A combined sealed oil-free screw blower

Abstract

The present invention relates to the field of air compressors, and in particular to a combined sealed oil-free screw blower, comprising: a fuselage with a compression chamber and a lubrication chamber; a female rotor and a male rotor rotatably arranged in the fuselage, a rotating shaft is arranged at both ends of the female rotor and the male rotor, the rotating shaft is connected to the fuselage through a bearing, and the bearing is located in the lubrication chamber; a sealing structure is arranged on the side of the bearing close to the compression chamber, the sealing structure is arranged on the outer peripheral surface of the rotating shaft, and the sealing structure prevents the lubricating oil in the lubrication chamber from entering the compression chamber; the sealing structure comprises: an oil retaining ring, a spiral sealing seat and a carbon ring arranged in sequence along the axial direction, the oil retaining ring is located on one side of the bearing, a spiral seal is formed between the spiral sealing seat and the rotating shaft, and a floating seal is formed between the carbon ring and the rotating shaft. The advantages of the present invention are that the sealing performance of the compression chamber is improved through the combination of multiple sealing methods, oil and gas can be effectively isolated, and the operating reliability of the machine is ensured.

Description

Technical Field

[0001] The invention relates to the field of air compressors, in particular to a combined sealed oil-free screw blower. Background Art

[0002] The oil-free screw blower includes a female rotor and a male rotor arranged in the fuselage. The female rotor and the male rotor are not in direct contact with each other. The two are connected by a synchronous gear arranged at one end. When one of the rotors rotates, the rotor drives the other rotor to rotate in the opposite direction through the synchronous gear to achieve air compression. Unlike the oil-injected screw blower, during the operation of the oil-free screw blower, the female rotor and the male rotor do not need to be sprayed with oil, so the air will not come into contact with the oil, thereby obtaining pure compressed air. However, the bearings on the female rotor and the male rotor and the synchronous gear still need to be cooled by the lubricating oil lubrication box, and the lubricating oil must be prevented from entering the compression chamber. Therefore, in the oil-free screw blower, the sealing at both ends of the compression chamber is particularly important. Summary of the invention

[0003] To solve the above-mentioned problem, the object of the present invention is to provide a combined sealed oil-free screw blower, in which an oil retaining ring, a spiral sealing seat and a carbon ring are arranged in sequence along the axial direction on the side of the bearing close to the compression chamber, and the main lubricating oil is blocked by the oil retaining ring, and the remaining small amount of lubricating oil is blocked outside the compression chamber under the action of the spiral sealing seat and the carbon ring, thereby ensuring the sealing performance of the compression chamber.

[0004] For the purpose of the present invention, the following technical solutions are adopted to implement:

[0005] A combined sealed oil-free screw blower, comprising:

[0006] a body having a compression chamber and a lubrication chamber;

[0007] The female rotor and the male rotor are rotatably arranged in the machine body, and both ends of the female rotor and the male rotor are provided with a rotating shaft, and the rotating shaft is connected to the machine body through a bearing, and the bearing is located in the lubrication cavity;

[0008] A sealing structure is arranged on the side of the bearing close to the compression chamber, and the sealing structure is arranged on the outer peripheral surface of the rotating shaft, and the sealing structure prevents the lubricating oil in the lubricating chamber from entering the compression chamber;

[0009] The sealing structure includes: an oil retaining ring, a spiral sealing seat and a carbon ring which are arranged in sequence along the axial direction. The oil retaining ring is located on one side of the bearing. A spiral seal is formed between the spiral sealing seat and the rotating shaft, and a floating seal is formed between the carbon ring and the rotating shaft.

[0010] Preferably, the radial outer end of the oil retaining ring extends to the outer ring of the bearing; an oil return channel is provided on the fuselage at a position corresponding to the oil retaining ring, and the oil return channel is connected to the lubrication cavity; the lubricating oil blocked by the oil retaining ring flows back to the lubrication cavity through the oil return channel.

