Shaft sealing structure and coal feeder

Abstract

The utility model discloses a shaft sealing structure and a coal feeder, and belongs to the technical field of shaft sealing, the shaft sealing structure comprises a cylinder body, annular packing and a gland, the cylinder body is used for being installed at a shaft hole of a shell, the interior of the cylinder body is used for allowing a shaft body to penetrate through, and a packing chamber is formed between the inner wall face of the cylinder body and the shaft face of the shaft body; the annular filler is arranged in the filler chamber; the gland comprises a cover plate and an annular plug connected to the cover plate, the annular plug can be plugged into the filler chamber, and the end of the annular plug is used for extruding the annular filler. The annular packing in the packing chamber is extruded by the annular plug of the gland, the sealing state of the annular packing can be improved and maintained, the sealing structure has the characteristics of wear resistance, dust permeation prevention and long-acting sealing, and the problems of powder leakage, bearing failure and poor equipment reliability are solved.

Description

Technical Field

[0001] This utility model relates to the field of shaft sealing technology, and in particular to a shaft sealing structure and a coal feeder. Background Technology

[0002] The NJGC-30 fully enclosed pressure-resistant weighing coal feeder is a key piece of equipment in the pulverizing system of a pulverized coal boiler in a thermal power plant. It quantitatively transports coal blocks from the raw coal bunker to the next-stage coal mill via a control gate, ensuring the continuous and stable operation of the pulverizing system. This equipment adopts a fully enclosed structure design. The internal conveyor belt is driven by both a conveyor belt drive shaft and a cleaning chain drive shaft. The shaft ends are equipped with F211 and F210 type spherical square bearings with mounting brackets, and the shaft ends are sealed to the housing using rubber skeleton oil seals (specifications 55×75×12 and 50×75×12).

[0003] However, in actual operation, existing sealing methods have significant drawbacks. Because the coal feeder operates under positive pressure and is filled with high-density coal dust particles, traditional rubber-framed oil seals are constantly exposed to high-concentration dust conditions, severely challenging their sealing performance. On the one hand, the friction and penetration of coal dust particles cause rapid wear of the oil seal lip, leading to seal failure and coal dust leakage. This not only pollutes the environment but may also cause safety hazards such as dust explosions. On the other hand, coal dust penetrating into the bearings contaminates the lubricating grease and exacerbates ball wear, causing bearing jamming or overheating, forcing unplanned equipment shutdowns and severely affecting the stability of the power generation system. Statistics show that such failures increase the annual maintenance frequency by more than 30%, while frequent replacement of oil seals and bearings significantly increases spare parts costs and maintenance time.

[0004] In the existing technology, the sealing solution that relies solely on rubber skeleton oil seals is no longer able to meet the special requirements of fully enclosed, high-dust, and positive-pressure environments. Utility Model Content

[0005] The purpose of this utility model is to provide a shaft sealing structure and a coal feeder to solve the problems existing in the prior art. By using the annular plug of the gland to squeeze the annular packing in the packing chamber, the sealing state of the annular packing can be improved and maintained. It has the characteristics of wear resistance, dust penetration prevention and long-term sealing, and solves the problems of powder leakage, bearing failure and poor equipment reliability.

[0006] To achieve the above objectives, this utility model provides the following solution:

[0007] This utility model provides a shaft sealing structure, including a cylinder, an annular packing, and a gland. The cylinder is used to be installed at the shaft hole of the housing, and the interior of the cylinder is used for the shaft to pass through. A packing chamber is formed between the inner wall surface of the cylinder and the axial surface of the shaft. The annular packing is disposed in the packing chamber. The gland includes a cover plate and an annular plug connected to the cover plate. The annular plug can be inserted into the packing chamber, and the end of the annular plug is used to compress the annular packing.

[0008] In one embodiment, the annular packing is in the form of a first stepped shape, and the annular plug is in the form of a second stepped shape, wherein the steps of the second stepped shape correspond to and contact the steps of the first stepped shape.

[0009] In one embodiment, the first stepped type includes a first packing and a second packing that are nested together, wherein the axial length of the first packing is greater than the axial length of the second packing; the second stepped type includes a first plug and a second plug that are nested together, wherein the axial length of the first plug is greater than the axial length of the second plug; the first plug abuts against the second packing, and the second plug abuts against the first packing.

[0010] In one embodiment, the annular packing is made of graphite packing, and the first and last ends of the graphite packing are connected in an annular shape, with the first and last ends being wedge-shaped.

[0011] In one embodiment, the angle of the wedge-shaped surface is 40° to 50°.

