An air compressor and a double oil seal sealing structure at the outlet shaft end thereof

Abstract

The present invention relates to a shaft sealing structure of an air compressor, in particular to an air compressor and a double oil seal sealing structure of an output shaft end thereof, comprising a rotating shaft, a shaft seat, an oil seal sleeve, a first oil seal, a second oil seal and an oil seal seat; the rotating shaft is rotatably arranged on the shaft seat, the oil seal seat is fixedly arranged on the outer side of the shaft seat, and the output end of the rotating shaft extends outward through the shaft seat and the oil seal seat; an oil seal sleeve is coated on the output end of the rotating shaft, and the first oil seal and the second oil seal are coated on the oil seal sleeve from the inside to the outside; the first oil seal and the second oil seal are arranged in the oil seal seat; an annular first cavity is formed between the oil seal sleeve, the first oil seal, the second oil seal and the oil seal seat; a second cavity is formed between the inner side of the oil seal seat and the shaft seat, an oil inlet hole is arranged on the inner side of the oil seal seat, and the oil inlet hole is connected to the first cavity and the second cavity; an oil outlet hole is arranged at the bottom of the first cavity. This patent effectively reduces the pressure acting on the oil seal and prolongs the service life of the oil seal.

Description

Technical Field

[0001] The invention relates to a shaft sealing structure of an air compressor, in particular to an air compressor and a double oil seal sealing structure of an outlet shaft end thereof. Background Art

[0002] At present, due to the market and energy and environmental protection needs, the requirements for the quality of air compressors and the environmental protection performance of equipment are getting higher and higher. Machines with low life and low environmental protection performance can only be eliminated. The seal between the main engine and the motor of the existing oil-injected screw air compressor is mainly sealed by oil seals, but the simple oil seal sealing method is prone to oil seal failure and oil leakage. The leaked oil directly enters the motor, affecting the normal operation of the motor and causing motor failure. In addition, due to the friction heat generated by the continuous rotation of the main engine's screw rotor and the heat transfer generated during the compression process, the temperature at the oil seal position continues to rise, affecting the life of the oil seal and the sealing effect. In the second-stage oil seal of the two-stage compression screw structure, the oil seal has a continuous pressure on the lip during normal operation, and the friction resistance is greater, which makes it easier for the oil seal to fail and leak.

[0003] Existing sealing structures, such as the Chinese utility model patent (publication number: CN208364787U, publication date: 20190111), disclose a screw compressor shaft sealing structure, which includes a rotating shaft, an oil seal sleeve covering the rotating shaft, a main oil seal and a secondary oil seal covering the rotating shaft, and an oil seal seat covering the main oil seal and the secondary oil seal, a static seal is formed between the oil seal sleeve and the rotating shaft, the oil seal seat is arranged on the outer surface of the oil seal sleeve, the main oil seal, the secondary oil seal and the oil seal seat all form a static seal, a cavity is formed between the main oil seal, the oil seal seat and the oil seal sleeve, the oil seal seat has a hole channel connected to the outside and a through hole connected to the inside, and the hole channel of the oil seal seat is connected to the cavity via the through hole of the oil seal seat. The utility model has a simple structure, strong adaptability, low cost and convenient installation. In harsh environmental conditions or when compressing toxic media, this structure can achieve effective sealing. Once a leak occurs, the leaked material can be recovered and processed, greatly improving environmental friendliness.

[0004] However, in the above structure, since the inner side of the main oil seal is subjected to continuous pressure when the compressor is working, the oil seal may fail and leak oil. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide an air compressor and a double oil seal sealing structure for its output shaft end, by arranging two layers of oil seals, and arranging a cavity between the two layers of oil seals, and the inner side of the first oil seal is connected with the cavity through an oil inlet hole, so as to reduce the pressure inside the machine, extend the life of the first oil seal, and ensure the reliability of the second oil seal.

[0006] For the purpose of the present invention, the following technical solutions are adopted to implement:

[0007] A double oil seal sealing structure for an output shaft end of an air compressor comprises a rotating shaft, a shaft seat, an oil seal sleeve, a first oil seal, a second oil seal and an oil seal seat; the rotating shaft is rotatably arranged on the shaft seat, the oil seal seat is fixedly arranged on the outer side of the shaft seat, and the output end of the rotating shaft extends outward through the shaft seat and the oil seal seat; an oil seal sleeve is coated on the output end of the rotating shaft, and a first oil seal and a second oil seal are coated on the oil seal sleeve from the inside to the outside; the first oil seal and the second oil seal are arranged in the oil seal seat; a first annular cavity is formed between the oil seal sleeve, the first oil seal, the second oil seal and the oil seal seat; a second cavity is formed between the inner side of the oil seal seat and the shaft seat, an oil inlet hole is arranged on the inner side of the oil seal seat, and the oil inlet hole connects the first cavity and the second cavity; an oil outlet hole is arranged at the bottom of the first cavity, and the oil outlet hole is used to pass the oil-gas mixture back to the low-pressure end of the air compressor suction port.

