Hammer mill negative pressure suction feeding and discharging system

Abstract

The application discloses a kind of hammer mill negative pressure suction material discharge systems of hammer mill technical field, including pulverizing box, hammer driving shaft, hammer piece assembly screen and material collecting tank, material collecting tank includes first material collecting tank and two second material collecting tanks, the top of three is equipped with adjustable sealing assembly, the outside of pulverizing box is equipped with transmission box, first suction material discharge component and two second suction material discharge components, transmission box is equipped with transmission component and clutch assembly, hammer driving shaft is connected with first suction material discharge component, and is connected with transmission component by clutch assembly, two second suction material discharge components are connected with transmission component correspondingly.The application controls material flow by adjustable sealing assembly, controls power distribution by clutch assembly, can be flexibly switched between normal working condition and full load / emergency working condition, effectively solve the problem that single suction material discharge structure is influenced when the whole processing of material quantity or equipment failure, improve the stability and reliability of discharge system.

Description

Technical Field

[0001] This invention relates to the field of hammer mill technology, specifically to a negative pressure suction and discharge system for a hammer mill. Background Technology

[0002] Hammer mills are widely used crushing equipment in industries such as feed, grain, food, and chemicals. Their working principle is to crush materials by impacting them with high-speed rotating hammers. The crushed materials pass through a screen and fall into a collection trough, and are then conveyed to the next process by a discharge device.

[0003] To improve discharge efficiency and working environment, existing technologies include solutions that use negative pressure suction to discharge crushed materials. For example, a hammer mill with patent application number 201120062878.X uses fan blades between the turntables to automatically suck up materials using the negative pressure formed at the center of the turntables; a feed hammer mill with patent application number 202323662519.X has an industrial vacuum cleaner installed on the side of the machine to remove dust generated during the crushing process.

[0004] However, existing hammer mill negative pressure discharge systems typically only have one suction and discharge structure, meaning a single collection trough is located at the bottom of the crushing chamber, with a corresponding negative pressure discharge device. This single-path design has significant shortcomings in actual production: When the amount of material to be crushed suddenly increases, the single collection trough and single suction discharge structure are unable to cope with the instantaneous increase in discharge load, which can easily cause the material to accumulate and block at the collection trough. When the only material suction and discharge component malfunctions, such as blockage, wear, or reduced efficiency, the entire material discharge system will be paralyzed, forcing the entire production line to shut down and severely impacting the stability and production efficiency of continuous operation.

[0005] Based on this, the present invention designs a negative pressure suction and discharge system for a hammer mill to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a negative pressure suction and discharge system for a hammer mill to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A negative pressure suction and discharge system for a hammer mill includes a crushing box, a feed inlet at the top of the crushing box, a hammer drive shaft rotatably connected at the center of the box, a screen and a collection trough at the bottom, and multiple hammer assemblies evenly arranged along the circumferential direction on the hammer drive shaft, with one end of the hammer drive shaft connected to an external drive device via a drive pulley. The material collection trough includes a first material collection trough located in the middle of the bottom of the crushing box and two second material collection troughs symmetrically located on both sides of the first material collection trough, and the top of the first material collection trough and the two second material collection troughs are provided with an adjustable sealing assembly. A transmission box is provided on the side of the crushing box away from the drive pulley. A first suction and discharge assembly is provided on the upper part of the outer side of the transmission box, and two second suction and discharge assemblies are symmetrically provided on the lower part. The first suction and discharge assembly is connected to the first collection trough, and the second suction and discharge assembly is connected to the second collection trough accordingly. The transmission box is equipped with a transmission assembly and a clutch assembly. The end of the hammer drive shaft away from the drive pulley is connected to the first suction and discharge assembly and is connected to the transmission assembly through the clutch assembly. The two second suction and discharge assemblies are correspondingly connected to the transmission assembly.

