CN220869646U

CN220869646U - Vacuum pump

Info

Publication number: CN220869646U
Application number: CN202322675981.7U
Authority: CN
Inventors: 乔中涛; 丁德甲; 尚允坤; 范庭瑞
Original assignee: Dongguan Dacheng Intelligent Equipment Co ltd; Shenzhen Dacheng Precision Equipment Co ltd; Changzhou Dacheng Vacuum Technology Co ltd
Current assignee: Dongguan Dacheng Intelligent Equipment Co ltd; Shenzhen Dacheng Precision Equipment Co ltd; Changzhou Dacheng Vacuum Technology Co ltd
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2024-04-30
Anticipated expiration: 2033-09-28

Abstract

The utility model relates to the technical field of vacuum pumps, in particular to a vacuum pump. The sealing structure of the vacuum pump comprises an exhaust end oil sealing ring and a cavity side sealing spiral shaft sleeve which are sequentially arranged in the axial direction of the rotor, wherein the exhaust end oil sealing ring can seal a lubricating medium and prevent the lubricating medium from flowing to the rotor cavity, and the cavity side sealing spiral shaft sleeve can prevent gas in the rotor cavity from leaking outwards under the action of the cavity side sealing spiral teeth when rotating. The gas outlet of the gas seal channel is used for introducing target pressure gas between the gas exhaust end oil seal ring and the cavity side seal spiral shaft sleeve, so that the gas leaked by the cavity side seal structure can be prevented from flowing to the lubrication cavity, and the lubrication medium leaked by the bearing side seal structure can be prevented from flowing to the rotor cavity. The vacuum pump adopts different sealing structures aiming at different mediums, and adopts auxiliary gas in the middle, so that the leakage of the mediums can be prevented and the sealing effect of the vacuum pump is improved due to the fact that the auxiliary gas has certain pressure.

Description

Vacuum pump

Technical Field

The utility model relates to the technical field of vacuum pumps, in particular to a sealing structure of a vacuum pump.

Background

Vacuum pumps generally comprise a pump housing including a pump body and end caps at both ends of the pump body, and a rotor rotatably mounted to both end caps through bearings, respectively. Because of the high rotor speeds, it is often necessary to provide lubrication cavities in the end caps to lubricate the bearings. In order to prevent leakage of gas in the vacuum pump from the end cap while preventing entry of lubricating oil into the rotor cavity of the pump casing, a seal structure needs to be provided between the end cap and the rotor. At present, a lip-shaped sealing structure or a labyrinth sealing structure is adopted for sealing the rotor of the vacuum pump at the end cover, but the sealing effect of the sealing structure is poor.

Disclosure of utility model

The utility model provides a vacuum pump with a good sealing effect.

According to a first aspect, there is provided in one embodiment a vacuum pump comprising:

The pump comprises a pump shell, a pump body and an exhaust end cover, wherein the exhaust end cover is positioned at the end part of the pump body; a rotor cavity is formed in the pump shell; the exhaust end cover is provided with a rotor mounting hole;

A rotor, at least a portion of the rotor being in the rotor cavity;

An exhaust end bearing through which one end of the rotor is fitted in the rotor mounting hole; an exhaust end lubrication cavity for lubricating the exhaust end bearing is arranged on the exhaust end cover;

the exhaust end sealing structure comprises an exhaust end oil sealing ring and a cavity side sealing spiral shaft sleeve;

The cavity side sealing spiral shaft sleeve is fixedly sleeved on the rotor, and comprises cavity side sealing spiral teeth; when the cavity side sealing spiral shaft sleeve rotates along with the rotor, gas in the rotor cavity is prevented from leaking to the exhaust end lubrication cavity; in the axial direction of the rotor, the exhaust end oil seal ring is positioned between the exhaust end bearing and the cavity side seal spiral sleeve;

The exhaust end cover is provided with an airtight sealing channel, and the airtight sealing channel is provided with an air outlet positioned on the wall of the rotor mounting hole; and in the axial direction of the rotor, the air outlet is used for introducing target pressure air between the exhaust end oil seal ring and the cavity side seal spiral sleeve.

Further, in an embodiment, the exhaust end sealing structure includes an auxiliary sealing spiral sleeve fixedly sleeved on the rotor, the auxiliary sealing spiral sleeve is located between the exhaust end oil seal ring and the air outlet in the axial direction of the rotor, the auxiliary sealing spiral sleeve includes auxiliary sealing spiral teeth, and the auxiliary sealing spiral teeth are used for preventing air exhausted from the air outlet from flowing to the exhaust end lubrication cavity when rotating along with the rotor.

Still further, in one embodiment, the exhaust end sealing structure comprises a labyrinth seal collar; in the axial direction of the rotor, the labyrinth seal retainer ring is positioned between the cavity side seal spiral shaft sleeve and the exhaust end oil seal ring; the axial side of the labyrinth sealing retainer ring is provided with a labyrinth-shaped gap.

In a further embodiment, the exhaust end sealing structure includes a pressure relief cavity at the periphery of the labyrinth seal collar, the pressure relief cavity being in communication with the labyrinth gap, the pressure relief cavity being in the path of gas flowing from the labyrinth gap to the exhaust end oil seal ring.

Further, in one embodiment, the labyrinth-shaped gap includes a decompression section, the decompression section includes an expansion section and a reduction section connected to the expansion section, and the expansion section is downstream of the reduction section on a path of the gas discharged from the gas outlet to the gas discharge end oil seal ring, so that the gas is decompressed after passing through the reduction section and the expansion section in sequence.

Further, in one embodiment, the exhaust end seal arrangement includes an auxiliary lip seal; in the axial direction of the rotor, the auxiliary lip seal is positioned between the auxiliary sealing spiral sleeve and the cavity side sealing spiral sleeve and is used for preventing gas and oil from flowing to the auxiliary sealing spiral sleeve.

