Hydraulic oil cylinder of coal mill

Abstract

The hydraulic oil cylinder of the coal mill comprises an oil cylinder body, dustproof shells, a connecting assembly and a sealing element, the two dustproof shells are folded to form a dustproof channel for a piston rod to penetrate through, the connecting assembly is used for connecting the two dustproof shells into a whole, and the sealing element is arranged in a sealing groove. The sealing element is in contact with the piston rod, impurities such as coal powder and dust can be prevented from being brought into the cylinder body along with the piston rod, and the dustproof effect is achieved. The two dustproof shells are designed in a split mode, installation can be completed on the premise that the oil cylinder body is not disassembled, operation is easy, the installation and replacement efficiency of sealing elements is improved, the downtime of equipment is saved, and the labor intensity of maintenance personnel is relieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydraulic cylinders, in particular to a hydraulic cylinder for a coal mill. Background Art

[0002] Coal mills are common equipment in thermal power plants, used to grind coal into pulverized coal, which can be used for thermal power generation. A common coal mill model is the ZGM medium-speed coal mill. Its grinding force is generated by a hydraulic loading system, which includes components such as a high-pressure oil pump, oil pipelines, a reversing valve, a hydraulic cylinder, and an accumulator. The hydraulic cylinder, as the actuator of the hydraulic loading system, applies the grinding force to the grinding rollers. The grinding rollers apply pressure to the coal layer on the grinding disc, and the rotation of the grinding disc drives the rollers to rotate, continuously producing pulverized coal. Corresponding to the number of grinding rollers, the ZGM medium-speed coal mill also has three hydraulic cylinders.

[0003] The hydraulic cylinder of a coal mill is vertically mounted with its piston rod pointing upward. Due to ash leakage from the mill base and the falling of coal dust, coal dust and ash easily accumulate on the top of the hydraulic cylinder. Although the hydraulic cylinders manufactured by manufacturers include sealing dust rings, these rings are primarily designed to prevent internal hydraulic oil leakage. Since the piston rod extends outward from the upper end of the cylinder body during operation, if coal dust or ash adheres to the outer wall of the piston rod, it enters the guide sleeve with the piston rod's telescopic movement, causing wear on the guide sleeve, shortening the cylinder's service life and leading to hydraulic oil leakage and contamination.

[0004] To address these issues, thermal power plants often modify the hydraulic cylinders of coal mills, installing dust covers on top to prevent coal dust or dust from entering the seals of the hydraulic cylinder guide sleeves, potentially damaging the seals or contaminating the hydraulic fluid. However, conventional dust covers are often integrated annular components. Installation requires disassembly of the piston rod and roller joints, followed by a top-down fit of the dust cover over the piston rod, making this an inconvenient process. The dust cover also wears out during use, and the rubber ring inside ages, requiring regular replacement. Each replacement requires extensive disassembly and assembly of the equipment, resulting in significant downtime. Utility Model Content

[0005] The utility model provides a coal mill hydraulic cylinder, aiming to solve the problem in the prior art that a dust-proof mechanism of the hydraulic cylinder needs to be disassembled and assembled during installation.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is to provide a coal mill hydraulic cylinder, comprising:

[0007] The oil cylinder body comprises a cylinder body and a piston rod extending vertically upward from the cylinder body;

[0008] Two dustproof shells are arranged on the top of the cylinder body opposite to each other, the dustproof shells are semi-annular, and the two dustproof shells are matched to form a dustproof channel for the piston rod to pass through. The semi-annular inner wall of the dustproof shell is provided with a sealing groove, and the two sealing grooves are matched to form an annular first groove body;

[0009] a connecting assembly detachably connected between the two dustproof shells and applying a pre-tightening force to the two dustproof shells so as to bring the two dustproof shells closer to each other; and

[0010] The sealing element is annular and is accommodated in the first groove body, and the inner ring of the sealing element is in contact with the piston rod.

[0011] In one possible implementation, the dustproof shell includes:

[0012] A first connecting portion, in the shape of a semi-annular plate, for connecting to the cylinder body;

[0013] a second connecting portion, which is semi-annular and is disposed above the first connecting portion; the second connecting portions of the two dustproof shells are aligned to form the dustproof passage; and the sealing groove is formed on a side of the second connecting portion adjacent to the piston rod; and

[0014] Two third connecting parts are provided on two opposite sides of the second connecting part, and the connecting assembly is connected to the second connecting part.

