A dry grinding equipment for processing lithium battery raw materials

Abstract

This invention discloses a dry grinding equipment for processing lithium battery raw materials, belonging to the field of lithium battery production technology. It includes: a grinding mechanism comprising a hydraulic coupling drive system and a grinding structure, wherein the output speed of the hydraulic coupling drive system is inversely proportional to the resistance generated by the grinding structure during grinding; a feeding mechanism, which controls the feeding amount of the feeding mechanism through the hydraulic coupling drive system to ensure that the amount of material in the grinding structure is always within the permissible load range; and a discharge structure, which uses airflow in conjunction with the discharge structure to screen powder of acceptable size, and cleans the discharge structure through the feeding mechanism to ensure stable discharge. Thus, by utilizing the negative correlation between the output speed of the hydraulic coupling drive system and the load, the state of the grinding core is converted into a power signal in real time. This signal drives the sealing sleeve through linkage components to adjust the opening of the feeding port, forming instant feedback and enabling sensitive response to changes in the material content within the grinding chamber. The equipment always operates within the optimal load cycle.

Description

Technical Field

[0001] This invention relates to a dry grinding equipment for processing lithium battery raw materials, belonging to the field of lithium battery production technology. Background Technology

[0002] Lithium-ion batteries are rechargeable batteries that use the migration of lithium ions between positive and negative electrodes to achieve charging and discharging. They possess core advantages such as high energy density, long cycle life, and low self-discharge rate, and are widely used in consumer electronics, electric vehicles, and energy storage systems. The raw materials for lithium-ion batteries mainly include positive electrode materials, such as lithium iron phosphate and ternary nickel-cobalt-manganese oxide; negative electrode materials, primarily graphite with some silicon-carbon composites; and electrolytes, such as lithium hexafluorophosphate dissolved in organic solvents like ethylene carbonate and dimethyl carbonate, and polyolefin separators. The preparation of the positive and negative electrode active powders widely employs dry grinding processes. This process, in a solvent-free environment, uses high-energy ball milling or air jet milling to achieve ultra-fine and uniform mixing of raw materials, significantly improving specific surface area and particle consistency, thereby enhancing lithium-ion diffusion rate and electrochemical performance. Especially in the dry electrode technology promoted by Tesla, this process is further extended to solvent-free binder fibrillation molding, where PTFE fibers encapsulate the active material to form a self-supporting film, significantly increasing the compaction density of lithium iron phosphate to 3.05 g / cm³. 3 This improves efficiency by 32.6% and avoids the high energy consumption and environmental risks of NMP solvent recovery in wet processes, making it a core path for the manufacturing of next-generation high-energy-density batteries.

[0003] In the field of lithium battery raw material processing, dry grinding equipment is widely used for the ultrafine processing of positive and negative electrode materials to improve electrochemical performance. In existing technologies, the hopper of grinding equipment usually adopts a fully enclosed structure to prevent contamination. However, the feed rate control relies on the statistical calculation of the discharge pipe. This method has significant drawbacks. The discharge pipe may produce measurement errors due to material residue or airflow fluctuations, resulting in inaccurate statistics. At the same time, the pipeline delay makes the feeding operation unable to respond to changes in the material in the hopper in real time, which can easily lead to overfeeding or underfeeding. For example, when the discharge rate fluctuates due to equipment wear or blockage, the delayed feedback will exacerbate the control lag, affecting the grinding uniformity and production efficiency. To solve the above problems, a dry grinding equipment that can directly monitor the hopper status and dynamically adjust the feed rate is needed to achieve accurate and timely material feeding control. Summary of the Invention

[0004] The purpose of this invention is to provide a dry grinding equipment for processing lithium battery raw materials, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: Compared with the prior art, the present invention provides a dry grinding equipment for processing lithium battery raw materials, comprising: A grinding mechanism includes a hydraulic coupling drive system and a grinding structure, wherein the output rotational speed of the hydraulic coupling drive system is inversely proportional to the resistance generated by the grinding structure during grinding; The feeding mechanism is located above the grinding structure. The feeding amount of the feeding mechanism is controlled by the hydraulic coupling drive system to ensure that the amount of material in the grinding structure is always within the load range. The discharge structure is located above the feeding mechanism. It uses airflow to screen powders that meet the required size. The feeding mechanism cleans the discharge structure to ensure stable discharge.

