Shaft seal leaked oil collecting structure and screw compressor

Abstract

The utility model discloses a shaft seal oil leakage collecting structure and a screw compressor, the shaft seal oil leakage collecting structure comprises a shaft seal gland, a shaft seal assembly and an oil return pipeline, the shaft seal gland is installed on the outer end face of a shaft hole of a main machine body of the compressor, a rotor of the screw compressor is installed in the shaft hole, and a shaft sleeve outside the rotor is arranged opposite to the shaft seal gland. A lubricating oil flowing path is formed between the shaft seal assembly and the shaft seal assembly, the shaft seal assembly comprises a double-lip shaft seal and a dustproof and oilproof shaft seal, the double-lip shaft seal and the dustproof and oilproof shaft seal are arranged in the lubricating oil flowing path in a spaced mode, two sealing lip pieces in the same direction are arranged on the inner end face of the double-lip shaft seal, and two sealing lip pieces arranged oppositely are arranged on the inner end face of the dustproof and oilproof shaft seal. A lubricating oil collecting pipeline is arranged in the shaft seal gland and the main machine body and used for collecting lubricating oil leaked from the double-lip shaft seal, and the leaked lubricating oil is conveyed into the main machine body through the oil return pipeline. The leaked oil collecting structure for the shaft seal can greatly reduce the risk of oil leakage of the main machine shaft seal of the compressor.

Description

Technical Field

[0001] The utility model specifically relates to a shaft seal oil leakage collection structure and a screw compressor comprising the shaft seal oil leakage collection structure. Background Art

[0002] Screw compressors are the mainstream general equipment for providing compressed air on the market, and are widely used in steel, electricity, metallurgy, shipbuilding, textiles, electronics, chemicals, petroleum, mining, light industry, machinery manufacturing, papermaking and printing, transportation facilities, food, casting and spraying, shipping terminals, technology, automobile industry, aerospace, infrastructure and other fields. The main engine is the core component of the screw compressor, and the stability and operating efficiency of the main engine directly determine the quality of the compressor.

[0003] The shaft seal in the main engine is a consumable part that needs to be replaced regularly. It is also a wearing part. If the size processing deviation of the shaft sleeve, shaft seal gland, etc. is too large, or the lip of the shaft seal is scratched by foreign objects during assembly, the shaft seal may fail in a short time, resulting in oil leakage. Although a slight oil leakage of the shaft seal does not affect the normal use of the compressor, the leaked oil accumulates on the compressor chassis, affecting the user's intuitive impression. Moreover, if the oil seal leaks seriously and the shaft seal is not replaced in time, the compressor will be short of oil and shut down due to high temperature, affecting the normal production of the factory. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a shaft seal oil leakage collection structure and a screw compressor including the shaft seal oil leakage collection structure in view of the above-mentioned deficiencies in the prior art. The shaft seal oil leakage collection structure can greatly reduce the risk of oil leakage of the compressor host shaft seal, and can collect and reuse the lubricating oil leaked from the double-lip shaft seal.

[0005] In order to solve the above problems, the utility model adopts the following technical solutions:

[0006] A shaft seal oil leakage collection structure comprises a shaft seal gland, a shaft seal assembly and an oil return pipeline, wherein the shaft seal gland is mounted on the outer end face of the shaft hole of the main body of the screw compressor, the rotor of the screw compressor is mounted in the shaft hole through a bearing, the shaft sleeve outside the rotor is arranged opposite to the shaft seal gland, and the gap between the two forms a lubricating oil flow path, the shaft seal assembly comprises a double-lip shaft seal and a dust-proof and oil-proof shaft seal, the double-lip shaft seal and the dust-proof and oil-proof shaft seal are arranged at intervals in the lubricating oil flow path, and the dust-proof and oil-proof shaft seal is located outside the double-lip shaft seal, the outer end faces of the double-lip shaft seal and the dust-proof and oil-proof shaft seal are both mounted on the inner side face of the shaft seal gland, and two sealing lips in the same direction are arranged on the inner end face of the double-lip shaft seal, and the bottom end of the sealing lip is aligned with the outer side of the shaft sleeve. Side contact is used to prevent lubricating oil leakage; two sealing lips arranged opposite to each other are provided on the inner end face of the dust-proof and oil-proof shaft seal, the bottom ends of the sealing lips are in contact with the outer side face of the shaft sleeve, the sealing lip close to the shaft hole opening is used to prevent external pollutants from entering the shaft hole, and the sealing lip close to the inside of the shaft hole is used to prevent oil leaking from the double-lip shaft seal from flowing out of the shaft hole; a lubricating oil collecting pipeline is provided inside the shaft seal gland and the main engine body, and the inlet end of the lubricating oil collecting pipeline is connected to the lubricating oil flow path between the double-lip shaft seal and the dust-proof and oil-proof shaft seal; the return oil pipeline includes a connecting pipe, which is connected to the outlet end of the lubricating oil collecting pipeline, and the outlet end is connected to the air inlet of the main engine body, so as to re-transport the leaked lubricating oil to the main engine body.

