Sealing device for machine base of coal mill

Abstract

The utility model provides a coal mill base sealing device which comprises an inner sealing structure and an outer sealing structure, the inner sealing structure comprises a sealing ring seat, a plurality of sealing rings and a pushing bolt, an annular air duct is formed between every two adjacent sealing rings, a first sealing gap is formed between the upper end face of each sealing ring and the lower end face of a disc bottom sealing sleeve, and a second sealing gap is formed between the upper end face of each sealing ring and the lower end face of the disc bottom sealing sleeve. The pushing bolt is used for adjusting the size of the first sealing gap; the outer sealing structure is connected with an air inlet pipe used for supplying sealing air into the sealing air cavity. According to the coal mill base sealing device provided by the utility model, when high-pressure airflow passes through the first sealing gap by utilizing the plurality of annular air ducts, the pressure loss is gradually accumulated and increased, so that the pressure in the sealing air chamber is ensured, and the problem of leakage of dust and primary hot air is solved; the size of the first sealing gap is adjusted through the pushing bolt, an effective dynamic sealing gap is guaranteed, and the sealing performance of the coal mill base sealing device is effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal mills, and in particular relates to a sealing device for a coal mill base. Background Art

[0002] Coal mill is a machine that breaks up coal blocks and grinds them into coal powder. Its internal grinding parts are composed of two sets of grinding bodies that move relative to each other. The coal blocks are squeezed and ground between the surfaces of these two sets of grinding bodies and are crushed. At the same time, the hot air entering the coal mill dries the coal and sends the coal powder to the separator at the top of the grinding area. After separation, the coal powder of a certain particle size is carried out of the mill with the air flow, and the coarse coal powder is returned to the grinding area for re-grinding.

[0003] The coal mill base seal refers to the sealing structure between the transmission shaft of the coal mill drive disc and the coal mill base, which is used to prevent the dust inside the coal mill from leaking out with the primary hot air. The existing coal mill base seal usually adopts a sealing shell set on the coal mill base shell, the upper end of the sealing shell is dynamically sealed with the bottom sealing sleeve of the transmission disc, and the lower end of the sealing shell is dynamically sealed with the transmission shaft of the transmission disc, so that a sealed air chamber is formed between the sealing shell and the transmission shaft. Then, a sealed air with a certain pressure is introduced into the sealed air chamber to prevent the dust generated in the coal mill from entering the sealing shell with the primary hot air, causing wear or even damage to the transmission shaft and the sealing structure.

[0004] However, the existing coal mill base sealing structure has a large matching clearance due to the long-term extrusion and wear of the dynamic sealing structure by dust, which reduces the sealing wind pressure, thereby making it easy for dust to enter the sealed air chamber and cause wear on the seal between the lower end of the sealing shell and the transmission shaft, thereby reducing the sealing performance of the coal mill base seal and shortening the overall service life of the equipment. Utility Model Content

[0005] The embodiment of the utility model provides a coal mill base sealing device, which can ensure the pressure in the sealed air chamber and an effective dynamic sealing gap, and effectively improves the sealing performance of the coal mill base sealing device.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide a coal mill base sealing device, including an inner sealing structure and an outer sealing structure, the inner sealing structure includes a sealing ring seat slidably sleeved on the outer periphery of the sealing sleeve, a plurality of sealing rings sleeved on the sealing ring seat and a push bolt abutting against the bottom surface of the sealing ring seat, the plurality of sealing rings are arranged at intervals along the radial direction of the sealing ring seat, and an annular air duct is formed between two adjacent sealing rings, a first sealing gap is formed between the upper end surface of the sealing ring and the lower end surface of the sealing sleeve at the bottom of the disk, and the push bolt is used to push the sealing ring seat upward to adjust the size of the first sealing gap; the outer sealing structure is connected with an air inlet pipe for supplying sealing air into the sealed air chamber.

