Dry friction mechanical sealing structure for screw vacuum pump

Abstract

The utility model discloses a dry friction mechanical seal structure for a screw vacuum pump, which relates to the technical field of screw vacuum pumps and comprises a transmission gear, the inner wall of the transmission gear is fixedly connected with a rotor shaft, the surface of the rotor shaft is sleeved with a bearing and a dry friction mechanical seal shaft sleeve, the surface of the bearing is provided with a bearing seat, and the dry friction mechanical seal shaft sleeve is sleeved with a dry friction mechanical seal shaft sleeve. The surface of the bearing seat is sleeved with a gear oil tank, the surface of the dry friction mechanical seal shaft sleeve is provided with a dry friction mechanical seal moving ring part, and the surface of the dry friction mechanical seal moving ring part is provided with a dry friction mechanical seal static ring part. The screw vacuum pump has the advantages that the screw vacuum pump can pump medium gas and can also serve as a compressor to convey pressure gas, in the actual using process, the screw vacuum pump replaces a traditional framework oil seal and a labyrinth seal, the screw vacuum pump can serve as a vacuum pump and can also serve as the compressor, and the exhaust pressure can reach 0.5 kg.

Description

Technical Field

[0001] The utility model relates to the technical field of screw vacuum pumps, in particular to a dry friction mechanical seal structure for a screw vacuum pump. Background Art

[0002] A screw vacuum pump is a gas extraction device that uses a pair of screws to rotate synchronously and at high speed in opposite directions in a pump casing to generate suction and exhaust effects. It is an updated product of oil-sealed vacuum pumps and can extract gases containing a large amount of water vapor and a small amount of dust. It is widely used in domestic enterprises such as pharmaceuticals, chemicals, and semiconductors that have high requirements for clean vacuum.

[0003] For example, a mechanical seal structure for an oil-free screw vacuum pump disclosed in the patent with the publication number CN220850033U. Although the beneficial effects of this utility model are: by clamping the clamping plate between the two arms of the U-shaped plate, and then clamping the two convex rods into the two L-shaped card slots, and then placing the airbag between the connecting plate and the machine body, and clamping the two convex strips into the grooves on the connecting plate and the machine body respectively, and then the user injects gas into the conduit using an air pump to make the airbag expand, and then the airbag will squeeze the connecting plate away from the machine body, making the clamping plate abut against the U-shaped plate and making the two convex rods move to the other end of the L-shaped card slot, so as to limit the connecting plate and make the airbag seal the housing, so that the housing can be quickly disassembled and assembled, which is convenient for the user to use; however, the currently commonly used screw vacuum pumps in the above patent are all skeleton oil seals or labyrinth seals, which will generate a relatively high exhaust temperature during operation, not only accelerating the aging of the sealing material, resulting in a decrease in its elasticity and sealing performance, especially for the skeleton oil seal, the oil inside it is prone to leakage problems at high temperatures.

[0004] In view of the above problems, the utility model provides a dry friction mechanical seal structure for a screw vacuum pump. Content of the Utility Model

[0005] The purpose of the utility model is to provide a dry friction mechanical seal structure for a screw vacuum pump. During the actual use process, the utility model replaces the traditional skeleton oil seal and labyrinth seal, enabling the screw vacuum pump to act as both a vacuum pump and a compressor. The exhaust pressure can reach 0.5 kg / cm². The utility model adopts dry friction sealing for the sealing surface when the screw shaft rotates at high speed. Due to the gas or liquid pumped in, a gas film or liquid film is generated, separating the sealing friction surfaces, avoiding the situation of high-temperature vaporization of lubricating oil caused by relative friction between the sealing surfaces and leakage, and enabling the screw vacuum pump to work under a positive inlet pressure, acting as a compressor to transport chemical medium gases, thus solving the problems in the background art.