[0012] In one embodiment, the docking positions of the graphite packings from different groups are staggered.

[0013] In one embodiment, the angle of the staggered arrangement of the docking positions is 160° to 180°.

[0014] In one embodiment, the end face of the cylinder near the gland is provided with a threaded hole, the cover plate is provided with a through hole, the through hole is provided corresponding to the threaded hole, and a bolt is also included, the bolt passes through the through hole and is connected to the threaded hole, and there is a gap between the cylinder and the cover plate.

[0015] In one embodiment, the end face of the cylinder away from the gland is provided with a flange extending toward the inner diameter side, the inner diameter of the flange being larger than the diameter of the shaft.

[0016] This utility model also provides a coal feeder, including a coal feeder body and a shaft sealing structure as described above disposed on the coal feeder body, wherein the end face of the cylinder away from the pressure cover is welded to the shell of the coal feeder body.

[0017] The present invention achieves the following technical advantages over the prior art:

[0018] The cylindrical body of this invention can be installed at the shaft hole of the shell, and the shaft passes through the interior of the cylindrical body, forming a packing chamber between the shaft and the cylindrical body. The annular plug of the gland is used to squeeze the annular packing in the packing chamber, and the annular packing seals the gap of the annular plug, so that the annular plug and the annular packing cooperate to achieve a seal. Thus, through the squeezing of the annular plug, the sealing state of the annular packing can be improved and maintained. The entire sealing structure has the characteristics of wear resistance, dust penetration prevention and long-term sealing, solving the problems of powder leakage, bearing failure and poor equipment reliability.

[0019] Other technical solutions included in this utility model can also achieve the following technical effects:

[0020] When the shaft seal structure of this utility model is applied to the NJGC-30 fully enclosed pressure-resistant weighing coal feeder, it can solve the problem of frequent damage to the oil seal of the drive shaft seal skeleton during operation and coal powder leakage when the seal fails. It can also prevent the drive end bearing from jamming due to coal powder leakage, avoid the coal feeder from stopping, reduce the impact on the safe and stable operation of the coal feeder and environmental pollution, and solve the problem of large workload for maintenance personnel and waste of spare parts and materials. Attached Figure Description

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

[0022] Figure 1 This is a schematic diagram of the shaft seal structure when closed in an embodiment of this utility model;

[0023] Figure 2 This is a schematic diagram of the shaft seal structure when it is separated in an embodiment of this utility model;

[0024] Figure 3 This is a schematic diagram of the axial cross-section of the shaft seal structure in an embodiment of this utility model;

[0025] Figure 4 This is a schematic diagram of the axial cross-section of the cylinder in an embodiment of this utility model;

[0026] Figure 5 This is a schematic diagram of the axial cross-section of the gland in an embodiment of this utility model;

[0027] Figure 6 This is a schematic diagram of another axial cross-section of the cylinder in an embodiment of this utility model;

[0028] The components include: 1. cylinder; 2. gland; 3. shaft; 4. annular packing.

[0029] 11. Flange;

[0030] 21. Cover plate; 22. Ring plug;

[0031] 221. First plug body; 222. Second plug body;

[0032] 41. First packing material; 42. Second packing material. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] The purpose of this utility model is to provide a shaft sealing structure and a coal feeder to solve the problems existing in the prior art. By using the annular plug of the gland to squeeze the annular packing in the packing chamber, the sealing state of the annular packing can be improved and maintained. It has the characteristics of wear resistance, dust penetration prevention and long-term sealing, and solves the problems of powder leakage, bearing failure and poor equipment reliability.

[0035] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 1-6As shown, this utility model provides a shaft sealing structure, including a cylinder 1, an annular packing 4, and a gland 2. The cylinder 1 is installed at the shaft hole of the housing, and the shaft hole allows the shaft 3 to pass through, so as to transmit power from the outside of the housing to the inside of the housing through the shaft 3, or from the outside to the inside. The end of the cylinder 1 is connected to the housing and maintains the seal at the joint. The inside of the cylinder 1 is used for the shaft 3 to pass through. A packing chamber is formed between the inner wall surface of the cylinder 1 and the axial surface of the shaft 3. The inner wall surface of the cylinder 1 is kept circular to match the shaft 3. After the annular packing 4 is installed, the uniformity and consistency of each part are maintained. The annular packing 4 is disposed in the packing chamber to seal the gaps in the packing chamber, so that a sealed state is formed between the shaft 3 and the cylinder 1. The gland 2 includes a cover plate 21 and an annular plug 22 connected to the cover plate 21. The cover plate 21 and the annular plug 22 are coaxially arranged. The annular plug 22 can be inserted into the packing chamber. The end of the annular plug 22 is used to compress the annular packing 4, so that the annular packing 4 is in a compressed state, which can maintain its fixed position and effective sealing. It should be noted that: one end of the cylinder 1 is connected to the gland 2, and the other end of the cylinder 1 is connected to the shell. Thus, the annular plug 22 compresses one end of the annular packing 4 towards the shell, and the other end of the annular packing 4 is limited by the shell. In another embodiment, the other end of the annular packing 4 can also be limited by an annular structure connected to the cylinder 1.

