Sealing structure of oil-free screw compressor for fuel cell

Abstract

The utility model relates to the field of sealing devices, in particular to a sealing structure of an oil-free screw compressor for a fuel cell, which comprises a high-pressure side air seal, a low-pressure side air seal, a fixing ring and an oil seal, the high-pressure side air seal and the low-pressure side air seal are arranged in a compression cavity along the length of the compression cavity, and the low-pressure side air seal is close to an oil cavity; the fixing ring is arranged in the shell and corresponds to the part between the oil cavity and the compression cavity; the oil seal is arranged in the oil cavity; the gap between the high-pressure side air seal and the rotating shaft and the gap between the low-pressure side air seal and the rotating shaft are smaller than the gap between the part between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft. By means of the design, under the condition that the gear, the bearing and other parts are fully lubricated, clean gas is provided, it is guaranteed that gas from the compressor is free of oil, the industry requirement is met, and the energy-saving and pollution-reducing effects are achieved.

Description

Technical Field

[0001] The utility model relates to the field of sealing devices, in particular to a sealing structure of an oil-free screw compressor for a fuel cell. Background Art

[0002] The pair of rotors of the oil-free screw compressor for fuel cells are not in direct contact, and there is a certain gap between them. The male rotor drives the female rotor to rotate through the synchronous gear. The so-called "oil-free" means that the gas does not come into contact with oil at all during the compression process, but the bearings, synchronous gears and other parts of the compressor still need to be lubricated with lubricating oil. The rotating shaft in the traditional compressor needs to fit in the oil chamber at one end and in the compression chamber at the other end. Therefore, the oil chamber and the compression chamber need to be sealed respectively in the form of gas seals and seals. However, gas is easy to leak, and single-stage gas seals and seals still have the risk of gas leakage or lubricating oil in the oil chamber leaking into the compression chamber, affecting the purity of the gas. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a sealing structure of an oil-free screw compressor for a fuel cell which adopts a multi-stage sealing design and improves the sealing performance.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is: a sealing structure of an oil-free screw compressor for a fuel cell, which is arranged in a shell of the compressor, and an oil chamber and a compression chamber are sequentially arranged in the shell of the compressor along its length direction, and a rotating shaft passing through the oil chamber and the compression chamber is arranged in the shell of the compressor, including a high-pressure side air seal, a low-pressure side air seal, a fixing ring and an oil seal, and a high-pressure side air seal and a low-pressure side air seal are arranged in the compression chamber along its length, and the low-pressure side air seal is close to the oil chamber; the fixing ring is arranged in the portion corresponding to the oil chamber and the compression chamber in the shell; the oil seal is arranged in the oil chamber; the gap between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft is smaller than the gap between the portion between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft.

[0005] Furthermore, it also includes a spacer ring, a spacer ring is provided between the high-pressure side air seal and the low-pressure side air seal, and the gap between the spacer ring and the rotating shaft is larger than the gap between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft.

[0006] Furthermore, it also includes a wave spring, and the wave spring is connected to the inner wall of the compression chamber on the side of the high-pressure side air seal away from the partition ring.

[0007] Furthermore, a wave spring is connected to the spacer ring on one side of the low-pressure side air seal close to the spacer ring.

[0008] Furthermore, a sealing member is provided between the fixing ring and the inner wall of the shell.

[0009] Furthermore, the inner wall of the shell is provided with a channel communicating with the outside, and the channel is opposite to a side of the fixing ring close to the inner wall of the shell.

[0010] Furthermore, the oil seal is a double-lip oil seal.

[0011] Further, the oil seal includes a first lip and a second lip, the first lip faces a side of the fixing ring, and the second lip faces a side away from the fixing ring.

[0012] Furthermore, a plurality of through holes are provided on the inner wall of the shell body opposite to the fixing ring, and the plurality of through holes are all connected to the channel.

[0013] Furthermore, a groove is provided on the inner wall of the shell body opposite to the fixing ring, and the channel is communicated with the groove.

[0014] The beneficial effects of the utility model are: a multi-stage seal is formed for the hydrogen in the compression chamber through the high-pressure side air seal and the low-pressure side air seal, and a throttling effect is produced by the design of the gap between the high-pressure side air seal and the low-pressure side air seal and the part between them and the rotating shaft. The throttling and pressure reduction effect prevents the hydrogen in the compression chamber from flowing into the oil chamber; the lubricating oil in the oil chamber is sealed by the oil seal on the fixed ring to prevent the lubricating oil in the oil chamber from flowing into the compression chamber. The above design can ensure that the gears and bearings and other parts are fully lubricated, provide clean gas, ensure that the gas coming out of the compressor is oil-free, meet industry requirements, and achieve the effect of energy saving and pollution reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the sealing structure of an oil-free screw compressor for a fuel cell according to a specific embodiment of the utility model.

