A boiler slag crusher FKM skeleton type sealing structure

Abstract

This invention discloses an FKM skeleton-type sealing structure for a boiler ash remover, belonging to the field of sealing structure technology. It includes an FKM elastic sealing body, fixedly connected to the inner end face of the bearing cap of the boiler ash remover. The inner side of the sealing body has an inwardly wound sealing lip, forming an annular winding space. A self-tightening helical spring is embedded within the winding space, with the spring's free inner diameter smaller than the inner diameter of the winding space, and is in a pre-stretched state. The sealing lip is interference-fitted with the rotating shaft. The sealing body has a U-shaped cross-section, with circumferentially spaced anchoring grooves on its back. The inner wall and bottom surface of the U-shaped groove have circumferentially spaced anti-rotation protrusions for anti-torsion, enhanced pressure and extrusion resistance, and installation guidance. This invention replaces the original positioning ring, achieving self-positioning installation without auxiliary tooling, significantly extending the maintenance cycle, providing reliable sealing, and is suitable for boiler ash removal systems.

Description

Technical Field

[0001] This invention relates to the field of sealing structure technology, and in particular to the FKM skeleton-type sealing structure for boiler slag crushers. Background Technology

[0002] In boiler ash removal systems, ash crushers are typically located below the ash hopper of the ash remover to crush large pieces of ash and ensure smooth operation of the ash removal system. The bearings and rotating parts of the ash crusher operate in a high-dust, high-temperature environment for extended periods. Existing ash crusher bearings typically use a locating ring structure for axial positioning, relying on the locating ring for basic protection. During assembly, the locating ring and the rotating shaft often use a clearance fit, making it impossible to automatically determine the accurate installation position. This necessitates manual adjustment by the operator, using auxiliary tooling or structures to complete the assembly, resulting in cumbersome on-site installation and requiring a high level of assembly skill.

[0003] Chinese patent CN202927047U discloses a bearing sealing device for a scraper-type coal boiler slag remover. The device includes a rotating shaft with a bearing seat at one end. A skeleton sealing groove is formed on the bearing seat, and a skeleton seal is embedded within the groove. A bearing is installed inside the bearing seat, and a bearing cap is located at the outer end of the bearing seat. The device involves machining a skeleton sealing groove on the existing bearing seat and installing a skeleton seal on top of the groove. This effectively prevents small coal slag particles from entering the bearing along the shaft. Multiple sealing lips can be provided on the skeleton seal to further prevent small coal slag particles from entering the bearing.

[0004] However, in actual operation, fine ash and slag in the slag hopper can easily penetrate into the bearing through the shaft end gap, causing accelerated bearing wear, grease contamination and failure, and ultimately equipment failure. The frequent occurrence of ash and slag intrusion severely impacts the continuous operating efficiency of the slag removal system. Furthermore, traditional positioning ring structures only provide axial positioning and cannot effectively prevent ash and slag from entering the bearing area axially. Moreover, their assembly requires additional auxiliary positioning structures, increasing assembly complexity and failing to address the fundamental issue of sealing protection.

[0005] To address these issues, this invention proposes an FKM skeleton-type sealing structure for a boiler slag crusher. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention is proposed.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an FKM skeleton-type sealing structure for a boiler ash crusher, comprising an FKM elastic sealing body, the FKM elastic sealing body being fixedly connected to the inner end face of the bearing cover of the boiler ash crusher, a sealing lip being provided in the inner region of the FKM elastic sealing body, the sealing lip being an inwardly wound structure forming an annular wound space; a self-tightening helical spring being embedded in the wound space, the self-tightening helical spring being used to apply a continuous radial contraction force to the sealing lip, and the sealing lip forming an interference fit with the outer circumferential surface of the rotating shaft.

[0008] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the free inner diameter of the self-tightening helical spring is smaller than the inner diameter of the sealing lip winding space.