[0007] As another embodiment of the utility model, a plurality of steps with increasing diameters from top to bottom are provided on the outer peripheral wall of the sealing ring seat, and the sealing rings are connected to the outer peripheral walls of the steps one by one.

[0008] As another embodiment of the utility model, the inner sealing structure further includes a first flange connected to the outer periphery of the sealing sleeve, and the push bolt is threadedly connected to the first flange.

[0009] As another embodiment of the utility model, the inner sealing structure further comprises a slag stop ring sleeved on the outer periphery of the disc bottom sealing sleeve, and a second sealing gap is formed between the upper end surface of the slag stop ring and the lower end surface of the transmission disc.

[0010] As another embodiment of the utility model, the first flange is also connected to a support ring seat extending upward, the slag retaining ring is provided with a long positioning groove extending in the up and down directions, and the support ring seat is threadedly connected with an adjusting bolt arranged through the long positioning groove, and the adjusting bolt is used to adjust the size of the second sealing gap.

[0011] As another embodiment of the utility model, the sealing ring includes a plurality of first arc-shaped portions spliced ​​in sequence, and adjacent first arc-shaped portions are connected by a first fastener; the slag retaining ring includes a plurality of second arc-shaped portions spliced ​​in sequence, and adjacent second arc-shaped portions are connected by a second fastener.

[0012] As another embodiment of the utility model, the external sealing structure includes a second flange connected to the base body, a sealing sleeve connected to the bottom of the second flange and sleeved on the outer periphery of the transmission shaft, and a sealing assembly located between the sealing sleeve and the transmission shaft, and the outlet end of the air inlet pipe is located above the sealing assembly.

[0013] As another embodiment of the utility model, the sealing assembly includes a plurality of dynamic sealing rings and flexible sealing strips sealed on the outer periphery of the transmission shaft, and the dynamic sealing rings and the flexible sealing strips are alternately arranged in sequence along the axial direction of the sealing sleeve.

[0014] As another embodiment of the utility model, the inner periphery of the sealing sleeve is provided with a ventilation groove located above the sealing assembly and extending in the circumferential direction, and the outlet end of the air inlet pipe is connected to the ventilation groove.

[0015] As another embodiment of the utility model, a tension spring is provided on the outer periphery of the dynamic sealing ring, and the tension spring is used to press the dynamic sealing ring toward the axial center side of the transmission shaft so that the dynamic sealing ring is pressed against the transmission shaft.

[0016] The beneficial effects of the coal mill base sealing device provided by the utility model are as follows: compared with the prior art, the coal mill base sealing device of the utility model introduces high-pressure gas into the sealed air chamber through the air inlet pipe, so that the high-pressure gas bypasses the gap between the sealing sleeve and the bottom sealing sleeve of the disc and then sprays out through the first sealing gap to prevent dust from entering the sealed air chamber; at the same time, by using multiple annular air ducts between the sealing rings, the pressure loss gradually accumulates and increases when the high-pressure airflow passes through the first sealing gap, thereby ensuring the pressure in the sealed air chamber and solving the problem of dust and primary hot air leakage; on this basis, when the first sealing gap increases due to dust extrusion and wear, the size of the first sealing gap can be adjusted by rotating the push bolt to push the sealing ring seat and the sealing ring upward, thereby ensuring an effective dynamic sealing gap. The sealing performance of the coal mill base sealing device is effectively improved by the above structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic structural diagram of a coal mill base sealing device provided by an embodiment of the utility model;

[0019] Figure 2 For the utility model embodiment Figure 1 A schematic diagram of the enlarged structure of the middle part A;

[0020] Figure 3 For the utility model embodiment Figure 1 The enlarged structural diagram of the middle B part;

[0021] Figure 4 A schematic diagram of the structure of a sealing ring provided in an embodiment of the utility model;

[0022] Figure 5 A schematic diagram of the structure of a slag retaining ring provided in an embodiment of the utility model;

[0023] Figure 6 A schematic structural diagram of a sealing ring seat provided in an embodiment of the utility model.

