Sealing device for coal mill base

Abstract

The utility model relates to the technical field of coal mills, and discloses a coal mill base sealing device which is characterized in that the end part of a limiting rod is fixedly connected with a push block, one side of the push block is provided with a supporting inclined block in a fitting manner, and one side of the supporting inclined block is provided with a self-lubricating sealing ring at the side edge of a transmission shaft of a coal mill; through the arrangement of the double-layer sealing assembly, on one hand, rotation and radial swing of the transmission shaft of the coal mill can be adapted, on the other hand, compensation can be conducted on relative displacement between the sealing piece and the transmission shaft of the coal mill, the sealing effect is guaranteed, and the overhaul and maintenance workload is reduced; a one-layer sealing structure and a two-layer sealing structure are backward and are not suitable for the change of existing coal types, the base is more advanced in sealing after existing modification, more suitable for ash change combustion of various coal types, higher in abrasion resistance and long in service life, the sealing effect of the whole base can be guaranteed, the maintenance cost is reduced, and safe and long-period operation of a unit is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to coal mill technical field, concretely is a coal mill base seal device. BACKGROUND

[0002] When the coal mill is working, in order to make the coal powder can be sent out the coal mill along with the airflow smoothly, the hot air will form the greater wind pressure in the coal mill, on the one hand, the coal powder sent out plays the drying effect, on the other hand, the coal powder is sent out from the coal powder outlet in the upper part of the coal mill, this will lead to the coal powder to appear the phenomenon of finding a crack under the internal wind pressure, and the main shaft is the rotating state when working, and there will be a gap between the main shaft and the coal mill shell, therefore, the coal powder will drill out from the gap between the main shaft and the coal mill shell under the wind pressure, causes the massive leakage of coal powder, pollutes the environment, and the current coal mill generally sets up a sealing air chamber around the main shaft below the grinding disc, and installs the carbon ring sealing piece between the sealing air chamber and the main shaft, and the coal mill works through the sealing air chamber into the sealing air, carries out the wind pressure compensation to the hot air in the coal mill, prevents the leakage of coal powder under the action of hot air;

[0003] However, the prior art adopts the base seal of carbon sealing ring type, and the sealing performance of this type of seal is good under the condition that the coal quality is stable and the stone coal is not much, at present, the coal quality is poor, and the stone coal is much, which has become the normal state, and the amount of stone coal often cannot be discharged in time, leading to the high damage rate of carbon sealing ring, which seriously affects the safe and stable operation of the coal mill and the load carrying capacity of the unit, and the maintenance and repair cost is high, the workload and risk are big, therefore, it is urgent to change the structure of the base seal of the coal mill, to adapt to the poor coal quality condition, ensure the safe and stable operation of the coal mill, reduce the spare parts procurement cost and repair workload and risk. SUMMARY

[0004] (I) technical problem solved

[0005] In view of the defects of the prior art, the utility model provides a coal mill base seal device, solves the problem that the prior art adopts the base seal of carbon sealing ring type, and the sealing performance of this type of seal is good under the condition that the coal quality is stable and the stone coal is not much, at present, the coal quality is poor, and the stone coal is much, which has become the normal state, and the amount of stone coal often cannot be discharged in time, leading to the high damage rate of carbon sealing ring, which seriously affects the safe and stable operation of the coal mill and the load carrying capacity of the unit, and the maintenance and repair cost is high, the workload and risk are big.

[0006] (II) technical scheme

[0007] To achieve the above object, the utility model provides following technical scheme: a coal mill base sealing device, including coal mill base, the bottom of coal mill base is provided with steel sheet, and the middle part of coal mill base and steel sheet is provided with coal mill transmission shaft, the bottom of coal mill base is provided with first support ring frame at the outside position of coal mill transmission shaft, the bottom of first support ring frame is provided with second support ring frame, the outside of coal mill transmission shaft is provided with double -layer metal flange at the bottom position of first support ring frame and second support ring frame,

[0008] The bottom end of the double -layer metal flange of the top layer is fixedly connected with a plurality of groups of special-shaped connecting rings along the circumferential direction at equal angles, each group of special-shaped connecting rings is provided with a thin sleeve pipe and a thick sleeve pipe on the side edge portion close to the coal mill transmission shaft, the thin sleeve pipe is located on the top of the thick sleeve pipe, and the outer sides of the thin sleeve pipe and the thick sleeve pipe are both provided with supporting springs, the inner sides of the thin sleeve pipe and the thick sleeve pipe are respectively embedded with limit rods in sliding connection, the end portion of the limit rod is fixedly connected with a push block, the side of the push block is provided with a supporting inclined block, and the side of the supporting inclined block is provided with a self-lubricating sealing ring at the side edge position of the coal mill transmission shaft.