[0009] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the cross-section of the FKM elastic sealing body is a U-shaped groove structure, and multiple anchoring grooves are provided in the back area at intervals along the circumference.

[0010] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the inner wall and bottom surface of the U-shaped groove of the FKM elastic sealing body are provided with a plurality of anti-rotation protrusions distributed circumferentially, and the anti-rotation protrusions and the FKM elastic sealing body are integrally formed.

[0011] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the FKM elastic sealing body is made of fluororubber material.

[0012] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the anchoring groove is one or more of the following: trapezoidal, inverted trapezoidal, rectangular, square, V-shaped, U-shaped, arc-shaped, semi-circular, triangular, dovetail-shaped, or right-angled trapezoidal.

[0013] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the self-tightening helical spring is in the shape of an oil seal spring, the spring wire of the self-tightening helical spring has a circular cross-section, and the spring ring of the self-tightening helical spring is tightly fitted to the wall surface of the sealing lip.

[0014] As a preferred embodiment of the FKM skeleton-type sealing structure of the boiler slag crusher described in this invention, the inner wall of the U-shaped groove winding space of the FKM elastic sealing body is provided with a plurality of spring guide grooves distributed circumferentially, and the spring guide grooves extend axially to accommodate and circumferentially limit the spring wire of the self-tightening helical spring.

[0015] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the width of the spring guide groove matches the diameter of the spring wire of the self-tightening helical spring, and a portion of the spring wire of the self-tightening helical spring is embedded in the corresponding spring guide groove to limit the displacement of the self-tightening helical spring relative to the FKM elastic seal body.

[0016] As a preferred embodiment of the FKM skeleton-type sealing structure for the boiler slag crusher described in this invention, the cross-sectional shape of the spring guide groove is semi-circular.

[0017] The beneficial effects of this invention are:

[0018] By setting an FKM elastic seal body fixedly connected to the inner end face of the bearing cover, the inner area of ​​the seal lip with an inwardly coiled structure is provided, and a self-tightening helical spring is embedded in the coiled space. The self-tightening helical spring continuously applies radial contraction force to the seal lip. When the shaft rotates, the FKM elastic seal body forms a dynamic sealing interface, which can effectively prevent fine ash and slag in the slag hopper from entering the bearing through the shaft end gap, avoiding bearing wear, lubrication failure and equipment failure caused by ash and slag intrusion, significantly extending the maintenance cycle of the slag crusher and ensuring the continuous operation efficiency of the slag removal system.

[0019] Furthermore, the self-tightening helical spring is embedded in the winding space of the sealing lip and applies a continuous radial contraction force to the sealing lip. This contraction force drives the sealing lip to automatically grip the outer circumference of the shaft, forming an interference fit. During installation, without any auxiliary positioning fixtures or manual adjustment, the FKM elastic seal can automatically determine the accurate installation position on the shaft, achieving self-positioning during installation, simplifying the assembly process, reducing the skill requirements for operators, and improving installation efficiency and consistency.

[0020] In addition, the FKM elastic seal is fixedly connected to the inner end face of the original bearing cover of the boiler slag crusher, directly replacing the original positioning ring. No modification to the main structure of the slag crusher is required. The FKM elastic seal has a simple structure, low modification cost, and is easy to promote and apply on existing equipment. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a semi-sectional front view of the FKM skeleton sealing structure in this invention.

[0023] Figure 2 This is a three-dimensional isometric schematic diagram of the FKM skeleton-type sealing structure in this invention;

[0024] Figure 3 This is a front view schematic diagram of the FKM elastic seal body in this invention;

[0025] Figure 4 This is a rear view schematic diagram of the FKM elastic seal body in this invention;

[0026] Figure 5 This is a schematic diagram of the structure of the self-tightening helical spring in this invention;

[0027] Figure 6 This is a schematic diagram of a half-section of the FKM elastic seal body in this invention.