[0024] Among them, the reference numerals in the figure are:

[0025] 1. Inner sealing structure; 11. Sealing ring seat; 111. Step; 12. Sealing ring; 121. Annular air duct; 122. First arc-shaped portion; 123. First fastener; 13. First sealing gap; 14. Push bolt; 15. First flange; 151. Rib plate; 16. Slag retaining ring; 161. Long positioning groove; 162. Second arc-shaped portion; 163. Second fastener; 17. Second sealing gap; 18. Support ring seat; 19. Adjusting bolt; 2. Outer sealing structure; 21. Sealing sleeve; 211. Annular groove; 212. Ventilation groove; 22. Sealing assembly; 221. Dynamic sealing ring; 222. Flexible sealing strip; 223. Tension spring; 23. Air inlet pipe; 24. Second flange; 10. Transmission disc; 101. Disc bottom sealing sleeve; 20. Sealing sleeve; 30. Transmission shaft; 40. Machine base; 50. Sealed air chamber. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on another element or indirectly on another element. It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "back", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meanings of "multiple" and "several" are two or more, unless otherwise clearly and specifically defined.

[0028] Please also read Figure 1 and Figure 6The coal mill base sealing device provided by the utility model is now described. The coal mill base sealing device comprises an inner sealing structure 1 and an outer sealing structure 2, wherein the inner sealing structure 1 comprises a sealing ring seat 11 slidably sleeved on the outer periphery of a sealing sleeve 20, a plurality of sealing rings 12 sleeved on the sealing ring seat 11, and a push bolt 14 abutting against the bottom surface of the sealing ring seat 11, wherein the plurality of sealing rings 12 are arranged at intervals along the radial direction of the sealing ring seat 11, and an annular air duct 121 is formed between two adjacent sealing rings 12, a first sealing gap 13 is formed between the upper end surface of the sealing ring 12 and the lower end surface of the disc bottom sealing sleeve 101, and the push bolt 14 is used to push the sealing ring seat 11 upward to adjust the size of the first sealing gap 13; and the outer sealing structure 2 is connected with an air inlet pipe 23 for supplying sealing air into the sealing air chamber 50.

[0029] Compared with the prior art, the coal mill base sealing device provided in this embodiment introduces high-pressure gas into the sealed air chamber 50 through the air inlet pipe 23, so that the high-pressure gas bypasses the gap between the sealing sleeve 20 and the disc bottom sealing sleeve 101 and then sprays out through the first sealing gap 13 to prevent dust from entering the sealed air chamber 50; at the same time, by using multiple annular air ducts 121 between the sealing rings 12, the pressure loss gradually accumulates and increases when the high-pressure airflow passes through the first sealing gap 13, thereby ensuring the pressure in the sealed air chamber 50, thereby solving the problem of dust and primary hot air leakage; on this basis, when the first sealing gap 13 increases due to dust extrusion and wear, the size of the first sealing gap 13 can be adjusted by rotating the push bolt 14 to push the sealing ring seat 11 and the sealing ring 12 upward, thereby ensuring an effective dynamic sealing gap. The sealing performance of the coal mill base sealing device is effectively improved by the above structure.

[0030] It should be noted that the coal mill in the prior art is vertically arranged on the foundation, the transmission disc 10 of the coal mill is horizontally arranged, the lower side of the transmission disc 10 is provided with a transmission shaft 30 vertically arranged in the up-down direction, and the lower side of the transmission disc 10 is also coaxially provided with a disc bottom sealing sleeve 101 vertically arranged in the up-down direction. The sealing sleeve 20 is connected to the machine base body 40 and coaxially arranged on the inner side of the disc bottom sealing sleeve 101, and a gap for sealing air to flow is formed between the sealing sleeve 20 and the disc bottom sealing sleeve 101, and a sealing air chamber 50 is formed between the sealing sleeve 20 and the transmission shaft 30. Primary hot air for blowing coal powder flows on the periphery of the transmission disc 10, and the pressure of the sealing air in the sealing air chamber 50 is greater than the pressure of the primary hot air, so as to prevent the primary hot air from escaping.