[0006] To achieve the above object, the present utility model provides the following technical solution: A dry friction mechanical seal structure for a screw vacuum pump, including a transmission gear, an inner wall of the transmission gear is fixedly connected to a rotor shaft, a bearing and a dry friction mechanical seal sleeve are sleeved on a surface of the rotor shaft, a bearing seat is arranged on a surface of the bearing, a gear oil tank is sleeved on a surface of the bearing seat, a dry friction mechanical seal dynamic ring part is arranged on a surface of the dry friction mechanical seal sleeve, a dry friction mechanical seal static ring part is arranged on a surface of the dry friction mechanical seal dynamic ring part, a transmission pin is commonly penetrated through one side of the dry friction mechanical seal dynamic ring part and the dry friction mechanical seal sleeve, and the dry friction mechanical seal dynamic ring part and the dry friction mechanical seal sleeve are fixedly connected through the transmission pin. A labyrinth seal is sleeved on the surface of the rotor shaft and on the left side of the dry friction mechanical seal sleeve. A pump body is sleeved on surfaces of the bearing seat and the dry friction mechanical seal static ring part. A labyrinth seal seat is arranged on the left side of the pump body on a surface of the labyrinth seal. A medium gas seal cavity is formed between the labyrinth seal seat and the dry friction mechanical seal static ring part. An O-ring I is arranged on a surface of the bearing seat, and a surface of the O-ring I is in contact with the pump body.

[0007] The dry friction mechanical seal dynamic ring part includes a sealing weir, and a logarithmic spiral groove group I and a logarithmic spiral groove group II are opened on one side of the sealing weir.

[0008] Further, a connecting screw I and a connecting screw II are commonly penetrated through one side of the bearing seat and the dry friction mechanical seal static ring part. The O-ring I and the dry friction mechanical seal static ring part are fixedly connected through the connecting screw I, and a lock nut is arranged on a surface of the connecting screw II.

[0009] Further, an O-ring II is sleeved on one side of the dry friction mechanical seal static ring part, and one side of the O-ring II is in contact with the bearing seat.

[0010] Further, an O-ring III is arranged on an inner wall of the dry friction mechanical seal sleeve, and the O-ring III is sleeved on a surface of the rotor shaft.

[0011] Further, a circulating cooling water hole is opened at a top of the pump body. A cooling water cavity is formed between the pump body, the dry friction mechanical seal static ring part and the labyrinth seal seat, and the circulating cooling water hole is communicated with the cooling water cavity.

[0012] Further, an O-ring IV is sleeved on a surface of the dry friction mechanical seal static ring part, and a surface of the O-ring IV is in contact with the labyrinth seal seat.

[0013] Further, an O-ring V is arranged on one side of the labyrinth seal seat, and a surface of the O-ring V is in contact with the pump body.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] A dry friction mechanical seal structure for a screw vacuum pump provided by the present utility model has the advantages that the screw vacuum pump can not only pump and transport medium gas but also act as a compressor to transport pressurized gas. During actual use, the present utility model replaces the traditional skeleton oil seal and labyrinth seal, enabling the screw vacuum pump to serve as both a vacuum pump and a compressor. The exhaust pressure can reach 0.5 kg. The present utility model uses a dry friction seal for the sealing surface when the screw shaft rotates at high speed. Due to the gas film or liquid film generated by the pumped gas or liquid, the sealing friction surface is separated, avoiding the situation of high-temperature vaporization of lubricating oil caused by relative friction between the sealing surfaces and leakage, and enabling the screw vacuum pump to work under a positive inlet pressure and act as a compressor to transport chemical medium gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the present utility model;

[0017] Figure 2 In the present utility model Figure 1 is a partial enlarged view of A;

[0018] Figure 3 is a partial structural side sectional view of the dynamic ring part of the dry friction mechanical seal in the present utility model.