[0028] Figure 7 For the present invention Figure 6 Enlarged view of the structure of part A.

[0029] Explanation of reference numerals in the attached drawings: 11, FKM elastic seal; 111, anchor groove; 112, anti-rotation boss; 12, sealing lip; 121, spring guide groove; 21, bearing cap; 31, self-tightening helical spring; 311, spring wire. Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0033] The technical background of this invention is further explained below: The working environment of a boiler ash crusher is extremely harsh. Its bearings not only bear high radial loads and axial impacts, but are also exposed to slag dust, high-temperature steam, and periodic water mist for extended periods. Traditional positioning rings, due to their clearance fit, inevitably have an annular gap between themselves and the rotating shaft. During dynamic operation, the rotation of the shaft "pumps" or "screws" ash particles into the bearing, causing abrasive wear. The Chinese patent CN202927047U, concerning a scraper-type coal boiler ash discharge machine bearing sealing device, [further details are needed].

[0034] While a solution of machining a skeleton seal groove on the bearing housing and installing the skeleton seal has been proposed, this solution requires mechanically grooving the existing bearing housing. This modification not only increases the difficulty of on-site construction but also requires a significant downtime for disassembling the bearing housing and precisely machining the seal groove on an already installed crusher, resulting in poor economic efficiency. More importantly, the skeleton seal in this solution relies solely on its own lip contacting the shaft, lacking a continuous radial force compensation mechanism. After long-term operation, lip wear will inevitably lead to a decrease in sealing effectiveness. This invention presents a comprehensive solution addressing the dual shortcomings of the aforementioned prior art.

[0035] Example 1:

[0036] Reference Figures 1-5 As shown, this is the first embodiment of the present invention. This embodiment provides an FKM skeleton-type sealing structure for a boiler slag crusher, which is installed at the bearing end of the boiler slag crusher to replace the original positioning ring, thereby achieving sealing protection and self-positioning of the bearing.

[0037] The boiler ash crusher includes a bearing, a rotating shaft, a bearing housing, and a bearing cover 21 fixedly installed on the bearing housing. The bearing cover 21 is fixedly installed on the bearing housing by bolts and presses against the end face of the bearing for axial positioning of the bearing. The bearing, rotating shaft, and bearing housing in this application are all conventional existing components in the boiler ash crusher, and their specific structures have not been modified in any way, so they are not shown in the accompanying drawings.

[0038] The sealing structure of this invention includes an FKM elastic seal 11. The FKM elastic seal 11 is made of fluororubber, which possesses excellent high-temperature resistance, corrosion resistance, and wear resistance. The long-term operating temperature of the fluororubber FKM elastic seal 11 can adapt to the high-temperature environment that may occur near the slag crusher bearing; fluororubber has good chemical inertness to sulfides, water vapor, and lubricating grease in ash slag, and will not age rapidly due to corrosion; at the same time, fluororubber has better wear resistance than ordinary nitrile rubber, and its volumetric wear rate is significantly reduced under repeated friction conditions, which is crucial for maintaining sealing performance over long maintenance cycles. Furthermore, the FKM material has a moderate elastic modulus, which allows for sufficient compression deformation under the push of the self-tightening helical spring 31 without causing installation difficulties due to excessive elasticity.

[0039] The FKM elastic seal 11 is annular in shape and is fixedly connected to the inner end face of the bearing cap 21 by adhesive or glue to replace the original positioning ring installed at the end of the bearing.