[0008] Preferably, the adjustable sealing assembly includes two symmetrically arranged arc-shaped adjusting plates, the centers of which coincide with the central axis of the hammer drive shaft, and the bottom of the adjusting plates is slidably connected to the top of the first and second collection troughs. Limiting frames are symmetrically fixed between the bottom sides of the screen and the side wall of the crushing box. One end of the adjusting plate passes through and extends out of the limiting frame. Each limiting frame is equipped with a motor and an adjusting gear at its top. The bottom of the adjusting plate on the corresponding side is provided with an arc-shaped groove, which is evenly distributed with teeth and meshes with the corresponding adjusting gear through the teeth.

[0009] Preferably, the transmission assembly includes symmetrical rotating shafts rotatably connected to both sides of the lower part of the transmission box. A fourth gear is fixed on the rotating shaft, and a third gear meshes between the two fourth gears. A transmission shaft is fixed at the center of the third gear. The transmission shaft is rotatably connected to the lower part of the transmission box, and its outer end is connected to the second suction and discharge assembly, while its inner end is correspondingly connected to the clutch assembly.

[0010] Preferably, the clutch assembly includes a first gear fixed on the hammer drive shaft, a second gear meshing with the bottom of the first gear, the gear shaft of the second gear being rotatably connected to the side wall of the crushing box, and a first transmission disc fixed to the outer end of the gear shaft, with a plurality of grooves evenly provided on the first transmission disc along the circumferential direction. A movable cylinder is slidably connected to the drive shaft. The movable cylinder is rotatably connected to the movable frame. The movable frame is connected to the outer wall of the crushing box through two movable telescopic rods. Multiple sliding grooves are evenly provided on the inner side wall of the movable cylinder along the circumferential direction. Sliding strips are fixed on the side wall of the drive shaft and are slidably connected in the sliding grooves. The inner end of the moving cylinder is fixed with a ring-shaped second transmission disk. Multiple spring grooves are evenly arranged on the second transmission disk along the circumferential direction. Spring blocks are connected to the spring grooves through springs, and one end of the spring block extends out of the spring groove and corresponds to the position of the groove on the first transmission disk.

[0011] Preferably, the first transmission disk has a shaft hole at its center, an intermediate shaft is fixed at the center of the inner end of the transmission shaft, and one end of the intermediate shaft passes through the second transmission disk and is rotatably connected to the center of the first transmission disk.

[0012] Preferably, the second suction and discharge assembly includes a horizontally arranged cylindrical second suction chamber, a second discharge pipe on the circumferential side wall of the second suction chamber, a second suction pipe connected to the center of the outer end of the second suction chamber, and the bottom end of the second suction pipe communicating with the second collection trough. A second negative pressure fan is provided in the second suction chamber, and a rotating shaft is fixed at the center of the second negative pressure fan. The rotating shaft is rotatably connected to the side wall of the transmission box and the crushing box, and is fixedly connected to the end of the rotating shaft.

[0013] Preferably, the first suction and discharge assembly includes a horizontally arranged cylindrical first suction chamber, a first discharge pipe is provided on the circumferential side wall of the first suction chamber, the first suction pipe is connected to the center of the outer end of the first suction chamber, and the bottom end of the first suction pipe is connected to the first collection trough. A first negative pressure fan is provided in the first suction chamber, and the first negative pressure fan is fixedly connected to the end of the hammer drive shaft.

[0014] Preferably, the crushing chamber is equipped with a first pressure sensor, the first suction pipe is equipped with a second pressure sensor, and the first discharge pipe is equipped with a third pressure sensor. The first pressure sensor, the second pressure sensor, and the third pressure sensor are electrically connected to the controller.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention sets up three collection troughs, namely a first collection trough and two second collection troughs, and correspondingly configures three suction and discharge components. When the material volume is too large, it can divert and unload, disperse the pressure of material accumulation at a single point, and effectively avoid the problem of discharge blockage caused by overload of a single collection trough. 2. This invention achieves one-button switching between two working modes, energy-saving single suction and powerful multi-suction, through the coordinated control of the adjustable sealing component and the clutch component, without the need to stop the machine to change equipment, thus significantly improving production continuity; 3. The two second suction and discharge components of the invention are not driven by a new motor, but obtain power from the original hammer drive shaft through a clutch component. There is no need to configure an additional motor, frequency converter and control circuit, which greatly reduces equipment cost and energy consumption.