[0007] Preferably, the top of the sealing lip is fixedly mounted on the bottom of the double-lip shaft seal or the dust-proof and oil-proof shaft seal, and extends downwardly and tilts, turning in the middle to increase the inclination angle, and its bottom end abuts against the outer surface of the shaft sleeve; wherein the two sealing lips of the double-lip shaft seal and a sealing lip of the dust-proof and oil-proof shaft seal close to the inside of the shaft hole have the same inclination direction; a sealing lip of the dust-proof and oil-proof shaft seal close to the shaft hole opening is inclined in the opposite direction.

[0008] Preferably, the sealing lip is made of PTFE material.

[0009] Preferably, the lubricating oil collecting pipeline is located at the bottom of the shaft seal gland and the main engine body.

[0010] Preferably, the lubricating oil collecting pipeline includes a first pipeline, a second pipeline and a sealing unit; the first pipeline is located inside the shaft seal gland, and the second pipeline is located inside the main engine body; the first pipeline includes a first vertical pipe, a first horizontal pipe, a second vertical pipe, and a second horizontal pipe, and the sealing unit includes a first spherical plug and a second spherical plug, the input end of the first vertical pipe is connected to the lubricating oil flow path between the double lip shaft seal and the dust and oil proof shaft seal, and its output end is connected to the first horizontal pipe, the first horizontal pipe extends outward in a horizontal direction and is connected to the outside world, the second vertical pipe is connected to the first horizontal pipe, extends downward and is connected to the outside world, the input end of the second horizontal pipe is connected to the second vertical pipe, and the output end is connected to the second pipeline, and when the lubricating oil collecting pipeline is working, the first spherical plug blocks the external opening of the first horizontal pipe, and the second spherical plug blocks the external opening of the second vertical pipe.

[0011] Preferably, the oil return pipeline also includes an oil return one-way valve, which is installed on the connecting pipe to ensure that the lubricating oil can only flow from the outlet end of the lubricating oil collection pipeline to the air inlet of the main engine body.

[0012] Preferably, the oil return pipeline further includes a quick connector, the input end of the connecting pipe is connected to the outlet of the second pipeline through the quick connector, and the output end thereof is connected to the air inlet of the main engine body through the quick connector.

[0013] Preferably, the shaft seal oil leakage collection structure also includes a limit assembly, the limit assembly includes a first elastic retaining ring and a second elastic retaining ring, the shaft seal gland is provided with a first convex portion, a second convex portion, a first groove and a second groove, the first elastic retaining ring is installed in the first groove, the second elastic retaining ring is installed in the second groove, the double lip shaft seal is installed between the first elastic retaining ring and the first convex portion, and its two sides are respectively abutted against the first elastic retaining ring and the first convex portion; the dust and oil proof shaft seal is installed between the second elastic retaining ring and the second convex portion, and its two sides are respectively abutted against the second elastic retaining ring and the second convex portion.

[0014] Preferably, the shaft seal oil leakage collection structure further comprises a sealing assembly, wherein the sealing assembly comprises a plurality of sealing rings, and the plurality of sealing rings are arranged at the connection between the main engine body and the shaft seal gland.