[0040] The FKM elastic seal 11 has a U-shaped groove structure in its cross-section, specifically divided into a back region and an inner region. The back region is the side that fits against the inner end face of the bearing cap 21. Multiple circumferentially spaced anchoring grooves 111 are provided in the back region. These grooves can be trapezoidal, inverted trapezoidal, rectangular, square, V-shaped, U-shaped, arc-shaped, semi-circular, triangular, dovetail-shaped, or right-angled trapezoidal shapes or combinations thereof. The anchoring grooves 111 are used to accommodate adhesive. After the adhesive cures, solid adhesive columns are formed within the anchoring grooves 111, interlocking with the groove walls, thus creating a mechanical interlocking structure between the FKM elastic seal 11 and the bearing cap 21. This mechanical interlocking structure, combined with the chemical adhesion of the adhesive itself, improves the connection strength and anti-peeling ability between the FKM elastic seal 11 and the bearing cap 21, effectively preventing the FKM elastic seal 11 from detaching even under long-term high temperature, vibration, and ash impact conditions. In addition, the opening of the anchor groove 111 reduces the actual contact area between the back of the FKM elastic seal 11 and the inner end face of the bearing cap 21, reduces the pressing resistance of the FKM elastic seal 11 during installation and the peeling resistance during disassembly, and facilitates the assembly, maintenance and replacement of the FKM elastic seal 11.

[0041] Regarding the specific distribution and dimensions of the anchoring grooves 111, those skilled in the art can optimize the design based on the overall diameter and thickness of the FKM elastic seal 11. Generally, the number of anchoring grooves 111 should be appropriate, and the groove width, depth, and spacing should ensure sufficient adhesive filling and sufficient support strength. Different cross-sectional shapes of the anchoring grooves 111 will bring different technical effects: trapezoidal, dovetail, and other "wider at the bottom and narrower at the top" shapes form the strongest mechanical locking after the adhesive cures, with the best pull-out resistance; rectangular and semi-circular shapes are simple to process and suitable for mass production; V-shaped grooves have the advantage of self-centering to guide the flow of adhesive. In actual products, they can be flexibly selected or combined according to manufacturing processes and cost requirements.

[0042] The inner region of the FKM elastic seal 11 is provided with a sealing lip 12, which has an inwardly wound structure forming an annular winding space. A self-tightening helical spring 31 is embedded within this winding space. The self-tightening helical spring 31 is preferably made of stainless steel, and its free inner diameter is smaller than the inner diameter of the winding space of the sealing lip 12. During installation, the self-tightening helical spring 31 is in a pre-stretched state, thereby applying a continuous radial contraction force to the sealing lip 12. The sealing lip 12 is configured with an interference fit with the outer circumferential surface of the rotating shaft.

[0043] The self-tightening helical spring 31 is in the shape of an oil seal spring. The spring wire 311 of the self-tightening helical spring 31 has a circular cross-section. The spring coil of the self-tightening helical spring 31 is tightly fitted to the wall surface of the sealing lip 12.

[0044] To further improve the installation stability and structural strength of the seal, the FKM elastic seal 11 has a plurality of anti-rotation protrusions 112 distributed circumferentially on the inner wall and bottom surface of the U-shaped groove. The anti-rotation protrusions 112 are simultaneously attached to the bottom surface of the U-shaped groove and the inner wall surface away from the sealing lip 12.

[0045] The anti-rotation boss 112 is fitted against the outer ring end face of the bearing. When the shaft rotates, the tangential friction force generated on the sealing lip 12 attempts to cause the FKM elastic seal 11 to twist circumferentially. At this time, the anti-rotation boss 112 generates a reverse resistance torque through mechanical interference with the stationary outer ring end face of the bearing, preventing the FKM elastic seal 11 from twisting itself, thereby ensuring a uniform and stable interference fit between the sealing lip 12 and the shaft. The anti-rotation boss 112 does not participate in the sealing function; its sole purpose is to fix the circumferential position of the FKM elastic seal 11. During the operation of the crusher, the rotational motion of the shaft will apply a tangential force to the FKM elastic seal 11 through the contact surface of the sealing lip 12. Without the constraint of the anti-rotation boss 112, the FKM elastic seal 11 will gradually undergo circumferential creep, eventually causing the sealing lip 12 to twist and deform, resulting in a decrease or increase in local interference. A decrease in local interference will cause leakage gaps, while an increase in local interference will exacerbate local wear.