[0019] In the figure: 1, driving gear; 2, locking nut; 3, rotor shaft; 4, bearing; 5, O-ring I; 6, bearing housing; 7, connecting screw I; 8, O-ring II; 9, static ring part of dry friction mechanical seal; 10, dynamic ring part of dry friction mechanical seal; 101, logarithmic spiral groove group I; 102, sealing weir; 103, logarithmic spiral groove group II; 11, O-ring III; 12, dry friction mechanical seal shaft sleeve; 13, driving pin; 14, labyrinth seal; 15, pump body; 16, gear oil tank; 17, circulating cooling water hole; 18, cooling water cavity; 19, O-ring IV; 20, O-ring V; 21, medium gas sealing cavity; 22, labyrinth seal seat; 23, connecting screw II. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] To solve the technical problems, as Figures 1-3 shown, the following preferred technical solutions are provided:

[0022] A dry friction mechanical seal structure for a screw vacuum pump, comprising a transmission gear 1. The inner wall of the transmission gear 1 is fixedly connected to a rotor shaft 3. A bearing 4 and a dry friction mechanical seal sleeve 12 are sleeved on the surface of the rotor shaft 3. A bearing seat 6 is arranged on the surface of the bearing 4. A gear oil tank 16 is sleeved on the surface of the bearing seat 6. A dry friction mechanical seal dynamic ring part 10 is arranged on the surface of the dry friction mechanical seal sleeve 12. A dry friction mechanical seal static ring part 9 is arranged on the surface of the dry friction mechanical seal dynamic ring part 10. A transmission pin 13 is commonly penetrated through one side of the dry friction mechanical seal dynamic ring part 10 and the dry friction mechanical seal sleeve 12. And the dry friction mechanical seal dynamic ring part 10 and the dry friction mechanical seal sleeve 12 are fixedly connected through the transmission pin 13. A labyrinth seal 14 is sleeved on the surface of the rotor shaft 3 and on the left side of the dry friction mechanical seal sleeve 12. A pump body 15 is commonly sleeved on the surfaces of the bearing seat 6 and the dry friction mechanical seal static ring part 9. A labyrinth seal seat 22 is arranged on the surface of the labyrinth seal 14 and on the left side of the pump body 15. A medium gas seal cavity 21 is formed between the labyrinth seal seat 22 and the dry friction mechanical seal static ring part 9. An O-ring one 5 is arranged on the surface of the bearing seat 6. The surface of the O-ring one 5 is in contact with the pump body 15.

[0023] The dry friction mechanical seal dynamic ring part 10 includes a seal weir 102. A logarithmic spiral groove group one 101 and a logarithmic spiral groove group two 103 are opened on one side of the seal weir 102.

[0024] A connecting screw one 7 and a connecting screw two 23 are commonly penetrated through one side of the bearing seat 6 and the dry friction mechanical seal static ring part 9. The O-ring one 5 and the dry friction mechanical seal static ring part 9 are fixedly connected through the connecting screw one 7. A lock nut 2 is arranged on the surface of the connecting screw two 23. Through the combined use of the connecting screw one 7 and the connecting screw two 23, a fixed connection is formed between the bearing seat 6 and the dry friction mechanical seal static ring part 9. And when the dry friction mechanical seal static ring part 9 rotates, the bearing seat 6 will also be driven to rotate.

[0025] An O-ring two 8 is sleeved on one side of the dry friction mechanical seal static ring part 9. One side of the O-ring two 8 is in contact with the bearing seat 6. Through the arrangement of the O-ring two 8, the function of sealing the bearing seat 6 and the dry friction mechanical seal static ring part 9 is achieved, avoiding the situation of gas entering.

[0026] An O-ring three 11 is arranged on the inner wall of the dry friction mechanical seal sleeve 12. The O-ring three 11 is sleeved on the surface of the rotor shaft 3. Through the arrangement of the O-ring three 11, the function of sealing between the rotor shaft 3 and the dry friction mechanical seal sleeve 12 is achieved, and thus the function of improving the rotation safety of the rotor shaft 3 and the dry friction mechanical seal sleeve 12 is facilitated.