[0037] The cylinder 1 of this invention can be installed at the shaft hole of the shell, and the shaft 3 passes through the interior of the cylinder 1, forming a packing chamber between the shaft 3 and the cylinder 1. The annular plug 22 of the pressure cap 2 is used to squeeze the annular packing 4 in the packing chamber, and the annular packing 4 is used to seal the gap of the annular plug 22, so that the annular plug 22 and the annular packing 4 cooperate with each other to achieve a seal. Thus, through the compression of the annular plug 22, the sealing state of the annular packing 4 can be improved and maintained. The entire sealing structure has the characteristics of wear resistance, dust penetration prevention and long-term sealing, solving the problems of powder leakage, bearing failure and poor equipment reliability.

[0038] In one embodiment, the annular packing 4 is in the form of a first step shape, which has at least two steps, and the annular plug 22 is in the form of a second step shape, which has at least two steps. The steps of the second step shape are in corresponding contact with the steps of the first step shape. After the gland 2 is fastened, a multi-stage contact seal between the second step shape and the first step shape can be achieved, further improving the sealing effect.

[0039] In one implementation, such as Figure 3As shown, the first stepped type includes a first packing 41 and a second packing 42 nested together, with the axial length of the first packing 41 greater than the axial length of the second packing 42, forming two steps. The second stepped type includes a first plug 221 and a second plug 222 nested together, with the axial length of the first plug 221 greater than the axial length of the second plug 222, forming two steps. The first plug 221 abuts against the second packing 42, and the second plug 222 abuts against the first packing 41, forming a two-stage contact seal. Each stage of the seal maintains effective contact, effectively improving the sealing effect compared to a single-stage seal.

[0040] In one embodiment, the annular packing 4 uses graphite packing, a sealing material made of woven or pressed graphite fibers, commonly used in dynamic or static sealing applications in industrial equipment. Graphite packing uses graphite as its main component, typically with the addition of a small amount of lubricant (such as polytetrafluoroethylene) to enhance its self-lubricating properties. Graphite packing can be customized into annular or filler shapes as needed. In this example, the raw material for the graphite packing is a long strip structure, with a cross-section that can be rectangular or circular. After cutting a certain length of graphite packing, the end faces are joined together to form an annular shape, which is the annular packing 4. The end faces of the graphite packing are wedge-shaped, which increases the contact area of ​​the end faces and ensures the contact stability of the joint.

[0041] In one embodiment, the angle of the wedge surface is 40° to 50°. In this example, 45° is selected. This angle of the wedge surface facilitates the fitting of the head and tail ends.

[0042] In one embodiment, the mating positions of different groups of graphite packing are staggered so that the mating positions do not form leakage channels in the axial direction, thus ensuring the sealing performance of the graphite packing after installation.

[0043] In one embodiment, the angle of the staggered arrangement of the docking positions is 160° to 180°. In this example, 180° is selected. This staggered arrangement can maximize the spacing between different docking positions and prevent the gaps between different docking positions from being interconnected.

[0044] In one embodiment, the end face of the cylinder 1 near the gland 2 is provided with a threaded hole, and the cover plate 21 is provided with a through hole corresponding to the threaded hole. A bolt is also included, passing through the through hole and connecting to the threaded hole, thereby pressing the gland 2 onto the cylinder 1. After the gland 2 is pressed, a gap can be maintained between the cylinder 1 and the cover plate 21. At this time, the annular plug 22 can press against the annular packing 4 and maintain a compressed state. Adjusting the tightness of the bolt can also adjust the degree of compression of the annular plug 22 onto the annular packing 4.

[0045] In one embodiment, the end face of the cylinder 1 away from the gland 2 is provided with a flange 11 extending toward the inner diameter side. The inner diameter of the flange 11 is larger than the diameter of the shaft 3. The shaft 3 can penetrate the inner diameter of the flange 11. The flange 11 can form a limiting structure that defines the position of the annular packing 4.

