A flour mill and method thereof

Abstract

The application discloses a flour mill, which comprises a crushing cylinder, a feeding hopper is arranged on the upper end side of the crushing cylinder, a pipeline is connected to the bottom of the feeding hopper and extends into the crushing cylinder, a rotating shaft is arranged in the middle of the crushing cylinder, a motor is arranged on the bottom of the rotating shaft, the motor is fixed to the lower surface of the crushing cylinder, a grinding assembly is fixedly sleeved on the rotating shaft, a plurality of air channels are formed in the wall thickness of the crushing cylinder, the bottom of each air channel is communicated with the inside of the crushing cylinder, side holes are formed in the outer wall of the crushing cylinder, a sealing cover is arranged on the upper surface of the crushing cylinder, a powder collecting pipe is connected to the upper surface of the sealing cover, and an air guide is connected to the tail end of the powder collecting pipe. In the application, the grinding assembly can revolve around the rotating shaft, and the grinding ring can rotate around the connecting shaft at the same time, so that a double-motion grinding mode is formed. The arc centers of the inner concave arc surface of the grinding ring and the outer convex arc surface of the grinding ring are coincident, the grinding gap has high adhesion, and the raw materials are repeatedly ground in the gap, so that the grinding thoroughness and the flour fineness uniformity are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of flour production technology, specifically relating to a flour milling machine and its method. Background Technology

[0002] Most existing traditional flour mills adopt a single fixed grinding disc and a unidirectional rotating cutting and grinding structure, which only has a single grinding motion and a single grinding force. This results in insufficient grinding of wheat raw materials, uneven flour fineness, and a large number of coarse particles and impurities. The grinding components lack a self-limiting structure, which can easily lead to radial displacement, loosening and falling off during long-term high-speed operation. The grinding gap cannot be kept constant, which directly affects the uniformity of the finished flour. Most of them use open or semi-open grinding chambers, which cause a large amount of flour dust to leak out during the grinding process. This not only wastes raw materials and pollutes the food processing environment, but also poses a dust safety hazard. At the same time, the flour collection efficiency is low and the residue is large. Raw materials are prone to accumulation and flour agglomeration and blockage in the cylinder, resulting in poor material feeding and powder collection. With only a single-stage grinding structure, large raw materials directly enter the fine grinding station, resulting in high equipment operating load, high energy consumption, rapid wear of grinding tools, and short service life. The disassembly and assembly of grinding components are cumbersome, making later maintenance and repair difficult. Moreover, the power transmission is prone to slippage and idling, resulting in poor overall machine operation stability.

[0003] While existing patents in the same field have optimized the grinding mill, they still have core defects. For example, a grinding mill with authorization announcement number CN113399035B uses multiple grinding rollers to grind together, but relies on a single rotational motion, resulting in limited surface adhesion and no negative pressure powder collection mechanism, making it easy for flour to remain inside the machine.

[0004] In summary, current flour mills generally suffer from technical shortcomings such as limited grinding methods, insufficient grinding precision, incomplete powder collection, and inconvenient maintenance. They cannot meet the requirements of modern flour processing for efficient, precise, low-consumption, and easy-to-maintain equipment. There is an urgent need to develop a new type of flour mill that can achieve thorough grinding, efficient powder collection, and convenient maintenance. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] To address the problems mentioned in the background section, the present invention adopts the following technical solution.

[0007] A flour mill includes a grinding drum, a feed hopper mounted on the upper side of the grinding drum, and a pipe extending from the bottom of the feed hopper into the grinding drum. A rotating shaft is centrally located inside the grinding drum, and a motor is mounted at the bottom of the rotating shaft. The motor is fixed to the lower surface of the grinding drum. A grinding assembly is fixedly sleeved on the rotating shaft. The grinding assembly includes a lower connecting plate with multiple grinding stones arranged circumferentially on it. A connecting shaft is mounted on each grinding stone, allowing the grinding stones to rotate. An upper connecting plate covers the grinding stones. Multiple grooves are formed on the inner wall of the grinding drum. A grinding ring is embedded in the trough, and a gap is left between the grinding ring and the grinding components. The raw material falls into the gap and is ground into powder by the revolution of the grinding components and the rotation of the grinding stones. Multiple air channels are opened in the wall of the grinding cylinder, and the bottom of the air channels is connected to the inside of the grinding cylinder. Side holes are opened on the outer wall of the grinding cylinder. A sealing cover is installed on the upper surface of the grinding cylinder, and a powder collecting pipe is connected to the upper surface of the sealing cover. An induced draft fan is connected to the end of the powder collecting pipe. The induced draft fan draws out the negative pressure in the grinding cylinder, and the flour falls into the air channels and enters the powder collecting pipe for collection.