[0046] During installation, first, stop the crusher and remove the bearing cap 21. Clean the original locating ring residue, oil, and ash from the inner end face of the bearing cap 21 to ensure the surface is clean and dry. At the same time, check the shaft surface for scratches or severe wear, and polish it if necessary. Then, prepare the FKM elastic seal 11, check its sealing lip 12 for defects, ensure the self-tightening coil spring 31 is installed correctly, and ensure there are no foreign objects in the anchoring groove 111.

[0047] Apply a high-temperature resistant adhesive evenly to the inner end face of the bearing cap 21 and the back anchoring groove 111 area of ​​the FKM elastic seal 11. The amount of adhesive applied should be sufficient to fill most of the volume of the anchoring groove 111, avoiding excessive overflow. Then, gently press the FKM elastic seal 11 onto the inner end face of the bearing cap 21, ensuring that the opening direction of the sealing lip 12 is aligned with the shaft installation direction. Apply uniform pressure to ensure the adhesive fully wets the groove wall of the anchoring groove 111. Subsequently, place the assembly at room temperature for curing, or accelerate curing in an oven at a suitable temperature. After curing, the adhesive within the anchoring groove 111 forms solid adhesive columns that interlock with the groove wall, thus forming a mechanical interlocking structure.

[0048] Once the shredder is in operation, the shaft rotates at high speed. Under the force of the spring, the sealing lip 12 remains in contact with the shaft, forming a very thin lubricating oil film to achieve boundary lubrication and sealing. For larger ash particles, the sealing lip 12 acts like a scraper, blocking them from entering; for smaller, extremely fine dust particles, the continuous compression of the spring force prevents the dust from passing through due to the contact pressure between the sealing lip 12 and the shaft. Furthermore, because the anti-rotation boss 112 tightly abuts against the outer ring end face of the bearing, the FKM elastic seal 11 does not twist with the shaft, and the force on the sealing lip 12 remains uniform.

[0049] Over time, slight wear will occur on the contact surface of the sealing lip 12, and the inner diameter of the winding space will increase slightly. At this point, the self-tightening coil spring 31 will automatically contract due to its elastic recovery characteristics, maintaining a constant contact pressure between the sealing lip 12 and the shaft. The self-compensation process of the self-tightening coil spring 31 will continue until it contracts to its limit position. When the self-tightening coil spring 31 can no longer compensate for the wear, the contact pressure between the sealing lip 12 and the shaft will begin to decrease. At this point, a small amount of ash or slag leakage into the bearing area can be observed, indicating that the seal needs to be replaced. By regularly checking for ash or slag accumulation around the bearing, the remaining life of the seal can be accurately determined.

[0050] During installation, the FKM elastic seal 11 is fixedly connected to the inner end face of the bearing cap 21 with adhesive, and the sealing lip 12 faces the rotating shaft. When the bearing cap 21 and the FKM elastic seal 11 are installed together on the bearing seat, the sealing lip 12 fits onto the outer circumferential surface of the rotating shaft. Since the free inner diameter of the self-tightening coil spring 31 is smaller than the inner diameter of the winding space of the sealing lip 12, the self-tightening coil spring 31 is stretched and embedded in the winding space during installation, and is in a pre-stretched state. The pre-stretched self-tightening coil spring 31 continuously applies a radially inward contraction force to the sealing lip 12, driving the sealing lip 12 to automatically hug the outer circumferential surface of the rotating shaft, forming a uniform interference fit. During this process, without any auxiliary positioning fixtures or manual adjustment, the FKM elastic seal 11 can automatically determine the accurate installation position on the rotating shaft, realizing self-positioning during installation.