[0008] Preferably, the rotating shaft is rotatably arranged on the shaft seat via a bearing.

[0009] Preferably, the bearing and the oil seal sleeve are separated by a spacer sleeve.

[0010] Preferably, the diameter of the oil inlet end of the oil inlet hole is 8 mm, and the diameter of the oil outlet end is 1.5 mm.

[0011] Preferably, the diameter of the oil outlet hole is 6 mm.

[0012] Preferably, a first positioning hole for positioning the first oil seal and a second positioning hole for positioning the second oil seal are provided on the inner side of the oil seal seat, and the first positioning hole and the second positioning hole are separated by a receiving hole.

[0013] Preferably, an inner hole is provided along the axial inner side of the first positioning hole, and the inner hole is communicated with the second cavity.

[0014] Preferably, an outer hole is arranged along the axial outer side of the second positioning hole, and a channel extending downward with an outlet located at the lower part of the oil seal seat is arranged at the bottom of the outer hole; the channel is used to suck the oil leaked from the second oil seal back into the air compressor head.

[0015] Preferably, a dust ring is provided at the connection between the outer end of the oil seal seat and the rotating shaft.

[0016] An air compressor, the shaft outlet end sealing structure of the air compressor adopts the above-mentioned double oil seal sealing structure of the shaft outlet end of the air compressor.

[0017] In summary, the advantages of the present invention are: the oil-gas mixture with continuous working pressure in the second cavity acts on the first oil seal, and the oil-gas mixture in the second cavity enters the first cavity through the oil inlet hole to achieve the effect of reducing pressure, and the shape of the oil inlet hole plays a role of intercepting flow. At the same time, the oil-gas mixture entering the first cavity provides the second oil seal with compressed oil for lubrication and cooling, ensuring the operational reliability of the second oil seal and extending its service life. An anti-leakage oil return device is set at the outlet end of the channel to ensure that the leaked oil can be sucked back into the machine head after the second oil seal is damaged, and does not flow to the outside to affect the quality of the machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a cross-sectional view of the sealing structure at the shaft end of the air compressor. DETAILED DESCRIPTION

[0019] An air compressor, the shaft outlet end sealing structure of the air compressor adopts the following double oil seal sealing structure of the shaft outlet end of the air compressor.

[0020] like Figure 1 As shown, a double oil seal sealing structure of the output shaft end of an air compressor includes a rotating shaft 1, a shaft seat 2, an oil seal sleeve 3, a first oil seal 4, a second oil seal 5 and an oil seal seat 6. The rotating shaft 1 is rotatably set on the shaft seat 2 through a bearing 11. The oil seal seat 6 is fixedly set on the outer side of the shaft seat 2, and the output end of the rotating shaft 1 extends outward through the shaft seat 2 and the oil seal seat 6. A dust ring 9 is set at the connection between the outer end of the oil seal seat 6 and the rotating shaft 1. The oil seal sleeve 3 is coated on the output end of the rotating shaft 1, and the bearing 11 and the oil seal sleeve 3 are separated by a spacer sleeve 12. The first oil seal 4 and the second oil seal 5 are coated on the oil seal sleeve 3 from the inside to the outside. The first oil seal 4 and the second oil seal 5 are set in the oil seal seat 6. An annular first cavity 7 is formed between the oil seal sleeve 3, the first oil seal 4, the second oil seal 5 and the oil seal seat 6. A second cavity 8 is formed between the inner side of the oil seal seat 6 and the shaft seat 2. An oil inlet hole 61 is provided on the inner side of the oil seal seat 6. The oil inlet hole 61 connects the first cavity 7 and the second cavity 8. The oil inlet end diameter of the oil inlet hole 61 is 8 mm, and the oil outlet end diameter is 1.5 mm, which plays a role of interception. An oil outlet hole 62 is provided at the bottom of the first cavity 7. The oil outlet hole 62 is used to pass the oil-gas mixture back to the low-pressure end of the air compressor suction port. The diameter of the oil outlet hole 62 is 6 mm.