[0008] Preferably, the lower connecting plate has multiple circumferentially shaped positioning grooves, the lower end of the connecting shaft is inserted into the positioning grooves, and the upper connecting plate has shaft holes for the connecting shaft to pass through, and the depth of the shaft holes is equal to the length of the upper end of the connecting shaft.

[0009] A support ring is provided in the center of the upper surface of the lower connecting plate, and the upper connecting plate overlaps the support ring. Screw holes are provided on the upper connecting plate and the support ring, and the upper connecting plate is fixed to the support ring by screws.

[0010] The inner surface of the grinding ring is a concave arc surface, and the grinding stones protrude from the edges of the lower and upper connecting plates. The sides of the grinding stones are convex arc surfaces. The concave arc surface of the grinding ring and the convex arc surface of the grinding stones are matched to have their arc centers coincide. A gap is maintained between the concave arc surface and the convex arc surface, allowing the flour raw materials to enter the gap for grinding.

[0011] The inner concave arc surface of the grinding ring is evenly provided with multiple grinding teeth, which are inclined. The convex arc surface of the grinding ring is provided with multiple ridges and grooves at equal intervals, which are vertically opened, and the included angle between the grinding teeth and the ridges and grooves is an acute angle.

[0012] A material distribution plate is fixedly sleeved at the bottom of the rotating shaft. The surface of the material distribution plate is inclined, and the diameter of the material distribution plate is smaller than the inner diameter of the crushing cylinder. The flour accumulates between the material distribution plate and the crushing cylinder to facilitate negative pressure adsorption.

[0013] A grinding disc is fixedly installed at the upper end of the grinding cylinder. The edge of the grinding disc is an upward slope, and material leakage holes are evenly opened on the horizontal surface of the grinding disc. A round hole is opened in the center of the grinding disc for the rotating shaft to pass through. The round hole and the rotating shaft are connected by a bearing.

[0014] A convex shaft is integrally connected to the upper surface of the rotating shaft, and a bushing is fitted onto the convex shaft. Multiple cylinders are circumferentially mounted on the side of the bushing, and grinding rollers are rotatably fitted onto the cylinders. The grinding rollers are in contact with the upper surface of the grinding disc. A screw hole is opened on the upper surface of the convex shaft, and an end cap is threaded onto the screw hole.

[0015] A flat key is integrally connected to the side of the shaft, and keyways are provided on the components that are fixedly sleeved with the shaft.

[0016] In another aspect, the present invention also provides a method for using a flour mill, which adopts the following technical solution.

[0017] A method for using a flour mill includes the following steps: S1: Start the motor to drive the rotating shaft to rotate, causing the grinding assembly to revolve around the center, and at the same time, the grinding stones on the grinding assembly rotate around their own connecting shaft; S2: The raw material is fed into the crushing cylinder through the feed hopper. The raw material falls into the gap between the grinding ring and the grinding component. It is ground into powder through the revolution of the grinding component and the rotation of the grinding wheel. S3: Turn on the external blower. The negative pressure is formed in the grinding cylinder through the powder collection pipe on the sealed cover. The ground flour enters the powder collection pipe through the air passage in the wall of the grinding cylinder, thus completing the flour collection.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, the grinding component can revolve with the rotating shaft, and the grinding piece can rotate around the connecting shaft to form a dual-motion grinding mode; the inner concave arc surface of the grinding ring and the outer convex arc surface of the grinding piece coincide, the grinding gap fit is high, the raw material is repeatedly ground in the gap, which greatly improves the grinding fullness and the uniformity of flour fineness. Furthermore, the inner concave surface of the grinding ring is provided with inclined grinding teeth, and the outer convex surface of the grinding piece is provided with vertical ridge grooves. The two are intersected at an acute angle, forming a triple action of shearing and crushing, crushing and grinding, and kneading and refining under the compound motion, which not only significantly improves the grinding efficiency, but also effectively avoids the raw material from getting stuck in the grinding gap, ensuring continuous and smooth grinding.