[0006] Furthermore, the grinding structure includes: The grinding chamber and the stirring shaft disposed within the grinding chamber are used to crush and grind the material.

[0007] Furthermore, the feeding mechanism includes: A feeding bin, wherein a feeding port is provided on the side wall of the feeding bin; The movable sleeve is installed inside the feeding hopper by means of a linkage opening and closing mechanism; A sealing sleeve is fitted onto the inner wall of the discharge hopper and connected to the movable sleeve. It rises and falls synchronously with the movable sleeve and is used to open or close the discharge port of the discharge hopper.

[0008] Furthermore, the linkage opening and closing component includes: An airflow screening chamber is located between the feeding chamber and the grinding structure, and its side wall is provided with an airflow pipe for introducing screening airflow. A centrally located rotating shaft is rotatably inserted through the airflow screening chamber and is connected to the output end of the hydraulic coupling drive system. The movable sleeve is coaxially slidably fitted onto the outside of the central rotating shaft and can rotate with the central rotating shaft.

[0009] Furthermore, the outer wall of the movable sleeve is fixedly fitted with fan blades; the fan blades are externally fixedly supported by a sealing sleeve, and the sleeve also includes: A limiting ring located within the feeding hopper is used to limit the extreme positions of the rising of the movable sleeve and the sealing sleeve.

[0010] Furthermore, the hydraulic coupling drive system includes: Hydraulic chamber; A drive motor, the output shaft of which extends into the hydraulic chamber and is connected to an active pump wheel, the active pump wheel having active fan blades on its outer side; The driven hydraulic impeller is rotatably mounted in the hydraulic chamber via bearings and is positioned opposite to the driving pump impeller. The inner side of the driven hydraulic impeller is provided with a fluid flow protrusion and a driven fan blade. The power shaft is fixedly mounted inside the driven hydraulic wheel, and its top end is fixedly connected to the bottom surface of the stirring shaft.

[0011] Furthermore, the outer wall of the grinding chamber is provided with a heat dissipation sleeve, and the outer wall of the grinding chamber is embedded with a heat-conducting block that connects the inside and outside. A heat exchange pipe is connected to the heat dissipation sleeve.

[0012] Furthermore, the discharge structure includes: A discharge hopper is located above the feeding hopper, and a discharge pipe is fixedly installed on the top of the discharge hopper; The filter cloth body is located in the discharge hopper and is used to screen the ground powder.

[0013] Furthermore, it also includes a cleaning sleeve, which is fixedly installed above the feeding mechanism, and the bottom end of the discharge pipe is supported by a support frame for supporting the filter cloth body.

[0014] Furthermore, the material feeding hopper is externally fitted with a material feeding sleeve that is fitted outside the material feeding port. The material feeding sleeve is internally fitted with a material feeding guide block. The material feeding sleeve is externally provided with a feeder for replenishing material to the material feeding sleeve.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By utilizing the negative correlation between the output speed and load of the hydraulic coupling drive system, the state of the grinding core is converted into a power signal in real time. The signal is then used to drive the sealing sleeve through the linkage components to adjust the opening of the feed port. This creates an instant feedback mechanism where the load resistance increases, the drive speed decreases, and the feed opening decreases. This allows for sensitive response to changes in the amount of material in the grinding chamber, ensuring that the equipment always operates within the optimal load cycle. This improves grinding efficiency, stabilizes product quality, and reduces energy consumption and the risk of equipment overload.