[0051] When the boiler slag crusher is running, the rotating shaft rotates at high speed in the inner ring of the bearing, while the outer ring of the bearing, the bearing housing, the bearing cap 21, and the FKM elastic seal 11 fixed to the inner end face of the bearing cap 21 remain stationary. The sealing lip 12 forms an interference fit with the outer circumferential surface of the rotating shaft, constituting a dynamic sealing interface.

[0052] During rotation, the self-tightening helical spring 31 continuously provides radial contraction force to compensate for wear of the sealing lip 12 or stress relaxation of the fluororubber material caused by long-term operation, ensuring that the sealing lip 12 always maintains a stable interference contact with the rotating shaft. Even under high dust and high temperature conditions, the sealing lip 12 can tightly fit the surface of the rotating shaft, effectively preventing ash and slag from entering the bearing along the axial direction.

[0053] When the shaft rotates, due to the interference fit between the sealing lip 12 and the outer circumferential surface of the shaft, the shaft generates a tangential frictional force on the sealing lip 12. This tangential frictional force tends to cause the FKM elastic seal 11 to rotate circumferentially along with the shaft.

[0054] To prevent the FKM elastic seal 11 from twisting, multiple anti-rotation protrusions 112 are provided on the inner wall and bottom surface of the U-shaped groove of the FKM elastic seal 11, spaced apart circumferentially. These anti-rotation protrusions 112 are fitted against the outer ring end face of the bearing. Since the outer ring of the bearing is fixed within the bearing housing and is stationary, when the tangential frictional force of the shaft attempts to twist the FKM elastic seal 11, mechanical interference occurs between the anti-rotation protrusions 112 and the stationary outer ring end face of the bearing, creating a reverse resistance torque. This reverse resistance torque counteracts the torsional effect caused by the shaft friction, thereby preventing the FKM elastic seal 11 from twisting circumferentially and ensuring that the interference fit between the sealing lip 12 and the shaft remains uniform and stable.

[0055] During the operation of the slag crusher, fine ash and slag in the slag hopper move axially towards the bearing along the rotating shaft. When the ash and slag reach the contact interface between the sealing lip 12 and the rotating shaft, due to the interference fit between the sealing lip 12 and the rotating shaft, and the continuous radial contraction force provided by the self-tightening helical spring 31, the ash and slag cannot pass through this dynamic sealing interface, thus preventing the ash and slag from entering the internal area of ​​the bearing.

[0056] Example 2:

[0057] Reference Figure 6 and 7 As shown, this is the second embodiment of the present invention, which is based on the previous embodiment and further improves the FKM elastic seal 11. The difference from embodiment 1 is that the inner wall of the U-shaped groove winding space of the FKM elastic seal 11 is provided with a plurality of circumferentially spaced spring guide grooves 121. The spring guide grooves 121 extend axially to accommodate and circumferentially limit the spring wire 311 of the self-tightening helical spring 31.

[0058] The width of the spring guide groove 121 matches the diameter of the spring wire 311 of the self-tightening helical spring 31. A portion of the spring wire 311 of the self-tightening helical spring 31 is embedded in the corresponding spring guide groove 121 to limit the self-tightening helical spring 31 from shifting relative to the FKM elastic seal 11.

[0059] Preferably, the cross-sectional shape of the spring guide groove 121 is semi-circular.

[0060] During installation, a portion of the spring wires 311 of the self-tightening helical spring 31 are placed into the corresponding spring guide grooves 121. Then, the spring, along with the FKM elastic seal 11, is installed on the inner end face of the bearing cap 21. During the operation of the crusher, when the shaft rotates or vibrates, the spring guide grooves 121 provide circumferential restraint to the spring wires 311 of the self-tightening helical spring 31, preventing circumferential twisting or local displacement of the self-tightening helical spring 31 within the winding space. This ensures that the radial contraction force of the self-tightening helical spring 31 is evenly distributed circumferentially along the sealing lip 12, thereby maintaining the consistency of the interference fit between the sealing lip 12 and the shaft.

