A seal structure for a rotating shaft and a sealing method thereof

Abstract

The application discloses a sealing structure for a rotating shaft and a sealing method thereof, and belongs to the technical field of shaft sealing, and sequentially comprises a sealing gland, a packing gland, a packing, a first skeleton oil seal, a copper sleeve and a second skeleton oil seal which are arranged in a superposition mode; the sealing gland is internally provided with a glue injection channel, the glue injection channel comprises a glue injection main channel and an annular glue injection groove, and the bottom of the annular glue injection groove is communicated with the glue injection main channel; the glue injection main channel is formed with a first glue injection hole at a position on the outer side surface of the gland main body, and the glue injection main channel is formed with a second glue injection hole at a position on the inner side surface of the gland main body; and the surface of the sealing gland, on which the annular glue injection groove is arranged, is arranged on the side surface of the packing gland which is far away from the packing. The application has the beneficial effect that the problem of easy wearing of commonly used sealing components such as the packing, the skeleton oil seal and the copper sleeve is solved by adopting the sealing gland mode of covering installation, and the rotating machinery can be injected with glue to reduce the wearing gap and eliminate leakage without stopping operation.

Description

Technical Field

[0001] This invention relates to the field of shaft sealing technology, and more specifically, to a sealing structure and sealing method for a rotating shaft. Background Technology

[0002] The common sealing structure for rotating shafts used in water is a skeleton oil seal + copper sleeve + skeleton oil seal + packing + packing gland. During use, due to impurities in the water, wear of various components will occur, resulting in leakage at the packing. Moreover, there is a problem that leakage defects cannot be dealt with during operation.

[0003] Taking the low-speed vortex device configured in the WBS2800 type rubber ball cleaning device produced by Wuxi Hongxiang Power Auxiliary Equipment Factory as an example, the function of the vortex device is to rotate the blades around the dead zone area near the rubber ball collection net of the circulating water pipe at the condenser outlet, where rubber balls are very easy to accumulate. After the motor passes through the reduction device, the vortex device rotates and flows around the ball at a speed of no more than 16 revolutions per minute.

[0004] The commonly used sealing method at the packing of the vortex blade shaft is copper sleeve + skeleton oil seal + high water-based packing. In actual use, due to the impurities in the circulating water, the copper sleeve, skeleton oil seal and high water-based packing will wear after a period of use. At this time, leakage will occur at the packing. Since the system cannot be shut down and isolated, the leakage defect is not easy to deal with during operation.

[0005] For example, the invention patent application with publication number CN115405553A discloses a shaft seal structure for a multi-stage centrifugal pump used in mining, including a shaft sleeve and a stuffing box fitted outside the shaft sleeve. The inner side of the stuffing box has an annular groove, and an annular cavity is formed between the annular groove and the shaft sleeve. In the annular cavity, a front packing, a front pressure ring, a spring, a rear pressure ring, and a rear packing are arranged sequentially from the inside to the outside. A packing gland is provided on the outside of the rear packing. The packing gland presses the rear packing into the annular cavity. The spring is compressed and set between the front pressure ring and the rear pressure ring to form a sealed packing space. The packing space is filled with mud-like soft packing. The main advantage is that the mud-like soft packing does not cause wear between itself and the shaft sleeve, which greatly improves the service life of the pump and reduces the workload of pump maintenance and repair without the need for shutdown. However, there is still a risk of wear and leakage.

[0006] In view of this, the inventor has been conducting in-depth research to address this need, which led to the creation of this invention. Summary of the Invention

[0007] To overcome the problem that in the prior art, the copper sleeve, skeleton oil seal, and high water-based packing at the packing of the rotating shaft will wear after a period of use, resulting in leakage at the packing. Since the system cannot be shut down for isolation, the leakage defect is difficult to handle during operation. This invention provides a sealing structure for a rotating shaft, which includes, in sequence, a sealing gland, a packing gland, a packing, a first skeleton oil seal, a copper sleeve, and a second skeleton oil seal stacked together. The sealing gland, the packing gland, the packing, the first skeleton oil seal, the copper sleeve, and the second skeleton oil seal are all sleeved on the rotating shaft and are coaxial with the rotating shaft.