Further, in one embodiment, the vacuum pump includes a bushing in the rotor mounting hole, the cavity side seal screw boss is located in the bushing, and the cavity side seal screw teeth are in clearance fit with an inner wall surface of the bushing; the bushing is provided with a plurality of vent holes, and the hole wall of the rotor mounting hole is provided with an annular air groove communicated with the air outlet; the annular air groove is communicated with each vent hole.

Still further, in one embodiment, the exhaust end sealing structure comprises a labyrinth seal collar; in the axial direction of the rotor, the labyrinth seal retainer ring is positioned between the cavity side seal spiral shaft sleeve and the exhaust end oil seal ring; and a labyrinth-shaped gap is formed between the labyrinth sealing check ring and one end of the bushing.

Further, in an embodiment, the exhaust end oil seal ring is a lip seal ring.

In a second aspect, an embodiment provides a vacuum pump comprising:

The pump shell comprises a pump body and an air extraction end cover positioned at the end part of the pump body; a rotor cavity is formed in the pump shell; the air extraction end cover is provided with a rotor mounting hole;

A rotor, at least a portion of the rotor being in the rotor cavity;

The air extraction end bearing is used for assembling one end of the rotor in the rotor mounting hole; the air extraction end cover is provided with an air extraction end lubrication cavity for lubricating the air extraction end bearing;

the air extraction end sealing structure comprises an air extraction end oil sealing ring and a cavity side sealing spiral shaft sleeve;

The cavity side sealing spiral shaft sleeve is fixedly sleeved on the rotor, and comprises cavity side sealing spiral teeth; the air extraction end oil seal ring is positioned between the air extraction end bearing and the cavity side seal spiral shaft sleeve; the cavity side sealing spiral shaft sleeve can prevent leaked lubricating medium from entering the rotor cavity when rotating along with the rotor;

The air extraction end cover is provided with an air sealing channel, the air sealing channel is provided with an air outlet positioned on the wall of the rotor mounting hole, and in the axial direction of the rotor, the air outlet is used for introducing target pressure air between the air extraction end oil sealing ring and the cavity side sealing spiral shaft sleeve.

In a further embodiment, the labyrinth gap is in communication with the gas outlet, the labyrinth gap comprises a pressure reducing section, the pressure reducing section comprises an expanding section and a contracting section connected with the expanding section, the expanding section is downstream of the contracting section in the path of the gas outlet exhaust gas flowing to the cavity-side sealing spiral sleeve, so that the gas is reduced in pressure after passing through the contracting section and the expanding section in sequence.

Further, in an embodiment, the labyrinth seal collar and the air outlet are arranged in a radial direction of the rotor, and the air outlet is located radially outside the labyrinth seal collar.

Further, in an embodiment, the air extraction end sealing structure includes a sealing retaining sleeve, the sealing retaining sleeve includes a sleeve body extending along the axial direction of the rotor and an end plate at one end of the sleeve body, the end plate is sleeved on the rotor and fixed at one end of the cavity side sealing spiral shaft sleeve facing the rotor cavity, and the air extraction end cover includes a retaining sleeve matching part extending into the sleeve body and in clearance fit with the inner wall surface of the sleeve body.

According to the vacuum pump of the embodiment of the first aspect, the sealing structure of the vacuum pump comprises the exhaust end oil sealing ring and the cavity side sealing spiral shaft sleeve which are sequentially arranged in the axial direction of the rotor, wherein the exhaust end oil sealing ring can seal the lubricating medium, so that the lubricating medium is prevented from flowing to the rotor cavity, and the cavity side sealing spiral shaft sleeve can prevent gas in the rotor cavity from leaking outwards under the action of the cavity side sealing spiral teeth when rotating. The gas outlet of the gas seal channel is used for introducing target pressure gas between the gas exhaust end oil seal ring and the cavity side seal spiral shaft sleeve, so that the gas leaked by the cavity side seal structure can be prevented from flowing to the lubrication cavity, and the lubrication medium leaked by the bearing side seal structure can be prevented from flowing to the rotor cavity. The vacuum pump adopts different sealing structures aiming at different mediums, and adopts auxiliary gas in the middle, so that the leakage of the mediums can be prevented and the sealing effect of the vacuum pump is improved due to the fact that the auxiliary gas has certain pressure.

According to the vacuum pump of the embodiment of the second aspect, the oil seal ring of the air extraction end seal structure seals the lubricating medium, so that the lubricating medium is prevented from flowing to the rotor cavity. When the vacuum pump operates, the air extraction end of the rotor cavity is in a negative pressure state, and the cavity side sealing spiral shaft sleeve can prevent external air from entering the rotor cavity. The air outlet of the air sealing channel is used for introducing target pressure air between the air extraction end oil sealing ring and the cavity side sealing spiral shaft sleeve, so that leaked lubricating medium can be prevented from flowing to the rotor cavity. The vacuum pump adopts different sealing structures aiming at different media, and adopts auxiliary gas in the middle, so that the leakage of the lubricating medium can be prevented due to the fact that the auxiliary gas has certain pressure, and the sealing effect of the vacuum pump is improved.

Drawings

FIG. 1 is a schematic view of an exhaust end seal structure according to an embodiment;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a seal line diagram of an exhaust end seal configuration of an embodiment;

FIG. 4 is a schematic view of an embodiment of an exhaust end seal structure;

FIG. 5 is an enlarged view of portion B of FIG. 4;

Fig. 6 is a seal line diagram of an exhaust end seal structure of an embodiment.