[0019] (2) In this invention, the whole machine adopts a two-stage grinding structure of upper grinding roller pre-grinding and lower grinding wheel fine grinding. First, the grinding roller completes the primary pre-crushing of large particles of raw material, and then sends it to the lower fine grinding station, which greatly reduces the workload of the fine grinding components, reduces equipment energy consumption and grinding wheel wear speed, and effectively extends the service life of the whole machine; the rotating shaft is integrally formed with a flat key drive, which is tightly engaged with the keyway of the sleeve component to achieve torque transmission without loss, completely eliminating the problem of power transmission slippage and idle running. All rotating components operate synchronously and uniformly, greatly improving the stability of the whole machine operation. Moreover, the grinding components adopt a modular design of upper and lower connecting plates. The grinding wheel achieves precise bidirectional positioning through the positioning groove of the lower connecting plate and the shaft hole of the upper connecting plate. There is no radial movement, axial runout and offset fall off during high-speed operation, and the grinding gap remains constant for a long time; the grinding ring is fixed by the groove fitting method, which can be firmly installed without bolts, with precise positioning and no displacement, and convenient disassembly and assembly, which greatly reduces the difficulty of later maintenance and repair.

[0020] (3) The equipment in this invention adopts a fully sealed cylinder and sealed cover structure, which isolates external impurities throughout the process, ensures that the flour processing meets hygiene standards, completely eliminates dust leakage during the grinding process, and eliminates raw material waste, environmental pollution and dust safety hazards; in conjunction with an external blower, a closed negative pressure powder collection system is formed, and the flour is directionally conveyed through the built-in air channel in the cylinder wall, realizing powder collection while grinding, with a high degree of automation, high efficiency and no residue; the inclined material distribution plate at the bottom of the cylinder rotates with the shaft, which evenly disperses the flour, avoids bottom accumulation and blockage, increases the contact area between the flour and the negative pressure airflow, and in conjunction with the side hole to balance the negative pressure inside the cylinder, further improves the smoothness and thoroughness of powder collection. Attached Figure Description

[0021] Figure 1 The appearance and structure of the flour mill in this invention Figure 1 .

[0022] Figure 2 The appearance and structure of the flour mill in this invention Figure 2 .

[0023] Figure 3 This is a cross-sectional view of the flour milling machine in this invention. Figure 1 .

[0024] Figure 4 This is an exploded view of the flour milling machine in this invention.

[0025] Figure 5 This is a cross-sectional view of the flour milling machine in this invention. Figure 2 .

[0026] Figure 6 This is a cross-sectional view of the pulverizing cylinder in this invention.

[0027] Figure 7 This is an exploded view of the internal structure of the crushing cylinder in this invention.

[0028] Figure 8 This is a structural diagram of the grinding assembly and grinding ring in this invention.

[0029] Figure 9 This is an exploded view of the grinding assembly in this invention.

[0030] The correspondence between the labels and component names in the attached figures is as follows: 100. Crushing cylinder; 100a. Air passage; 100b. Groove; 100c. Side hole; 101. Sealing cover; 101a. Powder collecting pipe; 102. Feed hopper; 103. Motor; 104. Grinding ring; 104a. Grinding teeth; 105. Rotating shaft; 105a. Flat key; 105b. Protruding shaft; 105c. End cover; 106. Distributor plate; 107. Grinding disc; 108. Bushing; 108a. Grinding roller; 200. Grinding assembly; 201. Lower connecting plate; 201a. Positioning groove; 201b. Support ring; 202. Grinding ring; 202a. Connecting shaft; 203. Upper connecting plate; 203a. Shaft hole. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments. The present invention provides the following embodiments.

[0034] To address the shortcomings of existing traditional flour mills, such as single grinding force, insufficient grinding of wheat raw materials, inconsistent flour fineness, and a large amount of coarse impurities, most of which use open or semi-open grinding chambers, resulting in a large amount of flour dust leakage during the grinding process, causing raw material waste, pollution of the food processing environment, and dust safety hazards, as well as low flour collection efficiency and large residue; raw material accumulation and flour clumping are prone to occur inside the cylinder, and the feeding and collection of flour are not smooth. This patent, through an integrated structural design, comprehensively improves the grinding structure, power transmission, sealed flour collection, pre-grinding and dispersing, and component positioning, completely solving all the defects of the existing technology, and achieving efficient, fine, sealed, stable, and low-consumption continuous flour grinding operation. The specific device structure is as follows: Example