[0021] A first positioning hole for positioning the first oil seal 4 and a second positioning hole for positioning the second oil seal 5 are provided inside the oil seal seat 6, and the first positioning hole and the second positioning hole are separated by a receiving hole 63. An inner hole 64 is provided inside the axial direction of the first positioning hole, and the inner hole 64 is connected to the second cavity 8. An outer hole 65 is provided outside the axial direction of the second positioning hole, and a channel 66 extending downward and having an outlet located at the bottom of the oil seal seat 6 is provided at the bottom of the outer hole 65. The channel 66 is used to suck the oil leaked from the second oil seal 5 back into the air compressor head.

[0022] When the machine is running, the oil-gas mixture with continuous working pressure in the second cavity 8 acts on the first oil seal 4. The oil-gas mixture in the second cavity 8 enters the first cavity 7 through the oil inlet hole 61 to achieve the effect of reducing pressure. The shape of the oil inlet hole 61 plays a role of interception. At the same time, the oil-gas mixture entering the first cavity 7 provides the second oil seal 5 with compressed oil for lubrication and cooling, ensuring the operating reliability of the second oil seal 5 and extending its service life. An anti-leakage oil return device is set at the outlet end of the channel 66 to ensure that the leaked oil can be sucked back into the machine head after the second oil seal 5 is damaged, and does not flow outside to affect the quality of the machine.

[0023] This structure is suitable for the shaft seal of the second-stage head of a two-stage compression machine. Compared with the first stage, the second stage has a continuous working pressure during operation, which can easily greatly reduce the service life of the oil seal. This structure can effectively reduce the pressure on the oil seal, extend the service life of the oil seal, and ensure the reliability of the machine operation.

Claims

1. A double oil seal sealing structure at the shaft end of an air compressor, comprising a rotating shaft (1), a shaft seat (2), an oil seal sleeve (3), a first oil seal (4), a second oil seal (5) and an oil seal seat (6); characterized in that: The rotating shaft (1) is rotatably arranged on the shaft seat (2) via a bearing (11); an oil seal seat (6) is fixedly arranged on the outer side of the shaft seat (2); the output end of the rotating shaft (1) passes through the shaft seat (2) and the oil seal seat (6) and extends outward; an oil seal sleeve (3) is arranged on the output end of the rotating shaft (1); a first oil seal (4) and a second oil seal (5) are arranged on the oil seal sleeve (3) from the inside to the outside; the first oil seal (4) and the second oil seal (5) are arranged in the oil seal seat (6); the oil seal shaft An annular first cavity (7) is formed between the sleeve (3), the first oil seal (4), the second oil seal (5) and the oil seal seat (6); a second cavity (8) is formed between the inner side of the oil seal seat (6) and the shaft seat (2); an oil inlet hole (61) is provided on the inner side of the oil seal seat (6), and the oil inlet hole (61) communicates with the first cavity (7) and the second cavity (8); an oil outlet hole (62) is provided at the bottom of the first cavity (7), and the oil outlet hole (62) is used to pass the oil-gas mixture back to the low-pressure end of the air compressor suction port; A first positioning hole for positioning the first oil seal (4) and a second positioning hole for positioning the second oil seal (5) are provided on the inner side of the oil seal seat (6), and the first positioning hole and the second positioning hole are separated by a receiving hole (63); an inner hole (64) is provided on the inner side of the first positioning hole along the axial direction, and the inner hole (64) is communicated with the second cavity (8).

2. A double oil seal sealing structure at the outlet shaft end of an air compressor according to claim 1, characterized in that: The bearing (11) and the oil seal sleeve (3) are separated by a spacer sleeve (12).

3. The double oil seal sealing structure of the air compressor output shaft end according to claim 1, characterized in that: The diameter of the oil inlet end of the oil inlet hole (61) is 8 mm, and the diameter of the oil outlet end is 1.5 mm.

4. The double oil seal sealing structure of the air compressor output shaft end according to claim 1, characterized in that: The oil outlet hole (62) has a diameter of 6 mm.

5. The double oil seal sealing structure of the air compressor output shaft end according to claim 1, characterized in that: An outer hole (65) is provided along the axial outer side of the second positioning hole, and a channel (66) extending downward and having an outlet located at the lower part of the oil seal seat (6) is provided at the bottom of the outer hole (65); the channel (66) is used to absorb oil leaking from the second oil seal (5) back into the air compressor head.

6. The double oil seal sealing structure of the air compressor output shaft end according to claim 1, characterized in that: A dust ring (9) is provided at the connection between the outer end of the oil seal seat (6) and the rotating shaft (1).

7. An air compressor, characterized in that: The air compressor shaft outlet end sealing structure adopts the double oil seal sealing structure of the air compressor shaft outlet end as described in any one of claims 1 to 6.

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