[0016] Description of labels:

[0017] 1. Shell; 2. Oil chamber; 3. Compression chamber; 4. High-pressure side air seal; 5. Low-pressure side air seal; 6. Fixed ring; 7. Oil seal; 8. Spacer ring; 9. Wave spring; 10. Seal; 11. Channel; 12. Groove. DETAILED DESCRIPTION

[0018] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0019] Please refer to Figure 1A sealing structure of an oil-free screw compressor for a fuel cell is provided in a housing 1 of the compressor, wherein an oil chamber 2 and a compression chamber 3 are sequentially arranged in the housing 1 of the compressor along its length direction, a rotating shaft passing through the oil chamber 2 and the compression chamber 3 is arranged in the housing 1 of the compressor, and the structure comprises a high-pressure side gas seal 4, a low-pressure side gas seal 5, a fixing ring 6 and an oil seal 7, a high-pressure side gas seal 4 and a low-pressure side gas seal 5 are arranged in the compression chamber 3 along its length, and the low-pressure side gas seal 5 is close to the oil chamber 2; the fixing ring 6 is arranged in the housing 1 corresponding to the portion between the oil chamber 2 and the compression chamber 3; the oil seal 7 is arranged in the oil chamber 2; the gap between the high-pressure side gas seal 4 and the low-pressure side gas seal 5 and the rotating shaft is smaller than the gap between the portion between the high-pressure side gas seal 4 and the low-pressure side gas seal 5 and the rotating shaft.

[0020] From the above description, it can be seen that the beneficial effects of the utility model are: a multi-stage seal is formed for the hydrogen in the compression chamber 3 through the high-pressure side gas seal 4 and the low-pressure side gas seal 5, and a throttling effect is produced by the design of the gap between the high-pressure side gas seal 4 and the low-pressure side gas seal 5 and the part between them and the rotating shaft, and the hydrogen in the compression chamber 3 is prevented from flowing into the oil chamber 2 through the throttling and pressure reduction effect; the lubricating oil in the oil chamber 2 is sealed by the oil seal 7 on the fixed ring 6, and the lubricating oil in the oil chamber 2 is prevented from flowing into the compression chamber 3. The above design can ensure that the gears and bearings and other parts are fully lubricated, provide clean gas, ensure that the gas coming out of the compressor is oil-free, meet industry requirements, and achieve the effect of energy saving and pollution reduction.

[0021] Furthermore, it also includes a spacer ring 8, a spacer ring 8 is provided between the high-pressure side gas seal 4 and the low-pressure side gas seal 5, and the gap between the spacer ring 8 and the rotating shaft is larger than the gap between the high-pressure side gas seal 4 and the low-pressure side gas seal 5 and the rotating shaft.

[0022] From the above description, it can be seen that the spacer ring 8 is used as a partition structure between the high-pressure side gas seal 4 and the low-pressure side gas seal 5. At the same time, by designing the gap between the spacer ring 8 and the rotating shaft, matching the gap design between the high-pressure side gas seal 4 and the low-pressure side gas seal 5 and the rotating shaft, a throttling effect is formed, which effectively prevents the gas in the compression chamber 3 from leaking into the oil chamber 2.

[0023] Furthermore, a wave spring 9 is included. The wave spring 9 is connected to the inner wall of the compression chamber 3 on the side of the high-pressure side gas seal 4 away from the partition ring 8 .

[0024] From the above description, it can be seen that the design of the wave spring 9 can utilize the gas pressure and its elastic force to make the contact surface between the high-pressure side gas seal 4 and the spacer ring 8 fit tightly, thereby preventing the gas from leaking radially along the high-pressure side gas seal 4 and increasing the friction between the high-pressure side gas seal 4 and the spacer ring 8, thereby preventing the high-pressure side gas seal 4 from rotating.

[0025] Furthermore, a wave spring 9 is connected to the spacer ring 8 at one side of the low-pressure side air seal 5 close to the spacer ring 8 .

[0026] From the above description, it can be seen that the design of the wave spring 9 can utilize the gas pressure and its elastic force to make the contact surface between the low-pressure side gas seal 5 and the fixed ring 6 fit tightly, prevent the gas from leaking radially along the low-pressure side gas seal 5 and increase the friction between the low-pressure side gas seal 5 and the fixed ring 6, thereby preventing the low-pressure side gas seal 5 from rotating.

[0027] Furthermore, a sealing member 10 is provided between the fixing ring 6 and the inner wall of the housing 1 .

[0028] It can be seen from the above description that the design of the sealing member 10 prevents gas from leaking from the contact surface between the fixing ring 6 and the housing 1 .

[0029] Furthermore, a channel 11 communicating with the outside is provided on the inner wall of the shell 1 , and the channel 11 is opposite to a surface of the fixing ring 6 close to the inner wall of the shell 1 .