[0008] The sealing cap includes a cap body, which is annular and has an internal glue injection channel. The glue injection channel includes four main glue injection channels penetrating the inner and outer sides of the cap body and an annular glue injection groove disposed on the bottom surface of the cap body and coaxial with the cap body. The bottom of the annular glue injection groove communicates with the main glue injection channels. A first glue injection hole is formed on the outer side of the main glue injection channel, and a second glue injection hole is formed on the inner side of the main glue injection channel.

[0009] The annular injection groove on the sealing cap is located on the side of the packing cap away from the packing.

[0010] A sealing cap with an injection channel is provided. The design of the injection channel allows the sealing cap to be pressed onto the packing, and the continuous injection of adhesive into the injection hole ensures a good sealing effect between the sealing cap and the packing, and between the packing and the rotating shaft. The annular injection groove serves to divert the flow and distribute the sealant evenly.

[0011] Preferably, the straight line containing the central axis of each of the second injection holes passes through the central axis of the cap body, and the second injection holes are evenly distributed on the inner sidewall of the cap body along the circumferential direction of the cap body.

[0012] Preferably, the pressure cap body has four mounting through holes evenly distributed along the circumference near its outer edge, and the central axis of the mounting through holes is parallel to the central axis of the pressure cap body.

[0013] Preferably, the inner sidewall of the pressure cap body has a concave arc surface near the bottom, the central axis of the arc surface is coaxial with the pressure cap body, and the second injection hole is located on the arc surface.

[0014] The system includes a first injection hole, a second injection hole, and an annular injection groove. This allows the sealant injected from the first injection hole to be evenly distributed at the bottom of the sealing cap via the annular injection groove, and then reaches the injection channel on the sealing cap, between the sealing cap and the packing cap, between the sealing cap and the rotating shaft, and between the packing cap and the rotating shaft, thus achieving a uniform distribution of the sealant.

[0015] The present invention also provides a sealing method for the above-mentioned sealing structure. When injecting glue, the glue outlet of the hydraulic glue gun is connected to the first glue injection hole, and the hydraulic glue gun is turned on to inject glue into the glue injection channel.

[0016] Preferably, when the material of the rotating shaft at the sealing gland is #20 steel or higher, or the material with a hardness of 200HB or higher, or the sealing pressure is greater than 0.2MPa, or the rotation speed is greater than 300rpm, a sealing glue rod containing copper wire is used as the sealing glue raw material for injection, and the diameter of the copper wire is less than 0.4mm.

[0017] Preferably, when the diameter of the rotating shaft is greater than 200mm, a sealant rod containing copper wire is used as the sealant material for injection, and the diameter of the copper wire is less than 0.8mm.

[0018] The bottom surface of the annular glue injection groove is connected to the second glue injection hole, and the bottom or side surface of the annular glue injection groove is connected to the first glue injection hole.

[0019] Preferably, when the material hardness of the rotating shaft at the sealing gland is below 200HB, or the sealing pressure is greater than 0.2MPa, a sealing rod containing nylon fiber and graphite is used as the sealing material for injection.

[0020] Preferably, the rotational speed of the rotating shaft does not exceed 500 rpm, the temperature of the medium inside the sealing structure is less than 100°C, and the pressure is not greater than 1 MPa.

[0021] Preferably, the rotational speed of the rotating shaft is less than 50 rpm.

[0022] Beneficial effects:

[0023] The beneficial effects of adopting the technical solution of this invention are as follows:

[0024] (1) A sealing cap with an injection channel is provided. The design of the injection channel allows the sealing cap to be pressed onto the packing, and the continuous injection of adhesive into the injection hole enables the sealant to achieve a good sealing effect between the sealing cap and the packing, and between the packing and the rotating shaft.