[0016] The cleaning sleeve is connected to the movable sleeve or sealing sleeve used to adjust the material feeding. The material feeding is controlled during the lifting and lowering of the movable sleeve due to the load, while the cleaning sleeve is lifted and lowered synchronously. This continuously scrapes off the coarse particles attached to the surface of the filter cloth, and performs real-time active cleaning of the filter element to prevent the filter screen from clogging easily and requiring machine shutdown for cleaning. This ensures the efficiency and stability of the material screening.

[0017] The equipment features a robust and stable structural design. Its hydraulic coupling drive system avoids overload slip protection, absorbs startup impacts, and prevents instantaneous overloads, effectively protecting core components such as the drive motor and stirring shaft. This enhances the inherent safety and lifespan of the equipment. The active heat dissipation design effectively dissipates grinding heat, ensuring material performance and the equipment's sustained stable operation. The entire system is based on a physical and mechanical structure, offering strong anti-interference capabilities, easy maintenance, high stability, low maintenance costs, and good economic benefits. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the disassembled structure of the present invention; Figure 3 This is a schematic diagram of the hydraulic chamber structure of the present invention; Figure 4 This is a schematic diagram of the heat sink structure of the present invention; Figure 5 This is a schematic diagram of the airflow screening chamber structure of the present invention; Figure 6 This is a schematic diagram of the sealing sleeve structure of the present invention; Figure 7 This is a schematic diagram of the material feeding hopper structure of the present invention; Figure 8 This is a schematic diagram of the feeding sleeve structure of the present invention; Figure 9 This is a schematic diagram of the filter cloth structure of the present invention.

[0020] In the diagram: 1. Grinding chamber; 2. Airflow screening chamber; 3. Feeding chamber; 4. Discharge chamber; 5. Hydraulic chamber; 6. Drive motor; 7. Active pump wheel; 8. Active fan blade; 9. Driven hydraulic wheel; 10. Power shaft; 11. Liquid flow protrusion; 12. Driven fan blade; 13. Stirring shaft; 14. Heat dissipation sleeve; 15. Heat conduction block; 16. Airflow duct; 17. Connecting shaft; 18. Central rotating shaft; 19. Movable sleeve; 20. Fan blade; 21. Sealing sleeve; 22. Limiting ring; 23. Feeding sleeve; 24. Feeding guide block; 25. Feeder; 26. Discharge duct; 27. Support frame; 28. Filter cloth body; 29. ​​Cleaning sleeve; 30. Exchanger duct. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0022] Please see Figure 1-9 This invention provides a dry grinding device for processing lithium battery raw materials: The equipment mainly includes, from top to bottom: discharge bin 4, feed bin 3, airflow screening bin 2 and grinding bin 1, as well as an external support frame. The feeder 25 is used to replenish raw materials. The hydraulic coupling drive system is connected to the control mechanism in the feed bin 3 through transmission components such as connecting shaft 17. The amount of material in the grinding structure is always within the permissible load range.

[0023] Grinding and driving section: Grinding chamber 1 is the main cavity for material crushing. Inside it is a stirring shaft 13 driven by a hydraulic coupling drive system, which can hold grinding media such as grinding balls.

[0024] Hydraulic coupling drive system: See Figure 3 The drive motor 6 drives the active pump wheel 7 and its active fan blade 8 to rotate, stirring the hydraulic oil in the hydraulic chamber 5 to form a high-speed oil flow. The oil flow impacts the fluid flow protrusion 11 and the driven fan blade 12 on the inner side of the driven hydraulic wheel 9, thereby driving the driven hydraulic wheel 9 to rotate. The power is transmitted to the stirring shaft 13 through the power shaft 10. The core characteristic of this system is that the output speed is automatically and steplessly adjusted according to the load, that is, the grinding resistance experienced by the stirring shaft 13. The greater the load, the greater the slip, and the lower the output speed.

