A bearing protection device for a mechanical classifier mill
By employing a dual-bearing structure and comprehensive protection measures, the problems of lubrication, airtightness, and bearing clearance in the bearing system of the mechanical classifier mill were solved, achieving efficient protection of the bearings and stable operation of the equipment, thereby improving the capacity and product quality of the classifier mill.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NETZCH (SHANGHAI) MASCH & INSTR CO LTD
- Filing Date
- 2025-09-15
- Publication Date
- 2026-06-26
AI Technical Summary
Existing mechanical classifier bearing systems have defects in lubrication, airtightness, and bearing clearance, which lead to accelerated bearing wear, poor equipment stability, and reduced service life.
The dual-bearing structure, through independent drive of hollow and solid shafts, combined with lubrication system, gas seal ring and pressure spring support, achieves uniform distribution and effective lubrication of bearings, eliminates bearing inner ring clearance, and adjusts gas seal clearance to protect bearings.
It significantly reduces bearing load, improves the grinding and grading efficiency of the equipment, extends bearing service life, and ensures the stability and high productivity of the equipment during efficient operation.
Smart Images
Figure CN224414882U_ABST
Abstract
Description
[Technical Field]
[0001] This utility model relates to the field of mechanical classifying mill technology, specifically a bearing protection device for a mechanical classifying mill. [Background Technology]
[0002] A mechanical classifying mill is a process that uses a dual-shaft design, controlled by grinding conditions, to drive a grinding disc and a classifying wheel with two motors of different power. This creates a relative speed difference, and the grinding disc grinds large particles into smaller ones, while the classifying wheel performs the classification, thus separating materials according to different particle sizes. Its core principle is to effectively separate materials of different sizes using mechanical, fluid, and centrifugal forces. High-speed airflow propels the particles, causing them to collide with the grinding disc and classifying wheel. The centrifugal force generated by the grinding disc throws the particles towards the classifying wheel; finer particles are discharged through the gaps between the classifying wheel blades, while coarser particles fall back into the grinding zone, thereby improving grinding efficiency and product uniformity. Through its integrated grinding and classification design, the classifying mill reduces over-grinding and energy consumption, saving 20%-40% more energy than traditional mills. It is an important piece of equipment for the efficient and selective pulverization of materials and is widely used in the production of ultrafine powders, pharmaceuticals, food, and new energy industries.
[0003] Furthermore, many existing bearing systems currently face various challenges during operation, with bearing protection defects concentrated in lubrication and sealing aspects. These shortcomings directly affect bearing lifespan and equipment stability. The main problems and technical drawbacks are as follows:
[0004] (1) Defects in the lubrication system: The bearing cooling device in patent publication number CN110770459A uses a fluid storage tank and built-in heat sinks for cooling to ensure that the bearing temperature will not rise sharply in a short period of time. However, if the equipment operates at high speed for a long time, the internal structure does not have a good heat exchange device from the inside to the outside. Moreover, the grinding disc and the grading wheel in the structure are driven by the same drive shaft. All transmission is transmitted through the thrust bearing, which makes the bearing bear a large load. In addition, the cooling effect is not obvious, which will aggravate the wear of the bearing.
[0005] (2) Defects in the air seal structure: Patent publication number CN101216111 uses compressed air to form its air seal cavity, which can prevent waste oil and fine dust from entering the electric spindle bearing, thereby protecting the bearing. However, since this structure cannot adjust the size of its gap, it is difficult to form the most effective seal under the premise of protecting the bearing. If the gap is too large, dust will enter; if the gap is too small, heat dissipation will be difficult, which will also lead to damage to the bearing.
[0006] (3) Elimination of bearing clearance defects: Patent publication number CN 114274443 A effectively eliminated the clearance between the inner and outer rings of the bearing by adjusting the shims. When the shaft rotates at high speed, the rotor may move due to centrifugal force. Therefore, it has certain drawbacks for high-speed rotating shafts and its application is limited. [Utility Model Content]
[0007] The purpose of this invention is to address the aforementioned shortcomings by providing a bearing protection device for a mechanical classifying mill, which can improve the service life of the bearing, reduce bearing wear and failure risk, and thus improve the grinding and classification effect of the equipment.