[0035] See Figure 1 , Figure 2 and Figure 3This embodiment discloses a flour mill, which includes a grinding cylinder 100. The grinding cylinder 100 serves as the core load-bearing and sealed grinding chamber of the entire machine. It is integrally formed, has high structural strength, excellent wear resistance, and a smooth, burr-free inner wall, which can prevent flour adhesion and residue. At the same time, the vertical sealed cylinder structure isolates external impurities throughout the process, ensuring that the flour processing meets hygiene standards and completely preventing dust leakage. A feed hopper 102 is fixedly installed on the upper side of the grinding cylinder 100. The feed hopper 102 adopts a conical guide structure that is larger at the top and smaller at the bottom, with a conical slope. The raw materials can slide smoothly under their own weight, avoiding accumulation and bridging at the feed inlet. A conveying pipe is fixedly connected to the bottom of the feed hopper 102, extending horizontally and sealed into the internal cavity of the grinding cylinder 100. The pipe outlet is precisely aligned with the central grinding station, ensuring that wheat raw materials are conveyed to the grinding area without deviation, preventing waste caused by raw materials spilling directly to the bottom of the cylinder. This ensures that all raw materials can enter the grinding station for thorough grinding, preventing unground raw materials from falling directly to the ground. A vertically coaxial rotating shaft 10 is located in the center of the grinding cylinder 100. 5. The rotating shaft 105, as the core power transmission shaft of the entire machine, is made of high-rigidity alloy steel, which is resistant to bending, torsion, and deformation. It can maintain coaxiality during long-term high-speed rotation, avoiding operational shaking. A motor 103 is fixedly installed at the bottom of the rotating shaft 105. The motor 103 is sealed and fixed to the center of the lower surface of the crushing cylinder 100 by multiple sets of fastening bolts. The motor 103 is a low-speed, high-torque variable frequency drive motor, which operates at a stable speed without severe vibration and can output constant driving force to ensure uniform and stable operation of the entire machine, avoiding speed fluctuations that could affect the grinding of fine particles. The grinding component 200 is fixedly sleeved on the rotating shaft 105. The rotating shaft 105 and the grinding component 200 are coaxially and tightly connected. When the motor 103 drives the rotating shaft 105 to rotate at a uniform speed, it can synchronously drive the grinding component 200 to make a stable central circumferential revolution, providing the core active power for the grinding operation. In addition, in order to ensure the grinding quality, this embodiment has multiple sets of annular closed grooves 100b on the inner side wall of the crushing cylinder 100. The grinding ring 104 is embedded in the groove 100b. The grinding component 200 and the grinding ring 104 cooperate to complete the grinding.

[0036] See Figure 4 and Figure 7The grinding assembly 200 in this embodiment includes a lower connecting plate 201, which is tightly sleeved with the rotating shaft 105. It serves as the bottom support base for the grinding stones 202, providing a stable structure and strong load-bearing capacity. Multiple grinding stones 202 are symmetrically and evenly arranged on the lower connecting plate 201, with equal spacing around the rotating shaft 105. This ensures completely uniform force during circumferential grinding of the cylinder, avoiding problems of excessive or insufficient grinding in certain areas. Each grinding stone 202 has a fixed connecting shaft 202a at its center axial position. The grinding stone 202 is movably mounted on the lower connecting plate 201 via the connecting shaft 202a, allowing it to rotate freely and flexibly around its own connecting shaft 202a without the need for an additional independent drive motor. The passive rotation of the grinding ring 104 is achieved entirely by the frictional resistance between the raw material and the grinding ring. Combined with its own revolution, it forms a dual composite grinding mode of revolution crushing + rotation kneading. Compared with the existing single rotary grinding structure, the grinding force is multiplied, the raw material is crushed more thoroughly, the flour is finer and more uniform, and the grinding efficiency is greatly improved. The upper connecting plate 203 is fixedly covered on the grinding ring 202. The upper connecting plate 203 and the lower connecting plate 201 are correspondingly matched and cooperate to form a two-way limit and axial positioning constraint on the grinding ring 202. This fundamentally avoids the problems of radial movement, axial jump, and displacement and fall-off of the grinding ring 202 during high-speed rotation. It maintains a constant grinding gap for a long time and solves the technical defects of easy displacement of grinding parts and unstable grinding gap in the existing technology.