[0009] The bottom end of the second support ring frame is connected with a clamping ring, the inner side of the clamping ring is embedded with a high-temperature-resistant high-elasticity compensation ring, and the edge end of the self-lubricating sealing ring and the high-temperature-resistant high-elasticity compensation ring is provided with a wear-resistant ring.

[0010] As a preferred technical scheme of the coal mill base sealing device of the utility model, the side edge of the self-lubricating sealing ring is provided with an inclined surface, the inclined edge of the supporting inclined block is matched with the inclined surface of the self-lubricating sealing ring, the wear-resistant rings at the edge ends of the self-lubricating sealing ring and the high-temperature-resistant high-elasticity compensation ring are tightly matched with the edge portion of the coal mill transmission shaft, the self-lubricating sealing ring is made of nanometer high-carbon fiber composite material, and the wear-resistant ring is made of composite polyurethane rubber material.

[0011] As a preferred technical scheme of the coal mill base sealing device of the utility model, the push block is tightly attached to the side edge of the supporting inclined block under the pushing of the supporting spring, and the limit rods are guided and limited to slide in the corresponding thin sleeve pipe and thick sleeve pipe.

[0012] As a preferred technical scheme of the coal mill base sealing device of the utility model, the first support ring frame and the second support ring frame are connected between the steel plate through the fixed screw rods penetratingly connected in the interiors thereof;

[0013] The double -layer metal flange is also installed and fixed through the fixed screw, and the connecting position between the fixed screw and the double -layer metal flange is provided with a fixed nut.

[0014] As a kind of coal mill base sealing device preferred technical scheme of the utility model, the top of steel plate is provided with fixed hole corresponding fixed screw rod, fixed screw rod is connected in fixed hole by thread, double-layer metal flange is fixed in the outside of fixed screw rod by fixed nut.

[0015] As a kind of coal mill base sealing device preferred technical scheme of the utility model, the inside of first support ring frame is embedded with dynamic sealing ring, the inside of second support ring frame is embedded with static sealing ring.

[0016] As a kind of coal mill base sealing device preferred technical scheme of the utility model, the inside of first support ring frame and second support ring frame is formed with step groove, the end face shape of first support ring frame and second support ring frame is L type, dynamic sealing ring and static sealing ring are connected in step groove respectively, and dynamic sealing ring and static sealing ring are closely combined with the side of coal mill transmission shaft, dynamic sealing ring and static sealing ring are high elasticity, high wear resistance, high temperature resistant nanometer composite fluorine rubber material.

[0017] (Three) beneficial effects

[0018] Compared with prior art, the utility model provides a kind of coal mill base sealing device, with following beneficial effects:

[0019] 1, by supporting inclined block, self-lubricating sealing ring and wear ring, the outside of coal mill transmission shaft can be effectively sealed, and with the aid of high-temperature-resistant high-elasticity compensation ring in the inside of clamping ring, the sealing effect can be further improved, the slag powder and hot air are effectively isolated and sealed, the coal mill sealing air pressure is not lost, the coal dust leakage damage to main shaft is prevented, the working surface sealing state between self-lubricating sealing ring and high-temperature-resistant high-elasticity compensation ring and coal mill transmission shaft is ensured, and based on thin sleeve pipe, thick sleeve pipe, supporting spring, limiting rod and push block, supporting inclined block is tightly attached to the side of self-lubricating sealing ring, so that self-lubricating sealing ring and wear ring can be tightly attached to the side of coal mill transmission shaft under the action of elastic force, to ensure the pre-tightening force of the seal therebetween, so that self-lubricating sealing ring can be displaced and compensated in time when wear occurs, to ensure that it is in close contact state, and improve the sealing effect.