[0008] To achieve the above objectives, a bearing protection device for a mechanical classifying mill is designed, comprising a frame 17, a grinding disc 9, a classifying wheel 10, and a grinding chamber 1. The grinding chamber 1 is fixed on the frame 17, and its position is located in the middle of the frame 17. A main motor 3 and a main motor 4 are respectively installed on both sides of the frame 17. A classifying wheel drive 7 and a grinding disc drive 6 are respectively installed at the output ends of the main motor 3 and the main motor 4. The grinding disc drive 6 and the classifying wheel drive 7 are respectively connected to a hollow shaft 14 and a solid shaft 15 via V-belts. The solid shaft 15 is placed inside the hole of the hollow shaft 14. The grinding disc... The grading wheel 10 is mounted on the hollow shaft 14 and located inside the grinding chamber 1. The grading wheel 10 is mounted on the solid shaft 15 and located above the grinding disc 9 inside the chamber. The hollow shaft 14 is provided with large bearings 20 at its upper and lower ends and is supported by the large bearings 20. The solid shaft 15 is provided with small bearings 21 at its upper and lower ends and is supported by the small bearings 21. The outer ring of the grinding disc 9 is provided with a toothed grinding ring 13. An air guide ring 16 is provided on the lower side of the grinding chamber 1. The air guide ring 16 is located below the toothed grinding ring 13 and is used to fully guide the airflow to the upper part of the chamber.
[0009] Furthermore, both the hollow shaft 14 and the solid shaft 15 are located inside the grinding chamber 1. Both the hollow shaft 14 and the solid shaft 15 are fixed to the bottom of the chamber through mounting holes on the bearing seat, thereby preventing the machine from vibrating during high-speed rotation.
[0010] Furthermore, a pressure spring 18 is circumferentially arranged around the bottom of the bearing housing, and the pressure spring 18 supports the outer ring of the bearing. The inner ring of the bearing is positioned by a bushing, thereby making the inner and outer rings of the bearing completely positioned, which not only provides support and shock absorption, but also effectively eliminates the gap in the inner ring of the bearing.
[0011] Furthermore, an air sealing ring 12 is installed on the cavity cover at the top of the grinding chamber 1. The air sealing ring 12 is coated and is located between the grading wheel 10 and the cavity cover. The air sealing ring 12 is used to prevent dust and material accumulation at the grading wheel 10 and the cavity cover, which could lead to wear of the grading wheel and damage to the bearing.
[0012] Furthermore, a thin shim 19 is provided below the grading wheel 10, and the gap between the grading wheel 10 and the cavity cover is adjusted by varying the thickness of the thin shim 19, which effectively protects the bearing and achieves the goal of high production and high efficiency.
[0013] Furthermore, a diffusion ring 8 is installed inside the grinding chamber 1. The diffusion ring 8 is located below the grinding disc 9. The diffusion ring 8 is designed with angled guide vanes along the circumference, and the guide vanes guide the airflow to distribute the material evenly throughout the grinding area.
[0014] Furthermore, it also includes an immersion ring 11, which is located in the inner hole of the classifier 10. Fine particulate material is discharged from the top of the classifier 10 through the immersion ring 11 in the classifier 10, so that the whole device can be well integrated into the production process of the closed-loop system.
[0015] Furthermore, it also includes a lubrication system 2, which includes a lubrication system motor, a lubrication system pump, and a lubrication system oil tank. The liquid oil in the lubrication system oil tank is driven by the lubrication system motor and the lubrication system pump, and is delivered through a distributor and high-pressure hose to the two large bearings 20 of the hollow shaft 14. The bottom of the solid shaft 15 is provided with an oil nozzle, and grease is periodically injected through the oil nozzle. The grease covers the entire small bearing 21, so that the temperature will not rise rapidly even during high-speed rotation.
[0016] Compared with the prior art, this utility model has the following advantages:
[0017] (1) This utility model uses two main motors to drive the hollow shaft and the solid shaft. The bearings are arranged at different positions on the two shafts, so as to evenly distribute the weight of the load on the shaft, greatly reduce the load on the bearing, effectively protect the bearing, and thus improve the grinding and grading effect of the equipment.
[0018] (2) The lubrication system of this utility model can uniformly supply oil to the drive shaft at a set rate of 1.7L per minute through the oil distributor in the circuit. The liquid oil in the circuit plays a sufficient lubricating role for the bearing and at the same time carries away a large amount of heat in the cavity. During the oil return process, it is ensured that the oil returns freely to the oil tank. The optimal angle of the oil pipe is set to 3 degrees (see attached diagram). Figure 2This ensures that the equipment is in a stable working state, preventing the bearing temperature from rising too quickly due to high-speed grinding and grading, which could lead to equipment shutdown and guarantee high quality and high productivity.