List of feature names corresponding to reference numerals in the figure: 1. a pump housing; 11. a pump body; 12. an end cap; 1201. an air extraction end cover; 1202. an exhaust end cap; 121. a lubrication chamber; 1211. a lubrication cavity at the air extraction end; 1212. an exhaust end lubrication chamber; 1221. an exhaust end cap body; 1222. an exhaust end cap; 1223. an air extraction end cover body; 1224. an air extraction end cap; 1225. a stop sleeve mating portion; 1226. an annular air groove; 13. a rotor cavity; 2. a rotor; 21. a rotating shaft; 22. a rotor sleeve; 23. spiral teeth; 3. a bearing; 31. an exhaust end bearing; 32. an air extraction end bearing; 4. an exhaust end bearing side sealing structure; 41. an exhaust end oil seal ring; 42. a first sleeve; 43. a first sleeve seal ring; 5. an air exhaust end auxiliary air sealing structure; 51. an air outlet at the air exhaust end; 52. the exhaust end seals the channel; 53. auxiliary sealing of the spiral shaft sleeve; 531. auxiliary sealing helical teeth; 54. an exhaust end labyrinth seal retainer ring; 541. a labyrinth-shaped gap at the exhaust end; 5411. an exhaust end expansion section; 5412. an exhaust end narrowing section; 55. a pressure reducing chamber; 56. an auxiliary lip seal; 57. a second sleeve; 58. a graphite packing seal; 6. an exhaust end cavity side sealing structure; 61. the exhaust end cavity side seals the spiral shaft sleeve; 611. the exhaust end cavity side seals the spiral teeth; 7. a bushing; 71. a vent hole; 8. an exhaust end bearing seat; 9. a bearing seat of the air extraction end; 91. a fixed flange; 10. a third sleeve; 101. a third sleeve seal ring; 40. a bearing side sealing structure of the air extraction end; 401. an oil sealing ring at the air extraction end; 50. the air extraction end is an auxiliary air sealing structure; 501. an air outlet of the air exhaust end; 502. the air extraction end is used for sealing the channel in an airtight manner; 503. labyrinth sealing check ring at air extraction end; 504. labyrinth-shaped gaps at the air extraction end; 5041. an air extraction end expansion section; 5042. the air extraction end is reduced; 60. a cavity side sealing structure of the air extraction end; 601. the cavity side of the air extraction end is sealed with a spiral shaft sleeve; 6011. sealing spiral teeth at the cavity side of the air extraction end; 602. sealing the retaining sleeve; 6021. a sleeve body; 6022. end plates.

Description of bracketed reference numerals in the drawings: in the bracketed reference numerals in the drawings, features indicated by the reference numerals are features indicated by both numerals in the brackets and numerals outside the brackets.

Detailed Description

The utility model will be described in further detail below with reference to the drawings by means of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present utility model. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, related operations of the present utility model have not been shown or described in the specification in order to avoid obscuring the core portions of the present utility model, and may be unnecessary to persons skilled in the art from a detailed description of the related operations, which may be presented in the description and general knowledge of one skilled in the art.

Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The term "coupled" as used herein includes both direct and indirect coupling (coupling), unless otherwise indicated.

In one embodiment, referring to fig. 1 to 6, a vacuum pump includes a pump housing 1 and a rotor 2. The pump housing 1 includes a pump body 11 and an end cap 12, and the rotor 2 is in rotational engagement with the end cap 12 through a bearing 3. End cap 12 is at an end of pump body 11 in the axial direction of rotor 2. Within the pump housing 1 is a rotor cavity 13, at least a part of the rotor 2 being located in the rotor cavity 13. The end cover 12 is provided with a lubrication cavity 121 for lubricating the bearing 3; the lubrication chamber 121 is on the side of the bearing 3 facing away from the rotor chamber 13.

In one embodiment, the vacuum pump is a dry vacuum pump. In an embodiment, referring to fig. 1 and 4, the vacuum pump is a screw vacuum pump, the rotor 2 includes a rotating shaft 21 and a rotor sleeve 22, the periphery of the rotor sleeve 22 has spiral teeth 23, and the rotor sleeve 22 and the rotating shaft 21 are fixed together, and specific fixing modes include interference fit, welding, key connection, and the like. In the axial direction of the rotor 2, one end of the vacuum pump is an air inlet end, and the other end is an air outlet end. When the vacuum pump works, the gas in the rotor cavity 13 at the exhaust end is compressed, the air pressure is high, and the gas in the rotor cavity 13 at the air inlet end is communicated with the vacuumized equipment and is usually in a negative pressure state.

Due to the pressure difference between the rotor chamber 13 of the vacuum pump and the outside, the bearing 3 between the rotor 2 and the end cap 12 needs to be lubricated, and the lubrication chamber 121 and the rotor chamber 13 need to be sealed with air and oil to prevent lubricating oil from entering the rotor chamber 13, and also need to prevent gas from channeling between the two chambers. To achieve a better seal, the vacuum pump comprises a sealing structure that seals the rotor 2 with the end cap 12.

Referring to fig. 1-6, the vacuum pump has two end caps 12, namely, a suction end cap 1201 and an exhaust end cap 1202. The exhaust end cap 1202 has an exhaust end rotor mounting hole and the bleed end cap 1201 has a bleed end rotor mounting hole. Lubrication chamber 121 on suction end cap 1201 is suction end lubrication chamber 1211 and lubrication chamber 121 on discharge end cap 1202 is discharge end lubrication chamber 1212. Therefore, the sealing structure of the vacuum pump is divided into an air extraction end sealing structure and an air exhaust end sealing structure. Of course, in some other embodiments, the vacuum pump may employ only one of the suction end seal and the exhaust end seal. The suction end sealing structure and the exhaust end sealing structure are respectively described in detail below with reference to the accompanying drawings.

In one embodiment, referring to fig. 1-3, an exhaust end seal structure seals the rotor 2 and the exhaust end cap 1202. The exhaust end sealing structure comprises an exhaust end bearing side sealing structure 4, an exhaust end sealing structure 5 and an exhaust end cavity side sealing structure 6 which are sequentially arranged in the axial direction of the rotor 2; the exhaust end chamber side seal 6 is on the side of the exhaust end seal 5 facing the rotor chamber 13. In the axial direction of the rotor 2, the exhaust end seal structure 5 is located between the exhaust end bearing side seal structure 4 and the exhaust end chamber side seal structure 6.