[0027] A circulating cooling water hole 17 is provided at the top of the pump body 15. A cooling water chamber 18 is formed between the pump body 15, the static ring part 9 of the dry friction mechanical seal, and the labyrinth seal seat 22, and the circulating cooling water hole 17 communicates with the cooling water chamber 18. Through the combined use of the circulating cooling water hole 17 and the cooling water chamber 18, the cooling water enters the inner cavity of the cooling water chamber 18 through the circulating cooling water hole 17, effectively preventing the seal from being deformed due to high temperature.

[0028] An O-ring IV 19 is sleeved on the surface of the static ring part 9 of the dry friction mechanical seal, and the surface of the O-ring IV 19 contacts the labyrinth seal seat 22. Through the setting of the O-ring IV 19, the situation that the cooling water in the inner cavity of the cooling water chamber 18 enters the inner cavity of the medium gas seal chamber 21 is avoided, effectively achieving the purpose of separating the cooling water from the medium gas.

[0029] An O-ring V 20 is provided on one side of the labyrinth seal seat 22, and the surface of the O-ring V 20 contacts the pump body 15. Through the setting of the O-ring V 20, it plays a role in increasing the sealing performance between the pump body 15 and the labyrinth seal seat 22, and provides auxiliary sealing to prevent the cooling water from leaking into the inner cavity of the medium gas seal chamber 21.

[0030] Working principle: The static ring part 9 of the dry friction mechanical seal is fixed to the end face of the bearing housing 6 by connecting screw one 7 and connecting screw two 23, and sealed with O-ring two 8. With the setting of O-ring four 19, it effectively prevents cooling water from entering the inner cavity of the medium gas seal chamber 21. The dynamic ring part 10 of the dry friction mechanical seal and the dry friction mechanical seal sleeve 12 are integrally sleeved on the surface of the rotor shaft 3. The static ring part 9 of the dry friction mechanical seal is fixed on the bearing housing 6 with connecting screw one 7 and pressed in, and then connecting screw two 23 is tightened, and the locking nut 2 is locked. At this time, one end of the dry friction mechanical seal sleeve 12 abuts against the surface of the rotor shaft 3, and the other end presses the rotor shaft 3 through the bearing 4, so that the bearing 4 presses tightly against the dry friction mechanical seal sleeve 12 and the rotor shaft 3 to rotate at a high speed synchronously. Therefore, the dry friction mechanical seal has nothing to do with pressure during operation, thus realizing the sealing of the process medium gas by the mechanical seal. The static ring part 9 of the dry friction mechanical seal and the bearing housing 6 are fixed by connecting screw one 7 and connecting screw two 23, and sealed with O-ring one 5 and O-ring two 8. They are pressed tightly at both ends of the end face by the bearing 4 and the labyrinth seal 14 and locked by the locking nut 2. They rotate at a high speed with the rotor shaft 3. On the dynamic ring sealing surface of the dynamic ring part 10 of the dry friction mechanical seal, a group of logarithmic spiral grooves one 101 and a group of logarithmic spiral grooves two 103 are laser processed along the inner and outer circumferences. The dynamic ring part 10 of the dry friction mechanical seal and the static ring part 9 of the dry friction mechanical seal rotate relatively at a high speed to generate a pumping effect to suck in the sealing gas to form a gas film seal, avoiding contact friction between the sealing surfaces. The gear oil in the gear oil tank 16 is drawn into the bearing housing 6 by the transmission gear 1 and flows in to cool and lubricate the static ring part 9 and the dynamic ring part 10 of the dry friction mechanical seal, so that the screw vacuum pump can not only pump the medium gas but also act as a compressor to transport the pressurized gas.