[0037] See Figure 9In this embodiment, multiple positioning grooves 201a corresponding to the grinding wheel 202 are evenly distributed in a circular pattern on the lower connecting plate 201. The lower end of the connecting shaft 202a is tightly inserted and positioned in the positioning groove 201a. The positioning groove 201a provides precise radial positioning of the bottom of the connecting shaft 202a, preventing the bottom of the connecting shaft 202a from shaking or shifting. The upper connecting plate 203 has coaxial corresponding shaft holes 203a. The shaft holes 203a are precisely for the upper end of the connecting shaft 202a to pass through, and the depth of the shaft holes 203a is exactly equal to the length of the upper end of the connecting shaft 202a, so that the upper end surface of the connecting shaft 202a is flush with the upper surface of the upper connecting plate 203, without protrusions or jamming. This ensures that the grinding wheel 202 rotates flexibly and smoothly without friction interference, and further enhances the positioning stability of the grinding wheel 202. Even after long-term operation, the upper connecting plate 203 maintains a precise assembly position. The upper surface of the lower connecting plate 201 is integrally formed with a support ring 201b, which provides stable support and coaxial positioning for the upper connecting plate 203. The bottom of the upper connecting plate 203 rests smoothly on the support ring 201b, ensuring that the upper connecting plate 203 is installed horizontally and with precise coaxiality. Corresponding coaxial fastening screw holes are opened on the upper connecting plate 203 and the support ring 201b. The upper connecting plate 203 and the support ring 201b are firmly fixed into one piece by tightening screws, so that the entire grinding assembly 200 forms a modular whole structure. Disassembly, replacement and maintenance do not require disassembling multiple scattered parts, making operation simple. At the same time, there will be no problem of loosening or falling off during high-speed operation, and the operational stability far exceeds that of existing grinding component structures.

[0038] See Figure 8 and Figure 9 In this embodiment, the inner surface of the grinding ring 104 is a concave arc-shaped surface, and the outer side of the grinding piece 202 protrudes beyond the outer edge of the lower connecting plate 201 and the upper connecting plate 203. The outer side of the grinding piece 202 is a convex arc-shaped surface. The concave arc-shaped surface of the grinding ring 104 and the convex arc-shaped surface of the grinding piece 202 are perfectly matched in curvature and their arc centers are completely coincident, so that the circumferential spacing of the grinding gap between the two is completely consistent. The raw material is subjected to uniform grinding force in the gap, and there will be no problem of excessive grinding in some areas or excessive grinding in some areas. This ensures that the fineness of the finished flour is highly uniform and completely solves the problem of uneven grinding gap and large differences in flour coarseness in the prior art. The concave arc-shaped surface of the grinding ring 104 is integrally formed with multiple inclined grinding teeth 104a. The grinding teeth 104a are inclined towards the grinding direction of the raw material, which has strong wear resistance and large grinding force. The convex arc-shaped surface of the grinding ring 202 has multiple vertical grooves at equal intervals. The inclined grinding teeth 104a and the vertical grooves form an acute angle. Under the combined motion of the grinding ring 202's revolution and rotation, the cross structure can perform three operations on the raw material: shearing and crushing, crushing and grinding, and kneading and refining. Compared with the existing planar grinding and single-tooth grinding structures, the crushing effect is better, and it can quickly grind large wheat particles into ultrafine flour. At the same time, it effectively avoids the raw material from clogging and sticking in the grinding gap, ensuring continuous and smooth grinding operation. See Figure 5 and Figure 6 The inner wall of the grinding cylinder 100 has multiple sets of annular closed grooves 100b. The inner wall of the grooves 100b is tightly fitted and fixed to the outer wall of the grinding ring 104. The grinding ring 104 is locked and positioned by the grooves 100b, without loosening or displacement. It can be firmly fixed without bolts, making disassembly and assembly more convenient. As a fixed grinding component, the grinding ring 104 maintains a uniform and constant grinding gap with the rotating grinding component 200. The raw material falls precisely into the gap without side leakage or accumulation. Through the continuous revolution of the grinding component 200 and the autonomous rotation of the grinding wheel 202, the raw material is subjected to multiple grinding operations such as crushing, kneading, and shearing, which quickly and thoroughly grinds the granular wheat raw material into fine flour and completely eliminates the residue of coarse particles.

[0039] See Figure 1 , Figure 2 , Figure 4 and Figure 6 In this embodiment, multiple sets of axially uniformly arranged air channels 100a are formed inside the wall of the grinding cylinder 100. The air channels 100a are vertically processed along the inner wall of the grinding cylinder 100, and the bottom of the air channels 100a is directly connected to the internal cavity of the grinding cylinder 100. The outer wall of the grinding cylinder 100 is provided with side holes 100c that communicate with the air channels 100a. The side holes 100c are used to balance the negative pressure in the cylinder, so as to avoid excessive negative pressure in the cylinder, which may cause material blockage and flour adsorption and failure to be conveyed. At the same time, it ensures smooth flow of negative pressure airflow. A sealing cover 101 is sealed and installed on the upper surface of the grinding cylinder 100. The sealing cover 101 is sealed and fitted to the upper end face of the grinding cylinder 100, completely sealing the upper opening of the cylinder and forming a fully enclosed grinding chamber. In this process, the leakage of flour dust, which pollutes the environment and wastes raw materials, is completely eliminated. A powder collection pipe 101a is sealed and connected to the center of the upper surface of the sealing cover 101. The end of the powder collection pipe 101a is connected to an external fan. The fan continuously draws air to form a stable and balanced negative pressure adsorption environment inside the sealed grinding cylinder 100. After grinding, the flour falls naturally to the bottom of the cylinder. Under the action of negative pressure suction, it is directionally transported upward along the air passage 100a and finally all flows into the powder collection pipe 101a to complete the sealed automatic collection. This achieves simultaneous grinding and powder collection, which is fully automated, dust-free, and residue-free. Compared with the existing open powder collection structure, the raw material utilization rate and powder collection efficiency are greatly improved, which fully meets the clean production requirements of food processing.

