direction and can be made of alloy or other materials.

[0081] Please see again Figure 10-12 As shown in the figures, the central fixed blade and the inclined fixed blade are respectively processed with a row of fixed blade teeth on the side facing the crushing roller shaft, and in the same row of fixed blade teeth, the groove formed between two adjacent fixed blade teeth is sufficient for the movable blade member 32 at the corresponding position during the working process to pass through. Through the cooperation of the fixed blade teeth and the movable blade head 322, the task of shredding flexible plastic waste can be completed.

[0082] The central fixed knives of the two sets of fixed knife assemblies (i.e., the first central fixed knife 16 and the second central fixed knife 14) are installed through the same central knife seat 15. The central fixed knives can be fixed to both sides of the central knife seat 15 by bolts and other structures, and the direction is horizontal. At the same time, the angle between the inclined fixed knife and the horizontal direction can be set to about 15°.

[0083] The height of the central fixed knife of the two groups of fixed knife assemblies is lower than the central axis of the crushing roller shaft.

[0084] Please see again Figure 8 and Fig. 9As shown, the screen assembly 17 is composed of several groups of screen units, each group of screen units includes a mounting base 173 located in the housing 7, a screen bracket 171 fixed on the mounting base 173, and a screen body 172 arranged on the screen bracket 171, and the screen body 172 is in an arc shape. The shape of the area enclosed by the screen assembly 17 is roughly similar to the lower part of the double-shaft crushing double-roller crushing shaft assembly. In addition, one end of the screen unit is connected to the housing 7 through the screen bracket 171, and the other end is connected to the middle bottom of the housing 7 through the mounting base 173. In order to simplify the structure of the middle area of ​​the housing 7, the mounting base 173 is preferably installed on the same center knife seat 15 as the center fixed knife of the above-mentioned fixed knife assembly, the difference being that the center fixed knife is installed on the upper part of the center knife seat 15, and the mounting base 173 is connected to the lower part of the center knife seat 15.

[0085] The distance between the screen body 172 and the moving cutter head 322 on the double-roll crushing shaft assembly during operation is 15 mm;

[0086] The screen body 172 is provided with hexagonal mesh holes (ie, screen holes) with an inscribed circle diameter of 20-60 mm.

[0087] The double-roll crushing device of this embodiment processes the flexible plastic waste sorted by the pre-treatment unit. During specific operation, the flexible plastic waste is fed in through the material guide port 6 by external equipment such as a grab bucket, and then, when passing through the double-roll crushing shaft assembly, the flexible plastic waste is mounted by the movable cutter head 322 during rotation. When the movable cutter head 322 on the crushing roller shaft passes through the fixed cutter tooth area of ​​the central fixed cutter and the inclined fixed cutter in turn, the task of shredding the flexible plastic waste is completed, and the material that meets the crushing size requirements leaks out from the sieve holes of the screen body 172 in the area of ​​the screen assembly 17 below to the outlet area below.

[0088] After one crushing, if the flexible plastic waste does not reach the specified size, it will be re-mounted by the rotating movable cutter head 322, and after repeated crushing, it will leak out and be output from the outlet after reaching the specified size.

[0089] Different from the existing crushing equipment, the differential self-cleaning double-roll crusher of the utility model has a safe and reliable overall structure, stable operation, good applicability to flexible plastic waste materials, high crushing efficiency, and can greatly improve the current situation of high equipment failure rate caused by flexible waste entanglement in the crushing shaft, reducing the production and operation and maintenance costs of the enterprise, which is beneficial to the enterprise to reduce costs and increase efficiency.

[0090] The above description of the embodiments is to facilitate the understanding and use of the utility model by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the utility model is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the utility model without departing from the scope of the utility model should be within the scope of protection of the utility model.

Claims

1. A differential self-cleaning double-roll crushing device, characterized in that: It includes a box body, and a double-roller crushing shaft assembly, a fixed knife assembly and a screen assembly arranged in the box body, wherein: The double-roll crushing shaft assembly includes two groups of crushing roller shafts with different rotation speeds, and a moving cutter installed on the crushing roller shafts. The fixed knife assembly is provided with two groups corresponding to the double-roll crushing shaft assembly, and each group of fixed knife assemblies includes a central fixed knife and an inclined fixed knife respectively located on both sides of the same crushing roller shaft, the central fixed knife is located in the middle area of ​​the box, and the inclined fixed knife is installed on the inner wall of the box and tilted downward. The screen assembly is located below the double-roll crushing shaft assembly and is used to leak out material fragments crushed to a specified size specification.

2. A differential self-cleaning double-roll crushing device according to claim 1, characterized in that: The crushing roller shaft is divided into a first crushing roller shaft rotating at a high speed and a second crushing roller shaft rotating at a low speed. The moving knife member includes a moving knife spacer sleeved on the crushing roller shaft and a moving knife head fixed on the moving knife spacer. The moving knife heads are arranged in several rows at equal intervals along the axial direction on the two groups of crushing roller shafts.

3. A differential self-cleaning double-roll crushing device according to claim 2, characterized in that: Each row of moving cutter heads located on the first crushing roller shaft is arranged in a W shape; Each row of moving cutter heads located on the second crushing roller shaft is arranged in an M shape.

4. A differential self-cleaning double-roll crushing device according to claim 2, characterized in that: The arrangement positions of two axially adjacent movable cutter heads satisfy that their projections along the axial direction overlap.

5. A differential self-cleaning double-roll crushing device according to claim 2, characterized in that: The movable knife spacer is welded to fix the movable knife seat, and the movable knife head is fixedly installed on the movable knife seat by means of threads; The movable cutter head is triangular in cross section along the axial direction.

6. A differential self-cleaning double-roll crushing device according to claim 1, characterized in that: The sides of the central fixed knife and the inclined fixed knife facing the crushing roller shaft are respectively processed with a row of fixed knife teeth, and in the same row of fixed knife teeth, the groove formed between two adjacent fixed knife teeth is sufficient for the moving knife member at the corresponding position during the working process to pass through.

7. A differential self-cleaning double-roll crushing device according to claim 6, characterized in that: The central fixed knives of the two groups of fixed knife assemblies are installed through the same central knife seat.

8. A differential self-cleaning double-roll crushing device according to claim 1 or 6, characterized in that: The height of the central fixed knife of the two groups of fixed knife assemblies is lower than the central axis of the crushing roller shaft.

9. The differential self-cleaning double-roll crushing device according to claim 1, characterized in that: The screen assembly is composed of several groups of screen units, each group of screen units includes a mounting base located in the box, a screen bracket fixed on the mounting base, and a screen body arranged on the screen bracket, and the screen body is in an arc shape.

10. A differential self-cleaning double-roll crushing device according to claim 9, characterized in that: The distance between the screen body and the moving blade on the double-roll crushing shaft assembly during operation is 12-18 mm; The screen body is provided with hexagonal mesh holes with an inscribed circle diameter of 20-60 mm.

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