A sealing device for a large-scale water brake

Abstract

The present application belongs to the technical field of sealing device, and relates to a sealing device of a large-scale hydraulic dynamometer. The sealing device comprises a sealing box body and a sealing gland. The outer side wall of the sealing box body is provided with a first shaft shoulder and a circular columnar groove, the groove is embedded with a sealing ring, and the inner side wall is provided with a second shaft shoulder. The bottom of the sealing gland is provided with a sealing cover shaft shoulder embedded in the second shaft shoulder, and the two are fixedly connected through fastening bolts. An oil-immersed hemp rope packing is arranged between the inner side wall of the sealing box body and the end face of the sealing cover shaft shoulder. The sealing box body and the sealing gland are both composed of two symmetrical half circular columns, so that the packing can be quickly replaced without disassembling the main structure of the dynamometer. The sealing device adopts multiple sealing synergies, is reliable in sealing, convenient to maintain, effectively prevents working water leakage, guarantees the dynamometer precision, is made of stainless steel, is strong in corrosion resistance, significantly prolongs the service life of the device, and reduces the maintenance cost.

Description

Technical Field

[0001] This invention belongs to the field of sealing device technology, and relates to a sealing device for a large hydraulic dynamometer. Background Technology

[0002] Large hydraulic dynamometers are indispensable key equipment in bench testing of marine low-speed diesel engines. Their main function is to absorb the main engine's output power and accurately measure the main engine load. During use, the main shaft bearings and main shaft seals are vulnerable components that require regular inspection and replacement. Existing large hydraulic dynamometers, in their initial design phase, often focus on the dynamometer's performance, with insufficient consideration given to the timeliness and ease of maintenance of the main shaft sealing structure.

[0003] Common sealing structures often employ an integral design, tightly fitting with the dynamometer stator housing and main shaft. In actual maintenance, the complex connections between the sealing device and the main shaft and surrounding components, coupled with limited disassembly space, prevent the inspection and replacement of the sealing packing without disassembling the main structure of the hydraulic dynamometer. Maintenance personnel must extensively disassemble the hydraulic dynamometer to access the sealing device, resulting in prolonged maintenance cycles, high labor intensity, and an increased risk of equipment damage.

[0004] Furthermore, with prolonged operation, the original sealing structure experiences wear and aging of the sealing packing, leading to a decline in sealing effectiveness and significant leakage of working water inside the dynamometer. This substantial leakage not only prevents the dynamometer from maintaining an effective volume of working water, directly affecting dynamometer accuracy and the stability of main unit load measurement, but also results in severe water waste and negatively impacts the test site environment. Therefore, the urgent technical problem to be solved in the existing technology is: how to provide a new sealing device that can guarantee long-term stable sealing performance and prevent working water leakage, while also allowing for convenient inspection and replacement of the sealing packing without disassembling the main body of the hydraulic dynamometer. This would overcome the drawbacks of existing large hydraulic dynamometer sealing structures, such as difficult maintenance and unreliable sealing performance. Summary of the Invention

[0005] To address the problems of difficult maintenance and unreliable sealing performance of existing sealing devices for large hydraulic dynamometers, this invention proposes a sealing device for a large hydraulic dynamometer, comprising a sealing housing and a sealing cap. The sealing housing is generally cylindrical, with a first shoulder protruding from the bottom of its outer side wall and a second shoulder protruding from the middle of its inner side wall; both the first and second shoulders are cylindrical; a cylindrical groove is provided at the connection between the middle of the outer side wall of the sealing housing and the first shoulder; a sealing ring is embedded in the cylindrical groove; the upper part of the sealing housing is provided with several sealing housing through holes penetrating its side wall, which are used to connect to the stator housing of the hydraulic dynamometer; several threaded holes for sealing housing are provided on the inner side wall of the second shoulder;

[0006] The sealing gland is cylindrical in shape, with a sealing gland shoulder protruding from the bottom outer side wall; the upper part of the side wall of the sealing gland is provided with several sealing gland through holes that mate with the threaded holes of the sealing box; the sealing gland shoulder is embedded in the bottom of the second shoulder of the sealing box, and the sealing box and the sealing gland are fixedly connected by sealing gland fastening bolts that pass through the sealing gland through holes and the threaded holes of the sealing box.