[0015] The utility model also provides a screw compressor, comprising a main engine body, a rotor, and the above-mentioned shaft seal oil leakage collection structure.

[0016] The shaft seal oil leakage collection structure in the utility model can effectively prevent lubricating oil leakage through the combined effect of the double-lip shaft seal and the oil-proof and dust-proof shaft seal, thereby reducing the oil leakage risk of the compressor main engine shaft seal; even if the double-lip shaft seal leaks, the oil-proof and dust-proof shaft seal can prevent the lubricating oil from leaking to the outside of the compressor. In addition, the lubricating oil collection pipeline in the shaft seal oil leakage collection structure can collect the lubricating oil leaking from the double-lip shaft seal and transport it to the air inlet of the compressor, thereby reusing the lubricating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional structural diagram of the screw compressor in Embodiment 2 of the present utility model;

[0018] Figure 2 It is a front view of the screw compressor in Embodiment 2 of the present utility model;

[0019] Figure 3 yes Figure 2 Sectional view of the AA section;

[0020] Figure 4 yes Figure 2 Sectional view of the middle BB section;

[0021] Figure 5 This is a front view of the shaft seal gland of the shaft seal oil leakage collection structure in Example 1 of the utility model;

[0022] Figure 6 It is a cross-sectional view of the shaft seal gland of the shaft seal oil leakage collection structure in Example 1 of the utility model;

[0023] Figure 7 It is a three-dimensional diagram of the shaft seal gland of the shaft seal oil leakage collection structure in Example 1 of the utility model;

[0024] Figure 8 This is a front view of the double-lip shaft seal of the shaft seal oil leakage collection structure in Example 1 of the utility model;

[0025] Fig. 9 is a cross-sectional view of a double-lip shaft seal of the shaft seal oil leakage collection structure in Example 1 of the utility model;

[0026] Fig.10 This is a front view of the dust and oil proof shaft seal of the shaft seal oil leakage collection structure in Example 1 of the utility model;

[0027] Fig.11 It is a cross-sectional view of the dust and oil proof shaft seal of the shaft seal oil leakage collection structure in Example 1 of the utility model.

[0028] In the figure: 100-main body, 110-shaft hole, 120-air inlet, 130-rotor, 140-shaft sleeve, 150-bearing, 200-shaft seal cover, 210-first elastic retaining ring, 220-second elastic retaining ring, 230-third elastic retaining ring, 300-double-lip shaft seal, 310-dust and oil-proof shaft seal, 400-first vertical pipe, 410-first horizontal pipe, 420-second vertical pipe, 430-second horizontal pipe, 440-first spherical plug, 450-second spherical plug, 460-second pipeline, 500-connecting screws, 600-connecting pipe, 610-oil return one-way valve, 700-first O-ring, 710-second O-ring. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the utility model to clearly and completely describe the technical solution in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the utility model.

[0030] In the description of the present invention, it should be noted that the directions or positional relationships indicated by “upper” and the like are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as a limitation on the present invention.

[0031] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connection", "setting", "installation", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0033] The utility model provides a shaft seal oil leakage collection structure, comprising a shaft seal gland, a shaft seal assembly, and an oil return pipeline, wherein the shaft seal gland is mounted on the outer end surface of the shaft hole of the main engine body of the screw compressor, the rotor of the screw compressor is mounted in the shaft hole through a bearing, the shaft sleeve outside the rotor is arranged opposite to the shaft seal gland, and the gap between the two forms a lubricating oil flow path, the shaft seal assembly comprises a double-lip shaft seal and a dust-proof and oil-proof shaft seal, the double-lip shaft seal and the dust-proof and oil-proof shaft seal are arranged at intervals in the lubricating oil flow path, and the dust-proof and oil-proof shaft seal is located outside the double-lip shaft seal, the outer end surfaces of the double-lip shaft seal and the dust-proof and oil-proof shaft seal are both mounted on the inner side surface of the shaft seal gland, and the inner end surface of the double-lip shaft seal is provided with two sealing lips in the same direction, and the bottom end of the sealing lip is aligned with the shaft The outer side surface of the sleeve is used to prevent the lubricating oil from leaking; two sealing lips arranged opposite to each other are provided on the inner end surface of the dust and oil proof shaft seal, the bottom ends of the sealing lips are in contact with the outer side surface of the shaft sleeve, the sealing lip close to the shaft hole opening is used to prevent external pollutants from entering the shaft hole, and the sealing lip close to the inside of the shaft hole is used to prevent the oil leaking from the double-lip shaft seal from flowing out of the shaft hole; a lubricating oil collecting pipeline is provided inside the shaft seal gland and the main engine body, and the inlet end of the lubricating oil collecting pipeline is connected to the lubricating oil flow path between the double-lip shaft seal and the dust and oil proof shaft seal; the return oil pipeline includes a connecting pipe, which is connected to the outlet end of the lubricating oil collecting pipeline, and the outlet end is connected to the air inlet of the main engine body, so as to re-transport the leaked lubricating oil to the main engine body.