[0019] (3) The airtight effect of this utility model is achieved by using an attached... Figure 4 The gap between the grading wheel and the end cap is adjusted to the optimal gap using different thicknesses of shims, thereby better ensuring the bearing, guaranteeing the fineness of the graded particles, and improving the grading quality.
[0020] (4) The way this utility model eliminates bearing clearance is to use 40 pressure springs at the bottom of the bearing housing to provide certain support for the outer ring of the bearing, and to use a bushing to position the inner ring, thereby ensuring that the inner and outer rings of the bearing are completely positioned. Even during the high-speed operation of the rotor, the bearing will not move at all. This not only provides support and shock absorption, but also effectively eliminates the clearance of the inner ring of the bearing, which is very beneficial to the protection of the bearing.
[0021] (5) Before the dual shafts of the classifier mill are running, the lubrication system can be turned on for about 10-15 seconds to fill the entire oil circuit with liquid oil. At this time, the dual shafts are driven by two motors. Due to the centrifugal force, the classifier wheels on the solid shaft will inevitably have a lateral movement due to the bearing clearance. At this time, the 40 springs in the transmission shaft assembly can effectively eliminate the clearance and prevent the lateral movement, thus efficiently ensuring the stability of the classifier wheel operation.
[0022] (6) In order to ensure that the bearing is not blocked by the product and thus not cause additional load, and to ensure the fineness and uniformity of the graded product, this utility model adopts an air-tight structure at the product outlet after grading by the grading wheel. The most effective distance between the grading wheel and the cavity cover is adjusted by thin gaskets, which effectively protects the bearing and achieves the goal of high production and high efficiency. [Image Description]
[0023] Figure 1a This is a schematic diagram of the structure of this utility model;
[0024] Figure 1b This is a schematic diagram of the structure of this utility model. Figure 2 ;
[0025] Figure 2 This is a schematic diagram of the bearing housing pressure spring arrangement of this utility model;
[0026] Figure 3 This is a structural schematic diagram of the solid shaft, hollow shaft, and bearing in the transmission shaft assembly of this utility model;
[0027] Figure 4 This is a schematic diagram of the gap between the air sealing ring and the grader at the cavity cover of this utility model;
[0028] Figure 5 This is a schematic diagram of the oil circuit lubrication system and the arrangement of the staged mill of this utility model;
[0029] Figure 6 This is a schematic diagram of the arrangement of the lubricating oil pipe and drive shaft assembly of this utility model;
[0030] In the diagram: 1. Grinding chamber; 2. Lubricating oil system; 3. Main motor one; 4. Main motor two; 5. Transmission shaft assembly; 6. Grinding disc drive; 7. Grading wheel drive; 8. Diffuser ring; 9. Grinding disc; 10. Grading wheel; 11. Immersion ring; 12. Air seal ring; 13. Toothed grinding ring; 14. Hollow shaft; 15. Solid shaft; 16. Air guide ring; 17. Frame; 18. Pressure spring; 19. Thin gasket; 20. Large bearing; 21. Small bearing. [Detailed Implementation]
[0031] As attached Figure 1a Appendix Figure 1b and appendix Figure 2 To be continued Figure 6 As shown, this utility model relates to a protection device for the bearing of a classifying mill that combines a mechanical impact mill with an integrated dynamic air classifier. It improves the service life of the bearing and reduces the risk of bearing wear and failure through multiple protection mechanisms.
[0032] The bearing protection device of the mechanical classifying mill of this utility model includes a frame 17, a grinding disc 9, a classifying wheel 10, and a grinding chamber 1. The grinding chamber 1 is fixed on the frame 17, and the grinding chamber 1 is located in the middle of the frame 17. A main motor 3 and a main motor 4 are respectively installed on both sides of the frame 17. A classifying wheel drive 7 and a grinding disc drive 6 are respectively installed at the output ends of the main motor 3 and the main motor 4. The grinding disc drive 6 and the classifying wheel drive 7 are respectively connected to a hollow shaft 14 and a solid shaft 15 through V-belts. The solid shaft 15 is placed in the hole of the hollow shaft 14. The grading wheel 10 is mounted on the hollow shaft 14 and is located inside the grinding chamber 1. The grading wheel 10 is mounted on the solid shaft 15 and is located above the grinding disc 9 inside the chamber. The hollow shaft 14 is provided with large bearings 20 at its upper and lower ends and is supported by the large bearings 20. The solid shaft 15 is provided with small bearings 21 at its upper and lower ends and is supported by the small bearings 21. The outer ring of the grinding disc 9 is provided with a toothed grinding ring 13. An air guide ring 16 is provided on the lower side of the grinding chamber 1. The air guide ring 16 is located below the toothed grinding ring 13 and is used to fully guide the airflow to the upper part of the chamber.