[0030] From the above description, it can be seen that in the case of failure of the air seal and the oil seal 7 to cause leakage, the gas leaked from the compression chamber 3 is prevented from leaking into the oil chamber 2 and the lubricating oil leaked from the oil chamber 2 is prevented from leaking into the compression chamber 3. The design of the channel 11 can discharge the leaked gas and lubricating oil to the outside.

[0031] Furthermore, the oil seal 7 is a double-lip oil seal 7.

[0032] As can be seen from the above description, the design of the compound lip oil seal 7 prevents impurities in the atmosphere from entering the housing 1 through the channel 11 and damaging the oil seal 7, causing it to lose its sealing effect; the multi-lip oil seal 7 ensures reliable sealing and dustproofing.

[0033] Furthermore, the oil seal 7 includes a first lip and a second lip, wherein the first lip faces a side of the fixing ring 6 , and the second lip faces a side away from the fixing ring 6 .

[0034] From the above description, it can be seen that the first lip serves as a dustproof lip. When installed, its lip faces the fixing ring 6 to ensure that atmospheric impurities that may be introduced into the channel 11 are blocked, while the second lip serves as a sealing lip to block the lubricating oil in the oil chamber 2 and prevent it from leaking into the compression chamber 3.

[0035] Furthermore, a plurality of through holes are provided on the inner wall of the housing 1 opposite to the fixing ring 6 , and the plurality of through holes are all connected to the channel 11 .

[0036] It can be seen from the above description that the design of multiple through holes on the inner wall of the housing 1 can improve the ability to recover and discharge the leaked gas or lubricating oil.

[0037] Furthermore, a groove 12 is provided on the inner wall of the housing 1 opposite to the fixing ring 6 , and the channel 11 is connected to the groove 12 .

[0038] It can be seen from the above description that the design of the groove 12 on the inner wall of the housing 1 can ensure that the leaked gas or lubricating oil can be quickly collected and discharged through the channel 11 .

[0039] Reference Figure 1 , Embodiment 1:

[0040] Application scenario: In a traditional compressor, the rotating shaft needs to fit in the oil chamber 2 at one end and in the compression chamber 3 at the other end, so it is necessary to use gas seals and seals to seal the oil chamber 2 and the compression chamber 3 respectively. However, gas is easy to leak, and single-stage gas seals and seals still have the risk of gas leakage or lubricating oil in the oil chamber 2 leaking into the compression chamber 3, affecting the purity of the gas.

[0041] like Figure 1 As shown, the sealing structure of the oil-free screw compressor for a fuel cell of this embodiment is arranged in a housing 1 of the compressor, and an oil chamber 2 and a compression chamber 3 are sequentially arranged in the housing 1 of the compressor along its length direction. A rotating shaft passing through the oil chamber 2 and the compression chamber 3 is arranged in the housing 1 of the compressor, and the sealing structure includes a high-pressure side air seal 4, a low-pressure side air seal 5, a fixing ring 6, a spacer ring 8, an oil seal 7 and a wave spring 9.

[0042] The compression chamber 3 is provided with a high-pressure side gas seal 4 and a low-pressure side gas seal 5 along its length, and the low-pressure side gas seal 5 is close to the oil chamber 2; the fixing ring 6 is provided in the housing 1 corresponding to the portion between the oil chamber 2 and the compression chamber 3; the oil seal 7 is provided in the oil chamber 2; a spacer ring 8 is provided between the high-pressure side gas seal 4 and the low-pressure side gas seal 5; the gap between the spacer ring 8 and the rotating shaft is greater than the gap between the high-pressure side gas seal 4 and the low-pressure side gas seal 5 and the rotating shaft. Since there is a gap between the above-mentioned gas seal and the rotating shaft, solid friction is avoided, and it can be applied to the case where the compressor runs at high speed.

[0043] A multi-stage gas seal is formed by the low-pressure side gas seal 5 and the high-pressure side gas seal 4 to prevent the gas in the compression chamber 3 from leaking into the oil chamber 2. The gap between the spacer ring 8 and the rotating shaft and the gap between the above-mentioned gas seal and the rotating shaft are designed to form a throttling effect to further improve the gas sealing effect. The oil seal 7 is designed to prevent the lubricating oil in the oil chamber 2 from leaking into the compression chamber 3.

[0044] The side of the high-pressure side gas seal 4 away from the spacer ring 8 is connected to the inner wall of the compression chamber 3 with a wave spring 9; the side of the low-pressure side gas seal 5 close to the spacer ring 8 is connected to the spacer ring 8 with a wave spring 9. The wave spring 9 design can make the high-pressure side gas seal 4 and the spacer ring 8 fit tightly, and the low-pressure side gas seal 5 and the fixed ring 6 fit tightly through gas pressure and its own spring, thereby improving the gas sealing effect and preventing rotation.