[0016] 4. When the first suction and discharge assembly becomes clogged, worn, or its efficiency decreases, the two second suction and discharge assemblies can start working immediately, avoiding the risk of the entire production line stopping due to a single negative pressure source failure, and greatly improving the stability and reliability of continuous operation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the transmission assembly and clutch assembly of the present invention; Figure 3 This is a schematic diagram of the internal structure of the crushing chamber of the present invention; Figure 4 for Figure 3 Schematic diagram of the structure at point A in the middle; Figure 5 This is a schematic diagram of the lower part of the inner cavity of the crushing chamber of the present invention; Figure 6 for Figure 5 Schematic diagram of the structure at point B.

[0019] The attached diagram lists the components represented by each number as follows: 100-Crushing box, 101-Feed inlet, 102-Hammer assembly, 103-Hammer drive shaft, 104-Drive pulley, 105-Screen, 106-First collection trough, 107-Second collection trough, 108-Adjusting plate, 109-Adjusting gear, 110-Limiting frame; 200-Transmission box, 201-First suction chamber, 202-Second suction chamber, 203-First discharge pipe, 204-Second discharge pipe, 205-First suction pipe, 206-Second suction pipe; 400-First gear, 401-First negative pressure fan plate, 402-Second gear, 403-First transmission plate, 404-Second transmission plate, 405-Moving cylinder, 406-Moving frame, 407-Moving telescopic cylinder, 408-Spring block; 500 - Rotating shaft, 501 - Third gear, 502 - Second negative pressure fan, 503 - Fourth gear, 504 - Transmission shaft, 505 - Central shaft. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0021] Example 1 Please refer to the accompanying drawings. This invention provides a technical solution: A negative pressure suction and discharge system for a hammer mill includes a crushing box 100. The top of the crushing box 100 is provided with a feed inlet 101. A hammer drive shaft 103 is rotatably connected at the center of the inside. A screen 105 and a collection trough are provided at the bottom. Multiple hammer assemblies 102 are evenly arranged on the hammer drive shaft 103 along the circumferential direction. One end of the hammer drive shaft 103 is connected to an external drive device through a drive pulley 104. The material collection trough includes a first material collection trough 106 located in the middle of the bottom of the crushing box 100 and two second material collection troughs 107 symmetrically located on both sides of the first material collection trough 106, and the top of the first material collection trough 106 and the two second material collection troughs 107 are provided with an adjustable sealing assembly. A transmission box 200 is provided on the side of the crushing box 100 away from the drive pulley 104. A first suction and discharge assembly is provided on the upper part of the outer side of the transmission box 200, and two second suction and discharge assemblies are symmetrically provided on the lower part. The first suction and discharge assembly is connected to the first collection trough 106, and the second suction and discharge assembly is connected to the second collection trough 107 respectively. The transmission box 200 is equipped with a transmission assembly and a clutch assembly. The end of the hammer drive shaft 103 away from the drive pulley 104 is connected to the first suction and discharge assembly and is connected to the transmission assembly through the clutch assembly. The two second suction and discharge assemblies are correspondingly connected to the transmission assembly.

[0022] The system of this invention achieves two distinct operating states through the synergy of material path control and power path control: 1. Normal working status The adjustable sealing assembly seals the tops of the two second collection troughs 107. The crushed material passing through the screen 105 can only fall into the middle first collection trough 106 because the two sides are blocked. The hammer drive shaft 103 directly drives the first suction and discharge assembly to rotate synchronously. The high-speed rotation of the internal structure of the assembly generates a strong negative pressure, which makes the first collection trough 106 form a negative pressure zone, continuously sucking away the fine powder material that falls in and discharging it to the next process.