[0015] In a possible implementation, the outer diameter of the second connecting portion is no more than 10 mm greater than the diameter of the piston rod.

[0016] In a possible implementation, the first connecting portion is provided with a first mounting hole that penetrates the first connecting portion, a first screw is passed through the first mounting hole, and the top surface of the cylinder body is provided with a second mounting hole that is threadedly engaged with the first screw.

[0017] In one possible implementation, the third connecting portion is provided with a third mounting hole that penetrates its own thickness, and the connecting assembly includes a second screw that passes through the third mounting hole, and a nut that is threadedly engaged with the second screw, and the nut and the nut cap of the second screw respectively abut against the sides of the third connecting portions of the two dustproof shells that are away from each other.

[0018] In a possible implementation, a semi-annular accommodating groove is provided on the top inner wall of the dustproof shell, and two of the accommodating grooves are joined to form an annular second groove body, in which a dustproof felt is provided.

[0019] In a possible implementation, the coal mill hydraulic cylinder further includes two pressure plates, which are respectively arranged around the piston rod, and the pressure plate cover is arranged above the dustproof felt, and the pressure plate is detachably connected to the dustproof shell.

[0020] In a possible implementation, the dustproof housing is provided with a plurality of sealing grooves along the axial direction of the piston rod, and a plurality of sealing elements are provided corresponding to the sealing grooves.

[0021] In a possible implementation, the sealing element is a K-type or Y-type sealing ring.

[0022] In a possible implementation, the coal mill hydraulic cylinder further includes a blower mechanism, which is disposed on one side of the dustproof shell and has an air outlet facing the dustproof shell.

[0023] Compared with the prior art, the beneficial effects of the coal mill hydraulic cylinder provided by the utility model are:

[0024] The coal mill hydraulic cylinder provided by the present invention includes a cylinder body, a dustproof housing, a connecting assembly, and a sealing element. The two dustproof housings, when aligned, form a dustproof passage for the piston rod to pass through. The connecting assembly is used to connect the two dustproof housings into one body, and the sealing element is disposed within a sealing groove. During installation, the sealing element can be first cut open at a certain position so that the sealing element can be fitted around the outer circumference of the piston rod. The disconnected portion of the sealing element can then be glued back together to form a complete annular sealing ring. The two dustproof housings are then aligned and installed on the top of the cylinder body, so that the sealing element is accommodated within the first groove. Finally, the two dustproof housings are connected into one body via the connecting assembly. The sealing element contacts the piston rod, preventing impurities such as coal dust and dust from being carried into the cylinder body along with the piston rod, thereby providing dust protection. The two dustproof housings in the present invention adopt a split design and can be installed without disassembling the cylinder body. This simplifies operation, improves the efficiency of sealing element installation and replacement, saves equipment downtime, and reduces the labor intensity of maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic structural diagram of a hydraulic cylinder for a coal mill provided in one embodiment of the present utility model;

[0026] Figure 2 This is a schematic structural diagram of the dustproof housing, connecting assembly, sealing element, dustproof felt and pressing plate in an embodiment of the present invention;

[0027] Figure 3 This is a structural diagram of the dustproof shell, connecting assembly, sealing element, dustproof felt and pressure plate from another angle in an embodiment of the present invention;

[0028] Figure 4It is an exploded schematic diagram of the dustproof shell, connecting assembly, sealing element, dustproof felt and pressure plate in the embodiment of the present invention.

[0029] Description of reference numerals:

[0030] 1. Coal mill hydraulic cylinder; 10. Cylinder body; 11. Cylinder body; 12. Piston rod; 20. Dust cover; 21. First connecting portion; 22. Second connecting portion; 221. Sealing groove; 222. Accommodating groove; 23. Third connecting portion; 24. First screw; 30. Connecting assembly; 40. Sealing element; 50. Dustproof felt; 60. Press plate; DETAILED DESCRIPTION

[0031] 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 with reference to 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 intended to limit the present invention.