[0033] Both the hollow shaft 14 and the solid shaft 15 are located inside the grinding chamber 1. Both the hollow shaft 14 and the solid shaft 15 are fixed to the bottom of the chamber through the mounting holes on the bearing seat, which can prevent the machine from vibrating during high-speed rotation. A pressure spring 18 is circumferentially arranged around the bottom of the bearing seat, and the pressure spring 18 supports the outer ring of the bearing. The inner ring of the bearing is positioned by a bushing, so that the inner and outer rings of the bearing are completely positioned, which not only provides support and shock absorption, but also effectively eliminates the gap of the inner ring of the bearing.
[0034] An air sealing ring 12 is installed on the chamber cover at the top of the grinding chamber 1. The air sealing ring 12 is coated and is located between the classifying wheel 10 and the chamber cover. The air sealing ring 12 is used to prevent dust and material accumulation at the classifying wheel 10 and the chamber cover, which would lead to wear of the classifying wheel and damage to the bearing. A thin shim 19 is provided below the classifying wheel 10, and the gap between the classifying wheel 10 and the chamber cover is adjusted by adjusting the thickness of the thin shim 19. This effectively protects the bearing and achieves the goal of high production and high efficiency.
[0035] The grinding chamber 1 is equipped with a diffusion ring 8 and an immersion ring 11. The diffusion ring 8 is located below the grinding disc 9. The diffusion ring 8 is designed with angled guide vanes along the circumference, which guide the airflow and distribute the material evenly throughout the grinding area. The immersion ring 11 is located in the inner hole of the classifying wheel 10. Fine particles are discharged from the classifying wheel 10 from the top through the immersion ring 11, so that the whole equipment can be well integrated into the production process of the closed-loop system.
[0036] It also includes a lubrication system 2, which includes a lubrication system motor, a lubrication system pump, and a lubrication system oil tank. The liquid oil in the lubrication system oil tank is driven by the lubrication system motor and the lubrication system pump, and is delivered through a distributor and high-pressure hose to the two large bearings 20 of the hollow shaft 14. The bottom of the solid shaft 15 is equipped with an oil nozzle, and grease is periodically injected through the oil nozzle. The grease covers the entire small bearing 21, so that the temperature will not rise rapidly even during high-speed rotation.
[0037] This utility model consists of a grinding chamber assembly, a frame assembly, a lubrication system, two motors, a transmission shaft assembly, a grinding disc drive, a classifying wheel drive, a diffuser ring, a grinding disc, a classifying wheel, an immersion ring assembly, an air sealing ring, and a toothed grinding ring. The transmission shaft is composed of a solid shaft and a hollow shaft. This classifying mill primarily disperses material throughout the grinding chamber through an air inlet on the side of the chamber. Airflow is delivered into the chamber through a guide ring at the bottom. Material enters from the top cover of the classifying mill. The diffuser ring within the chamber guides the airflow through its circumferential guide blades, evenly distributing the material throughout the grinding area. The material is cut and pulverized through impact between the hammers on the grinding disc and the grinding toothed ring within the chamber. By adjusting the rotation speed of the classifying wheel, fine particles enter the classifying zone through the gaps between the blades, while coarse particles remain in the grinding area for further grinding. Finally, the fine particles are separated from the top of the classifying wheel through the immersion ring, thus achieving the classification purpose. The entire device can be seamlessly integrated into a closed-loop production system. The combination of solid shaft, hollow shaft, grading wheel and grinding disc in the classifying mill, with the solid shaft and hollow shaft controlled by their respective variable frequency motors, achieves grinding and grading complement each other. The grinding and grading speeds are controlled and adjusted by the frequency converter, which perfectly realizes the beneficial effects of grinding and grading, greatly reduces the load on the single bearing of the original classifying mill, and significantly improves the capacity and service life of the classifying mill.
