CN220167995U

CN220167995U - Corrosion-resistant sealing device and sealed vacuum pump

Info

Publication number: CN220167995U
Application number: CN202321985758.6U
Authority: CN
Inventors: 陈烽; 郁园赞; 丁莉莉; 潘辉
Original assignee: Zhenxin Turbine Machinery Co ltd
Current assignee: Zhenxin Turbine Machinery Co ltd
Priority date: 2023-07-26
Filing date: 2023-07-26
Publication date: 2023-12-12
Anticipated expiration: 2033-07-26

Abstract

The utility model provides a corrosion-resistant sealing device and a sealed vacuum pump, which comprise a volute, wherein a main shaft is rotatably connected in the volute in a penetrating way, an impeller module is fixedly sleeved on the main shaft, a plurality of sealing assemblies are sequentially sleeved between the main shaft and the volute, each sealing assembly comprises a shaft sleeve, the outer peripheral wall of each shaft sleeve is abutted against the volute, a plurality of annular grooves are formed in parallel in the inner peripheral wall of each shaft sleeve, sealing rings are embedded in the annular grooves, expansion gaskets are filled in gaps between the annular grooves and the sealing rings, and the inner periphery of each sealing ring is abutted against the main shaft. The sealing structure is made of corrosion-resistant materials, the sealing effect is improved, the service life is prolonged, and the service performance of the rotor is optimized. The concave-convex teeth are matched to form a reciprocating return sealing path, so that air flow is baffled between the sealer and the shaft teeth to form a throttling phenomenon, the gradual pressure drop is realized, the sealing effect is further optimized, and leakage is strictly avoided.

Description

Corrosion-resistant sealing device and sealed vacuum pump

Technical Field

The utility model belongs to the technical field of machinery, and relates to a pump body sealing structure, in particular to a corrosion-resistant sealing device and a sealed vacuum pump.

Background

The turbine can be applied to various industries, but working media in the chemical industry have certain acid-base corrosiveness, so that the sealing structure is challenged to a certain extent. Sealers, as a critical component in a turbine, directly affect the performance of the rotor. And the sealer needs to be considered for convenience of replacement. Because the working fluid is corrosive, restrictions are placed on materials and the like.

For example, chinese patent literature discloses a magnetic levitation turboexpander rotor wheel assembly and its positioning [ chinese patent No.: 201710448517.0 the utility model discloses a rotor impeller assembly of a magnetic suspension turboexpander and a positioning method thereof, belonging to the technical field of turbomachinery. The method for symmetrically machining the anti-rotation longitudinal surface at the end part of the rotor shaft enables the thread section to have the functions of axial connection and circumferential positioning anti-rotation, the impeller and the locking gasket are respectively machined and correspondingly assembled on the rotor shaft, the wind cap is in threaded connection with the rotor shaft to tightly press the impeller, the locking teeth outside the locking gasket are buckled into the wind cap locking groove to tightly lock the wind cap, the impeller sleeve is used as a sealing surface to tightly press the displacement sensor plate, axial limit of wind cap pressing force on a shaft seal rear part is achieved, and the tightly pressed displacement detection plate is in threaded connection with the rotor shaft to limit rotation and translation of the detection plate, so that the device is used as a rotor dynamic balance weight surface and a protection bearing limit surface. The rotor impeller assembly of the magnetic suspension turbine expander has the advantages of simple structure, convenience in assembly, safety and reliability.

The sealing structure who adopts among the above-mentioned technical scheme is more single, and the axial seal spare seals through unsmooth tooth only, and from this sealed effect is poor, influences rotor life-span and performance.

Disclosure of Invention

The utility model aims at solving the problems in the prior art, and provides a corrosion-resistant sealing device and a sealed vacuum pump, wherein a multi-piece spliced expansion sealing structure is formed by adopting multiple parts, so that the firmness of the sealing structure is improved, and meanwhile, the multi-layer sealing effect is improved.

The aim of the utility model can be achieved by the following technical scheme: the utility model provides a corrosion-resistant sealing device, includes the spiral case, be in the spiral case and rotate the cross-under main shaft, gu overlap impeller module on the main shaft, the main shaft with cup joint a plurality of seal assembly in order between the spiral case, seal assembly includes the axle cover, the peripheral wall butt of bearing seal cover the spiral case, a plurality of annular are seted up to the parallel of interior perisporium of bearing seal cover, the annular is embedded to establish the sealing ring, the annular with the expansion gasket is filled in the clearance of sealing ring, the interior periphery butt of sealing ring the main shaft.