The exhaust end bearing side seal structure 4 includes an exhaust end oil seal ring 41 for preventing the flow of the lubrication medium to the rotor chamber 13; the exhaust-end oil seal 41 is located between the exhaust-end bearing 31 and the exhaust-end seal structure 5, i.e., on the side of the exhaust-end bearing 31 facing the rotor chamber 13 in the axial direction of the rotor 2.

The exhaust end chamber side seal structure 6 includes an exhaust end chamber side seal screw boss 61 fixedly fitted on the rotor 2 with an exhaust end oil seal ring 41 interposed between the exhaust end bearing 31 and the exhaust end chamber side seal screw boss 61. The exhaust end cavity side seal screw boss 61 includes exhaust end cavity side seal screw teeth 611. When the vacuum pump is in operation, the rotor 2 rotates to drive the exhaust end cavity side sealing spiral shaft sleeve 61 to rotate, the exhaust end cavity side sealing spiral teeth 611 are spiral, and when the exhaust end cavity side sealing spiral shaft sleeve 61 rotates along with the rotor 2, the exhaust end cavity side sealing spiral teeth 611 have a tendency to convey gas to the rotor cavity 13 so as to prevent the gas in the rotor cavity 13 from leaking to the exhaust end lubrication cavity 1212, and a certain sealing effect is achieved.

The exhaust-side seal structure 5 includes an exhaust-side gas seal passage 52, the exhaust-side gas seal passage 52 having an exhaust-side gas outlet 51, the exhaust-side gas outlet 51 for introducing a target pressure gas into a gap between the rotor 2 and a rotor mounting hole wall, specifically, the exhaust-side gas outlet 51 for introducing the target pressure gas between the exhaust-side oil seal ring 41 and the exhaust-side chamber-side seal screw boss 61 in the axial direction of the rotor 2 for preventing passage of the gas leaked from the rotor chamber 13 and the lubrication medium leaked from the exhaust-side lubrication chamber 1212. By introducing the target pressure gas into the gap between the rotor 2 and the exhaust end cover 1202 through the exhaust end gas outlet 51, the pressure difference between the exhaust end of the rotor cavity 13 and the exhaust end sealing structure is reduced, the gas in the rotor cavity 13 is prevented from flowing to the exhaust end gas outlet 51, and simultaneously, under the pressure of the gas introduced into the exhaust end gas outlet 51, the lubrication medium in the exhaust end lubrication cavity 1212 can be prevented from flowing to the rotor cavity 13.

In the application, the lubrication medium is sealed by the exhaust end oil seal ring 41, so that the lubrication medium is prevented from flowing to the rotor cavity 13, the exhaust end cavity side seal spiral sleeve 61 can prevent the gas of the rotor cavity 13 from leaking outwards, the target pressure gas introduced by the exhaust end gas outlet 51 can prevent the gas leaked by the exhaust end cavity side seal structure 6 from flowing to the exhaust end lubrication cavity 1212, and the lubrication medium leaked by the exhaust end bearing side seal structure 4 can also be prevented from flowing to the rotor cavity 13. The vacuum pump adopts different sealing structures aiming at different mediums, and simultaneously adopts auxiliary gas in the middle, and the auxiliary gas has certain pressure, so that the leakage of the lubricating medium and the gas in the rotor cavity 13 can be prevented, and the sealing effect of the vacuum pump is improved.

Specifically, in one embodiment, the exhaust-side air outlet 51 is located between the exhaust-side oil seal ring 41 and the exhaust-side cavity-side seal spiral sleeve 61 in the axial direction of the rotor 2. In one embodiment, referring to FIG. 1, an exhaust end cap 1202 has an exhaust end gas seal passage 52. The other end of the air-tight sealing channel 52 is provided with an air inlet for externally connecting air supply equipment.

Regarding the structure of the exhaust lubrication cavity 1212, in some embodiments, the exhaust lubrication cavity 1212 may take any feasible form, for example, in one embodiment, referring to fig. 1 to 3, the exhaust end cover 1202 is a split structure including an exhaust end cover 1221 and an exhaust end cover cap 1222, the exhaust end cover 1221 is fixed to the pump body 11, the exhaust end cover cap 1222 is fixed to the exhaust end cover 1221 and encloses the exhaust lubrication cavity 1212, and one end of the rotor 2 is assembled to the exhaust end cover 1221 through the exhaust end bearing 31. One end of the rotor 2 protrudes into the lubrication chamber 121 through the exhaust end rotor mounting hole. Of course, to avoid oil leakage from the lubrication chamber 121, the exhaust end cap 1222 and the exhaust end cap 1221 are sealed by a seal ring. In order to prevent air leakage, the space between the pump body 11 and the exhaust end cover 1221 is also sealed by a seal ring. For another example, the exhaust end cap 1221 is integrally formed with the exhaust end cap 1222. Specifically, the exhaust-end air outlet 51 is located on the wall of the exhaust-end rotor mounting hole.

Regarding the exhaust end oil seal 41, in one embodiment, please refer to fig. 1-3, the exhaust end oil seal 41 is a lip seal. In some other embodiments, the exhaust end oil seal 41 may also be a packing.

The number of lip seals may be selected as desired, for example, referring to fig. 1, in one embodiment, the number of exhaust end oil seals 41 is two, and two exhaust end oil seals 41 are disposed side by side. In one embodiment, to reduce wear of the shaft 21, the exhaust end bearing side seal 4 includes a first sleeve 42 that fits over the rotor 2, and the exhaust end oil seal 41 is in sealing contact with the first sleeve 42. In this way, the exhaust end oil seal 41 is in contact with the first sleeve 42, reducing wear of the rotor 2 by the exhaust end oil seal 41. In order to ensure sealing performance, the exhaust-end bearing-side sealing structure 4 includes a first sleeve seal 43, the first sleeve seal 43 being for sealing a gap between the first sleeve 42 and the rotor 2.