[0020] 2, by the first support ring frame, second support ring frame inside respectively corresponding dynamic sealing ring, static sealing ring, slag powder can be effectively controlled, especially, large diameter stone coal or other foreign matters can be prevented from entering primary air chamber without wearing coal mill transmission shaft, and dynamic sealing ring can also be ensured to rotate together, and while blocking slag, sealing air is guided in the direction required by design, the air pressure of sealing air is higher than that of external hot air, and the pressure difference is used to ensure that hot air and dust do not enter the working surface of coal mill transmission shaft, to further alleviate wear.

[0021] In combination with the above, through the arrangement of the double-layer sealing assembly, on one hand, the rotation and radial swing of the coal mill transmission shaft can be adapted, and on the other hand, the relative displacement between the sealing element and the coal mill transmission shaft can be compensated, so that the sealing effect can be effectively ensured. Compared with the existing carbon ring sealing structure, the double-layer sealing structure can ensure the overall sealing effect, prolong the service life, improve the coal mill investment rate, reduce the maintenance workload, the original factory matching design carbon ring sealing structure adopts a two-layer sealing structure which is backward and not suitable for the change of the existing coal, and after the transformation, the base sealing is more advanced, more optimized, more suitable for the change of the burning of various coal ash, has higher wear resistance, longer service life, can ensure the overall base sealing effect, reduce the maintenance cost, and ensure the safety of the unit for long-period operation. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the utility model.

[0023] Figure 2 is an enlarged schematic diagram of the A area of the utility model.

[0024] Figure 3 is a structural schematic diagram of the support inclined block of the utility model.

[0025] Figure 4 is a top view of the first support ring frame of the utility model.

[0026] Among them:

[0027] 1-coal mill base; 2-steel plate; 3-coal mill transmission shaft; 4-first support ring frame; 5-second support ring frame; 6-fixing screw rod; 7-double-layer metal flange; 8-fixing nut; 9-irregular connecting ring; 10-fine sleeve pipe; 11-coarse sleeve pipe; 12-support spring; 13-limiting rod; 14-push block; 15-support inclined block; 16-self-lubricating sealing ring; 17-wear-resistant ring; 18-clamping ring; 19-high-temperature-resistant high-elasticity compensation ring; 20-moving sealing ring; 21-stationary sealing ring DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the utility model more clear and explicit, the utility model is further described in detail below through the drawings and examples. However, it should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the scope of the utility model. In addition, in the following description, the description of the known structure and technology is omitted to avoid unnecessary confusion of the concept of the utility model.

[0029] In the description of the utility model, it needs to explain, when the element is called " fixed to " or " set to " another element, it can be directly on another element or indirectly on the other element. When an element is called " connected to " another element, it can be directly connected to another element or indirectly connected to the other element.

[0030] In the description of the utility model, it needs to explain, the orientation or position relation indicated by the terms " center ", " length ", " width ", " thickness ", " upper ", " lower ", " front ", " rear ", " left ", " right ", " vertical ", " horizontal ", " top ", " bottom ", " inner ", " outer " is based on the orientation or position relation shown in the drawing, or the orientation or position relation of the product of the application when it is usually placed, which is only for the convenience of describing the application and simplifying the description, and is not indicative or implied that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the application. In addition, the terms " first ", " second ", " third " and the like are only used for differentiation, and cannot be understood as indicative or implied relative importance. Therefore, the features limited by " first " and " second " can be explicitly or implicitly included one or more features. In the description of the utility model, the meaning of " multiple " is two or more than two, unless otherwise explicitly specified and limited. The meaning of " several " is one or more than one, unless otherwise explicitly specified and limited.

[0031] In the description of the utility model, it also needs to explain that, unless otherwise explicitly specified and limited, the terms " set ", " install ", " connect " and " connect " should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances. Embodiment

[0032] Please refer to Figures 1-4 The utility model provides the following technical scheme: a coal mill base sealing device, including coal mill base 1, the bottom of coal mill base 1 is provided with steel sheet 2, and the middle part of coal mill base 1 and steel sheet 2 is provided with coal mill transmission shaft 3, the bottom of coal mill base 1 is provided with first support ring frame 4 at the outer side position of coal mill transmission shaft 3, the bottom of first support ring frame 4 is provided with second support ring frame 5, and the outer side of coal mill transmission shaft 3 is provided with double-layer metal flange 7 at the bottom position of first support ring frame 4 and second support ring frame 5;