In the corrosion-resistant sealing device, the first shaft sleeve, the balance disc and the second shaft sleeve are sequentially sleeved on the main shaft, the first shaft sleeve/the balance disc/the second shaft sleeve are provided with concave-convex tooth structures along the axial arrangement, the concave-convex tooth structures are alternately provided with convex teeth and concave teeth, a plurality of sealing rings arranged on the inner periphery of the shaft sleeve are alternately provided with short sealing rings and long sealing rings, the short sealing rings are abutted against the outer walls of the convex teeth, and the long sealing rings are abutted against the outer walls of the concave teeth.

In the corrosion-resistant sealing device, the shaft seal sleeve is specifically a stainless steel sleeve, the sealing ring is specifically a nickel ring piece, and the expansion gasket is specifically a copper ring piece.

In the corrosion-resistant sealing device, an annular clamping table is convexly arranged on the peripheral wall of the shaft seal sleeve, an annular clamping groove is concavely arranged on the volute correspondingly, and the annular clamping table is embedded into the annular clamping groove to be axially clamped and fixed.

In the corrosion-resistant sealing device, the shaft seal is sleeved at the annular clamping table and provided with the vent hole, the volute is provided with the air inlet hole at the annular clamping groove, and the air inlet hole is communicated with the vent hole.

In the corrosion-resistant sealing device, the bearings are symmetrically arranged at two ends of the interior of the volute, two ends of the main shaft are correspondingly connected with the two bearings in a penetrating manner to form rotary connection, an oil sealing piece is sleeved between the main shaft and the volute, and the oil sealing piece is positioned at the inner side of the bearings.

In the corrosion-resistant sealing device, the impeller module comprises an impeller I, an impeller II and an impeller III which are sequentially sleeved along the axial direction of the main shaft, and an air seal piece is sleeved between the impeller I and the volute.

In the corrosion-resistant sealing device, the first backflow component and the second backflow component are arranged in the volute in an array mode, and the main shaft penetrates through the centers of the first backflow component and the second backflow component.

In the corrosion-resistant sealing device, a shaft seal piece is sleeved between the main shaft and the first reflux component/the second reflux component; and an air seal piece is sleeved between the impeller II and the reflux part I, and an air seal piece is sleeved between the impeller III and the reflux part II.

A sealed vacuum pump comprises the corrosion-resistant sealing device.

Compared with the prior art, the corrosion-resistant sealing device and the sealing type vacuum pump have the following beneficial effects:

1. the sealing main body is provided with a groove, the groove is inserted with a sealing structure and a tensioning structure, the gap is filled by the tensioning structure, the sealing structure is fixed, the sealing structure is made of corrosion-resistant materials, the sealing effect is improved, the service life is prolonged, and the service performance of the rotor is optimized.

2. The concave-convex teeth are matched to form a reciprocating return sealing path, so that air flow is baffled between the sealer and the shaft teeth to form a throttling phenomenon, the gradual pressure drop is realized, the sealing effect is further optimized, and leakage is strictly avoided.

Drawings

FIG. 1 is a cross-sectional structural view of the corrosion-resistant sealing device.

Fig. 2 is an enlarged structural view of the corrosion-resistant sealing device.

FIG. 3 is a schematic diagram of the flow of air in the seal of the present corrosion resistant seal.

FIG. 4 is a schematic diagram of the pressure drop in the labyrinth seal of the present corrosion-resistant seal arrangement.

In the figure, 1, a volute; 2. a main shaft; 3. a bearing; 4. an oil seal; 5. an impeller I; 6. an impeller II; 7. an impeller III; 8. a first reflow member; 9. a second reflow member; 10. a shaft seal; 11. an air seal; 12. a shaft sleeve; 13. a short seal ring; 14. a long seal ring; 15. an expansion pad; 16. a first shaft sleeve; 17. a balancing disk; 18. a second shaft sleeve; 19. convex teeth; 20. concave teeth.

Detailed Description

The following are specific embodiments of the present utility model and the technical solutions of the present utility model will be further described with reference to the accompanying drawings, but the present utility model is not limited to these embodiments.

Example 1

As shown in fig. 1 and 2, the corrosion-resistant sealing device comprises a spiral case 1, wherein a spiral case 1 is internally provided with a main shaft 2 which is rotationally connected with the spiral case, an impeller module is fixedly sleeved on the main shaft 2, a plurality of sealing assemblies are sequentially sleeved between the main shaft 2 and the spiral case 1, each sealing assembly comprises a shaft sleeve 12, the outer peripheral wall of each shaft sleeve 12 is abutted against the spiral case 1, a plurality of annular grooves are formed in parallel with the inner peripheral wall of each shaft sleeve 12, sealing rings are embedded in the annular grooves, expansion gaskets 15 are filled in gaps between the annular grooves and the sealing rings, and the inner periphery of each sealing ring is abutted against the main shaft 2.