[0034] The utility model also provides a screw compressor, comprising a main engine body, a rotor, and the above-mentioned shaft seal oil leakage collection structure.

[0035] Example 1

[0036] like Figure 1-6 As shown, this embodiment discloses a shaft seal oil leakage collection structure, which is suitable for a screw compressor, and includes a shaft seal gland 200, a shaft seal assembly, and an oil return pipeline. The shaft seal gland 200 is installed on the outer end surface of the shaft hole 110 of the main body 100 of the screw compressor, and the rotor 130 of the screw compressor is installed in the shaft hole 110 through a bearing 150. The shaft sleeve 140 outside the rotor 130 is arranged opposite to the shaft seal gland 200, and the gap between the two forms a lubricating oil flow path (horizontal direction).

[0037] like Figure 3 , 9As shown in the present embodiment, the shaft seal assembly includes a double-lip shaft seal 300 and a dust-proof and oil-proof shaft seal 310. Both the double-lip shaft seal 300 and the dust-proof and oil-proof shaft seal 310 are annular structures, and both are arranged in the lubricating oil flow path along the axial direction of the rotor 130 at intervals. Compared with the double-lip shaft seal 300, the dust-proof and oil-proof shaft seal 310 is closer to the opening of the shaft hole 110. The outer end faces (outer rings) of the double-lip shaft seal 300 and the dust-proof and oil-proof shaft seal 310 are both installed on the inner side face (inner ring) of the shaft seal gland 200. Two sealing lips in the same direction are arranged on the inner end face of the double-lip shaft seal 300. The bottom ends of the sealing lips are in contact with the outer side face of the shaft sleeve 140 to prevent the lubricating oil from flowing out of the shaft hole 110 (such as Figure 3 to prevent the lubricating oil from flowing from right to left).

[0038] like Figure 3 , 11 As shown, in this embodiment, two sealing lips arranged opposite to each other are provided on the inner end surface of the dust and oil proof shaft seal 310, the bottom end of the sealing lip is in contact with the outer side surface (outer ring) of the shaft sleeve 140, and the sealing lip close to the opening of the shaft hole 110 is used to prevent external pollutants from entering the shaft hole 110 (such as Figure 3 As shown, it is used to prevent foreign matter from entering the lubricating oil flow path from left to right), and the sealing lip near the inside of the shaft hole 110 is used to prevent the oil leaking from the double-lip shaft seal 300 from flowing out of the shaft hole 110 (as shown Figure 3 As shown, it is used to prevent the lubricating oil from flowing from right to left).

[0039] like Figure 3 As shown, a lubricating oil collecting pipeline is provided inside the shaft seal gland 200 and the main engine body 100, and the inlet end of the lubricating oil collecting pipeline is communicated with the lubricating oil flow path between the double lip shaft seal 300 and the dust and oil proof shaft seal 310. The return oil pipeline includes a connecting pipe 600, which is connected to the outlet end of the lubricating oil collecting pipeline, and the outlet end is communicated with the air inlet 120 of the main engine body 100, and is used to re-transport the leaked lubricating oil into the main engine body 100. After the lubricating oil leaks from the double lip shaft seal 300 to the position between the double lip shaft seal 300 and the dust and oil proof shaft seal 310, the leaked lubricating oil is collected by the lubricating oil collecting pipeline and flows along the connecting pipe 600 to the air inlet 120 of the main engine body 100.