[0033] The bottom end of the double-layer metal flange 7 of the top layer is fixedly connected with a plurality of groups of special-shaped connecting rings 9 at equal angles in the circumferential direction, each group of special-shaped connecting rings 9 is provided with a thin sleeve pipe 10 and a thick sleeve pipe 11 on the side edge close to the coal mill transmission shaft 3, the thin sleeve pipe 10 is located on the top of the thick sleeve pipe 11, the outer sides of the thin sleeve pipe 10 and the thick sleeve pipe 11 are sleeved with supporting springs 12, the inner sides of the thin sleeve pipe 10 and the thick sleeve pipe 11 are respectively embedded with limiting rods 13 which are slidingly connected, the end of the limiting rod 13 is fixedly connected with a push block 14, the side of the push block 14 is provided with a supporting inclined block 15, the side of the supporting inclined block 15 is provided with a self-lubricating sealing ring 16 at the side edge position of the coal mill transmission shaft 3, the push block 14 is tightly attached to the side edge of the supporting inclined block 15 under the pushing of the supporting spring 12, the limiting rod 13 is guided and limited in the corresponding thin sleeve pipe 10 and thick sleeve pipe 11, the supporting spring 12 provides elastic supporting force for the supporting inclined block 15, so that the supporting inclined block 15 can tightly support the self-lubricating sealing ring 16, and ensures that the supporting inclined block 15 does not deviate when it is displaced;

[0034] The bottom end of the second supporting ring frame 5 is connected with a clamping ring 18, the inner side of the clamping ring 18 is embedded with a high-temperature-resistant and high-elasticity compensation ring 19, the edge end of the self-lubricating sealing ring 16 and the high-temperature-resistant and high-elasticity compensation ring 19 is provided with a wear-resistant ring 17, the side edge of the self-lubricating sealing ring 16 is provided with an inclined surface, the inclined edge of the supporting inclined block 15 is attached to the inclined surface of the self-lubricating sealing ring 16, the wear-resistant ring 17 at the edge end of the self-lubricating sealing ring 16 and the high-temperature-resistant and high-elasticity compensation ring 19 is tightly attached to the edge of the coal mill transmission shaft 3, the self-lubricating sealing ring 16 is made of nanometer high-carbon fiber composite material, the wear-resistant ring 17 is made of composite polyurethane rubber material, the tightness between the supporting inclined block 15 and the self-lubricating sealing ring 16 ensures the sealing performance of the self-lubricating sealing ring 16 and the high-temperature-resistant and high-elasticity compensation ring 19 to the edge of the coal mill transmission shaft 3.

[0035] The first supporting ring frame 4 and the second supporting ring frame 5 are connected between the steel plate 2 through the fixed screw rod 6 penetratingly connected inside;

[0036] The double-layer metal flange 7 is also installed and fixed through the fixed screw rod 6, and the connecting position between the fixed screw rod 6 and the double-layer metal flange 7 is provided with a fixed nut 8, the top of the steel plate 2 is provided with a fixed hole corresponding to the fixed screw rod 6, the fixed screw rod 6 is threadedly connected in the fixed hole, the double-layer metal flange 7 is fixed on the outer side of the fixed screw rod 6 through the fixed nut 8, the fixed screw rod 6 is convenient for connecting and fixing the first supporting ring frame 4 and the second supporting ring frame 5, and is also convenient for installing and fixing the double-layer metal flange 7 through the fixed screw rod 6.

[0037] The inner side of the first support ring frame 4 is embedded and clamped with a dynamic sealing ring 20, the inner side of the second support ring frame 5 is embedded and clamped with a static sealing ring 21, the inner sides of the first support ring frame 4 and the second support ring frame 5 are formed with stepped grooves, the end faces of the first support ring frame 4 and the second support ring frame 5 are L-shaped, the dynamic sealing ring 20 and the static sealing ring 21 are respectively connected in the stepped grooves, and the dynamic sealing ring 20 and the static sealing ring 21 are closely attached to the side edges of the coal mill transmission shaft 3, the dynamic sealing ring 20 and the static sealing ring 21 are made of high-elastic, high-wear-resistant and high-temperature-resistant nano composite fluorine rubber material, the installation of the dynamic sealing ring 20 and the static sealing ring 21 is facilitated, and the sealing and wear-resistant capacity of the dynamic sealing ring 20 and the static sealing ring 21 is improved.