[0046] Combined again Figures 1-6 As shown, this utility model also provides a coal feeder, including a coal feeder body and a shaft sealing structure as described above disposed on the coal feeder body. The end face of the cylinder 1 away from the pressure cover 2 is welded to the housing of the coal feeder body, and the circumferential sealing structure is used to ensure the sealing state of the shaft hole position.

[0047] When the shaft seal structure of this utility model is applied to the NJGC-30 fully enclosed pressure-resistant weighing coal feeder, it can solve the problem of frequent damage to the oil seal of the drive shaft seal skeleton during operation and coal powder leakage when the seal fails. It can also prevent the drive end bearing from jamming due to coal powder leakage, avoid the coal feeder from stopping, reduce the impact on the safe and stable operation of the coal feeder and environmental pollution, and solve the problem of large workload for maintenance personnel and waste of spare parts and materials.

[0048] The following is an embodiment of the shaft sealing structure provided by this utility model:

[0049] (1) Based on the dimensions of the drive shaft of the coal feeder conveyor belt and the drive shaft of the cleaning chain, respectively, carbon steel pipes are used to process cylinders 1 with diameters of 65mm×75mm×40mm and 60mm×70mm×40mm, with an outer diameter of 105mm and a thickness of 6mm.

[0050] (2) Based on the dimensions of its two journals, press caps 2 with diameters of 56mm×64mm×20mm and 51mm×59mm×20mm are machined from carbon steel. The outer diameter of the cover plate 21 is 105mm and the thickness is 6mm. Symmetrical 7mm through holes are drilled at 120 degrees on the outer edge.

[0051] (3) Remove the two drive motors, the outer spherical square bearing shaft, the drive roller and the sweeping chain drive shaft.

[0052] (4) Place the machined cylinder 1 onto both ends of the two drive shafts, and then reinstall the two drive shafts. Ensure that the drive shafts are concentric with the cylinder 1 and are firmly welded to the shell.

[0053] (5) Add 2 to 4 rings of 6mm graphite packing to the packing chamber. Each layer of graphite packing should be staggered by 180 degrees when it is installed, and then tighten the gland 2.

[0054] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A shaft seal structure, characterized in that, include: A cylindrical body, which is used to be installed at the shaft hole of the housing, the interior of the cylindrical body is used for the shaft to pass through, and a filling chamber is formed between the inner wall surface of the cylindrical body and the axial surface of the shaft; Annular packing, wherein the annular packing is disposed in the packing chamber; And a gland, the gland including a cover plate and an annular plug connected to the cover plate, the annular plug being able to be inserted into the packing chamber, the end of the annular plug being used to compress the annular packing.

2. The shaft seal structure according to claim 1, characterized in that: The annular packing is in the form of a first step, and the annular plug is in the form of a second step, with the steps of the second step corresponding to and contacting the steps of the first step.

3. The shaft seal structure according to claim 2, characterized in that: The first stepped type includes a first packing and a second packing that are nested together, wherein the axial length of the first packing is greater than the axial length of the second packing; the second stepped type includes a first plug and a second plug that are nested together, wherein the axial length of the first plug is greater than the axial length of the second plug; the first plug abuts against the second packing, and the second plug abuts against the first packing.

4. The shaft seal structure according to any one of claims 1-3, characterized in that: The annular packing uses graphite packing, and the first and last ends of the graphite packing are connected in an annular shape, with the first and last ends being wedge-shaped.

5. The shaft seal structure according to claim 4, characterized in that: The angle of the wedge-shaped surface is 40° to 50°.

6. The shaft seal structure according to claim 4, characterized in that: The docking positions of the graphite packing from different groups are staggered.

7. The shaft seal structure according to claim 6, characterized in that: The angle at which the docking positions are staggered is 160° to 180°.

8. The shaft seal structure according to claim 1, characterized in that: The cylinder body has a threaded hole on its end face near the pressure cap, and the cover plate has a through hole corresponding to the threaded hole. It also includes a bolt that passes through the through hole and connects to the threaded hole. There is a gap between the cylinder body and the cover plate.

9. The shaft seal structure according to claim 1, characterized in that: The end face of the cylinder away from the pressure cap is provided with a flange extending towards the inner diameter side, and the inner diameter of the flange is larger than the diameter of the shaft.

10. A coal feeder, characterized in that: The device includes a coal feeder body and a shaft sealing structure as described in any one of claims 1-9 disposed on the coal feeder body, wherein the end face of the cylinder away from the gland is welded to the housing of the coal feeder body.

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