[0032] It should be noted that when an element is referred to as being "fixed to," "fixed," or "fixedly disposed" on another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected to," "connected to" another element, it may be directly connected to the other element or there may also be an intermediate element. When an element is referred to as being "set on," "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. "Multiple" refers to two or more. "At least one" refers to one or more. "Several" refers to one or more.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0034] See also Figures 1 to 4 , the coal mill hydraulic cylinder 1 provided in the embodiment of the utility model is described below.

[0035] See also Figures 1 to 4The embodiment of the present invention provides a coal mill hydraulic cylinder 1, comprising a cylinder body 10, two dustproof shells 20, a connecting assembly 30 and a sealing element 40. The cylinder body 10 comprises a cylinder body 11 and a piston rod 12 extending vertically upward from the cylinder body 11; the two dustproof shells 20 are arranged oppositely at the top of the cylinder body 11, and the dustproof shells 20 are semi-annular. The two dustproof shells 20 are matched to form a dustproof passage for the piston rod 12 to pass through. The semi-annular inner wall of the dustproof shell 20 is provided with a sealing groove 221, and the two sealing grooves 221 are matched to form an annular first groove body; the connecting assembly 30 is detachably connected between the two dustproof shells 20, and applies a pre-tightening force to the two dustproof shells 20 so as to bring the two dustproof shells 20 closer to each other; the sealing element 40 is annular and is accommodated in the first groove body, and the inner ring of the sealing element 40 is in contact with the piston rod 12.

[0036] The coal mill hydraulic cylinder 1 provided by the embodiment of the present invention includes a cylinder body 10, a dustproof shell 20, a connecting assembly 30 and a sealing element 40. The two dustproof shells 20 are matched to form a dustproof passage for the piston rod 12 to pass through. The connecting assembly 30 is used to connect the two dustproof shells 20 into one body, and the sealing element 40 is arranged in the sealing groove 221. During installation, the sealing element 40 can be cut open at a certain position so that the sealing element 40 can be placed on the outer periphery of the piston rod 12. Then, the disconnected position of the sealing element 40 is glued again to form a complete annular sealing ring. The two dustproof shells 20 are then matched and installed on the top of the cylinder body 11, so that the sealing element 40 is accommodated in the first groove. Finally, the two dustproof shells 20 are connected into one body by the connecting assembly 30. The sealing element 40 contacts the piston rod 12, which can prevent impurities such as coal powder and dust from being brought into the cylinder body 11 along with the piston rod 12, thereby playing a dustproof role.

[0037] In the embodiment of the present invention, the two dustproof shells 20 adopt a split design, which can be installed without disassembling the cylinder body 10. The operation is simple, the installation and replacement efficiency of the sealing element 40 is improved, the equipment downtime is saved, and the labor intensity of the maintenance personnel is reduced.

[0038] The cylinder body 10 in the embodiment of the present invention is the hydraulic cylinder of the coal mill. Its structure and working principle are no different from those of the hydraulic cylinder in the existing design. The dust cover 20, the connecting assembly 30 and the sealing element 40 are components added to the cylinder body 10 during the modification and have no adverse effect on the operation of the cylinder body 10.

[0039] The dust cover 20 is a split-piece design. When the two dust covers 20 are aligned, they form an annular member surrounding the piston rod 12. The piston rod 12 passes through the dust-proof passage formed by the dust covers 20 and contacts the sealing element 40. This seal prevents impurities such as coal dust from entering the cylinder body 11 along with the piston rod 12. The dust cover 20 can be made of metal (such as cast iron or carbon steel) or non-metallic materials (such as engineering plastics). The dust cover 20 can be connected to the cylinder body 11 using fasteners, magnetic fastening, or snap-on fastening.

[0040] The connecting assembly 30 is used to realize the detachable connection between the two dustproof shells 20. The connecting assembly 30 can be a threaded fastener, a spring clip, a band, etc. When the sealing element 40 needs to be replaced, the connecting assembly 30 is removed to separate the two dustproof shells 20.