[0031] In this embodiment, the inner sealing structure 1 is arranged between the disc bottom sealing sleeve 101 and the sealing sleeve 20, and is located inside the machine base body 40. The outer sealing structure 2 is arranged between the machine base body 40 and the transmission shaft 30, and is located outside the machine base body 40. When the coal mill is running, the transmission shaft 30 drives the transmission disc 10 to rotate, and the disc bottom sealing sleeve 101 also rotates accordingly. The sealing ring 12 and the sealing ring seat 11 are connected to the sealing sleeve 20 and remain fixed, so that the lower end surface of the disc bottom sealing sleeve 101 and the upper end surface of the sealing ring 12 form a dynamic sealing structure. Since the high-pressure gas in the sealed air chamber 50 needs to be ejected from here to prevent the intrusion of dust, a first sealing gap 13 is set, and the size of the first sealing gap 13 is maintained between 0.5-1mm to form an effective dynamic sealing gap.

[0032] Specifically, when the high-pressure gas fills the sealed air chamber 50, it escapes through the gap between the bottom sealing sleeve 101 and the sealing sleeve 20 and is ejected from the first sealing gap 13. Since a plurality of spaced sealing rings 12 are arranged on the sealing ring seat 11, an annular air duct 121 is formed between each two adjacent sealing rings 12, so that each time the high-pressure gas passes through a sealing ring 12 and enters the corresponding annular air duct 121, a pressure loss is generated, thereby reducing the leakage of the sealed air, thereby ensuring the pressure in the sealed air chamber 50.

[0033] Furthermore, with the impact of high-pressure airflow and the extrusion and wear of dust, the first sealing gap 13 will gradually increase. At this time, the bottom surface of the sealing ring seat 11 can be pushed upward by rotating the pushing bolt 14 to move the sealing ring 12 upward to reduce the size of the first sealing gap 13 and prevent the hot air from carrying dust into the sealed air chamber 50.

[0034] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 2 and Figure 6 A plurality of steps 111 with increasing diameters from top to bottom are provided on the outer peripheral wall of the sealing ring seat 11 , and the sealing rings 12 are connected to the outer peripheral walls of the steps 111 in a one-to-one correspondence.

[0035] In this embodiment, the sealing ring 12 is detachably connected to the corresponding step 111 by fasteners such as bolts, which facilitates the subsequent replacement of the sealing ring 12. The widths of each sealing ring 12 and each step 111 are kept consistent, which facilitates the interchangeability of the sealing ring 12 and ensures the existence of the annular air duct 121.

[0036] It should be noted that the inner wall of the sealing ring seat 11 and the outer wall of the sealing sleeve 20 need to be tightly sealed, which can not only ensure the sealing performance of the sealed air chamber 50 but also enable the sealing ring seat 11 to slide smoothly along the outer wall of the sealing sleeve 20 under the pushing action of the pushing bolt 14.

[0037] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 1 and Figure 2 The inner sealing structure 1 further includes a first flange 15 connected to the outer periphery of the sealing sleeve 20 , and the thrust bolt 14 is threadedly connected to the first flange 15 .

[0038] In this embodiment, in order to facilitate the connection and operation of the push bolt 14, a first flange 15 is provided and fixedly connected to the sealing sleeve 20, and the push bolt 14 is threadedly connected to the first flange 15 from bottom to top, so as to facilitate manual rotation of the push bolt 14. Further, a plurality of ribs 151 may be provided at the bottom of the first flange 15, and the plurality of ribs 151 are arranged at intervals along the circumference of the sealing sleeve 20, the bottom end surface of the rib 151 is connected to the base body 40, and the inner end surface of the rib 151 is connected to the sealing sleeve 20, thereby ensuring the connection strength of the first flange 15.