[0025] (2) A first injection hole, a second injection hole and an annular injection groove are provided so that the sealant injected from the first injection hole is evenly distributed at the bottom of the sealing cap through the annular injection groove, and then reaches the injection channel on the sealing cap, between the sealing cap and the packing cap, between the sealing cap and the rotating shaft, and between the packing cap and the rotating shaft, so as to achieve a uniform distribution of sealant. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a preferred sealing structure for a rotating shaft according to the present invention;

[0028] Figure 2 This is a schematic diagram of the preferred three-dimensional structure of the sealing gland of the present invention. Figure 1 ;

[0029] Figure 3 This is a schematic diagram of the preferred three-dimensional structure of the sealing gland of the present invention. Figure 2 . Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] like Figure 1-3 As shown, the sealing structure for the rotating shaft includes, in sequence, a sealing cap 1, a packing cap 2, a packing 3, a first skeleton oil seal 4, a copper sleeve 5, and a second skeleton oil seal 6, all stacked together. The sealing cap 1, the packing cap 2, the packing 3, the first skeleton oil seal 4, the copper sleeve 5, and the second skeleton oil seal 6 are all sleeved on the rotating shaft 100 and are coaxial with the rotating shaft 100. A motor 200 is provided at one end of the rotating shaft 100.

[0032] The sealing cap 1 includes a cap body, which is annular and has an injection channel 11 inside. The injection channel 11 includes four main injection channels 111 penetrating the inner and outer sides of the cap body and an annular injection groove 112 disposed on the bottom surface of the cap body and coaxial with the cap body. The bottom of the annular injection groove 112 communicates with the main injection channels 111. A first injection hole 113 is formed on the outer side of the main injection channel 111, and a second injection hole 114 is formed on the inner side of the cap body.

[0033] The annular injection groove 112 on the sealing cap 1 is located on the side of the packing cap 2 away from the packing 3.

[0034] This method uses a covered sealing cap to solve the problem of easy wear of commonly used seals such as packing, skeleton oil seals, and copper sleeves. Rotating machinery can be injected with glue to reduce wear gaps and eliminate leakage without stopping operation.

[0035] The straight line containing the central axis of each of the second glue injection holes 114 passes through the central axis of the cap body, and the second glue injection holes 114 are evenly distributed on the inner sidewall of the cap body along the circumferential direction of the cap body.

[0036] The pressure cap body has four mounting through holes 12 evenly distributed along the circumference near the outer edge, and the central axis of the mounting through holes 12 is parallel to the central axis of the pressure cap body.

[0037] A concave arc surface 13 is formed on the inner side wall of the pressure cap body near the bottom surface. The central axis of the arc surface 13 is coaxial with the pressure cap body, and the second glue injection hole 114 is located on the arc surface 13.

[0038] This embodiment also provides a sealing method for the above-mentioned sealing structure. When injecting glue, the glue outlet of the hydraulic glue gun is connected to the first glue injection hole, and the hydraulic glue gun is turned on to inject glue into the glue injection channel.

[0039] When the material of the rotating shaft at the sealing gland is #20 steel or higher, or the hardness is 200HB or higher, or the sealing pressure is greater than 0.2MPa, or the rotation speed is greater than 300rpm, a sealing glue rod containing copper wire is used as the sealing glue raw material for injection, and the wire diameter of the copper wire is less than 0.4mm.

[0040] When the diameter of the rotating shaft is greater than 200mm, a sealing rod containing copper wire is used as the sealing material for injection, and the wire diameter of the copper wire is less than 0.8mm. Here, the wire diameter of the copper wire in the sealing rod is proportional to the diameter of the rotating shaft of the rotating machinery, mainly to prevent clogging of the sealing disc's adhesive channel.

[0041] The bottom surface of the annular glue injection groove is connected to the second glue injection hole, and the bottom or side surface of the annular glue injection groove is connected to the first glue injection hole.