[0045] A seal 10 is provided between the fixing ring 6 and the inner wall of the housing 1. The seal 10 is designed to prevent gas from leaking from the contact surface between the fixing ring 6 and the inner wall of the housing 1.

[0046] The inner wall of the housing 1 is provided with a channel 11 connected to the outside, and the channel 11 is opposite to a side of the fixing ring 6 close to the inner wall of the housing 1. The channel 11 is close to the side of the oil chamber 2. A groove 12 is provided on the inner wall of the housing 1 opposite to the fixing ring 6, and a plurality of through holes are provided in the groove 12, and the plurality of through holes are connected to the channel 11. Through the design of the channel 11, the groove 12 and the through holes, the leakage of gas and lubricating oil can be recovered and discharged.

[0047] The oil seal 7 is a compound lip oil seal 7. The oil seal 7 includes a first lip and a second lip, wherein the first lip faces the side of the fixing ring 6, and the second lip faces the side away from the fixing ring 6. The design of the compound lip oil seal 7 can prevent atmospheric impurities from invading through the channel 11 and causing the oil seal 7 to fail, and can also achieve good sealing of the oil chamber 2.

[0048] In summary, the sealing structure of the oil-free screw compressor for fuel cells provided by the utility model forms a multi-stage seal for the hydrogen in the compression chamber through the high-pressure side air seal and the low-pressure side air seal, and at the same time utilizes the design of the high-pressure side air seal and the low-pressure side air seal and the gap between the parts and the rotating shaft to produce a throttling effect, and through the throttling and pressure reduction effect, the hydrogen in the compression chamber is prevented from flowing into the oil chamber; the lubricating oil in the oil chamber is sealed by the oil seal on the fixed ring, and the lubricating oil in the oil chamber is prevented from flowing into the compression chamber. The above design can provide clean gas while ensuring that parts such as gears and bearings are fully lubricated, and ensure that the gas coming out of the compressor is oil-free, meet industry requirements, and achieve the effect of energy saving and pollution reduction.

[0049] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A sealing structure of an oil-free screw compressor for a fuel cell, which is arranged in a housing of the compressor, wherein an oil chamber and a compression chamber are sequentially arranged in the housing of the compressor along its length direction, and a rotating shaft passing through the oil chamber and the compression chamber is arranged in the housing of the compressor, characterized in that: It includes a high-pressure side air seal, a low-pressure side air seal, a fixed ring and an oil seal. The compression chamber is provided with a high-pressure side air seal and a low-pressure side air seal along its length, and the low-pressure side air seal is close to the oil chamber; the fixed ring is arranged in the portion between the corresponding oil chamber and the compression chamber in the shell; the oil seal is arranged in the oil chamber; the gap between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft is smaller than the gap between the portion between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft.

2. The sealing structure of the oil-free screw compressor for fuel cells according to claim 1, characterized in that: It also includes a spacer ring, which is arranged between the high-pressure side air seal and the low-pressure side air seal, and the gap between the spacer ring and the rotating shaft is larger than the gap between the high-pressure side air seal and the low-pressure side air seal and the rotating shaft.

3. The sealing structure of the oil-free screw compressor for fuel cells according to claim 2, characterized in that: It also includes a wave spring, and the wave spring is connected to the inner wall of the compression chamber on the side of the high-pressure side air seal away from the partition ring.

4. The sealing structure of the oil-free screw compressor for fuel cells according to claim 3, characterized in that: A wave spring is connected to the spacer ring at one side of the low-pressure side air seal close to the spacer ring.

5. The sealing structure of the oil-free screw compressor for fuel cells according to claim 1, characterized in that: A sealing member is arranged between the fixing ring and the inner wall of the shell.

6. The sealing structure of the oil-free screw compressor for fuel cells according to claim 1, characterized in that: The inner wall of the shell is provided with a channel communicating with the outside, and the channel is opposite to a side of the fixing ring close to the inner wall of the shell.

7. The sealing structure of the oil-free screw compressor for fuel cells according to claim 6, characterized in that: The oil seal is a compound lip oil seal.

8. The sealing structure of the oil-free screw compressor for fuel cells according to claim 7, characterized in that: The oil seal includes a first lip portion and a second lip portion, wherein the first lip portion faces a side of the fixing ring, and the second lip portion faces a side away from the fixing ring.

9. The sealing structure of the oil-free screw compressor for fuel cells according to claim 6, characterized in that: A plurality of through holes are arranged on the inner wall of the shell body opposite to the fixing ring, and the plurality of through holes are all communicated with the channel.

10. The sealing structure of the oil-free screw compressor for fuel cells according to claim 6, characterized in that: A groove is provided on the inner wall of the shell body opposite to the fixing ring, and the channel is communicated with the groove.

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