[0023] At this time, the two second suction and discharge components are stationary, and the transmission component does not consume power because the clutch component is disengaged.

[0024] 2. Full load / emergency working status When the material quantity is too large, causing the first collection trough 106 to overload, or when the first suction and discharge assembly malfunctions: The adjustable sealing component moves and opens the channels on both sides. After the material passes through the screen 105, it is evenly distributed and falls into the first collection trough 106 and the two second collection troughs on the left and right, which disperses the pressure of material accumulation at a single point. At the same time, the clutch assembly is activated, and the power of the hammer drive shaft 103 is transmitted through the transmission assembly and synchronously delivered to the two second suction and discharge assemblies. The three suction and discharge assemblies rotate at high speed at the same time, and negative pressure is established in the three collection troughs respectively, which simultaneously sucks away the dispersed materials. The total discharge cross-sectional area and air volume are multiplied, and the system is quickly cleared.

[0025] When using the system of this invention, operators do not need to stop the machine to change equipment. They can switch between energy-saving single suction and powerful multi-suction modes with just one click by switching the sealing and clutch, perfectly adapting to the needs of intermittent mass production.

[0026] When the first suction and discharge assembly becomes clogged, worn, or inefficient, the two second suction and discharge assemblies can immediately take effect, avoiding the risk of the entire production line shutting down due to a single negative pressure source failure and greatly improving the stability of continuous operation.

[0027] The power of the two second suction and discharge components of the present invention does not come from the newly added motor, but is obtained from the original hammer drive shaft 103 through the clutch assembly, eliminating the need for additional motors, frequency converters and control circuits.

[0028] The adjustable sealing assembly includes two symmetrically arranged arc-shaped adjusting plates 108. The center of each adjusting plate 108 coincides with the central axis of the hammer drive shaft 103. The bottom of the adjusting plate 108 is slidably connected to the top of the first collection trough 106 and the second collection trough 107. Limiting frames 110 are symmetrically fixed between the bottom sides of the screen 105 and the side wall of the crushing box 100. One end of the adjusting plate 108 passes through and extends out of the limiting frame 110. Each limiting frame 110 is equipped with a motor and an adjusting gear 109 at its top. The bottom of the adjusting plate 108 on the corresponding side is provided with an arc-shaped groove. The arc-shaped groove is evenly distributed with teeth and meshes with the corresponding adjusting gear 109 through the teeth.

[0029] When it is necessary to open the two second collection troughs 107, the motor is started and the adjusting gear 109 is driven to rotate. Then, through the interaction between the teeth of the adjusting gear 109 and the adjusting plate 108, the adjusting plate 108 slides outward relative to the first collection trough 106 and the second collection trough 107, opening the second collection trough 107 so that the first collection trough 106 and the second collection trough 107 work synchronously. Among them, the two symmetrically arranged arc-shaped adjusting plates 108 also have the function of inclined surface guiding, forcing the material to converge towards the bottom middle area of ​​the crushing box 100, effectively preventing material accumulation at the edges, and ensuring the concentration and thoroughness of material collection in the conventional mode.

[0030] Example 2 The structure of this embodiment is basically the same as that of Embodiment 1. The difference is that the transmission assembly includes symmetrical rotating shafts 500 rotatably connected to the lower two sides of the transmission box 200. A fourth gear 503 is fixed on the rotating shaft 500. A third gear 501 meshes between the two fourth gears 503. A transmission shaft 504 is fixed at the center of the third gear 501. The transmission shaft 504 is rotatably connected to the lower part of the transmission box 200. Its outer end is connected to the second suction and discharge assembly, and its inner end is connected to the clutch assembly. The power of the hammer drive shaft 103 is transmitted to the transmission shaft 504 through the clutch assembly. After being meshed by the third gear 501 and the fourth gear 503, the power is transported to the two rotating shafts 500 and then to the two second suction and discharge assemblies.