[0025] Heat dissipation design: see Figure 4 The heat generated during grinding is conducted through the heat-conducting block 15 embedded in the wall of the grinding chamber 1 to the space between the external heat dissipation sleeve 14 and the grinding chamber 1. The circulating coolant flows through the heat dissipation sleeve 14 through the exchange pipe 30 to achieve efficient heat dissipation.

[0026] Adaptive feeding control section: See Figure 5 , 6 7. The side wall of the feeding bin 3 has a feeding port, and its inner wall is fitted with a liftable sealing sleeve 21 for opening and closing the port. The sealing sleeve 21 is connected to the movable sleeve 19.

[0027] The central rotating shaft 18 passes through the airflow screening chamber 2. Its bottom end is linked to the driven end of the hydraulic coupling system through the connecting shaft 17. Therefore, its rotation speed is synchronized with the rotation speed of the stirring shaft 13. The movable sleeve 19 is slidably mounted on the central rotating shaft 18 and can rotate accordingly. Its outer wall is equipped with fan blades 20.

[0028] Pneumatic actuation: A constant upward airflow from the airflow duct 16 enters the airflow screening chamber 2. When the movable sleeve 19 rotates with the central rotating shaft 18, the fan blade 20 rotates in the airflow to generate lift. This lift drives the movable sleeve 19 to slide upward along the central rotating shaft 18, thereby driving the sealing sleeve 21 to rise and opening the discharge port. The limiting ring 22 prevents it from moving too high, causing the movable sleeve 19 to detach from the central rotating shaft 18.

[0029] When the grinding resistance increases, the output speed of the hydraulic coupling system, i.e., the speed of the central rotating shaft 18, decreases. The speed of the fan blade 20 decreases synchronously, and the resulting lift decreases. Under the action of gravity, the movable sleeve 19 and the sealing sleeve 21 sink, closing the feed port and reducing the feed. Conversely, when the resistance decreases, the speed increases, the lift increases, the feed port opens wider, and the feed increases.

[0030] Screening and self-cleaning section: See Figure 1 , 9 The discharge hopper 4 is located at the top, and its interior is equipped with a filter cloth body 28 supported by a support frame 27, with the top connected to the discharge pipe 26.

[0031] The ground powder is carried upward by the rising airflow in the airflow screening chamber 2. Powder with qualified fineness passes through the filter cloth body 28 and is collected through the discharge pipe 26; unqualified coarse particles are blocked by the filter cloth body 28 and fall back into the grinding chamber 1 for further grinding.

[0032] Self-cleaning: The cleaning sleeve 29 is fixedly installed above the movable sleeve 19. When the movable sleeve 19 moves up and down due to the adjustment of the feeding, the cleaning sleeve 29 moves up and down synchronously. It continuously scrapes the surface of the filter cloth body 28, scraping off the coarse particles attached to it, effectively preventing the filter screen from clogging, ensuring smooth airflow and long-lasting screening efficiency.

[0033] Auxiliary material feeding section: See Figure 7 , 8 The material feeding hopper 3 can be connected to the material feeding sleeve 23, and the material feeding guide block 24 inside it ensures that the material falls smoothly. The feeder 25 is used to continuously replenish the raw materials to the system.

[0034] The workflow of this embodiment is as follows: The power source drive motor 6 is started, and the output shaft of the drive motor 6 drives the active pump wheel 7 to rotate, which in turn drives the active fan blade 8 outside the active pump wheel 7 to rotate. During the rotation of the active pump wheel 7 and the active fan blade 8, the hydraulic oil in the inner cavity of the hydraulic chamber 5 will impact the liquid flow protrusion 11 and the driven fan blade 12 on the inner side of the driven liquid wheel 9, thereby driving the driven liquid wheel 9 to rotate. The drive shaft 10 is used to rotate, so that the driven liquid wheel 9 drives the stirring shaft 13 to start at low speed inside the grinding chamber 1. At the beginning, there is no material to be ground inside the grinding chamber 1, the resistance is small, and the drive system speed is relatively fast.