[0039] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 1 and Figure 2 The inner sealing structure 1 also includes a slag stop ring 16 sleeved on the outer periphery of the disc bottom sealing sleeve 101 , and a second sealing gap 17 is formed between the upper end surface of the slag stop ring 16 and the lower end surface of the transmission disc 10 .

[0040] In this embodiment, the slag ring 16 is used to block the stone coal particles that enter due to the untimely discharge of stone coal, and prevent the stone coal particles from causing impact wear on the sealing ring 12. Furthermore, a second sealing gap 17 is formed between the upper end surface of the slag ring 16 and the lower end surface of the transmission plate 10, so that the sealing wind discharged through the first sealing gap 13 passes through the second sealing gap 17, and the wind pressure is further attenuated, which helps to ensure the pressure in the sealing air chamber 50.

[0041] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 1 and Figure 2 The first flange 15 is also connected to a support ring seat 18 extending upward, and the slag stop ring 16 is provided with a positioning long groove 161 extending in the up-down direction. The support ring seat 18 is threadedly connected with an adjusting bolt 19 that passes through the positioning long groove 161. The adjusting bolt 19 is used to adjust the size of the second sealing gap 17.

[0042] In this embodiment, the support ring seat 18 is detachably connected to the first flange 15 by bolts and other fasteners, so that the slag retaining ring 16 and the support ring seat 18 can be removed to replace and maintain the sealing ring 12 inside. Furthermore, when the slag retaining ring 16 is worn by the impact of the stone coal, resulting in an increase in the second sealing gap 17, the slag retaining ring 16 can be moved upward along the positioning slot 161 until the second sealing gap 17 reaches a predetermined range by loosening the adjusting bolt 19, and then tightening the adjusting bolt 19 to press the slag retaining ring 16 against the support ring seat 18 to fix the position.

[0043] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 1 , Figure 4 and Figure 5 The sealing ring 12 includes a plurality of first arc-shaped portions 122 spliced ​​in sequence, and adjacent first arc-shaped portions 122 are connected by first fasteners 123; the slag stop ring 16 includes a plurality of second arc-shaped portions 162 spliced ​​in sequence, and adjacent second arc-shaped portions 162 are connected by second fasteners 163.

[0044] In this embodiment, since the inner sealing structure 1 is located inside the machine base body 40 and sleeved on the outer periphery of the transmission shaft 30, if the sealing ring 12 or the slag stop ring 16 is an integrated circular ring structure, when the sealing ring 12 or the slag stop ring 16 needs to be replaced, the transmission shaft 30 needs to be removed so that the sealing ring 12 or the slag stop ring 16 can be installed from the shaft end of the transmission shaft 30, which is very inconvenient. For this reason, in this embodiment, the sealing ring 12 and the slag stop ring 16 are both set as split structures, so that the sealing ring 12 or the slag stop ring 16 can be replaced without disassembling the transmission shaft 30.

[0045] Specifically, the number of the first arc-shaped portion 122 and the number of the second arc-shaped portion 162 are both six, and the six first arc-shaped portions 122 are sequentially connected and spliced ​​into the sealing ring 12, and the adjacent first arc-shaped portions 122 are detachably connected by the first fasteners 123, that is, in the radial section, the cross section of the sealing ring 12 is divided into six parts. Similarly, the six second arc-shaped portions 162 are sequentially connected and spliced ​​into the slag retaining ring 16, and the adjacent second arc-shaped portions 162 are detachably connected by the second fasteners 163. Furthermore, a positioning long groove 161 can be provided on each second arc-shaped portion 162, and an adjusting bolt 19 is slidably connected in each positioning long groove 161, and accordingly, six threaded holes are provided on the support ring seat 18 to connect the adjusting bolt 19.

[0046] The first fastener 123 and the second fastener 163 are both hexagonal head bolts with a strength not less than 8.8 grade.