[0007] Several oil-soaked hemp rope packings are coiled between the inner wall of the sealed housing and the protruding end face of the shoulder of the sealing cover.

[0008] According to the sealing device of the large hydraulic dynamometer described above, the sealing box and the sealing cover are both composed of two symmetrical semi-circular cylinders.

[0009] According to the sealing device of a large hydraulic dynamometer described above, the outer wall of the sealing box and the stator housing of the hydraulic dynamometer are interference fit, and the dimensional tolerance is 0-0.05mm.

[0010] According to the sealing device of a large hydraulic dynamometer described above, the sealing cover shoulder of the sealing gland is embedded in the second shoulder of the sealing box for a length ≥ 40 mm.

[0011] According to the sealing device of a large hydraulic dynamometer described above, there are 12 through holes in the sealing box, which are evenly distributed on the side wall of the sealing box. The sealing box is fixedly connected to the stator housing of the hydraulic dynamometer by 12 sealing box bolts passing through the through holes.

[0012] According to the sealing device of a large hydraulic dynamometer described above, there are 12 threaded holes in the sealing box, which are evenly distributed on the inner side wall of the second shoulder of the sealing box; there are 12 through holes in the sealing cover corresponding to the threaded holes in the sealing box, which are evenly distributed on the upper part of the side wall of the sealing cover; 12 sealing cover bolts are inserted between the threaded holes in the sealing box and the through holes in the sealing cover to fix the sealing cover to the sealing box.

[0013] According to the sealing device of the large hydraulic dynamometer described above, the sealing housing bolts and sealing gland bolts are both M16.

[0014] According to the sealing device of the large hydraulic dynamometer described above, the sealing ring is an O-ring with a diameter of Ф8.4mm.

[0015] According to the sealing device of a large hydraulic dynamometer described above, the sealing ring is embedded in the cylindrical groove of the annulus by applying sealant to the end face.

[0016] According to the sealing device of the large hydraulic dynamometer described above, both the sealing housing and the sealing gland are made of stainless steel.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. Significantly improves maintenance convenience and greatly reduces maintenance time. The sealing housing and sealing gland of this invention are both composed of two symmetrical semi-circular cylindrical bodies. This split structure allows for inspection or replacement of the oil-impregnated hemp rope packing without disassembling the main shaft and stator structure of the hydraulic dynamometer. Compared to the cumbersome process of disassembling the main equipment to access the sealing device in existing technologies, this invention only requires removing the connecting bolts to directly separate the sealing device from the main shaft, achieving "online" rapid replacement of the sealing packing. This greatly simplifies the operation process, reduces maintenance labor intensity, and shortens equipment downtime.

[0019] 2. Completely solves the problem of working water leakage and ensures dynamometer accuracy. This invention employs a multi-layered sealing mechanism. First, a reliable static seal is formed between the sealing housing and the stator housing through an interference fit and a sealing ring embedded in a cylindrical groove. Second, the sealing cap shoulder of the sealing gland is embedded in the second shoulder of the sealing housing, forming a sealing path. Finally, the tightening force on the three oil-impregnated hemp rope packings can be precisely controlled by adjusting the gland fastening bolts, forming a dynamic seal. Compared to the shortcomings of existing single-seal structures that are prone to wear and leakage, this invention effectively prevents large-scale leakage of working water, ensuring the effective volume of working water inside the dynamometer, thereby guaranteeing the accuracy and stability of the main unit load measurement.