[0035] The rotation of the drive system transmits the rotational power to the central rotating shaft 18 through the connecting shaft 17. The central rotating shaft 18 drives the outer movable sleeve 19 to rotate synchronously. At the same time, the airflow is delivered to the inner cavity of the airflow screening chamber 2 through the airflow pipe 16 on the outside of the airflow screening chamber 2, so that the airflow forms an upward airflow in the inner cavity of the airflow screening chamber 2. With the rotation of the movable sleeve 19 driving the fan blade 20 to rotate synchronously and the upward airflow, the fan blade 20 and the movable sleeve 19 are pushed to move upward outside the central rotating shaft 18. At the same time, the sealing sleeve 21 is lifted, so that the outer discharge chute of the discharge chamber 3 is opened, and the material inside the discharge sleeve 23 slides into the interior of the discharge chamber 3 through the discharge guide block 24. At the same time, the feeder 25 replenishes the material in time, and then it continues to fall downward into the interior of the grinding chamber 1. Grinding is carried out through the cooperation of the grinding chamber 1 and the stirring shaft 13. During the process of the sealing sleeve 21 rising, the limiting ring 22 will block and limit the highest position of the sealing sleeve 21 to prevent the movable sleeve 19 from detaching from the central rotating shaft 18.

[0036] During the grinding process, the resistance of the stirring shaft 13 increases due to the interaction of the material and grinding media in the grinding chamber 1 and the stirring shaft 13, which in turn leads to a decrease in the rotational speed of the stirring shaft 13. The resistance is fed back to the internal hydraulic system, increasing the load on the driven hydraulic wheel 9, which in turn leads to a decrease in the output speed of the hydraulic system. After the speed decreases, it will simultaneously affect the speed of the movable sleeve 19, which will then transmit a low speed signal to the sealing sleeve 21 to reduce the amount of material fed until the feeding port is closed. Conversely, if the material in the grinding chamber 1 is ground and discharged, the resistance decreases, the speed of the drive system increases, and the linkage mechanism will increase the opening of the feeding port to increase the feeding. This forms a closed-loop control, keeping the grinding workload at an appropriate level. During the grinding process, the high temperature inside the grinding chamber 1 is conducted outward through the heat-conducting block 15 to the inner cavity of the heat dissipation sleeve 14. The heat exchange pipe 30 continuously exchanges water into the inner cavity of the heat dissipation sleeve 14 to assist in efficient heat dissipation.

[0037] During the grinding process, the crushed material rises under the action of the upward airflow entering the airflow pipe 16. Powder with a qualified mesh size passes through the filter cloth 28 for screening and is collected through the discharge pipe 26. Particles with an unqualified mesh size cannot pass through the filter cloth 28 and fall back down to continue grinding. During the process of the movable sleeve 19 lifting and closing to feed, the movable sleeve 19 will simultaneously support the cleaning sleeve 29 to lift and lower, scraping off the coarse particles attached to the surface of the filter cloth 28 to prevent clogging and ensure the continuity of screening efficiency. The support frame 27 supports the filter cloth 28 internally to prevent the filter cloth 28 from collapsing under the action of airflow, which would affect the filtration efficiency. The discharge chamber 4, together with the grinding chamber 1, the airflow screening chamber 2, and the feeding chamber 3, forms a closed space, which guides the airflow to be discharged from the discharge pipe 26.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dry grinding equipment for processing lithium battery raw materials, characterized in that, include: A grinding mechanism includes a hydraulic coupling drive system and a grinding structure, wherein the output rotational speed of the hydraulic coupling drive system is inversely proportional to the resistance generated by the grinding structure during grinding; The feeding mechanism is located above the grinding structure. The feeding amount of the feeding mechanism is controlled by the hydraulic coupling drive system to ensure that the amount of material in the grinding structure is always within the load range. The discharge structure is located above the feeding mechanism. It uses airflow to screen powders that meet the required size. The feeding mechanism cleans the discharge structure to ensure stable discharge.