In an embodiment, referring to fig. 1 to 3, the exhaust end sealing structure 5 includes an auxiliary sealing spiral sleeve 53 fixedly sleeved on the rotor 2, the auxiliary sealing spiral sleeve 53 is located between the exhaust end oil seal ring 41 and the exhaust end air outlet 51 in the axial direction of the rotor 2, the auxiliary sealing spiral sleeve 53 includes auxiliary sealing spiral teeth 531, the auxiliary sealing spiral teeth 531 are spiral, and when the auxiliary sealing spiral teeth 531 rotate along with the rotor 2, the air introduced from the exhaust end air outlet 51 can be prevented from flowing to the lubrication cavity 121. The auxiliary sealing screw 531 can maintain a high pressure at the air outlet 51 of the air discharge end, thereby enhancing the sealing effect on the rotor chamber 13.

Specifically, the fixing form between the auxiliary sealing spiral sleeve 53 and the rotor 2 may be in the form of interference fit, welding, key connection, fastener fixation, etc.

In order to improve the sealing effect on the lubricating medium, in one embodiment, referring to fig. 1 to 3, the exhaust end sealing structure 5 includes an exhaust end labyrinth seal collar 54, the exhaust end labyrinth seal collar 54 is located between the auxiliary seal spiral sleeve 53 and the exhaust end oil seal collar 41, and an exhaust end labyrinth gap 541 is formed on an axial side of the exhaust end labyrinth seal collar 54. By the exhaust-end labyrinth gap 541, the blocking effect against the lubrication medium is improved, and the lubrication medium does not easily reach the position of the exhaust-end air outlet 51 through the exhaust-end labyrinth gap 541 even if it leaks through the exhaust-end oil seal ring 41. The first sleeve seal 43 is located between the first sleeve 42 and the exhaust end labyrinth seal collar 54.

Still further, in one embodiment, referring to fig. 1-3, the exhaust end seal structure 5 includes a relief chamber 55 at the periphery of the exhaust end labyrinth seal collar 54, the relief chamber 55 being in communication with the exhaust end labyrinth gap 541, and the relief chamber 55 being in the path of the gas flowing from the exhaust end labyrinth gap 541 to the exhaust end oil seal collar 41. Such that the gas is depressurized by the depressurization chamber 55 and less likely to enter the lubrication chamber 121 from the discharge end oil seal.

Specifically, the relief chamber 55 is located at the periphery of the exhaust end labyrinth seal collar 54. The vacuum pump includes a bushing 7 in the rotor mounting hole, one end of the bushing 7 forming an exhaust end labyrinth gap 541 with the exhaust end labyrinth seal collar 54. The decompression chamber 55 is defined by one end face of the bush 7, the exhaust-side labyrinth seal collar 54, the exhaust-side rotor mounting hole inner wall face, and the exhaust-side bearing housing 8 of the exhaust-side bearing 31. Wherein the exhaust bearing housing 8 of the exhaust end cap 1202 is fixed to the exhaust end cap 1202.

Regarding the exhaust labyrinth gap 541, in one embodiment, referring to fig. 1 to 3, the exhaust labyrinth gap 541 includes a decompression section, the decompression section includes an exhaust expansion section 5411 and an exhaust contraction section 5412 connected to the exhaust expansion section 5411, and the exhaust expansion section 5411 and the exhaust contraction section 5412 are relatively speaking, and generally, the cross-sectional area of the exhaust expansion section 5411 is larger than the cross-sectional area of the exhaust contraction section 5412. On the way that the gas discharged from the gas outlet 51 flows toward the gas-discharge-end oil seal ring 41, the gas-discharge-end expanding section 5411 is downstream of the gas-discharge-end narrowing section 5412 so that the gas is depressurized after passing through the gas-discharge-end narrowing section 5412 and the gas-discharge-end expanding section 5411 in order. The pressure of the gas can be reduced by the pressure reducing section when the gas passes through the labyrinth gap 541, so that the pressure of the gas is further reduced, and the gas cannot pass through the exhaust end oil seal ring 41 after flowing to the exhaust end oil seal ring 41, thereby improving the sealing performance.

Specifically, in one embodiment, referring to fig. 1 to 3, two pressure reducing sections are connected in series on the path of the gas flow, so as to further improve the pressure reducing effect. In some other embodiments, the number of pressure relief segments may be arbitrary, such as only one, or any number of three or more may be provided, as conditions allow.

More specifically, in one embodiment, referring to fig. 1 to 3, since the decompression chamber 55 is connected to the exhaust end labyrinth gap 541 in series, the gas is decompressed by the exhaust end labyrinth gap 541, and then enters the decompression chamber 55 for decompression again, so that the gas pressure is further reduced, and the sealing performance is further improved. In some other embodiments, the depressurization may also be performed through only the depressurization chamber 55 or through only the depressurization segment of the exhaust end labyrinth gap 541.

In order to further improve the sealing effect of the exhaust end sealing structure of the vacuum pump due to the high exhaust end pressure of the vacuum pump, further, in an embodiment, referring to fig. 1 to 3, the exhaust end sealing structure 5 includes an auxiliary lip seal ring 56, and the auxiliary lip seal ring 56 is located between the auxiliary seal screw sleeve 53 and the exhaust end cavity side seal screw sleeve 61, for preventing the gas exhausted from the exhaust end gas outlet 51 from flowing to the auxiliary seal screw sleeve 53. In order to reduce the wear of the lip seal on the rotor 2, referring to the structure of the exhaust end oil seal 41, a second sleeve 57 in sealing contact with the auxiliary lip seal 56 is also fixed to the rotor 2.