[0020] 3. Extended equipment lifespan and reduced maintenance costs: The sealing housing and sealing gland of this invention are both made of stainless steel, which has superior corrosion resistance compared to ordinary carbon steel used in existing technologies. Under the long-term operating conditions of the hydraulic dynamometer in a humid environment, stainless steel effectively eliminates rust caused by moisture corrosion. Reduced rust not only prevents damage to the sealing surface and seal failure caused by rust, but also prevents disassembly difficulties caused by rusted threads. This material selection improves the durability of the device from the source, reducing the cost of frequent maintenance and parts replacement due to corrosion.

[0021] 4. Enhanced flexibility in sealing adjustment, ensuring long-term sealing performance. In this invention, the length of the sealing cap shoulder embedded in the second shoulder of the sealing housing is set to ≥40mm. This relatively long embedding length provides ample axial adjustment space for the oil-impregnated hemp rope packing. As the equipment operates over time, when minor leaks occur in the packing due to wear, the operator can further tighten the cap fastening bolts to compensate for wear and restore the sealing effect. This adjustability allows the sealing device to maintain stable sealing performance over a longer period, avoiding the drawback of requiring complete replacement once leakage occurs in existing technologies.

[0022] 5. Achieving environmental protection and water conservation, and improving the working environment: Through the synergistic effect of the above-mentioned multiple sealing structures, this invention effectively seals the working water inside the hydraulic dynamometer, completely solving the problem of large-scale water leakage caused by unreasonable sealing structures in existing technologies. Working water leakage is controlled to a minimum, not only avoiding the waste of precious water resources, but also eliminating the safety hazards and slippery environment caused by leaked water flowing throughout the test site. This significantly improves the operating environment of the bench test, achieving the dual benefits of energy conservation, environmental protection, and operational safety. Attached Figure Description

[0023] Figure 1 This is a partial sectional view of the main view of the sealing device of a large hydraulic dynamometer according to the present invention.

[0024] Figure 2 This is a schematic diagram of the sealing housing of a sealing device for a large hydraulic dynamometer according to the present invention.

[0025] Figure 3 This is a schematic diagram of the sealing gland of a sealing device for a large hydraulic dynamometer according to the present invention.

[0026] In the figure: 1-sealing ring, 2-sealing box, 3-sealing box through hole, 4-sealing box threaded hole, 5-sealing gland, 6-oil-impregnated hemp rope packing, 7-sealing gland through hole, 10-circular cylindrical groove, 201-first shoulder, 202-second shoulder, 501-sealing cover shoulder. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0028] like Figures 1 to 3As shown: This embodiment of a sealing device for a large hydraulic dynamometer includes a sealing housing 2, a sealing ring 1, a sealing gland 5, and oil-impregnated hemp rope packing 6. The sealing housing 2 has an overall annular cylindrical structure, with a first shoulder 201 formed by radially outward protrusion at the bottom of its outer side wall, and a second shoulder 202 formed by radially inward protrusion at the middle of its inner side wall. Both the first shoulder 201 and the second shoulder 202 are annular cylindrical to enhance structural strength and facilitate installation and positioning. An annular cylindrical groove 10 is provided at the connection between the middle of the outer side wall of the sealing housing 2 and the first shoulder 201. This annular cylindrical groove 10 is used to embed the sealing ring 1. In this embodiment, the sealing ring 1 is preferably an O-ring with a diameter of Ф8.4mm. During installation, sealant is applied to the inner end face of the annular cylindrical groove 10, and then the sealing ring 1 is embedded to ensure the end face sealing effect between the sealing housing 2 and the stator housing of the hydraulic dynamometer.