[0040] like Figure 3 , 4As shown in Figures 9 and 10, the top of the sealing lip is fixedly mounted on the bottom of the double-lip shaft seal 300 or the dust-proof and oil-proof shaft seal 310, and extends downwardly and tilts, turning from the middle to increase the tilt angle, and the bottom end of the sealing lip abuts against the outer side (outer ring) of the shaft sleeve 140. The two sealing lips of the double-lip shaft seal 300 and the sealing lip of the dust-proof and oil-proof shaft seal 310 near the inside of the shaft hole 110 have the same tilt direction (tilted toward the inside of the shaft hole 110), and are both used to prevent lubricating oil leakage; the sealing lip of the dust-proof and oil-proof shaft seal 310 near the opening of the shaft hole 110 is tilted in the opposite direction (tilted toward the opening of the shaft hole 110), and is used to prevent foreign matter from entering the inside of the shaft hole 110. The sealing lip is made of PTFE material.

[0041] like Figure 3 As shown, the lubricating oil collecting pipeline is located at the bottom of the shaft seal gland 200 and the main engine body 100 .

[0042] like Figure 3 As shown, specifically, the lubricating oil collection pipeline includes a first pipeline, a second pipeline 460 and a plugging unit. The first pipeline is located inside the shaft seal gland 200, and the second pipeline 460 is located inside the mainframe 100. The first pipeline includes a first vertical pipe 400, a first horizontal pipe 410, a second vertical pipe 420, and a second horizontal pipe 430. The plugging unit includes a first spherical plug 440 and a second spherical plug 450. The first vertical pipe 400 is vertically arranged, and its input end is connected to the lubricating oil flow path between the double lip shaft seal 300 and the dust and oil proof shaft seal 310, and its output end is connected to the first horizontal pipe 410. The first horizontal pipe 410 extends outward in the horizontal direction and is connected to the outside world. The second vertical pipe 420 is vertically arranged, and its top is connected to the middle part of the first horizontal pipe 410, and extends downward to be connected to the outside world. The second horizontal pipe 430 is horizontally arranged, and its input end is connected to the middle part of the second vertical pipe 420, and its output end is connected to the second pipeline 460. The second pipeline 460 is L-shaped, with its input end being opened on the outer end surface of the axial hole of the host body 100, and its output end being opened on the bottom of the host body 100, and having threads processed inside the output end.

[0043] In order to facilitate the processing of the first transverse pipe 410 and the second vertical pipe 420, the first transverse pipe 410 and the second vertical pipe 420 are in a form of being connected to the outside. When the lubricating oil collecting pipeline is working, the first spherical plug 440 blocks the external opening of the first transverse pipe 410, and the second spherical plug 450 blocks the external opening of the second vertical pipe 420. The leaked lubricating oil flows along the first vertical pipe 400, the first transverse pipe 410, the second vertical pipe 420, the second transverse pipe 430, and the second pipeline 460, and finally flows back to the host body 100 along the connecting pipe 600.

[0044] like Figure 1As shown, in this embodiment, the return oil pipeline also includes a return oil one-way valve 610, which is installed on the connecting pipe 600 to ensure that the lubricating oil can only flow from the outlet end of the lubricating oil collection pipeline to the air inlet 120 of the main body 100 to prevent the lubricating oil from flowing in the opposite direction.

[0045] Optionally, the oil return line also includes a quick connector, the input end of the connecting pipe 600 is connected to the internal thread of the outlet of the second pipeline 460 through the quick connector, and the output end thereof is connected to the air inlet 120 of the main body 100 through the quick connector. The connecting pipe 600 is made of stainless steel pipe, and the quick connector is made of steel pipe joint.