[0011] Preferably, a thread is provided on the inner surface of the spiral seal seat, the position on the shaft connected to the spiral seal seat is smooth, and the rotation direction of the thread is the same as the rotation direction of the shaft, so that a spiral seal is formed between the spiral seal seat and the shaft.

[0012] Preferably, a locating end extending axially is provided on the side of the spiral seal seat facing the bearing, the locating end abuts against one side of the bearing, and the oil retaining ring is located on the inner side of the locating end.

[0013] Preferably, the positioning end is a plurality of protrusions arranged on the side of the spiral sealing seat and distributed around the circumference, with gaps formed between the protrusions.

[0014] Preferably, a carbon ring positioning assembly is provided between the spiral seal seat and the carbon ring, and the carbon ring positioning assembly prevents the carbon ring from moving axially.

[0015] Preferably, the carbon ring positioning assembly includes a carbon ring positioning seat arranged on one side of the spiral sealing seat and an elastic element arranged between the carbon ring positioning seat and the carbon ring. The carbon ring positioning seat is positioned by the fuselage, and the elastic element applies force to the carbon ring to position the carbon ring on the rotating shaft.

[0016] Preferably, a first positioning groove and a second positioning groove are provided on the fuselage, the carbon ring is provided in the first positioning groove, and the carbon ring positioning seat is provided in the second positioning groove; a through hole connected to the outside is provided between the first positioning groove and the second positioning groove, and the inner end of the through hole is located in the sealing structure.

[0017] In summary, the advantages of the present invention are: most of the lubricating oil in the bearing is blocked by the oil retaining ring and flows back to the lubricating cavity, a small part of the lubricating oil passes over the oil retaining ring and is blocked by the spiral sealing seat, and when the spiral sealing seat fails to seal, the carbon ring blocks the leaked lubricating oil. Through the combination of multiple sealing methods, the sealing performance of the compression chamber is improved, oil and gas can be effectively isolated, and the operating reliability of the machine is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A three-dimensional diagram of an oil-free screw blower.

[0019] Figure 2 This is the left side view of the oil-free screw blower.

[0020] Figure 3 for Figure 2 Cross-sectional view at the middle BB.

[0021] Figure 4 for Figure 3 A partial enlarged view of point A in the middle.

[0022] Figure 5 An exploded view of the combined sealing device. DETAILED DESCRIPTION

[0023] like Figure 1 and 3 As shown, an oil-free screw blower includes a body 10, a compression chamber 101 is arranged inside the body 10, and a female rotor 20 and a male rotor 30 with axes extending in the transverse direction are arranged side by side in the compression chamber 101, and the left and right ends of the female rotor 20 and the male rotor 30 are both rotating shafts 21, 31, and the rotating shafts 21, 31 at both ends are rotatably arranged in the body 10 through bearings 22, 32. The middle part of the female rotor 20 and the male rotor 30 is an asymmetric spiral tooth structure, and the female rotor and the male rotor are meshed with each other through the spiral teeth to achieve air compression. An air inlet 11 connected to the compression chamber 101 is arranged at the top of the body 10, and an exhaust port 12 connected to the compression chamber 101 is arranged at the bottom of the body 10. When the equipment is running, the female rotor 20 and the male rotor 30 rotate simultaneously and in opposite directions. External air is sucked into the compression chamber 101 from the air inlet 11 at the top of the fuselage 10. In the compression chamber 101, the air is compressed by the female rotor 20 and the male rotor 30. The compressed air flows downward and is discharged from the exhaust port 12 at the bottom of the fuselage 10.

[0024] like Figure 3 As shown, the left end of the body 10 is a driving end, which is used to connect a driving device (not shown). The output end of the driving device is connected to the female rotor 20 or the male rotor 30 to drive the rotor to rotate. Generally, the driving device can be a motor. In this embodiment, the driving device is connected to the female rotor 20, that is, the driving device is used to drive the female rotor 20 to rotate. Figure 2 As shown, a pair of mutually meshing synchronous gears 40, 40' are provided at the right ends of the female rotor 20 and the male rotor 30, so that when the driving device drives the female rotor 20 to rotate, the female rotor 20 drives the male rotor 30 to rotate in the opposite direction through the synchronous gears 40, 40'.