[0040] It is worth noting that, based on existing technology and common knowledge, in actual use, cyclone collectors or bag collectors are also used in conjunction with the induced draft fan. Fine powder enters the cyclone collector or bag collector with the airflow for gas-solid separation.

[0041] See Figure 3 and Figure 7In this embodiment, a material distribution plate 106 is fixedly sleeved at the bottom of the rotating shaft 105. The material distribution plate 106 rotates synchronously and uniformly with the rotating shaft. The surface of the material distribution plate 106 adopts an outward inclined slope structure, which can evenly disperse the flour falling to the bottom of the cylinder during rotation, completely avoiding the accumulation, clumping, and blockage of flour in the center of the bottom of the cylinder, ensuring that the flour is in a loose state throughout the grinding process. Moreover, the diameter of the material distribution plate 106 is smaller than the inner diameter of the grinding cylinder 100, leaving sufficient space for airflow and flour conveying. The loose flour is evenly distributed between the material distribution plate 106 and the inner wall of the grinding cylinder 100, greatly increasing the contact area between the flour and the negative pressure airflow, allowing the blower to adsorb flour from all directions, further improving the thoroughness of flour collection and eliminating flour residue at the bottom of the cylinder. Furthermore, a grinding disc is fixedly installed on the upper inner wall of the grinding cylinder 100. 107. The grinding disc 107 is located above the grinding assembly 200 and serves the dual functions of primary pre-grinding and uniform material distribution. The edge of the grinding disc 107 adopts an upward inclined surface structure, which can guide the falling raw material to the center, preventing the raw material from adhering to the cylinder wall and being wasted. Multiple fine material leakage holes are evenly opened on the horizontal surface of the grinding disc 107. The pre-ground small particles of raw material fall evenly to the work position of the grinding assembly 200 below through the material leakage holes, avoiding large particles of raw material from piling up and increasing the grinding load. A round hole is opened in the center of the grinding disc 107 for the rotating shaft 105 to pass through. The round hole and the rotating shaft 105 are connected by a sealed bearing. The bearing not only ensures that the rotating shaft 105 rotates at high speed without jamming or friction loss, but also achieves sealing and isolation to prevent raw materials and dust from entering the bearing and causing jamming and wear, thus extending the service life of the whole machine.

[0042] See Figure 4 and Figure 7In this embodiment, a convex shaft 105b is integrally connected to the upper surface of the rotating shaft 105. The convex shaft 105b rotates synchronously with the rotating shaft 105. A bushing 108 is fixedly sleeved on the convex shaft 105b. Multiple connecting cylinders are evenly distributed around the side circumference of the bushing 108. Grinding rollers 108a are rotatably sleeved on the cylinders. The bottom surface of the grinding rollers 108a is in close contact with the upper surface of the grinding disc 107. When the rotating shaft 105 rotates, it synchronously drives the grinding rollers 108a to continuously roll on the surface of the grinding disc 107, performing primary pre-crushing and grinding on the large-particle wheat raw materials. This pre-crushes and refines the large-particle raw materials before sending them to the lower part for fine compound grinding, significantly reducing the workload of the lower grinding assembly 200, reducing equipment energy consumption, slowing down the wear of the grinding tools, and further improving the efficiency of grinding. The overall fineness of the flour is improved by forming a two-stage grinding structure of upper pre-grinding and lower fine grinding, which has a grinding effect far superior to existing single-stage mills. The upper surface of the convex shaft 105b has a fastening screw hole, and the end cover 105c is connected to the screw hole by thread. The end cover 105c presses down to tighten the bushing 108, preventing the bushing 108 and the grinding roller 108a from axially slipping off, ensuring the long-term stable operation of the upper pre-grinding structure. The side of the rotating shaft 105 is integrally connected to the flat key 105a. All parts that are fixedly sleeved with the rotating shaft 105 have matching keyways. The flat key 105a and the keyway are tightly engaged to achieve lossless torque transmission, completely eliminating slippage and free rotation problems during power transmission, ensuring that all rotating parts operate synchronously and at a uniform speed, and further improving the overall stability of the machine.