In one embodiment, referring to fig. 1 and 2, to further enhance sealing performance, the exhaust end seal 5 includes a graphite packing seal 58 on the side of the auxiliary lip seal 56 facing the rotor cavity 13, the graphite packing seal 58 being fitted over the second sleeve 57 and sealingly engaging the second sleeve 57.

Further, in one embodiment, referring to fig. 1 and 2, a bushing 7 is disposed in the exhaust end rotor mounting hole, the bushing 7 having a plurality of ventilation holes 71 communicating with the exhaust end air outlet 51. The wall of the exhaust end rotor mounting hole is provided with an annular air groove 1226 communicated with the exhaust end air outlet 51, and the annular air groove 1226 is communicated with each vent hole 71. The gas in the gas-tight passage 52 at the exhaust end can be uniformly introduced into the liner 7 through the annular gas groove 1226.

In one embodiment, referring to fig. 1 and 2, a graphite packing seal 58 is juxtaposed with the auxiliary lip seal 56, and a seal hole is provided in the graphite packing seal 58 for venting the vent hole 71 to ensure venting.

Specifically, the auxiliary seal screw teeth 531 of the auxiliary seal screw boss 53 and the exhaust end chamber side seal screw teeth 611 of the exhaust end chamber side seal screw boss 61 are both in clearance fit with the inner wall surface of the bush 7, and gas passage in the target direction can be prevented in the rotation of the rotor 2. In some other embodiments, the sealing screw sleeve can also be directly in clearance fit with the hole wall surface of the rotor mounting hole of the exhaust end, and the bushing 7 is not required to be arranged.

The following describes the pumping end sealing structure in detail with reference to the accompanying drawings:

Referring to fig. 4 to 6, the suction end sealing structure seals the rotor 2 and the suction end cap 1201, and includes a suction end bearing side sealing structure 40, a suction end auxiliary air sealing structure 50, and a suction end chamber side sealing structure 60, which are sequentially arranged in the axial direction of the rotor 2; the suction side chamber side seal arrangement 60 is on the side of the suction side auxiliary air seal arrangement 50 facing the rotor chamber 13. In the axial direction of the rotor 2, the suction side auxiliary air seal structure 50 is located between the suction side bearing side seal structure 40 and the suction side chamber side seal structure 60.

The suction side bearing side seal 40 includes a suction side oil seal ring 401 capable of preventing the flow of the lubrication medium to the rotor cavity 13. The suction side oil seal 401 is located between the suction side bearing 32 and the suction side auxiliary air seal structure 50, i.e. on the side of the suction side bearing 32 facing the rotor chamber 13 in the axial direction of the rotor 2.

The air extraction end cavity side sealing structure 60 comprises an air extraction end cavity side sealing spiral shaft sleeve 601 fixedly sleeved on the rotor 2, and the air extraction end cavity side sealing spiral shaft sleeve 601 comprises air extraction end cavity side sealing spiral teeth 6011. When the vacuum pump operates, the rotor 2 rotates, the air extraction end cavity side sealing spiral shaft sleeve 601 can be driven to rotate, the air extraction end cavity side sealing spiral teeth 6011 are spiral, when the air extraction end cavity side sealing spiral shaft sleeve 601 rotates along with the rotor 2, under the action of the air extraction end cavity side sealing spiral teeth 6011, the trend of conveying gas back to the rotor cavity 13 exists, leaked lubricating medium can be prevented from entering the rotor cavity 13, and gas outside the rotor cavity 13 can be prevented from entering the rotor cavity 13, so that a certain sealing effect is achieved.

The auxiliary air-tight seal structure 50 of the air-extracting end comprises an air-extracting end air-tight seal channel 502, wherein the air-extracting end air-tight seal channel 502 is provided with an air-extracting end air outlet 501, the air-extracting end air outlet 501 is used for introducing target pressure air into a gap between the rotor 2 and the wall of an air-extracting end rotor mounting hole, in particular introducing the target pressure air into a gap between the air-extracting end oil seal ring 401 and the air-extracting end cavity side seal spiral sleeve 601 in the axial direction of the rotor 2 so as to prevent a lubricating medium leaked from the air-extracting end lubricating cavity 1211 from passing through. Because the air extraction end cavity side sealing spiral shaft sleeve 601 has a trend of exhausting air back to the rotor cavity 13, the pressure at the air extraction end air outlet 501 can be kept, so that the leaked lubricating medium can be better prevented from passing through by the air introduced from the air extraction end air outlet 501, and the sealing effect on the lubricating medium is improved.

In the present application, the lubrication medium is sealed by the pumping end oil seal ring 401, and the lubrication medium is prevented from flowing into the rotor chamber 13. When the vacuum pump operates, the air extraction end of the rotor cavity 13 is in a negative pressure state, and the air extraction end cavity side sealing spiral shaft sleeve 601 can prevent external air from entering the rotor cavity 13. The gas of the target pressure introduced from the gas extraction end gas outlet 501 can prevent the lubrication medium leaked from the gas extraction end bearing side seal structure 40 from flowing toward the rotor chamber 13. The vacuum pump adopts different sealing structures aiming at different media, and adopts auxiliary gas in the middle, so that the leakage of the lubricating medium can be prevented due to the fact that the auxiliary gas has certain pressure, and the sealing effect of the vacuum pump is improved.

In one embodiment, the bleed end air outlet 501 is axially between the bleed end oil seal ring 401 and the bleed end cavity side seal screw boss 601 in the rotor 2. In one embodiment, referring to fig. 4 and 5, the suction end cap 1201 has a suction end hermetic seal passage 502. The other end of the air extraction end air sealing channel 502 is provided with an air inlet for externally connecting air supply equipment.