[0046] like Figure 3 As shown, the shaft seal oil leakage collection structure also includes a limit assembly, which includes a first elastic retaining ring 210 and a second elastic retaining ring 220. The inner side (inner ring) of the shaft seal gland 200 is provided with a first convex portion, a second convex portion, a first groove and a second groove. The first elastic retaining ring 210 is installed in the first groove, and the second elastic retaining ring 220 is installed in the second groove. The double-lip shaft seal 300 is installed between the first elastic retaining ring 210 and the first convex portion, and its two sides are respectively against the first elastic retaining ring 210 and the first convex portion; the dustproof and oilproof shaft seal 310 is installed between the second elastic retaining ring 220 and the second convex portion, and its two sides are respectively against the second elastic retaining ring 220 and the second convex portion. The first elastic retaining ring 210 and the first convex portion are used to fix the position of the double-lip shaft seal 300 to prevent the double-lip shaft seal 300 from axial movement; the second elastic retaining ring 220 and the second convex portion are used to fix the position of the dustproof and oilproof shaft seal 310 to prevent the dustproof and oilproof shaft seal 310 from axial movement.

[0047] like Figure 3 , 4 As shown, the shaft seal oil leakage collection structure also includes a sealing assembly, which includes a plurality of sealing rings, and the plurality of sealing rings are arranged at the connection between the main engine body 100 and the shaft seal gland 200 .

[0048] Specifically, the cross section of the shaft seal gland 200 is L-shaped, including a vertical section and a horizontal section. The vertical section is attached to the outer end surface of the shaft hole 110 of the mainframe 100 and is fixedly connected to the mainframe 100 by a connecting screw 500. The horizontal section is inserted into the shaft hole 110, and a third groove is provided on the outer end surface of the horizontal section. A first O-type sealing ring 700 is provided in the third groove to prevent lubricating oil leakage. In addition, a second O-type sealing ring 710 is also provided at the connection between the output end of the second pipeline 460 and the second transverse pipe 430 to prevent lubricating oil leakage.

[0049] Specifically, during assembly, the top of the double-lip shaft seal 300 and the top of the dust-proof and oil-proof shaft seal 310 are coated with sealant and adhered to the inner side of the shaft seal gland 200 through the sealant. When the compressor main engine is in operation, the double-lip shaft seal 300 and the dust-proof and oil-proof shaft seal 310 are fixed, so that no leakage occurs at the connection between them and the shaft seal gland 200, and the inner rings of the double-lip shaft seal 300 and the dust-proof and oil-proof shaft seal 310 (the bottom end of the sealing lip) are in contact with the sleeve 140 to form a seal. The sleeve 140 rotates at high speed with the rotor 130, and the double-lip shaft seal 300 and the dust-proof and oil-proof shaft seal 310 are connected to the main engine body 100 through the shaft seal gland 200. Once the sealing lip of the double-lip shaft seal 300 is damaged, the lubricating oil will leak to the left from the gap between the sleeve 140 and the sealing lip of the double-lip shaft seal 300, and enter the position between the double-lip shaft seal 300 and the dust-proof and oil-proof shaft seal 310. If no lubricating oil collection pipeline is provided on the shaft seal gland 200, and if no dust and oil proof shaft seal 310 is provided, the lubricating oil leaking from the double lip shaft seal 300 will flow directly to the base frame of the compressor under the action of gravity. The high-speed rotation of the rotor 130 during operation will also cause some of the infiltrated lubricating oil to splash, resulting in some areas inside the compressor casing being filled with leaked lubricating oil.

[0050] Therefore, the shaft seal oil leakage collection structure in this embodiment can effectively avoid lubricating oil leakage and reduce the oil leakage risk of the compressor main engine shaft seal through the combined effect of the double-lip shaft seal 300 and the oil-proof and dust-proof shaft seal. Specifically, the two sealing lips of the double-lip shaft seal 300 are used to prevent lubricating oil leakage; even if the double-lip shaft seal 300 leaks, the sealing lip on the inside of the dust-proof and oil-proof shaft seal 310 can play a secondary sealing role to prevent lubricating oil from leaking to the outside; the sealing lip on the outside of the dust-proof and oil-proof shaft seal 310 can play a dust-proof role. In addition, the lubricating oil collection pipeline in the shaft seal oil leakage collection structure can collect the lubricating oil leaked from the double-lip shaft seal 300 and transport it to the air inlet 120 of the compressor, thereby reusing the lubricating oil.