[0038] The working principle and use process of the utility model are as follows: in the actual sealing process, first, the dynamic sealing ring 20 is sleeved on the outer side of the coal mill transmission shaft 3, and the top of the dynamic sealing ring 20 is closely attached to the bottom of the steel plate 2, then the first support ring frame 4 is also sleeved on the outer side of the coal mill transmission shaft 3, and the dynamic sealing ring 20 is embedded in the inner side of the first support ring frame 4, then the static sealing ring 21 and the second support ring frame 5 are respectively sleeved on the outer side of the coal mill transmission shaft 3, and the static sealing ring 21 is arranged between the first support ring frame 4 and the first support ring frame 4;

[0039] Then the clamping ring 18 and the high-temperature-resistant and high-elastic compensation ring 19 are sleeved on the outer side of the coal mill transmission shaft 3, the clamping ring 18 and the high-temperature-resistant and high-elastic compensation ring 19 are constrained and limited by the upper layer of the double-layer metal flange 7, then the self-lubricating sealing ring 16 is sleeved on the outer side of the coal mill transmission shaft 3, and finally the fine sleeve pipe 10, the thick sleeve pipe 11, the supporting spring 12, the limiting rod 13 and the push block 14 are arranged on the special-shaped connecting ring 9, so that the supporting inclined block 15 can support the self-lubricating sealing ring 16;

[0040] Through the above-mentioned sealing structure, through the dynamic sealing ring 20 and the static sealing ring 21 in the inner sides of the first support ring frame 4 and the second support ring frame 5, the slag powder can be effectively controlled, the larger diameter stone coal can be prevented from entering the primary air chamber without wearing the coal mill transmission shaft 3, and while blocking the slag powder, the sealing air flow is guided in the designed direction, the air pressure of the sealing air is higher than that of the external hot air, the hot air and the dust cannot enter the working surface of the coal mill transmission shaft 3 based on the pressure difference, and the wear is relieved;

[0041] And through the supporting inclined block 15, the self-lubricating sealing ring 16 and the wear-resistant ring 17, the outer side of the coal mill transmission shaft 3 can be effectively sealed, and the sealing effect is further improved with the help of the high-temperature-resistant and high-elastic compensation ring 19 in the inner side of the clamping ring 18, so that the slag powder and the hot air are effectively isolated and sealed, the sealing air of the coal mill does not lose pressure, the coal powder leakage is prevented from damaging the main shaft, the working surface between the self-lubricating sealing ring 16 and the high-temperature-resistant and high-elastic compensation ring 19 and the coal mill transmission shaft 3 is in good sealing state.

[0042] When the self-lubricating sealing ring 16 and the wear-resistant ring 17 are worn, the elastic constraint force provided by the supporting spring 12 pushes the push block 14, so that the push block 14 pushes the supporting inclined block 15 to tightly adhere to the side edge of the self-lubricating sealing ring 16, and the self-lubricating sealing ring 16 and the wear-resistant ring 17 can tightly adhere to the side edge of the coal mill transmission shaft 3 under the action of the elastic pushing force, so that the edge part of the self-lubricating sealing ring 16 and the wear-resistant ring 17 can also tightly adhere to the edge part of the coal mill transmission shaft 3 when they are worn, the pre-tightening force during sealing is ensured, and the self-lubricating sealing ring 16 can be timely compensated for displacement when it is worn, so that the self-lubricating sealing ring 16 can be kept in a tightly adhered state in real time, and the sealing effect is improved.

[0043] The sealing structure can adapt to the rotation and radial swing of the coal mill transmission shaft 3, and can compensate for the relative displacement between the sealing member and the coal mill transmission shaft 3, so that the sealing effect can be effectively ensured, and compared with the existing carbon ring sealing structure, the double-layer sealing structure can ensure the overall sealing effect and prolong the service life.