[0047] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 1 and Figure 3 The outer sealing structure 2 includes a second flange 24 connected to the base body 40, a sealing sleeve 21 connected to the bottom of the second flange 24 and sleeved on the outer periphery of the transmission shaft 30, and a sealing assembly 22 located between the sealing sleeve 21 and the transmission shaft 30. The outlet end of the air inlet pipe 23 is located above the sealing assembly 22.

[0048] In this embodiment, a through hole corresponding to the threaded hole on the machine base body 40 is provided on the second flange 24, and the sealing sleeve 21 is detachably connected to the machine base body 40 through the second flange 24 and fasteners such as bolts, so that it is convenient to implement the installation of the coal mill machine base sealing device of the utility model while maintaining the structure of the original equipment machine base body 40, thereby improving the applicability of the structure of the utility model.

[0049] The sealing assembly 22 is sealed on the outer periphery of the transmission shaft 30 and is located below the outlet end of the air inlet pipe 23 , so that the high-pressure gas entering from the air inlet pipe 23 can only flow upward and enter the sealed air chamber 50 , preventing the high-pressure gas from escaping from the bottom of the sealing sleeve 21 .

[0050] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 3 The sealing assembly 22 includes a plurality of dynamic sealing rings 221 and flexible sealing strips 222 sealed on the outer periphery of the transmission shaft 30 . The dynamic sealing rings 221 and the flexible sealing strips 222 are alternately arranged in sequence along the axial direction of the sealing sleeve 21 .

[0051] In this embodiment, a structure in which the dynamic sealing ring 221 and the flexible sealing strip 222 are alternately arranged in sequence is adopted, so that the sealing assembly 22 forms a labyrinth sealing structure, which effectively improves the sealing performance of the outer sealing structure 2.

[0052] Specifically, a plurality of annular grooves 211 arranged axially at intervals are provided on the inner wall of the sealing sleeve 21, and the dynamic sealing ring 221 and the flexible sealing strip 222 are sequentially arranged in the corresponding annular grooves 211. The dynamic sealing ring 221 can select a rubber-graphite combination ring or a graphite carbon fine sealing ring 12 according to the leakage amount. The dynamic sealing ring 221 rotates synchronously with the transmission shaft 30. During operation, due to the action of the high-pressure sealing wind, the bottom surface of the dynamic sealing ring 221 will be pressed against the bottom surface of the annular groove 211 to form a zero gap, thereby achieving a tight sealing effect. It should be noted that since the dynamic sealing ring 221 rotates synchronously with the transmission shaft 30, there is no relative rotation between the two, so the dynamic sealing ring 221 will not cause wear to the transmission shaft 30, and it is only necessary to regularly add lubricating grease to the dynamic sealing ring 221 and replace it in time.

[0053] The flexible sealing strip 222 is fixed in the annular groove 211 with pure wool felt, and its inner periphery forms a contact friction fit with the transmission shaft 30 to seal the transmission shaft 30. The flexible sealing strip 222 also needs to be regularly filled with lubricating grease and replaced in time.

[0054] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 1 and Figure 3 The inner circumference of the sealing sleeve 21 is also provided with a ventilation groove 212 which is located above the sealing assembly 22 and extends in the circumferential direction, and the outlet end of the air inlet pipe 23 is connected to the ventilation groove 212 .

[0055] In this embodiment, the air inlet pipe 23 is connected to an air source, and a valve is provided at the inlet end of the air inlet pipe 23 to control the on and off of the air flow and the adjustment of the air supply volume; the outlet end of the air inlet pipe 23 is connected to the ventilation groove 212, so that the air flow enters the ventilation groove 212 from the air inlet pipe 23, and then enters the sealed air chamber 50 upward through the gap between the sealing sleeve 21 and the transmission shaft 30 and the base body 40.

[0056] As a specific implementation of the coal mill base sealing device provided by the utility model, see Figure 3 A tension spring 223 is provided on the outer periphery of the dynamic sealing ring 221 . The tension spring 223 is used to press the dynamic sealing ring 221 toward the axial center side of the transmission shaft 30 so that the dynamic sealing ring 221 is pressed against the transmission shaft 30 .