[0043] Example 2 In another aspect, this embodiment also provides a method for using a flour mill. By employing the complete device described above and combining the advantages of the overall machine structure, continuous, efficient, and high-quality flour grinding operations can be achieved. The specific implementation steps are as follows: First, start the motor 103 at the bottom of the crushing cylinder 100. After the motor 103 is powered on, it runs and outputs a constant torque, precisely driving the central rotating shaft 105 to rotate at a uniform speed and coaxially. The rotating shaft 105 transmits power stably through the flat key 105a, synchronously driving the entire grinding assembly 200 to revolve stably around the center of the rotating shaft. During the revolution of the grinding assembly 200, the grinding wheel 202 generates directional frictional resistance between itself, the fixed grinding ring 104, and the raw material. Under the action of resistance, the grinding wheel 202 automatically rotates smoothly around its connecting shaft 202a. Without additional drive, it can form a two-stage composite grinding state of pre-grinding of the upper grinding roller and fine grinding of the lower grinding wheel by revolution and rotation. This allows the grinding mechanism of the whole machine to enter a stable working state in advance, ensuring that the subsequent raw materials can be put into the efficient grinding process immediately without waiting for the equipment to preheat, thus improving the continuity of operation. The wheat raw material to be ground is then fed into the feed hopper 102 at a uniform speed. Under the guidance of the conical feed hopper 102, the raw material is smoothly fed into the crushing cylinder 100 through the bottom pipe. It first falls onto the surface of the upper grinding disc 107 and is pre-crushed by the rolling and crushing of the rotating grinding roller 108a. The refined raw material falls evenly through the material leakage hole and enters the constant grinding gap between the grinding ring 104 and the grinding component 200. The raw material is continuously subjected to multiple compound grinding actions of the grinding disc 202, including revolution and rolling, rotation and kneading, and shearing by the grinding teeth. It is gradually refined and ground, and thoroughly processed into flour with the required fineness and uniform texture. The entire process is uniform, without blockage or waste of raw materials. With the cooperation of the two-stage grinding, coarse particles are completely eliminated, and the quality of the flour far exceeds that of traditional milling machine products. During the grinding process, an external induced draft fan is simultaneously activated, continuously drawing air. Combined with the fully sealed structure of the sealing cover 101, a stable and balanced negative pressure adsorption environment is formed inside the grinding cylinder 100. The ground flour naturally falls to the bottom of the cylinder, is evenly dispersed by the rotating material distribution plate 106, and then, under the action of negative pressure suction, is directionally conveyed upwards along multiple air channels 100a within the wall thickness of the grinding cylinder 100. All the flour smoothly flows into the powder collection pipe 101a and is directly transported to external collection equipment via the induced draft fan. The entire process is fully enclosed and automated, with grinding and powder collection completed simultaneously. There is no dust leakage, no flour residue, and no need for additional manual cleaning. The operation is simple and convenient, improving flour production efficiency, ensuring a clean and hygienic production environment, and guaranteeing stable finished flour quality, fully meeting food processing production standards.

[0044] It is worth noting that a valve is installed in the pipe at the end of the feed hopper 102. When starting the negative pressure, the valve needs to be closed to prevent air from entering the upper part of the crushing cylinder 100, which would cause the flour to be unable to be absorbed.

[0045] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A flour mill, comprising a grinding cylinder (100), wherein a feed hopper (102) is installed on the upper side of the grinding cylinder (100), a pipe is connected to the bottom of the feed hopper (102) extending into the grinding cylinder (100), a rotating shaft (105) is centrally located inside the grinding cylinder (100), a motor (103) is installed at the bottom of the rotating shaft (105), the motor (103) is fixed to the lower surface of the grinding cylinder (100), and a grinding assembly (200) is fixedly sleeved on the rotating shaft (105), characterized in that: The grinding assembly (200) includes a lower connecting plate (201), on which a plurality of grinding stones (202) are arranged in a circular pattern. Each grinding stone (202) is provided with a connecting shaft (202a). The grinding stones (202) rotate through the connecting shaft (202a), and an upper connecting plate (203) covers the grinding stones (202). The inner wall of the crushing cylinder (100) is provided with a plurality of grooves (100b). A grinding ring (104) is fitted into each groove (100b). A gap is maintained between the grinding ring (104) and the grinding assembly (200). The raw material falls into the gap and is processed by the revolution of the grinding assembly (200). The self-rotating grinding of the grinding wheel (202) produces powder. The grinding cylinder (100) has multiple air channels (100a) inside its wall. The bottom of the air channel (100a) is connected to the inside of the grinding cylinder (100). The outer wall of the grinding cylinder (100) has side holes (100c). A sealing cover (101) is installed on the upper surface of the grinding cylinder (100). A powder collecting pipe (101a) is connected to the upper surface of the sealing cover (101). An induced draft fan is connected to the end of the powder collecting pipe (101a). The induced draft fan draws out the powder and creates a negative pressure inside the grinding cylinder (100). After the flour falls, it enters the powder collecting pipe (101a) through the air channel (100a) to be collected.