Regarding the structure of the suction side lubrication chamber 1211, in some embodiments, referring to fig. 4 to 6, the suction side lubrication chamber 1211 may take any feasible manner, for example, the suction side end cover 1201 may be a split structure including a suction side end cover 1223 and a suction side end cover 1224, where the suction side end cover 1223 is fixed to the pump body 11, and the suction side end cover 1224 is fixed to the suction side end cover 1223 and encloses the suction side lubrication chamber 1211, and one end of the rotor 2 is assembled to the suction side end cover 1223 through the suction side bearing 32. One end of the rotor 2 extends into the suction end lubrication chamber 1211 through the suction end cap aperture. Of course, to avoid oil leakage from the bleed end lubrication chamber 1211, the bleed end cap 1224 is sealed to the bleed end cap body 1223 by a seal ring. In order to prevent air leakage, the space between the pump body 11 and the air extraction end cover 1223 is also sealed by a sealing ring. For another example, the bleed end cap 1223 and the bleed end cap 1224 are integrally formed. For another example, referring to fig. 4 and 5, the suction end cover 1223 is fixed with a suction end bearing seat 9, the suction end bearing seat 9 includes a fixing flange 91 disposed outside the suction end cover 1223, and the suction end cap 1224 is fixed on the fixing flange 91. Specifically, the air extraction end air outlet 501 is located on the hole wall of the air extraction end cover hole.

Regarding the pumping end oil seal 401, in one embodiment, please refer to fig. 4-6, the pumping end oil seal 401 is a lip seal. In some other embodiments, the bleed end oil seal 401 may also be a packing seal.

The number of the pumping-end oil seal rings 401 may be selected according to the need, for example, please refer to fig. 4, and in one embodiment, the number of pumping-end oil seal rings 401 is one. In some other embodiments, the number of the pumping-end oil seal rings 401 may be more than two. In one embodiment, referring to fig. 4 and 5, in order to reduce wear of the shaft 21, the suction end bearing side seal 40 includes a third sleeve 10 that is fitted over the rotor 2, and a suction end oil seal 401 is in sealing contact with the third sleeve 10. In this way, the pumping end oil seal ring 401 contacts the third shaft sleeve 10, and abrasion of the pumping end oil seal ring 401 to the rotor 2 is reduced. In order to ensure sealing performance, the suction end bearing side sealing structure 40 includes a third sleeve seal 101, and the third sleeve seal 101 is used to seal a gap between the third sleeve 10 and the rotor 2.

Further, referring to fig. 4 to 6, in an embodiment, the auxiliary air-extracting-end air-sealing structure 50 includes an air-extracting-end labyrinth seal collar 503, the air-extracting-end labyrinth seal collar 503 is located between the air-extracting-end cavity-side seal spiral sleeve 601 and the air-extracting-end oil seal ring 401 in the axial direction of the rotor 2, and an air-extracting-end labyrinth gap 504 is formed on a side of the air-extracting-end labyrinth seal collar 503 facing the air-extracting-end cavity-side seal spiral sleeve 601. The third sleeve seal 101 is located between the third sleeve 10 and the pumping end labyrinth seal collar 503. By the pumping end labyrinth gap 504, the blocking effect on the lubrication medium is improved, and the lubrication medium is not easy to reach the pumping end air outlet 501 by the pumping end labyrinth gap 504 even though the lubrication medium leaks through the pumping end oil seal ring 401.

Further, referring to fig. 4 to 6, the pumping end labyrinth gap 504 is in communication with the pumping end gas outlet 501, and the pumping end labyrinth gap 504 includes a decompression section, the decompression section includes a pumping end expansion section 5041 and a pumping end reduction section 5042 connected to the pumping end expansion section 5041, and the cross-sectional area of the pumping end expansion section 5041 is generally larger than that of the pumping end reduction section 5042 in comparison with the pumping end reduction section 5412 of the pumping end expansion section 5411. On the way that the gas in the gas-extraction-end gas outlet 501 flows to the gas-extraction-end cavity-side sealing spiral sleeve 601, the gas-extraction-end expansion section 5041 is downstream of the gas-extraction-end reduction section 5042, so that the gas is decompressed after passing through the gas-extraction-end reduction section 5042 and the gas-extraction-end expansion section 5041 in sequence. The pressure of the gas can be reduced when the gas passes through the labyrinth gap 504 at the air extraction end through the pressure reducing section, so that the pressure of the gas is further reduced, and the gas cannot pass through the air extraction end oil seal ring 401 after flowing to the air extraction end oil seal ring 401, thereby improving the sealing performance.

Specifically, in one embodiment, referring to fig. 5, two pressure reducing sections are connected in series on the path of the gas flow, so as to further improve the pressure reducing effect. In some other embodiments, the number of pressure relief segments may be arbitrary, such as only one, or any number of three or more may be provided, as conditions allow.

Further, in an embodiment, referring to fig. 4 and 5, the pumping end labyrinth seal ring 503 and the pumping end gas outlet 501 are arranged in the radial direction of the rotor 2, and the pumping end gas outlet 501 is located radially outside the pumping end labyrinth seal ring 503. Specifically, in one embodiment, the air extraction end bearing seat 9, the air extraction end labyrinth seal collar 503 and the air extraction end cover hole wall enclose a cavity that is communicated with the air extraction end air outlet 501.

Further, in an embodiment, referring to fig. 4 to 6, the suction side cavity side sealing structure 60 includes a sealing retaining sleeve 602, the sealing retaining sleeve 602 includes a sleeve body 6021 extending along the axial direction of the rotor 2 and an end plate 6022 at one end of the sleeve body 6021, the end plate 6022 is sleeved on the rotor 2 and fixed to one end of the suction side cavity side sealing spiral sleeve 601 of the suction side cavity side sealing structure 60 facing the rotor cavity 13, and the suction side end cover 1201 includes a retaining sleeve fitting portion 1225 extending into the sleeve body 6021 and in clearance fit with an inner wall surface of the sleeve body 6021. The clearance fit of the retainer fitting portion 1225 and the sleeve body 6021 can seal the air passage, reducing the entry of ambient air into the air extraction end of the rotor chamber 13.