[0025] In order to lubricate the bearings 22, 32 and the synchronous gears 40, 40', lubrication chambers 102 are provided at both ends of the body 10. The lubrication chamber 102 is sealed with the compression chamber 101 by a sealing structure to prevent the lubricating oil in the lubrication chamber from flowing into the compression chamber 101, thereby ensuring the normal operation of the equipment.

[0026] In this embodiment, the sealing structure on the left side of the female rotor 20 is taken as an example to illustrate the specific structure of the sealing structure.

[0027] like Figure 4 and 5As shown, a bearing 22 is arranged on the rotating shaft 21 of the female rotor 20, and the left side of the bearing 22 is connected to the lubrication chamber, and the lubricating oil in the lubrication chamber can lubricate and cool the bearing 22 (usually splash lubrication). The sealing structure is arranged on the right side of the bearing 22, that is, the side close to the compression chamber 101. The sealing structure is arranged on the outer peripheral surface of the rotating shaft 21, and the sealing structure includes: an oil retaining ring 50, a spiral sealing seat 60 and a carbon ring 70 arranged in sequence along the axial direction, and the oil retaining ring 50, the spiral sealing seat 60 and the carbon ring 70 are all annular structures, and the rotating shaft 21 is arranged inside the oil retaining ring 50, the spiral sealing seat 60 and the carbon ring 70.

[0028] As for the oil deflector 50, the oil deflector 50 is sleeved on the outer peripheral surface of the rotating shaft 21, and the left side of the oil deflector 50 is closely attached to the right side of the bearing 22. Furthermore, the inner ring of the oil deflector 50 is closely attached to the inner ring of the bearing 22 to position the bearing 22. The right side of the oil deflector 50 is positioned by the step 211 on the rotating shaft 21. In the radial direction, the outer end of the oil deflector 50 extends to the outer ring of the bearing 22, and the lubricating oil in the bearing 22 will be blocked by the oil deflector 50 once it flows out of the bearing 22. An oil return channel 13 is also provided on the fuselage 10, and the oil return channel 13 is located on the radial outer side of the oil deflector 50, so that the lubricating oil blocked by the oil deflector 50 can enter the oil return channel 13 and flow back to the lubrication cavity along the oil return channel 13.

[0029] As for the spiral seal seat 60, the inner surface of the spiral seal seat 60 is provided with a thread 61, which abuts on the outer peripheral surface of the rotating shaft 21, and the rotation direction of the thread 61 is the same as the rotation direction of the rotating shaft 21, so as to ensure the sealing of the inner side of the spiral seal seat 60. It should be noted that the outer peripheral surface of the rotating shaft 21 is a smooth surface, and the spiral seal seat 60 is not fixedly connected to the rotating shaft 21 through the thread 61, but a spiral seal is formed through the thread 61. The specific sealing principle will be described in detail later. The outer surface of the spiral seal seat 60 is provided with a first groove 62 extending around the circumference to form an annular shape, and a first sealing ring 621 is provided in the first groove 62. The first sealing ring 621 abuts on the inner wall of the fuselage 10, so as to ensure the sealing of the outer side of the spiral seal seat 60. The left side of the spiral seal seat 60 is provided with a positioning end 63 extending in the direction of the bearing 22, and the left side of the positioning end 63 abuts on the right side of the outer ring of the bearing 22 to position the bearing 22 axially. The positioning end 63 is located radially outside the oil retaining ring 50. Preferably, the positioning end 63 is a plurality of protrusions spaced apart along the circumferential direction, so that gaps are formed between adjacent protrusions, so that the lubricating oil in the oil retaining ring 50 can flow into the oil return channel 13 through the gaps.