[0041] The sealing element 40 is a rubber sealing ring, and its specific specifications and models are not limited. In order to reduce the workload of equipment disassembly and assembly, the sealing element 40 needs to be cut open before installation. After it is placed on the outer periphery of the piston rod 12, it is then bonded into an integrated ring shape using glue, hot melt, etc. It is understandable that cutting the sealing element 40 and then bonding it will not cause significant deformation of the sealing element 40, and will not have a significant impact on the sealing and protective effect, and can meet the use requirements. In order to improve the sealing and protective effect, multiple sealing rings can also be provided.

[0042] See also Figure 2 、 Figure 3 and Figure 4 In some possible embodiments, the dust cover 20 includes a first connecting portion 21, a second connecting portion 22, and a third connecting portion 23. The first connecting portion 21 is in the shape of a semi-annular plate and is used to connect to the cylinder body 11. The second connecting portion 22 is in the shape of a semi-annular plate and is located above the first connecting portion 21. The second connecting portions 22 of the two dust covers 20 are aligned to form a dustproof passage. A sealing groove 221 is defined on one side of the second connecting portion 22 adjacent to the piston rod 12. Two third connecting portions 23 are located on opposite sides of the second connecting portion 22, and the connecting assembly 30 is connected to the second connecting portion 22. The first connecting portion 21, the second connecting portion 22, and the third connecting portion 23 can be connected integrally by welding or other methods.

[0043] The more coal powder accumulates on the top of the second connecting portion 22, the easier it is for the piston rod 12 to carry the coal powder into the cylinder body 11. In order to avoid the second connecting portion 22 being too large, resulting in excessive accumulation of coal powder on the top and reducing the sealing and dustproof effect, in some possible embodiments, the thickness of the second connecting portion 22 should not be too thick. For example, the outer diameter of the second connecting portion 22 is no more than 10 mm larger than the diameter of the piston rod 12. The second connecting portion 22 can be formed as follows: Figure 2 The boss structure shown.

[0044] See also Figure 2 and Figure 4 In some possible embodiments, the first connecting portion 21 is provided with a first mounting hole that penetrates its own thickness, a first screw 24 is passed through the first mounting hole, and a second mounting hole that is threadedly matched with the first screw 24 is provided on the top surface of the cylinder body 11. The dustproof shell 20 is fixed with the first screw 24, which is convenient for installation and disassembly.

[0045] See also Figure 2 and 4 In some possible embodiments, the third connecting portion 23 is provided with a third mounting hole that penetrates its own thickness. The connecting assembly 30 includes a second screw that is passed through the third mounting hole, and a nut that is threadably matched with the second screw. The nut and the nut cap of the second screw are respectively abutted against the sides of the third connecting portions 23 of the two dustproof shells 20 that are away from each other, which facilitates installation and disassembly and provides convenience for maintenance personnel.

[0046] See also Figure 2 and 4 In some possible embodiments, a semi-annular receiving groove 222 is formed on the inner wall of the top of the dustproof housing 20. Two receiving grooves 222 are aligned to form an annular second groove body, and a dustproof felt 50 is disposed within the second groove body. In this embodiment, a second groove body is formed on the top of the dustproof housing 20, and a dustproof felt 50 is disposed within the second groove body. The dustproof felt 50 and the sealing element 40 work together to form multiple layers of protection, thereby improving the sealing and dustproofing effect of the hydraulic cylinder.

[0047] See also Figure 2 and 4 In some possible embodiments, the coal mill hydraulic cylinder 1 further includes two pressure plates 60, which are respectively arranged around the piston rod 12. The pressure plates 60 are covered on top of the dustproof felt 50. The pressure plates 60 are detachably connected to the dustproof shell 20. The pressure plates 60 are covered on top of the dustproof felt 50, which can not only prevent the dustproof felt 50 from detaching from the second trough body, but also exert a certain pressure on the dustproof felt 50, so that the dustproof felt 50 fits tightly against the outer periphery of the piston rod 12, thereby improving the dustproof effect.

[0048] In some possible embodiments, the dustproof shell 20 is provided with multiple sealing grooves 221 along the axial direction of the piston rod 12, and multiple sealing elements 40 are provided corresponding to the sealing grooves 221. The multiple sealing elements 40 work together to further improve the sealing and dustproof effect.