2. The dry grinding equipment for processing lithium battery raw materials according to claim 1, characterized in that, The grinding structure includes: The grinding chamber (1) and the stirring shaft (13) disposed in the grinding chamber (1) are used to crush and grind the material.

3. The dry grinding equipment for processing lithium battery raw materials according to claim 1, characterized in that, The feeding mechanism includes: The material feeding bin (3) has a material feeding port on its side wall; The movable sleeve (19) is installed inside the unloading bin (3) by means of a linkage opening and closing component; The sealing sleeve (21) is fitted on the inner wall of the feeding bin (3) and connected to the movable sleeve (19). It rises and falls synchronously with the movable sleeve (19) and is used to open or close the feeding port of the feeding bin (3).

4. The dry grinding equipment for processing lithium battery raw materials according to claim 3, characterized in that, The linkage opening and closing component includes: An airflow screening chamber (2) is located between the feeding chamber (3) and the grinding structure, and its side wall is provided with an airflow pipe (16) for introducing screening airflow. A centrally located rotating shaft (18) is rotatably inserted through the airflow screening chamber (2) and is connected to the output end of the hydraulic coupling drive system. The movable sleeve (19) is slidably fitted on the outside of the central rotating shaft (18) and can rotate with the central rotating shaft (18).

5. The dry grinding equipment for processing lithium battery raw materials according to claim 4, characterized in that, The outer wall of the movable sleeve (19) is fixedly fitted with fan blades (20); the fan blades (20) are externally fixedly supported by a sealing sleeve (21), and also include: A limiting ring (22) is provided in the feeding bin (3) to limit the extreme position of the rising of the movable sleeve (19) and the sealing sleeve (21).

6. The dry grinding equipment for processing lithium battery raw materials according to claim 2, characterized in that, The hydraulic coupling drive system includes: Hydraulic chamber (5); The drive motor (6) has its output shaft extending into the inner cavity of the hydraulic chamber (5) and connected to the active pump wheel (7). The active pump wheel (7) has an active fan blade (8) on its outer side. The driven hydraulic wheel (9) is rotatably disposed in the hydraulic chamber (5) via a bearing and is disposed opposite to the driving pump wheel (7). The inner side of the driven hydraulic wheel (9) is provided with a liquid flow protrusion (11) and a driven fan blade (12). The power shaft (10) is fixedly mounted on the inner side of the driven liquid wheel (9), and its top end is fixedly connected to the bottom surface of the stirring shaft (13).

7. The dry grinding equipment for processing lithium battery raw materials according to claim 6, characterized in that, The grinding chamber (1) is provided with a heat dissipation sleeve (14) on its outer wall. A heat-conducting block (15) connecting the inside and outside is embedded in the outer wall of the grinding chamber (1). A heat exchange pipe (30) is connected to the heat dissipation sleeve (14).

8. The dry grinding equipment for processing lithium battery raw materials according to claim 3, characterized in that, The discharge structure includes: The discharge bin (4) is located above the feeding bin (3), and the top of the discharge bin (4) is fixedly fitted with a discharge pipe (26). The filter cloth body (28) is set in the discharge hopper (4) and is used to screen the ground powder.

9. A dry grinding apparatus for processing lithium battery raw materials according to claim 8, characterized in that, It also includes a cleaning sleeve (29), which is fixedly installed above the movable sleeve (19), and the bottom end of the discharge pipe (26) is supported by a support frame (27) for supporting the filter cloth body (28).

10. A dry grinding apparatus for processing lithium battery raw materials according to claim 3, characterized in that, The material feeding hopper (3) is fixedly fitted with a material feeding sleeve (23) fitted outside the material feeding port. The material feeding sleeve (23) is fitted with a material feeding guide block (24) inside. The material feeding sleeve (23) is provided with a feeder (25) for replenishing material to the material feeding sleeve (23) outside.

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