[0031] The clutch assembly includes a first gear 400 fixed on the hammer drive shaft 103, a second gear 402 meshing at the bottom of the first gear 400, the gear shaft of the second gear 402 being rotatably connected to the side wall of the crushing box 100, and a first transmission disk 403 fixed at the outer end of the gear shaft, with a plurality of grooves evenly provided on the first transmission disk 403 along the circumferential direction. A movable cylinder 405 is slidably connected to the drive shaft 504. The movable cylinder 405 is rotatably connected to the movable frame 406. The movable frame 406 is connected to the outer wall of the crushing box 100 through two movable telescopic cylinders 407. Multiple sliding grooves are evenly provided on the inner side wall of the movable cylinder 405 along the circumferential direction. Sliding strips are fixed on the side wall of the drive shaft 504, and the sliding strips are slidably connected in the sliding grooves. The inner end of the movable cylinder 405 is fixed with an annular second transmission disk 404. Multiple spring grooves are evenly provided on the second transmission disk 404 along the circumferential direction. A spring block 408 is connected to the spring groove through a spring. One end of the spring block 408 extends out of the spring groove and corresponds to the position of the groove on the first transmission disk 403.

[0032] When the second suction and discharge assembly is working, the movable telescopic cylinder 407 drives the movable frame 406 and its movable cylinder 405 and second transmission disc 404 to move towards the first transmission disc 403, so that the spring block 408 gradually enters the corresponding groove on the first transmission disc 403 until the end faces of the first transmission disc 403 and the second transmission disc 404 are in close contact; the power of the hammer drive shaft 103 is transmitted to the first transmission disc 403 through the first gear 400 and the second gear 402, and through the transmission of the first transmission disc 403 and the second transmission disc 404, the power is transmitted to the movable cylinder 405 and the transmission shaft 504, realizing the transmission of power from the hammer drive shaft 103 to the rotating shaft 500 in the second suction and discharge assembly.

[0033] The clutch assembly of the present invention achieves flexible buffer engagement through the progressive engagement of the spring block 408 and the groove, which significantly reduces the impact load during startup and allows for a certain angular compensation, effectively protecting the transmission gears and shaft system.

[0034] Example 3 The structure of this embodiment is basically the same as that of embodiment two, except that the second suction and discharge assembly includes a horizontally arranged cylindrical second suction chamber 202, a second discharge pipe 204 is provided on the circumferential side wall of the second suction chamber 202, a second suction pipe 206 is connected to the center of the outer end of the second suction chamber 202, and the bottom end of the second suction pipe 206 is connected to the second collection trough 107. A second negative pressure fan plate 502 is provided in the second suction chamber 202, and a rotating shaft 500 is fixed at the center of the second negative pressure fan plate 502. The rotating shaft 500 is rotatably connected to the side wall of the transmission box 200 and the crushing box 100, and is fixedly connected to the end of the rotating shaft 500.

[0035] When the power is delivered to the rotating shaft 500 via the clutch assembly and transmission assembly, the rotating shaft 500 drives the second negative pressure fan 502 to rotate, thereby generating negative pressure, which allows the material in the second collection trough 107 to move along the second suction pipe 206, be sucked into the second suction chamber 202, and discharged outward along the second discharge pipe 204.

[0036] The first suction and discharge assembly includes a horizontally arranged cylindrical first suction chamber 201, a first discharge pipe 203 is provided on the circumferential side wall of the first suction chamber 201, a first suction pipe 205 is connected to the center of the outer end of the first suction chamber 201, and the bottom end of the first suction pipe 205 is connected to the first collection trough 106. A first negative pressure fan plate 401 is provided in the first suction chamber 201, and the first negative pressure fan plate 401 is fixedly connected to the end of the hammer drive shaft 103.

[0037] When the hammer drive shaft 103 is working, it drives the first negative pressure fan 401 to rotate, generating a negative pressure effect, so that the material in the first collection trough 106 can enter the first suction chamber 201 along the first suction pipe 205 and be discharged through the first discharge pipe 203 for subsequent processing.