2. The flour mill according to claim 1, characterized in that: The lower connecting plate (201) has multiple positioning grooves (201a) in a circular pattern. The lower end of the connecting shaft (202a) is inserted into the positioning groove (201a). The upper connecting plate (203) has a shaft hole (203a) for the connecting shaft (202a) to pass through, and the depth of the shaft hole (203a) is equal to the length of the upper end of the connecting shaft (202a).

3. The flour mill according to claim 2, characterized in that: The upper surface of the lower connecting plate (201) is provided with a support ring (201b) in the center, and the upper connecting plate (203) overlaps on the support ring (201b). The upper connecting plate (203) and the support ring (201b) are provided with screw holes, and the upper connecting plate (203) is fixed on the support ring (201b) by screws.

4. The flour mill according to claim 1, characterized in that: The inner surface of the grinding ring (104) is a concave arc surface. The grinding piece (202) protrudes from the edge of the lower connecting plate (201) and the upper connecting plate (203). The side of the grinding piece (202) is a convex arc surface. The concave arc surface of the grinding ring (104) and the convex arc surface of the grinding piece (202) are adapted to coincide with their arc center. A gap is maintained between the concave arc surface and the convex arc surface, and the flour raw material enters the gap to achieve grinding.

5. The flour mill according to claim 4, characterized in that: The concave arc surface of the grinding ring (104) is uniformly provided with a plurality of grinding teeth (104a), and the grinding teeth (104a) are inclined. The protruding arc surface of the grinding ring (202) is provided with a plurality of ridge grooves at equal intervals, and the ridge grooves are opened vertically. The included angle between the grinding teeth (104a) and the ridge grooves is an acute angle.

6. The flour mill according to claim 1, characterized in that: The bottom of the rotating shaft (105) is fixedly fitted with a material tray (106). The surface of the material tray (106) is inclined, and the diameter of the material tray (106) is smaller than the inner diameter of the crushing cylinder (100). The flour is piled up between the material tray (106) and the crushing cylinder (100) to facilitate negative pressure adsorption.

7. The flour mill according to claim 1, characterized in that: The grinding cylinder (100) is fixedly installed with a grinding disc (107) at its upper end. The edge of the grinding disc (107) is an upper inclined surface, and the grinding disc (107) has uniformly opened material leakage holes on its horizontal surface. The grinding disc (107) has a round hole in the center for the rotating shaft (105) to pass through. The round hole and the rotating shaft (105) are connected by a bearing.

8. The flour mill according to claim 7, characterized in that: The upper surface of the rotating shaft (105) is integrally connected with a convex shaft (105b), and a bushing (108) is sleeved on the convex shaft (105b). Multiple cylinders are circumferentially mounted on the side of the bushing (108), and a grinding roller (108a) is rotatably sleeved on the cylinder. The grinding roller (108a) is in contact with the upper surface of the grinding disc (107). A screw hole is opened on the upper surface of the convex shaft (105b), and an end cap (105c) is threadedly connected to the screw hole.

9. The flour mill according to claim 7, characterized in that: The side of the rotating shaft (105) is integrally connected with a flat key (105a), and keyways are provided on the components that are fixedly sleeved with the rotating shaft (105).

10. A method of using a flour mill, for operating the flour mill described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Start the motor (103) to drive the rotating shaft (105) to rotate, causing the grinding assembly (200) to revolve as a whole, and at the same time causing the grinding stones (202) on the grinding assembly (200) to rotate around their own connecting shaft (202a); S2: The raw material is fed into the crushing cylinder (100) through the feed hopper (102). The raw material falls into the gap between the grinding ring (104) and the grinding component (200). It is ground into powder by the revolution of the grinding component (200) and the rotation of the grinding wheel (202). S3: Turn on the external blower. The negative pressure is formed in the grinding cylinder (100) through the powder collection pipe (101a) on the sealing cover (101). The ground flour enters the powder collection pipe (101a) through the air passage (100a) in the wall thickness of the grinding cylinder (100) to complete the flour collection.

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