[0051] Example 2

[0052] This embodiment discloses a screw compressor, including a main body 100, a rotor 130, and also includes the shaft seal oil leakage collection structure in Embodiment 1.

[0053] like Figure 1 , 2 As shown, in this embodiment, an air inlet 120 is provided on the top of the main body 100, a cylindrical roller bearing is provided inside the shaft hole of the main body 100, and a rotor 130 and a sleeve 140 are rotatably mounted on the cylindrical roller bearing. A third groove is provided on the inner surface of the shaft hole 110, and a third elastic retaining ring 230 is installed in the third groove. The third elastic retaining ring 230 is abutted against the outside of the cylindrical roller bearing to prevent the cylindrical roller bearing from moving axially.

[0054] When the screw compressor is working, a negative pressure condition will occur at the air inlet 120, thereby sucking the outside gas into the compressor from the air inlet 120, and the driving mechanism drives the rotor 130 to rotate, thereby compressing the sucked gas. In this process, the lubricating oil flows from the inside of the shaft hole 110 to the outside of the shaft hole 110 along the axial direction of the rotor 130, lubricating and cooling the cylindrical roller bearing and the rotor 130. The negative pressure condition of the air inlet 120 is conducive to adsorbing the lubricating oil in the lubricating oil collection pipeline to the air inlet 120 of the main body 100, thereby realizing the recovery function of the leaked lubricating oil to reduce the risk of oil leakage from the main body's shaft seal.

[0055] The screw compressor in this embodiment can effectively avoid lubricating oil leakage and reduce the oil leakage risk of the compressor main engine shaft seal through the combined effect of the double-lip shaft seal 300 and the oil-proof and dust-proof shaft seal. Even if oil leakage occurs, the lubricating oil collection pipeline in the shaft seal leakage collection structure can collect the lubricating oil leaked from the double-lip shaft seal 300 and transport it to the air inlet 120 of the compressor, thereby reusing the lubricating oil and improving the utilization efficiency of the lubricating oil.

[0056] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A shaft seal oil leakage collection structure, characterized in that: It includes a shaft seal gland (200), a shaft seal assembly, and an oil return pipeline. The shaft seal gland (200) is mounted on the outer end surface of the shaft hole (110) of the main body (100) of the screw compressor. The rotor (130) of the screw compressor is mounted in the shaft hole (110) via a bearing (150). The shaft sleeve (140) outside the rotor (130) is arranged opposite to the shaft seal gland (200). The gap between the two forms a lubricating oil flow path. The shaft seal assembly comprises a double-lip shaft seal (300) and a dust-proof and oil-proof shaft seal (310). The double-lip shaft seal (300) and the dust-proof and oil-proof shaft seal (310) are arranged at intervals in the lubricating oil flow path, and the dust-proof and oil-proof shaft seal (310) is located outside the double-lip shaft seal (300). The outer end faces of the double-lip shaft seal (300) and the dust-proof and oil-proof shaft seal (310) are both mounted on the inner side face of the shaft seal gland (200); two sealing lips in the same direction are arranged on the inner end face of the double-lip shaft seal (300); the bottom ends of the sealing lips are in contact with the outer side face of the shaft sleeve (140) to prevent lubricating oil leakage; two sealing lips arranged opposite to each other are arranged on the inner end face of the dust-proof and oil-proof shaft seal (310); the bottom ends of the sealing lips are in contact with the outer side face of the shaft sleeve (140); the sealing lip close to the opening of the shaft hole (110) is used to prevent external pollutants from entering the shaft hole (110); and the sealing lip close to the inside of the shaft hole (110) is used to prevent oil leaking from the double-lip shaft seal (300) from flowing out of the shaft hole (110); A lubricating oil collecting pipeline is provided inside the shaft seal gland (200) and the main engine body (100), and the inlet end of the lubricating oil collecting pipeline is connected to the lubricating oil flow path between the double-lip shaft seal (300) and the dust and oil proof shaft seal (310); the oil return pipeline comprises a connecting pipe (600), and the connecting pipe (600) is connected to the outlet end of the lubricating oil collecting pipeline, and the outlet end is connected to the air inlet (120) of the main engine body (100), so as to transport the leaked lubricating oil back to the main engine body (100).