[0049] In some possible embodiments, the sealing element 40 is a K-type or Y-type sealing ring. Both the K-type sealing ring and the Y-type sealing ring are made of rubber or silicone, and are suitable for static and low-speed sealing applications, and can meet usage requirements.

[0050] In some possible embodiments, the coal mill hydraulic cylinder 1 further includes a blower mechanism, which is disposed on one side of the dust cover 20 and has an air outlet facing the dust cover 20. The blower mechanism can be a blower, fan, etc., and is capable of blowing away coal dust that has fallen onto the top of the cylinder body 11. The blower mechanism can be used at regular intervals to prevent excessive coal dust from accumulating above the cylinder body 11 and the dust cover 20, which could prevent excessive coal dust impurities from adhering to the piston rod 12 and affecting the sealing and dustproofing effect.

[0051] It can be understood that the various parts in the above embodiments can be freely combined or deleted to form different combination embodiments. The specific contents of each combination embodiment will not be repeated here. After this description, it can be considered that the specification of the utility model has recorded various combination embodiments and can support different combination embodiments.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Coal mill hydraulic cylinder, characterized in that: include: The oil cylinder body comprises a cylinder body and a piston rod extending vertically upward from the cylinder body; Two dustproof shells are arranged on the top of the cylinder body opposite to each other, the dustproof shells are semi-annular, and the two dustproof shells are matched to form a dustproof channel for the piston rod to pass through. The semi-annular inner wall of the dustproof shell is provided with a sealing groove, and the two sealing grooves are matched to form an annular first groove body; a connecting assembly detachably connected between the two dustproof shells and applying a pre-tightening force to the two dustproof shells so as to bring the two dustproof shells closer to each other; as well as The sealing element is annular and is accommodated in the first groove body, and the inner ring of the sealing element is in contact with the piston rod.

2. The coal mill hydraulic cylinder according to claim 1, characterized in that: The dustproof shell comprises: A first connecting portion, in the shape of a semi-annular plate, for connecting to the cylinder body; a second connecting portion, which is semi-annular and is disposed above the first connecting portion; the second connecting portions of the two dustproof shells are aligned to form the dustproof passage; and the sealing groove is formed on a side of the second connecting portion adjacent to the piston rod; and Two third connecting parts are provided on two opposite sides of the second connecting part, and the connecting assembly is connected to the second connecting part.

3. The coal mill hydraulic cylinder according to claim 2, characterized in that: The outer diameter of the second connecting portion is no more than 10 mm greater than the diameter of the piston rod.

4. The coal mill hydraulic cylinder according to claim 2, characterized in that: The first connecting portion is provided with a first mounting hole that passes through the first connecting portion, a first screw is passed through the first mounting hole, and the top surface of the cylinder body is provided with a second mounting hole that is threadedly matched with the first screw.

5. The coal mill hydraulic cylinder according to claim 2, characterized in that: The third connecting portion is provided with a third mounting hole that penetrates its own thickness. The connecting assembly includes a second screw that passes through the third mounting hole, and a nut that is threadably engaged with the second screw. The nut and the nut cap of the second screw are respectively abutted against the sides of the third connecting portions of the two dustproof shells that are away from each other.

6. The coal mill hydraulic cylinder according to claim 1, characterized in that: A semi-annular accommodating groove is provided on the top inner wall of the dustproof shell. Two of the accommodating grooves are matched to form an annular second groove body. A dustproof felt is provided in the second groove body.

7. The coal mill hydraulic cylinder according to claim 6, characterized in that: The coal mill hydraulic cylinder further comprises two pressure plates, which are respectively arranged around the piston rod. The pressure plate cover is arranged above the dustproof felt, and the pressure plate is detachably connected to the dustproof shell.

8. The coal mill hydraulic cylinder according to claim 1, characterized in that: The dustproof shell is provided with a plurality of sealing grooves along the axial direction of the piston rod, and a plurality of sealing elements are provided corresponding to the sealing grooves.

9. The coal mill hydraulic cylinder according to claim 1, characterized in that: The sealing element is a K-type or Y-type sealing ring.

10. The coal mill hydraulic cylinder according to claim 1, characterized in that: The coal mill hydraulic oil cylinder further includes a blower mechanism, which is arranged on one side of the dustproof shell and has an air outlet facing the dustproof shell.

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