[0057] In this embodiment, the tension spring 223 maintains a certain tension force, which can firmly fix the dynamic sealing ring 221 on the transmission shaft 30, preventing the dynamic sealing ring 221 from loosening and rotating relative to the transmission shaft 30, thereby causing wear on the transmission shaft 30. The tension spring 223 needs to be regularly maintained and replaced in time.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A coal mill base sealing device, characterized in that: It comprises an inner sealing structure and an outer sealing structure, wherein the inner sealing structure comprises a sealing ring seat slidably sleeved on the outer periphery of a sealing sleeve, a plurality of sealing rings sleeved on the sealing ring seat and a push bolt abutting against the bottom surface of the sealing ring seat, the plurality of sealing rings are arranged at intervals along the radial direction of the sealing ring seat, and an annular air duct is formed between two adjacent sealing rings, a first sealing gap is formed between the upper end surface of the sealing ring and the lower end surface of the sealing sleeve at the bottom of the disc, and the push bolt is used for pushing the sealing ring seat upward to adjust the size of the first sealing gap; the outer sealing structure is connected with an air inlet pipe for supplying sealing air into the sealed air chamber.

2. The coal mill base sealing device according to claim 1, characterized in that: The outer peripheral wall of the sealing ring seat is provided with a plurality of steps with diameters increasing from top to bottom, and the sealing rings are connected to the outer peripheral walls of the steps in a one-to-one correspondence.

3. The coal mill base sealing device according to claim 1, characterized in that: The inner sealing structure also includes a first flange connected to the outer periphery of the sealing sleeve, and the push bolt is threadedly connected to the first flange.

4. The coal mill base sealing device according to claim 3, characterized in that: The inner sealing structure also includes a slag stop ring sleeved on the outer periphery of the disc bottom sealing sleeve, and a second sealing gap is formed between the upper end surface of the slag stop ring and the lower end surface of the transmission disc.

5. The coal mill base sealing device according to claim 4, characterized in that: The first flange is also connected to a support ring seat extending upward, the slag retaining ring is provided with a long positioning groove extending in the up-down direction, the support ring seat is threadedly connected with an adjusting bolt penetrating the long positioning groove, and the adjusting bolt is used to adjust the size of the second sealing gap.

6. The coal mill base sealing device according to claim 5, characterized in that: The sealing ring includes a plurality of first arc-shaped portions spliced ​​in sequence, and adjacent first arc-shaped portions are connected by a first fastener; the slag retaining ring includes a plurality of second arc-shaped portions spliced ​​in sequence, and adjacent second arc-shaped portions are connected by a second fastener.

7. The coal mill base sealing device according to claim 1, characterized in that: The outer sealing structure includes a second flange connected to the base body, a sealing sleeve connected to the bottom of the second flange and sleeved on the outer periphery of the transmission shaft, and a sealing assembly located between the sealing sleeve and the transmission shaft. The outlet end of the air inlet pipe is located above the sealing assembly.

8. The coal mill base sealing device according to claim 7, characterized in that: The sealing assembly comprises a plurality of dynamic sealing rings and flexible sealing strips which are sealed on the outer periphery of the transmission shaft. The dynamic sealing rings and the flexible sealing strips are alternately arranged in sequence along the axial direction of the sealing sleeve.

9. The coal mill base sealing device according to claim 8, characterized in that: The inner circumference of the sealing sleeve is provided with a ventilation groove which is located above the sealing assembly and extends in the circumferential direction, and the outlet end of the air inlet pipe is communicated with the ventilation groove.

10. The coal mill base sealing device according to claim 8, characterized in that: A tension spring is sleeved on the outer periphery of the dynamic sealing ring. The tension spring is used to press the dynamic sealing ring toward the axial center side of the transmission shaft so that the dynamic sealing ring is pressed against the transmission shaft.

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