[0042] When the material hardness of the rotating shaft at the sealing gland is below 200HB, or the sealing pressure is greater than 0.2MPa, in order to prevent scratching the shaft diameter, a sealing glue rod containing nylon fiber and graphite is used as the sealing glue raw material for injection.

[0043] The rotational speed of the rotating shaft shall not exceed 500 rpm, the temperature of the medium inside the sealing structure shall be less than 100℃, and the pressure shall not exceed 1 MPa. Here, the sealing effect is better when the rotational speed of the rotating shaft is preferably less than 50 rpm.

[0044] When the packing clearance at the rotating shaft wears and begins to leak, the above-mentioned sealing method can be used to inject sealant at any time to reduce the wear clearance and eliminate leakage, without stopping the rotating shaft.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sealing structure for a rotating shaft, characterized in that, The assembly includes, in sequence, a sealing cap, a packing cap, a packing, a first skeleton oil seal, a copper sleeve, and a second skeleton oil seal, all of which are stacked together. The sealing cap, the packing cap, the packing, the first skeleton oil seal, the copper sleeve, and the second skeleton oil seal are all fitted onto the rotating shaft and are coaxial with the rotating shaft. The sealing cap includes a cap body, which is annular and has an internal glue injection channel. The glue injection channel includes four main glue injection channels penetrating the inner and outer sides of the cap body and an annular glue injection groove disposed on the bottom surface of the cap body and coaxial with the cap body. The bottom of the annular glue injection groove communicates with the main glue injection channels. A first glue injection hole is formed on the outer side of the main glue injection channel, and a second glue injection hole is formed on the inner side of the main glue injection channel. The annular injection groove on the sealing cap is located on the side of the packing cap away from the packing. The inner sidewall of the pressure cap body has a concave arc surface near the bottom. The central axis of the arc surface is coaxial with the pressure cap body, and the second injection hole is located on the arc surface.

2. The sealing structure for a rotating shaft according to claim 1, characterized in that, The straight line containing the central axis of each of the second glue injection holes passes through the central axis of the cap body, and the second glue injection holes are evenly distributed on the inner sidewall of the cap body along the circumferential direction of the cap body.

3. A sealing structure for a rotating shaft according to claim 1, characterized in that, The pressure cap body has four mounting through holes evenly distributed along the circumference near its outer edge, and the central axis of the mounting through holes is parallel to the central axis of the pressure cap body.

4. A sealing method for a sealing structure according to any one of claims 1-3, characterized in that, When applying glue, connect the glue outlet of the hydraulic glue gun to the first glue injection hole, and turn on the hydraulic glue gun to inject glue into the glue injection channel.

5. A sealing method according to claim 4, characterized in that, When the material of the rotating shaft at the sealing gland is #20 steel or higher, or the hardness is 200HB or higher, or the sealing pressure is greater than 0.2MPa, or the rotation speed is greater than 300rpm, a sealing glue rod containing copper wire is used as the sealing glue raw material for injection, and the wire diameter of the copper wire is less than 0.4mm.

6. A sealing method according to claim 4, characterized in that, When the diameter of the rotating shaft is greater than 200mm, a sealant rod containing copper wire is used as the sealant material for injection, and the diameter of the copper wire is less than 0.8mm. The bottom surface of the annular glue injection groove is connected to the second glue injection hole, and the bottom or side surface of the annular glue injection groove is connected to the first glue injection hole.

7. A sealing method according to claim 4, characterized in that, When the material hardness of the rotating shaft at the sealing gland is below 200HB, or the sealing pressure is greater than 0.2MPa, a sealing rod containing nylon fiber and graphite is used as the sealing material for injection.

8. A sealing method according to claim 4, characterized in that, The rotational speed of the rotating shaft shall not exceed 500 rpm, the temperature of the medium inside the sealed structure shall be less than 100℃, and the pressure shall not exceed 1 MPa.

9. A sealing method according to claim 8, characterized in that, The rotational speed of the rotating shaft is less than 50 rpm.

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