2. The shaft seal oil leakage collection structure according to claim 1, characterized in that: The top of the sealing lip is fixedly mounted on the bottom of the double-lip shaft seal (300) or the dust and oil proof shaft seal (310), and extends downwardly at an angle, turning from the middle thereof to increase the angle of inclination, and the bottom end thereof abuts against the outer surface of the shaft sleeve (140); The two sealing lips of the double-lip shaft seal (300) and a sealing lip of the dust-proof and oil-proof shaft seal (310) close to the inside of the shaft hole (110) are inclined in the same direction; and a sealing lip of the dust-proof and oil-proof shaft seal (310) close to the opening of the shaft hole (110) is inclined in the opposite direction.

3. The shaft seal oil leakage collection structure according to claim 1, characterized in that: The sealing lip is made of PTFE material.

4. The shaft seal oil leakage collection structure according to claim 1, characterized in that: The lubricating oil collecting pipeline is located at the bottom of the shaft seal gland (200) and the main engine body (100).

5. The shaft seal oil leakage collection structure according to claim 4, characterized in that: The lubricating oil collection pipeline comprises a first pipeline, a second pipeline (460) and a plugging unit; The first pipeline is located inside the shaft seal gland (200), and the second pipeline (460) is located inside the main engine body (100); The first pipeline comprises a first vertical pipe (400), a first horizontal pipe (410), a second vertical pipe (420), and a second horizontal pipe (430); the blocking unit comprises a first spherical plug (440) and a second spherical plug (450); the input end of the first vertical pipe (400) is in communication with the lubricating oil flow path between the double-lip shaft seal (300) and the dust and oil proof shaft seal (310); the output end of the first vertical pipe (400) is in communication with the first horizontal pipe (410); the first horizontal pipe (410) extends outward in a horizontal direction and is in communication with the outside; the second vertical pipe (420) is in communication with the first horizontal pipe (410), extends downward and is in communication with the outside; the input end of the second horizontal pipe (430) is in communication with the second vertical pipe (420), and the output end is in communication with the second pipeline (460); When the lubricating oil collection pipeline is in operation, the first spherical plug (440) blocks the external opening of the first horizontal pipe (410), and the second spherical plug (450) blocks the external opening of the second vertical pipe (420).

6. The shaft seal oil leakage collection structure according to claim 5, characterized in that: The oil return pipeline also includes an oil return one-way valve (610), which is installed on the connecting pipe (600) and is used to ensure that the lubricating oil can only flow from the outlet end of the lubricating oil collection pipeline to the air inlet (120) of the main engine body (100).

7. The shaft seal oil leakage collection structure according to claim 6, characterized in that: The oil return pipeline also includes a quick connector, and the input end of the connecting pipe (600) is connected to the outlet of the second pipeline (460) through the quick connector, and the output end is connected to the air inlet (120) of the main engine body (100) through the quick connector.

8. The shaft seal oil leakage collection structure according to claim 2, characterized in that: It also includes a limiting assembly, the limiting assembly including a first elastic retaining ring (210) and a second elastic retaining ring (220), The shaft seal gland (200) is provided with a first convex portion, a second convex portion, a first groove and a second groove. The first elastic retaining ring (210) is installed in the first groove, the second elastic retaining ring (220) is installed in the second groove, the double-lip shaft seal (300) is installed between the first elastic retaining ring (210) and the first convex portion, and its two sides respectively abut against the first elastic retaining ring (210) and the first convex portion; the dust and oil proof shaft seal (310) is installed between the second elastic retaining ring (220) and the second convex portion, and its two sides respectively abut against the second elastic retaining ring (220) and the second convex portion.

9. The shaft seal oil leakage collection structure according to claim 8, characterized in that: It also comprises a sealing assembly, which comprises a plurality of sealing rings, and the plurality of sealing rings are arranged at the connection between the main machine body (100) and the shaft seal gland (200).

10. A screw compressor, comprising a main body (100) and a rotor (130), characterized in that: It also includes the shaft seal oil leakage collection structure according to any one of claims 1-9.

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