[0038] Example 4 The structure of this embodiment is basically the same as that of Embodiment 2. The difference is that the first transmission disk 403 has a shaft hole at its center, and a central shaft 505 is fixed at the center of the inner end of the transmission shaft 504. One end of the central shaft 505 passes through the second transmission disk 404 and is rotatably connected to the center of the first transmission disk 403, forming a support structure at the end of the transmission shaft 504. This significantly enhances the radial and axial stiffness of the inner end of the transmission shaft 504 and effectively suppresses eccentric shaking during high-speed rotation. At the same time, this shaft provides precise guidance for the axial movement of the second transmission disk 404, ensuring the absolute alignment of the spring block 408 and the groove, and greatly improving the smoothness and repeatability of the clutch engagement process.

[0039] Example 5 The structure of this embodiment is basically the same as that of embodiment three. The difference is that a first pressure sensor is provided inside the crushing box 100, a second pressure sensor is provided in the first suction pipe 205, and a third pressure sensor is provided in the first discharge pipe 203. The first pressure sensor, the second pressure sensor and the third pressure sensor are electrically connected to the controller.

[0040] A real-time sensing network for the system's operating status was constructed through multi-point pressure monitoring, which can accurately identify abnormal operating conditions such as screen blockage, pipeline leakage, or poor material discharge, and trigger automatic switching or alarms accordingly, realizing closed-loop intelligent control of the material discharge process. At the same time, by comparing the pressure difference between the suction pipe and the discharge pipe, the current actual negative pressure efficiency can be quantitatively evaluated, providing accurate data decision-making basis for the system to adaptively switch between normal and high-efficiency modes.

[0041] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A negative pressure suction and discharge system for a hammer mill, comprising a crushing box (100), a feed inlet (101) at the top of the crushing box (100), a hammer drive shaft (103) rotatably connected at the center of the inside, a screen (105) and a collection trough at the bottom, a plurality of hammer assemblies (102) evenly arranged along the circumferential direction on the hammer drive shaft (103), and one end of the hammer drive shaft (103) connected to an external drive device through a drive pulley (104), characterized in that: The material collection trough includes a first material collection trough (106) located in the middle of the bottom of the crushing box (100) and two second material collection troughs (107) symmetrically located on both sides of the first material collection trough (106), and the top of the first material collection trough (106) and the two second material collection troughs (107) are provided with an adjustable sealing assembly. The crushing box (100) is provided with a transmission box (200) on the side away from the drive pulley (104). A first suction and discharge assembly is provided on the upper part of the outer side of the transmission box (200), and two second suction and discharge assemblies are symmetrically provided on the lower part. The first suction and discharge assembly is connected to the first collection trough (106), and the second suction and discharge assembly is connected to the second collection trough (107). The transmission box (200) is provided with a transmission assembly and a clutch assembly. The end of the hammer drive shaft (103) away from the drive pulley (104) is connected to the first suction and discharge assembly and is connected to the transmission assembly through the clutch assembly. The two second suction and discharge assemblies are connected to the transmission assembly respectively.

2. The negative pressure suction and discharge system for a hammer mill according to claim 1, characterized in that: The adjustable sealing assembly includes two symmetrically arranged arc-shaped adjusting plates (108). The center of each adjusting plate (108) coincides with the central axis of the hammer drive shaft (103). The bottom of the adjusting plate (108) is slidably connected to the top of the first collection trough (106) and the second collection trough (107). Limiting frames (110) are symmetrically fixed between the bottom sides of the screen (105) and the side wall of the crushing box (100). One end of the adjusting plate (108) passes through and extends out of the limiting frame (110). Each limiting frame (110) is equipped with a motor and an adjusting gear (109) at its top. The bottom of the adjusting plate (108) on the corresponding side is provided with an arc-shaped groove. The arc-shaped groove is evenly distributed with teeth and meshes with the corresponding adjusting gear (109) through the teeth.