Bearings 3 are symmetrically arranged at two ends inside the volute 1, two ends of the main shaft 2 are correspondingly connected with the two bearings 3 in a penetrating mode one by one to form rotary connection, an oil sealing piece 4 is sleeved between the main shaft 2 and the volute 1, and the oil sealing piece 4 is located on the inner side of the bearings 3. One end of the volute 1 is a closed end, the other end is an open end, and one end of the main shaft 2 extends out of the open end to be connected with a rotary driver.

The impeller module comprises an impeller I5, an impeller II 6 and an impeller III 7 which are sequentially sleeved along the axial direction of the main shaft 2, and an air seal 11 is sleeved between the impeller I5 and the volute 1.

The spiral case 1 is internally provided with a first backflow component 8 and a second backflow component 9 in an arrangement mode, and the main shaft 2 penetrates through the centers of the first backflow component 8 and the second backflow component 9.

A shaft seal piece 10 is sleeved between the main shaft 2 and the first reflux part 8/the second reflux part 9; an air seal 11 is sleeved between the impeller II 6 and the reflux part I8, and an air seal 11 is sleeved between the impeller III 7 and the reflux part II 9.

The shaft sleeve 12 is embodied as a stainless steel sleeve, the sealing ring is embodied as a nickel ring piece, and the expansion washer 15 is embodied as a copper ring piece. The nickel ring piece has good corrosion resistance, and the sealing and shaft protection effects can be achieved by selecting a relatively thin size of about 0.5 mm. The copper ring piece is soft and can be tightly expanded after being knocked, so that the copper ring piece has the functions of filling gaps and fastening the sealing ring.

The main shaft 2 is sequentially sleeved with a first shaft sleeve 16, a balance disc 17 and a second shaft sleeve 18, the outer peripheral walls of the first shaft sleeve 16/the balance disc 17/the second shaft sleeve 18 are provided with concave-convex tooth structures in an axial arrangement mode, the concave-convex tooth structures are alternately provided with convex teeth 19 and concave teeth 20, a plurality of sealing rings arranged on the inner periphery of the shaft sleeve 12 are alternately arranged into short sealing rings 13 and long sealing rings 14, the short sealing rings 13 are abutted against the outer walls of the convex teeth 19, and the long sealing rings 14 are abutted against the outer walls of the concave teeth 20.

The convex-concave and short interval match to form a reciprocating retraced labyrinth path. As shown in fig. 3, the gas flows from the high pressure end to the low pressure end under the action of the pressure difference between the front and rear sealing, and the gas flow speed is increased and the pressure and temperature are reduced when passing through the gap between the sealing teeth and the shaft. When flowing into the interdental cavity from the gap, the airflow forms strong vortex due to the sudden expansion of the area, the airflow speed in the tooth cavity which is much larger than the gap volume is almost equal to zero, the kinetic energy is totally changed into heat due to the vortex effect, and the gas self is heated, so the gas enthalpy is kept equal to the pre-tooth enthalpy, and for ideal gas, the gas temperature is raised from the temperature when flowing through the gap to the temperature before flowing into the gap, but the pressure in the cavity is little raised, and the pressure when flowing through the gap can be considered to be kept unchanged. From this space, the gas flows through the gap between the next seal tooth and the shaft and into the next tooth space again, repeating the above process. This way through each tooth and finally out of the entire seal. As shown in fig. 4, each time gas flows from one large interdental cavity through a small gap between a tooth and the shaft, the pressure decreases once again and as the specific volume of the flowing gas increases, the velocity through the gap increases, so that the pressure decreases more downstream through one tooth, i.e., the pressure drop across each tooth is different, and the pressure drop across the tooth is greater downstream. While the temperature, for ideal gases, is reduced while flowing through the gap, the inflow into the large interdental cavity is raised again and remains substantially unchanged until finally out of the sealing device. This phenomenon is commonly referred to as throttling. By utilizing the phenomenon, the sealing and leakage reduction effects can be realized, and the air leakage amount G1 is calculated according to a flow meter formula:

G1＝ρFsc

wherein ρ is the gas density; fs is the flow area through the gap; c is the velocity of the flow through the gap. The provision of the sealing means firstly allows the clearance between the sealing teeth and the shaft to be much smaller than when no seal is provided, reducing the flow area Fs, and secondly, the pressure difference across each tooth is much smaller than across the sealing means due to throttling. If the seal is rated as p1-p2 and the seal tooth count is z, then the differential pressure across each tooth is approximately equal to (p 1-p 2)/z. The pressure differential is reduced and the flow rate is reduced, and thus the air leakage is reduced.