[0061] Furthermore, the spring guide groove 121 and the anti-rotation boss 112 are circumferentially misaligned and do not interfere with each other. The anti-rotation boss 112 is used to prevent the FKM elastic seal 11 from circumferentially twisting relative to the bearing outer ring, and the spring guide groove 121 is used to prevent the self-tightening coil spring 31 from internally twisting relative to the FKM elastic seal 11. Under their combined action, the self-tightening coil spring 31 and the FKM elastic seal 11, as well as the FKM elastic seal 11 and the bearing outer ring, maintain relative circumferential stability, further improving the sealing reliability and service life of the FKM elastic seal 11.

[0062] It should be noted that the spring guide groove 121 only needs to be provided with multiple axial straight grooves evenly distributed along the circumference, which are located in the middle section of the winding space. After the self-tightening helical spring 31 is installed, its spring wire 311 is constrained by the spring guide groove 121 at several points in the circumferential direction, while the rest remains in a free state. This can effectively prevent the self-tightening helical spring 31 from twisting as a whole, without excessively restricting the deformation capacity of the self-tightening helical spring 31 during radial contraction.

[0063] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0064] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0065] In conclusion, 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A boiler slag crusher FKM skeleton type seal structure, characterized in that: The device includes an FKM elastic seal (11), which is fixedly connected to the inner end face of the bearing cap (21) of the boiler slag crusher. The inner area of ​​the FKM elastic seal (11) is provided with a sealing lip (12), which has an inwardly wound structure and forms an annular winding space. A self-tightening helical spring (31) is embedded in the winding space. The self-tightening helical spring (31) is used to apply a continuous radial contraction force to the sealing lip (12). The sealing lip (12) is configured to form an interference fit with the outer circumferential surface of the rotating shaft.

2. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 1, characterized in that: The free inner diameter of the self-tightening helical spring (31) is smaller than the inner diameter of the winding space of the sealing lip (12).

3. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 2, characterized in that: The cross-section of the FKM elastic seal (11) is a U-shaped groove structure, and multiple anchoring grooves (111) are provided on its back area at intervals along the circumference.

4. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 3, characterized in that: The inner wall and bottom surface of the U-shaped groove of the FKM elastic seal (11) are provided with a plurality of anti-rotation bosses (112) distributed circumferentially. The anti-rotation bosses (112) and the FKM elastic seal (11) are integrally formed.

5. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 4, characterized in that: The FKM elastic seal (11) is made of fluororubber material.

6. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 5, characterized in that: The anchoring groove (111) is one or more of the following: trapezoidal, inverted trapezoidal, rectangular, square, V-shaped, U-shaped, arc-shaped, semi-circular, triangular, swallowtail-shaped, or right-angled trapezoidal.

7. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 6, characterized in that: The self-tightening helical spring (31) is in the shape of an oil seal spring. The spring wire (311) of the self-tightening helical spring (31) has a circular cross-section. The spring ring of the self-tightening helical spring (31) is tightly fitted to the wall of the sealing lip (12).

8. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 7, characterized in that: The inner wall of the U-shaped groove winding space of the FKM elastic seal (11) is provided with a plurality of spring guide grooves (121) distributed circumferentially. The spring guide grooves (121) extend axially to accommodate and circumferentially limit the spring wire (311) of the self-tightening helical spring (31).

9. The FKM skeleton-type sealing structure for the boiler slag crusher as described in claim 8, characterized in that: The width of the spring guide groove (121) matches the diameter of the spring wire (311) of the self-tightening helical spring (31). A portion of the spring wire (311) of the self-tightening helical spring (31) is embedded in the corresponding spring guide groove (121) to limit the self-tightening helical spring (31) from shifting relative to the FKM elastic seal (11).

10. The boiler slag crusher FKM skeleton sealing structure as described in claim 9, characterized in that: The cross-sectional shape of the spring guide groove (121) is semi-circular.

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