It should be noted that, because the air pressure of the air outlet of the rotor cavity is higher than the air pressure of the air outlet of the rotor cavity, the pressure of the air discharged from the air outlet of the air outlet can be smaller than the pressure of the air discharged from the air outlet of the air outlet, and the two air pressures can be equal.

In one embodiment, a gas supply device is used to introduce 0.3Mpa of nitrogen into the gas-tight passageway at the exhaust end. In some other embodiments, the specific pressure value of the gas in the airtight channel of the gas inlet end can be adaptively adjusted according to the power of the vacuum pump. In some other embodiments, the pressure value of the gas introduced into the gas-tight passage of the exhaust end is smaller than the pressure of the gas introduced into the gas-tight passage of the exhaust end of the rotor cavity, and the pressure of the gas introduced into the gas-tight passage of the exhaust end is larger than the pressure of the gas introduced into the gas-tight passage of the exhaust end of the rotor cavity.

The sealing rings in the above embodiments may be O-ring, single-lip sealing ring, double-lip sealing ring, or the like, according to the installation requirement. With respect to the material of the sleeve, for applications requiring wear resistance, this includes, but is not limited to, 9Cr18MoV materials.

In the application, the gas exhausted from the gas exhaust port of the gas exhaust end and the gas exhausted from the gas exhaust port of the gas exhaust end is flowing gas, so that the auxiliary gas seal is realized, and meanwhile, the parts passing through the gas exhaust end can be cooled.

The foregoing description of the utility model has been presented for purposes of illustration and description, and is not intended to be limiting. Several simple deductions, modifications or substitutions may also be made by a person skilled in the art to which the utility model pertains, based on the idea of the utility model.

Claims

1. A vacuum pump, comprising:

A rotor, at least a portion of the rotor being in the rotor cavity;

2. The vacuum pump of claim 1, wherein the exhaust end seal structure comprises an auxiliary seal screw boss fixedly sleeved on the rotor, the auxiliary seal screw boss being located between the exhaust end oil seal ring and the air outlet in the axial direction of the rotor, the auxiliary seal screw boss comprising auxiliary seal screw teeth for preventing air exhausted from the air outlet from flowing toward the exhaust end lubrication chamber when rotating with the rotor.

3. The vacuum pump of claim 2, wherein the exhaust end seal comprises a labyrinth seal collar; in the axial direction of the rotor, the labyrinth seal retainer ring is positioned between the cavity side seal spiral shaft sleeve and the exhaust end oil seal ring; the axial side of the labyrinth sealing retainer ring is provided with a labyrinth-shaped gap.

4. A vacuum pump as claimed in claim 3, wherein the exhaust end seal arrangement comprises a relief chamber at the periphery of the labyrinth seal collar, the relief chamber being in communication with the labyrinth gap, the relief chamber being in the path of gas flow from the labyrinth gap to the exhaust end oil seal ring.

5. A vacuum pump according to claim 3, wherein the labyrinth gap comprises a decompression section including an expansion section and a reduction section connected to the expansion section, the expansion section being downstream of the reduction section in the path of the gas discharged from the gas outlet toward the exhaust-side oil seal ring, so that the gas is decompressed after passing through the reduction section and the expansion section in order.

6. The vacuum pump of claim 1, including a bushing in said rotor mounting bore, said cavity side seal screw boss being in said bushing, said cavity side seal screw teeth being in clearance fit with an inner wall surface of said bushing; the bushing is provided with a plurality of vent holes, and the hole wall of the rotor mounting hole is provided with an annular air groove communicated with the air outlet; the annular air groove is communicated with each vent hole.

7. The vacuum pump of claim 6, wherein the exhaust end seal comprises a labyrinth seal collar; in the axial direction of the rotor, the labyrinth seal retainer ring is positioned between the cavity side seal spiral shaft sleeve and the exhaust end oil seal ring; and a labyrinth-shaped gap is formed between the labyrinth sealing check ring and one end of the bushing.

8. The vacuum pump of any of claims 2-5, wherein the exhaust end seal comprises an auxiliary lip seal; in the axial direction of the rotor, the auxiliary lip seal is positioned between the auxiliary sealing spiral sleeve and the cavity side sealing spiral sleeve and is used for preventing gas and oil from flowing to the auxiliary sealing spiral sleeve.

9. A vacuum pump according to any one of claims 1 to 5, wherein the exhaust end oil seal is a lip seal.

10. A vacuum pump, comprising:

A rotor, at least a portion of the rotor being in the rotor cavity;

11. The vacuum pump of claim 10, wherein the pumping end seal structure comprises a labyrinth seal collar located between the cavity side seal screw boss and the pumping end oil seal collar in the rotor axial direction, the labyrinth seal collar being formed with a labyrinth gap on a side thereof facing the cavity side seal screw boss.

12. The vacuum pump of claim 11, wherein the labyrinth gap communicates with the outlet port, the labyrinth gap including a pressure reducing section including an expanding section and a contracting section connected to the expanding section, the expanding section being downstream of the contracting section in the path of the outlet port exhaust gas flowing toward the chamber-side seal screw boss, such that the gas is reduced in pressure after passing through the contracting section and the expanding section in order.

13. The vacuum pump of claim 11, wherein the labyrinth seal collar is disposed radially of the rotor with the air outlet radially outward of the labyrinth seal collar.

14. A vacuum pump according to any one of claims 10 to 13, wherein the suction end seal comprises a seal collar comprising a collar body extending axially of the rotor and an end plate at one end of the collar body, the end plate being fitted over the rotor and secured to the end of the chamber side seal screw boss facing the rotor chamber, the suction end cap comprising a collar mating portion extending into the collar body for clearance fit with the inner wall surface of the collar body.