[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:
[0039] A bearing protection device for a mechanical classifying mill has the following main component installation relationship: Two main motors for the grinding disc and classifying wheel are respectively installed on both sides of the frame. The motor-driven pulleys (driving pulleys) drive the driven pulleys (driven pulleys) on the shaft ends, thereby driving the hollow and solid shafts containing the classifying wheel and grinding disc to rotate, which in turn drives the classifying wheel and grinding disc to rotate at high speed. The grinding chamber 1 is also fixed to the frame, located in the middle of the frame, ensuring the optimal position of the pulleys. The lubrication system 2 is a separate control system, placed near the drive shaft assembly. Driven by a separate motor and pump, it delivers liquid oil from the lubrication system tank through an oil distributor and high-pressure hoses to the two bearings of the hollow shaft. The drive shaft assembly 5 (including the solid and hollow shafts) is located inside the cavity and is firmly fixed to the bottom of the cavity through mounting holes on the bearing seats, preventing machine vibration during high-speed rotation. The grinding disc drive 6 and the classifying wheel drive 7 are connected by a V-belt to achieve power transmission between the main motors and the hollow and solid shafts. A diffuser ring 8 is installed inside the cavity. Its angled blades effectively guide airflow to evenly distribute material throughout the grinding area. A grinding disc 9 is mounted on a hollow shaft inside the cavity, above the diffuser ring. The grinding disc can accommodate 36 grinding heads for effective grinding. A classifying wheel 10 is mounted on a solid shaft inside the cavity, above the grinding disc. A submerged ring 11 is located inside the classifying wheel's bore. Fine particles from the outer to the inner ring of the classifying wheel blades are ultimately discharged through the submerged ring. An air-sealing ring 12 is installed on the cavity cover. This ring is coated to prevent dust and material accumulation between the classifying wheel and the cavity cover, which could cause wear and damage to the bearings. This coating effectively protects against these issues. A toothed grinding ring 13 is located inside the cavity, on the outer ring of the grinding disc. This design allows the material ground by the grinding disc to be thrown out by centrifugal force, effectively impacting the grinding teeth on the outer ring, further grinding the material and significantly improving grinding efficiency. The air guide ring 16 is located on the lower side of the cavity and is used to guide the airflow to the upper part of the cavity and prevent small amounts of material from falling into the bottom of the cavity. The frame 17 is the main support of the equipment and is placed on the ground. The balance of the entire equipment can be adjusted by eight shock-absorbing blocks, so that the entire equipment can operate smoothly during high-speed grinding and grading.
[0040] Compared with existing technologies, the bearing protection device for the grading mill described above mainly avoids overload of a single bearing by independently driving the two shafts, thus achieving the grinding and grading process and significantly reducing the load on the bearings. The two large bearings on the hollow shaft can be fully lubricated by the continuous circulation of liquid oil in the lubrication system, and the bearings are always kept at a relatively stable temperature, providing effective protection for the bearings in multiple directions. The solid shaft is periodically injected with grease through the grease nipple at the bottom of the shaft, so that the grease covers the entire small bearing, and the temperature will not rise rapidly even during high-speed rotation.
[0041] This device employs a process of multiple refining and less grinding, along with timely classification, achieving energy saving, high output, high quality, and environmental friendliness in the classification process. It is currently the preferred technology for classification mills. Figure 2 Forty pressure springs can be used at the upper and lower pressure caps. The most effective adjustment value for the upper and lower pressure caps is 5mm. This ensures that the pressure springs can bear a certain load while effectively eliminating the axial clearance of the bearing and ensuring stable bearing operation. Figure 3 The solid and hollow shafts in the drive shaft assembly are driven by main motor one and main motor two, respectively, and multiple bearings are arranged in the transmission system, greatly reducing the bearing load. For example... Figure 4 The clearance range is 1.0-1.6mm, with a preferred value of 1.2-1.4mm. At the material outlet of the classifier mill, if this clearance is too small, material blockage will occur, increasing the load on the bearings and causing wear. If the clearance is too large, the classification effect will be insufficient, reducing classification quality and production capacity. Figure 5 The 3° angle at the return oil pipe effectively ensures that the liquid oil in the lubrication circuit flows freely back to the oil tank, providing sufficient lubrication for the bearings in the entire circuit. At the same time, it can remove a large amount of heat from the bearings, ensuring temperature stability in the system and greatly improving the equipment's productivity.
[0042] In summary, this utility model perfectly solves the defects of the existing technology. With a high-efficiency dynamic classifier as the core, it avoids the destructive impact of excessively coarse or hard materials on the grinding zone through precise classification control, thereby greatly reducing the load on the main bearing. It can not only effectively protect the bearing from the effects of temperature rise for a long time, but also effectively adjust the gap at the air seal, thus effectively realizing a high-precision grinding and classification process, and efficiently protecting the bearing of the grinding shaft from huge impacts and abnormal wear.