3. The negative pressure suction and discharge system for a hammer mill according to claim 1, characterized in that: The transmission assembly includes symmetrical rotating shafts (500) rotatably connected to the lower two sides of the transmission box (200). A fourth gear (503) is fixed on the rotating shaft (500). A third gear (501) meshes between the two fourth gears (503). A transmission shaft (504) is fixed at the center of the third gear (501). The transmission shaft (504) is rotatably connected to the lower part of the transmission box (200), and its outer end is connected to the second suction and discharge assembly, while its inner end is correspondingly connected to the clutch assembly.

4. The negative pressure suction and discharge system for a hammer mill according to claim 3, characterized in that: The clutch assembly includes a first gear (400) fixed on the hammer drive shaft (103), a second gear (402) meshing with the bottom of the first gear (400), the gear shaft of the second gear (402) being rotatably connected to the side wall of the crushing box (100), and a first transmission disc (403) fixed to the outer end of the gear shaft, and a plurality of grooves being uniformly provided on the first transmission disc (403) along the circumferential direction. A movable cylinder (405) is slidably connected to the drive shaft (504). The movable cylinder (405) is rotatably connected to the movable frame (406). The movable frame (406) is connected to the outer wall of the crushing box (100) through two movable telescopic rods (407). Multiple sliding grooves are evenly provided on the inner side wall of the movable cylinder (405) along the circumferential direction. Sliding strips are fixed on the side wall of the drive shaft (504) and are slidably connected in the sliding grooves. The inner end of the movable cylinder (405) is fixed with an annular second transmission disk (404). The second transmission disk (404) is uniformly provided with multiple spring grooves along the circumferential direction. A spring block (408) is connected to the spring groove through a spring. One end of the spring block (408) extends out of the spring groove and corresponds to the position of the groove on the first transmission disk (403).

5. The negative pressure suction and discharge system for a hammer mill according to claim 4, characterized in that: The first transmission disk (403) has a shaft hole at its center, and an intermediate shaft (505) is fixed at the center of the inner end of the transmission shaft (504). One end of the intermediate shaft (505) passes through the second transmission disk (404) and is rotatably connected to the center of the first rotating disk.

6. The negative pressure suction and discharge system for a hammer mill according to claim 3, characterized in that: The second suction and discharge assembly includes a horizontally arranged cylindrical second suction chamber (202), a second discharge pipe (204) is provided on the circumferential side wall of the second suction chamber (202), a second suction pipe (206) is connected to the center of the outer end of the second suction chamber (202), and the bottom end of the second suction pipe (206) is connected to the second collection trough (107). A second negative pressure fan (502) is provided in the second suction chamber (202), and a rotating shaft (500) is fixed at the center of the second negative pressure fan (502). The rotating shaft (500) is rotatably connected to the side wall of the transmission box (200) and the crushing box (100), and is fixedly connected to the end of the rotating shaft (500).

7. The negative pressure suction and discharge system for a hammer mill according to claim 1, characterized in that: The first suction and discharge assembly includes a first suction chamber (201) arranged in a horizontal cylindrical shape. A first discharge pipe (203) is provided on the circumferential side wall of the first suction chamber (201). A first suction pipe (205) is connected to the center of the outer end of the first suction chamber (201), and the bottom end of the first suction pipe (205) is connected to the first collection trough (106). A first negative pressure fan plate (401) is provided in the first suction chamber (201), and the first negative pressure fan plate (401) is fixedly connected to the end of the hammer drive shaft (103).

8. The negative pressure suction and discharge system for a hammer mill according to claim 7, characterized in that: The crushing box (100) is equipped with a first pressure sensor, the first suction pipe (205) is equipped with a second pressure sensor, and the first discharge pipe (203) is equipped with a third pressure sensor. The first pressure sensor, the second pressure sensor and the third pressure sensor are electrically connected to the controller.

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