The peripheral wall of the shaft sleeve 12 is convexly provided with an annular clamping table, the volute 1 is correspondingly concavely provided with an annular clamping groove, and the annular clamping table is embedded into the annular clamping groove to be axially clamped and fixed. By means of the concave-convex clamping fit, the assembly firmness and the tightness of the shaft sleeve 12 and the volute 1 are further enhanced, and meanwhile, the shaft sleeve 12 is prevented from being misplaced along the axial direction, so that the tightness of the shaft sleeve and the main shaft 2 is reduced.

The shaft sleeve 12 is provided with a vent hole at the annular clamping table, the volute 1 is provided with an air inlet hole at the annular clamping groove, and the air inlet hole is communicated with the vent hole. Other sealing gases such as nitrogen are introduced from the outside into the sealing space at the inner periphery of the shaft sleeve 12 to assist sealing.

Compared with the prior art, the corrosion-resistant sealing device has the following beneficial effects:

Example two

Based on the first embodiment, the present embodiment is different in that:

a sealed vacuum pump comprises the corrosion-resistant sealing device.

Compared with the prior art, the sealed vacuum pump has the following beneficial effects:

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the utility model. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the utility model or exceeding the scope of the utility model as defined in the accompanying claims.

Although the volute 1 is used more herein; a main shaft 2; a bearing 3; an oil seal 4; an impeller I5; an impeller II 6; an impeller III 7; reflow part one 8; a second reflow member 9; a shaft seal 10; a gas seal 11; a shaft sleeve 12; a short seal ring 13; a long seal ring 14; an expansion pad 15; sleeve one 16; a balancing disk 17; a second sleeve 18; the convex teeth 19; concave tooth 20, etc., but does not exclude the possibility of using other terms. These terms are used merely for convenience in describing and explaining the nature of the utility model; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present utility model.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Claims

1. The utility model provides a corrosion-resistant sealing device, includes the spiral case, be in the spiral case and rotate the cross-under main shaft, solid cover impeller module on the main shaft, its characterized in that, the main shaft with cup joint a plurality of seal assembly in order between the spiral case, seal assembly includes the axle sleeve, the outer perisporium butt of axle sleeve the spiral case, a plurality of annular are seted up to the interior perisporium parallel of axle sleeve, the annular is embedded to establish the sealing ring, the annular with the clearance intussuseption of sealing ring is filled with the expansion gasket, the interior peripheral butt of sealing ring the main shaft.

2. The corrosion-resistant sealing device according to claim 1, wherein a first shaft sleeve, a balance disc and a second shaft sleeve are sequentially sleeved on the main shaft, concave-convex tooth structures are arranged on the outer peripheral wall of the first shaft sleeve/the balance disc/the second shaft sleeve along the axial direction, convex teeth and concave teeth are alternately arranged on the concave-convex tooth structures, a plurality of sealing rings arranged on the inner periphery of the shaft sleeve are alternately arranged into short sealing rings and long sealing rings, the short sealing rings are abutted against the outer walls of the convex teeth, and the long sealing rings are abutted against the outer walls of the concave teeth.

3. The corrosion resistant seal of claim 1 wherein said shaft seal sleeve is embodied as a stainless steel sleeve, said seal ring is embodied as a nickel ring piece, and said expansion shim is embodied as a copper ring piece.

4. The corrosion-resistant sealing device according to claim 1, wherein an annular clamping table is convexly arranged on the peripheral wall of the shaft sleeve, an annular clamping groove is correspondingly concavely arranged on the volute, and the annular clamping table is embedded into the annular clamping groove to be axially clamped and fixed.

5. The corrosion-resistant sealing device according to claim 4, wherein the shaft seal is sleeved at the annular clamping table and provided with a vent hole, the volute is provided with an air inlet hole at the annular clamping groove, and the air inlet hole is communicated with the vent hole.

6. The corrosion-resistant sealing device according to claim 1, wherein bearings are symmetrically arranged at two ends of the interior of the volute, two ends of the main shaft are connected with the two bearings in a penetrating manner one by one to form a rotating connection, an oil sealing element is sleeved between the main shaft and the volute, and the oil sealing element is positioned at the inner side of the bearings.

7. The corrosion-resistant sealing device of claim 1, wherein the impeller module comprises a first impeller, a second impeller and a third impeller which are sequentially sleeved along the axial direction of the main shaft, and an air seal is sleeved between the first impeller and the volute.

8. The corrosion-resistant seal of claim 7, wherein said first and second backflow members are disposed in an array within said volute, said main shaft extending through the centers of said first and second backflow members.

9. The corrosion-resistant sealing device according to claim 8, wherein a shaft seal is sleeved between the main shaft and the first reflux member/the second reflux member; and an air seal piece is sleeved between the impeller II and the reflux part I, and an air seal piece is sleeved between the impeller III and the reflux part II.

10. A sealed vacuum pump comprising a corrosion resistant sealing arrangement according to any one of claims 1 to 9.