[0043] The contents not described in detail in this specification are existing technologies known to those skilled in the art. The standard parts used can be purchased from the market, and the irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the existing technology. The machinery, parts and equipment adopt conventional models in the existing technology, and the circuit connection adopts conventional connection methods in the existing technology, which will not be described in detail here.
[0044] This utility model is not limited to the above-described embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of this utility model shall be considered equivalent substitutions and shall be included within the protection scope of this utility model.
Claims
1. A bearing protection device for a mechanical classifying mill, comprising a frame (17), a grinding disc (9), a classifying wheel (10), and a grinding chamber (1), wherein the grinding chamber (1) is fixed on the frame (17), and the grinding chamber (1) is located at the middle position of the frame (17), characterized in that: Main motor 1 (3) and main motor 2 (4) are respectively installed on both sides of the frame (17). The output ends of the main motor 1 (3) and main motor 2 (4) are respectively installed with a grader drive (7) and a grinding disc drive (6). The grinding disc drive (6) and the grader drive (7) are respectively connected to the hollow shaft (14) and the solid shaft (15) through a V-belt. The solid shaft (15) is placed in the hole of the hollow shaft (14). The grinding disc (9) is installed on the hollow shaft (14) and is located inside the cavity of the grinding chamber (1). The grader (10) is installed on the solid shaft (15). The hollow shaft (14) is located above the grinding disc (9) inside the cavity. Large bearings (20) are provided at the upper and lower ends of the hollow shaft (14) and are supported by the large bearings (20). Small bearings (21) are provided at the upper and lower ends of the solid shaft (15) and are supported by the small bearings (21). A toothed grinding ring (13) is provided on the outer ring of the grinding disc (9). An air guide ring (16) is provided on the lower side of the cavity of the grinding chamber (1). The air guide ring (16) is located below the toothed grinding ring (13). The air guide ring (16) is used to guide the airflow to the upper part of the cavity.
2. The bearing protection device for a mechanical classifying mill as described in claim 1, characterized in that: The hollow shaft (14) and the solid shaft (15) are both located inside the cavity of the grinding chamber (1), and the hollow shaft (14) and the solid shaft (15) are both fixed to the bottom of the cavity through the mounting holes on the bearing seat.
3. The bearing protection device for a mechanical classifying mill as described in claim 2, characterized in that: A pressure spring (18) is provided around the bottom of the bearing housing in the circumferential direction. The pressure spring (18) supports the outer ring of the bearing, and the inner ring of the bearing is positioned by a bushing, so that the inner and outer rings of the bearing are completely positioned.
4. The bearing protection device for the mechanical classifier mill as described in claim 1, characterized in that: An air sealing ring (12) is installed on the cavity cover at the top of the grinding chamber (1). The air sealing ring (12) is coated and is located between the grading wheel (10) and the cavity cover. The air sealing ring (12) is used to prevent dust and material accumulation at the grading wheel (10) and the cavity cover.
5. The bearing protection device for a mechanical classifying mill as described in claim 4, characterized in that: A thin shim (19) is provided below the grading wheel (10), and the gap between the grading wheel (10) and the cavity cover is adjusted by the thickness of different thin shims (19).
6. The bearing protection device for a mechanical classifying mill as described in claim 1, characterized in that: The grinding chamber (1) is equipped with a diffusion ring (8) inside the chamber. The diffusion ring (8) is located below the grinding disc (9). The diffusion ring (8) is designed with angled guide vanes along the circumference and guides the airflow through the guide vanes to evenly distribute the material throughout the grinding area.
7. The bearing protection device for a mechanical classifying mill as described in claim 1, characterized in that: It also includes an immersion ring (11) located in the inner hole of the classifier (10), through which fine particulate material is discharged from the top of the classifier (10) via the immersion ring (11).
8. The bearing protection device for a mechanical classifying mill as described in any one of claims 1 to 7, characterized in that: It also includes a lubrication system (2), which includes a lubrication system motor, a lubrication system pump and a lubrication system oil tank. The liquid oil in the lubrication system oil tank is driven by the lubrication system motor and the lubrication system pump and is delivered to the two large bearings (20) of the hollow shaft (14) through a high-pressure hose via an oil distributor. The bottom of the solid shaft (15) is provided with an oil nozzle, and grease is periodically injected through the oil nozzle. The grease covers the entire small bearing (21).