[0029] On the upper part of the sealing housing 2, specifically on the side wall away from the first shoulder 201, a plurality of through-holes 3 are evenly distributed through the side wall. These through-holes 3 are used to connect the stator housing of the hydraulic dynamometer. In a preferred embodiment, there are 12 through-holes 3, evenly distributed circumferentially on the side wall of the sealing housing 2. During installation, 12 M16 sealing housing bolts are used, passing through each through-hole 3 and tightened into the corresponding threaded holes on the stator housing of the hydraulic dynamometer, thereby achieving a fixed connection between the sealing housing 2 and the stator housing of the hydraulic dynamometer. To ensure the stability of the connection and the reliability of the seal, an interference fit is used between the outer side wall of the sealing housing 2 and the stator housing of the hydraulic dynamometer, with dimensional tolerances controlled within the range of 0-0.05mm.

[0030] On the inner wall of the second shoulder 202 of the sealing housing 2, a plurality of sealing housing threaded holes 4 are provided. These sealing housing threaded holes 4 are used for fixed connection with the subsequent sealing gland 5. In a preferred embodiment, the number of sealing housing threaded holes 4 is 12, evenly distributed on the inner wall of the second shoulder 202.

[0031] The sealing gland 5 is also a cylindrical ring structure. A sealing gland shoulder 501 protrudes radially outward from the bottom outer wall of the sealing gland 5. Multiple sealing gland through holes 7, corresponding to the positions of the threaded holes 4 in the sealing box, are provided on the upper part of the side wall of the sealing gland 5. When the sealing gland 5 is assembled with the sealing box 2, the sealing gland shoulder 501 of the sealing gland 5 is embedded in the bottom of the second shoulder 202 of the sealing box 2. To ensure that the sealing gland 5 can apply effective pre-tightening force to the internal oil-impregnated hemp rope packing 6 and guarantee a long-term stable sealing effect, the axial length of the sealing gland shoulder 501 embedded in the second shoulder 202 of the sealing box 2 should be at least 40 mm. By embedding the sealing gland shoulder 501 into the second shoulder 202, a labyrinthine sealing path can be formed, further preventing leakage of working water.

[0032] The sealing housing 2 and the sealing gland 5 are fixedly connected by multiple gland fastening bolts. Specifically, the gland fastening bolts pass through the sealing gland through holes 7 in sequence and are screwed into the sealing housing threaded holes 4 on the sealing housing 2. In a preferred embodiment, corresponding to the 12 sealing housing threaded holes 4, there are also 12 sealing gland through holes 7, evenly distributed on the upper side wall of the sealing gland 5. The 12 M16 type sealing gland bolts pass through the sealing gland through holes 7 and are tightened into the sealing housing threaded holes 4, thereby firmly fixing the sealing gland 5 to the sealing housing 2.

[0033] Within the annular cavity formed between the inner wall of the sealing housing 2 and the protruding end face of the sealing cover shoulder 501, several oil-impregnated hemp rope packings 6 are coiled. In this embodiment, three oil-impregnated hemp rope packings 6, each with a cross-sectional dimension of 40mm × 40mm, are preferably provided. The oil-impregnated hemp rope packings 6 have good wear resistance, corrosion resistance, and self-lubricating properties, and can form an effective dynamic seal when the spindle rotates. By adjusting the tightening torque of the gland fastening bolts, the degree of compression of the sealing gland 5 onto the oil-impregnated hemp rope packings 6 can be controlled. When the compression force is appropriate, the oil-impregnated hemp rope packings 6 are compressed, their inner walls tightly adhering to the outer surface of the spindle, while their outer walls tightly adhering to the inner wall of the sealing housing 2, thereby blocking the axial leakage path of the working water.

[0034] Specifically, to enable disassembly and maintenance of the sealing device without disassembling the main structure of the hydraulic dynamometer, both the sealing housing 2 and the sealing gland 5 are composed of two symmetrical semi-circular cylindrical bodies. When it is necessary to inspect or replace the oil-impregnated hemp rope packing 6, maintenance personnel do not need to disassemble the dynamometer spindle and stator housing; they only need to remove the sealing housing bolts connecting the sealing housing 2 and the stator housing, and the gland fastening bolts connecting the sealing housing 2 and the sealing gland 5 in sequence. Since both the sealing housing 2 and the sealing gland 5 are split structures, the two semi-circular cylindrical bodies can be easily separated from the spindle, thereby directly exposing the internal oil-impregnated hemp rope packing 6 for quick inspection and replacement. This split structure completely solves the problem of the original integral sealing device requiring disassembly of the main equipment for maintenance.