[0044] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A mill base seal apparatus comprising a mill base (1) characterised in that: The bottom of the coal mill base (1) is provided with a steel plate (2), and the middle part of the coal mill base (1) and the steel plate (2) is provided with a coal mill transmission shaft (3), the bottom of the coal mill base (1) is sleeved with a first support ring frame (4) at the outer side of the coal mill transmission shaft (3), the bottom of the first support ring frame (4) is provided with a second support ring frame (5), and the outer side of the coal mill transmission shaft (3) is sleeved with a double-layer metal flange (7) at the bottom of the first support ring frame (4) and the second support ring frame (5). The bottom end of the double-layer metal flange (7) of the top layer is fixedly connected with a plurality of groups of special-shaped connecting rings (9) in the circumferential direction at equal angles, a fine sleeve pipe (10) and a thick sleeve pipe (11) are installed on one side edge of each group of special-shaped connecting rings (9) close to the coal mill transmission shaft (3), the fine sleeve pipe (10) is located at the top of the thick sleeve pipe (11), and the outer sides of the fine sleeve pipe (10) and the thick sleeve pipe (11) are sleeved with supporting springs (12), the inner sides of the fine sleeve pipe (10) and the thick sleeve pipe (11) are respectively embedded with limiting rods (13) in sliding connection, the end of the limiting rod (13) is fixedly connected with a push block (14), one side of the push block (14) is abutted with a supporting inclined block (15), and one side of the supporting inclined block (15) is provided with a self-lubricating sealing ring (16) at the side edge position of the coal mill transmission shaft (3). The bottom end of the second support ring frame (5) is connected with a clamping ring (18), the inner side of the clamping ring (18) is embedded with a high-temperature-resistant and high-elasticity compensation ring (19) in clamping connection, and the edge end of the self-lubricating sealing ring (16) and the high-temperature-resistant and high-elasticity compensation ring (19) is provided with a wear-resistant ring (17).

2. A mill base seal as claimed in claim 1, wherein: The side edge of the self-lubricating sealing ring (16) is provided with an inclined surface, the inclined edge of the supporting inclined block (15) is abutted with the inclined surface of the self-lubricating sealing ring (16), the wear-resistant rings (17) at the edge ends of the self-lubricating sealing ring (16) and the high-temperature-resistant and high-elasticity compensation ring (19) are tightly abutted with the edge of the coal mill transmission shaft (3), the self-lubricating sealing ring (16) is made of nanometer high-carbon fiber composite material, and the wear-resistant ring (17) is made of composite polyurethane rubber material.

3. A mill base seal as claimed in claim 1, wherein: The push block (14) is tightly abutted against the side edge of the supporting inclined block (15) under the pushing of the supporting spring (12), and the limiting rods (13) are respectively guided and limited to slide in the corresponding fine sleeve pipe (10) and thick sleeve pipe (11).

4. A mill base seal as claimed in claim 1, wherein: The first support ring frame (4) and the second support ring frame (5) are connected between the steel plate (2) through the fixed screw rods (6) penetratingly connected in the interiors thereof; The double-layer metal flange (7) is also installed and fixed through the fixed screw rods (6), and the connecting position between the fixed screw rod (6) and the double-layer metal flange (7) is installed with a fixed nut (8).

5. A mill base seal as claimed in claim 4, wherein: The top of the steel plate (2) is provided with a fixed hole corresponding to the fixed screw rod (6), the fixed screw rod (6) is threadedly connected in the fixed hole, and the double-layer metal flange (7) is fixed on the outer side of the fixed screw rod (6) through the fixed nut (8).

6. A mill base seal as claimed in claim 1, wherein: The inner side of the first support ring frame (4) is embedded with a dynamic sealing ring (20) through clamping, and the inner side of the second support ring frame (5) is embedded with a static sealing ring (21) through clamping.

7. A mill base seal as claimed in claim 6, wherein: The inner side of the first support ring frame (4) and the second support ring frame (5) are both formed with a stepped groove, the end face shape of the first support ring frame (4) and the second support ring frame (5) is L-shaped, the dynamic sealing ring (20) and the static sealing ring (21) are respectively connected in the stepped groove, the dynamic sealing ring (20) and the static sealing ring (21) are respectively closely combined with the side edge of the coal mill transmission shaft (3), and the dynamic sealing ring (20) and the static sealing ring (21) are both made of nanometer composite fluorine rubber material with high elasticity, high wear resistance and high temperature resistance.

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