[0031] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0032] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dry friction mechanical seal structure for a screw vacuum pump, comprising a transmission gear (1), characterized in that: The inner wall of the transmission gear (1) is fixedly connected to a rotor shaft (3); a bearing (4) and a dry friction mechanical seal sleeve (12) are sleeved on the surface of the rotor shaft (3); a bearing seat (6) is provided on the surface of the bearing (4); a gear oil tank (16) is sleeved on the surface of the bearing seat (6); a dry friction mechanical seal moving ring portion (10) is provided on the surface of the dry friction mechanical seal sleeve (12); a dry friction mechanical seal stationary ring portion (9) is provided on the surface of the dry friction mechanical seal moving ring portion (10); a transmission pin (13) is provided through one side of the dry friction mechanical seal moving ring portion (10) and the dry friction mechanical seal sleeve (12); and the dry friction mechanical seal moving ring portion (10) and the dry friction mechanical seal sleeve (12) are provided with a transmission pin (13) and the dry friction mechanical seal moving ring portion (10) and the dry friction mechanical seal moving ring portion (12) are provided with a transmission pin (13) through one side of the dry friction mechanical seal moving ring portion (10). 10) and the dry friction mechanical seal sleeve (12) are fixedly connected via a transmission pin (13); a labyrinth seal (14) is sleeved on the surface of the rotor shaft (3) and located on the left side of the dry friction mechanical seal sleeve (12); a pump body (15) is sleeved on the surfaces of the bearing seat (6) and the stationary ring portion (9) of the dry friction mechanical seal; a labyrinth seal seat (22) is sleeved on the surface of the labyrinth seal (14) and located on the left side of the pump body (15); a medium gas sealing chamber (21) is formed between the labyrinth seal seat (22) and the stationary ring portion (9) of the dry friction mechanical seal; an O-ring (5) is provided on the surface of the bearing seat (6); and the surface of the O-ring (5) is in contact with the pump body (15); The dry friction mechanical seal dynamic ring part (10) comprises a sealing weir (102), and one side of the sealing weir (102) is provided with a logarithmic spiral groove group 1 (101) and a logarithmic spiral groove group 2 (103).

2. A dry friction mechanical seal structure for a screw vacuum pump according to claim 1, characterized in that: The bearing seat (6) and one side of the dry friction mechanical seal static ring part (9) are jointly penetrated by a connecting screw 1 (7) and a connecting screw 2 (23); the O-ring 1 (5) and the dry friction mechanical seal static ring part (9) are fixedly connected by the connecting screw 1 (7); and a locking nut (2) is provided on the surface of the connecting screw 2 (23).

3. The dry friction mechanical seal structure for a screw vacuum pump according to claim 1, characterized in that: One side of the dry friction mechanical seal stationary ring part (9) is sleeved with an O-ring 2 (8), and one side of the O-ring 2 (8) is in contact with the bearing seat (6).

4. The dry friction mechanical seal structure for a screw vacuum pump according to claim 1, characterized in that: The inner wall of the dry friction mechanical seal sleeve (12) is provided with an O-ring three (11), and the O-ring three (11) is sleeved on the surface of the rotor shaft (3).

5. The dry friction mechanical seal structure for a screw vacuum pump according to claim 1, characterized in that: A circulating cooling water hole (17) is provided at the top of the pump body (15), a cooling water cavity (18) is formed between the pump body (15), the stationary ring part (9) of the dry friction mechanical seal, and the labyrinth seal seat (22), and the circulating cooling water hole (17) and the cooling water cavity (18) are connected.

6. The dry friction mechanical seal structure for a screw vacuum pump according to claim 1, characterized in that: The surface of the stationary ring part (9) of the dry friction mechanical seal is sleeved with an O-ring four (19), and the surface of the O-ring four (19) is in contact with the labyrinth seal seat (22).

7. The dry friction mechanical seal structure for a screw vacuum pump according to claim 1, characterized in that: An O-ring five (20) is provided on one side of the labyrinth seal seat (22), and the surface of the O-ring five (20) is in contact with the pump body (15).

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