[0035] In addition, to further improve the corrosion resistance of the device and extend its service life, both the sealing housing 2 and the sealing cover 5 are made of stainless steel, which can effectively resist the long-term erosion of working water and avoid sealing failure or disassembly difficulties caused by rust.

[0036] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A sealing device for a large hydraulic dynamometer, characterized in that, The device includes a sealing housing (2) and a sealing cap (5). The sealing housing (2) is generally cylindrical with a first shoulder (201) protruding from the bottom of its outer side wall and a second shoulder (202) protruding from the middle of its inner side wall. Both the first shoulder (201) and the second shoulder (202) are cylindrical. A cylindrical groove (10) is provided at the connection between the middle of the outer side wall of the sealing housing (2) and the first shoulder (201). A sealing ring (1) is embedded in the cylindrical groove (10). Several sealing box through holes (3) penetrating its side wall are provided at the upper part of the sealing housing (2). The sealing box through holes (3) are used to connect the stator housing of the hydraulic dynamometer. Several sealing box threaded holes (4) are provided on the inner side wall of the second shoulder (202). The sealing cover (5) is cylindrical in shape. The bottom outer wall of the sealing cover (5) has a sealing cover shoulder (501) protruding. The upper part of the side wall of the sealing cover (5) is provided with several sealing cover through holes (7) that cooperate with the threaded hole (4) of the sealing box. The sealing cover shoulder (501) of the sealing cover (5) is embedded in the bottom of the second shoulder (202) of the sealing box body (2). The sealing box body (2) and the sealing cover (5) are fixedly connected by the sealing cover fastening bolts that pass through the sealing cover through hole (7) and the threaded hole (4) of the sealing box. Several oil-soaked hemp rope packings (6) are coiled between the inner wall of the sealed box (2) and the protruding end face of the sealing cover shoulder (501).

2. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, The sealed box (2) and the sealed cover (5) are both composed of two symmetrical semi-circular cylinders.

3. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, The outer wall of the sealed housing (2) is interference-fitted with the stator housing of the hydraulic dynamometer, and its dimensional tolerance is 0-0.05mm.

4. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, The length of the sealing cover shoulder (501) of the sealing cover (5) embedded in the second shoulder (202) of the sealing box (2) is ≥40mm.

5. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, There are 12 through holes (3) in the sealing box, which are evenly distributed on the side wall of the sealing box body (2). The sealing box body (2) is fixedly connected to the stator housing of the hydraulic dynamometer by 12 sealing box bolts passing through the through holes (3).

6. The sealing device for a large hydraulic dynamometer according to claim 5, characterized in that, There are 12 threaded holes (4) in the sealing box, which are evenly distributed on the inner side wall of the second shoulder (202) of the sealing box body (2); there are 12 sealing cover through holes (7) corresponding to the threaded holes (4) in the sealing box, which are evenly distributed on the upper side wall of the sealing cover (5); 12 sealing cover bolts are inserted between the threaded holes (4) in the sealing box and the through holes (7) in the sealing cover to fix the sealing cover (5) to the sealing box body (2).

7. The sealing device for a large hydraulic dynamometer according to claim 6, characterized in that, The bolts for both the sealing housing and the sealing gland are M16.

8. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, The sealing ring (1) is an O-ring with a diameter of Ф8.4mm.

9. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, The sealing ring (1) is embedded in the annular cylindrical groove (10) by applying sealant to the end face.

10. The sealing device for a large hydraulic dynamometer according to claim 1, characterized in that, Both the sealed housing (2) and the sealing cover (5) are made of stainless steel.

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