[0030] As for the carbon ring 70, the carbon ring 70 is arranged in the first positioning groove 14 of the fuselage 10, and the inner side of the carbon ring 70 is tightly fitted with the rotating shaft 21. The carbon ring 70 is a floating sealing mechanism, which effectively prevents leakage by using the tension of the oil film. A carbon ring positioning assembly 80 for positioning the carbon ring 70 is arranged between the left side of the carbon ring 70 and the right side of the spiral seal seat 60. Specifically, the carbon ring positioning assembly 80 includes a carbon ring positioning seat 81 and an elastic element 82. The carbon ring positioning seat 81 is arranged in the second positioning groove 15 of the fuselage 10, and the left side of the carbon ring positioning seat 81 abuts against the right side of the spiral seal seat 60, which is used to position the spiral seal seat 60. An elastic element 82 (such as a spring, preferably a wave spring) is arranged on the right side of the carbon ring positioning seat 81. The elastic element 82 exerts force on the carbon ring 70 to fix the carbon ring 70 in the first positioning groove 14 to prevent it from moving axially. A second groove 811 extending in a circumferential direction and forming a ring is further provided on the wall surface on the right side of the carbon ring positioning seat 81 . A second sealing ring 8111 is provided in the second groove 811 . The second sealing ring 8111 abuts against the inner wall of the fuselage 10 .

[0031] A through hole 16 communicating with the outside air is provided between the first positioning groove 14 and the second positioning groove 15 of the fuselage 10 . The axis of the through hole 16 extends in the horizontal direction, and the inner end of the through hole 16 is located radially outside the carbon ring 70 .

[0032] The sealing principle of the sealing structure is described in detail below:

[0033] When the equipment is running, the lubricating oil in the lubricating chamber 102 enters the bearing 22 by splash lubrication, lubricating and cooling the bearing 22, and part of the lubricating oil will flow axially to the right side of the bearing 22. At this time, the oil retaining ring 50 blocks the lubricating oil to prevent the lubricating oil from continuing to move axially, so that most of the lubricating oil flows radially and flows into the oil return channel 13, and finally flows back to the lubricating chamber. However, a small part of the lubricating oil will pass through the oil retaining ring 50 and enter the spiral seal seat 60, that is, the lubricating oil flows into the thread 61 of the spiral seal seat 60. Since the rotation direction of the thread 61 is the same as the rotation direction of the shaft 21, the spiral seal seat 60 forms a propulsion device, which generates energy exchange with the medium, generating the so-called "pumping action", sucking air in the atmosphere into the thread 61 and transporting it toward the lubricating chamber, that is, generating a pumping pressure head, which is balanced with the pressure of the sealed medium (lubricating oil), thereby preventing the lubricating oil from leaking. If the spiral seal seat 60 fails, the lubricating oil will continue to flow to the right over the thread 61. At this time, the lubricating oil will be blocked by the carbon ring 70. The carbon ring 70 is a floating sealing mechanism that uses the tension of the oil film to seal the lubricating oil.

[0034] In summary, the advantages of the present invention are that most of the lubricating oil in the bearing is blocked by the oil retaining ring and flows back into the lubricating cavity, and a small amount of lubricating oil passes over the oil retaining ring and is blocked by the spiral seal seat. When the spiral seal seat fails to seal, the carbon ring blocks the leaked lubricating oil. Through the combination of multiple sealing methods, the sealing performance of the compression cavity is improved, oil and gas can be effectively isolated, and the operating reliability of the machine is ensured.

[0035] The above is a description of the embodiments of the present invention. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the present invention. Various modifications to these embodiments will be apparent to professionals and technicians in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will conform to the widest range consistent with the principles and novelties disclosed herein.

Claims

1. A combined sealed oil-free screw blower, comprising: A body (10) having a compression chamber (101) and a lubrication chamber (102); A female rotor (20) and a male rotor (30) are rotatably disposed in a machine body (10), wherein both ends of the female rotor (20) and the male rotor (30) are provided with rotating shafts (21, 31), the rotating shafts (21, 31) are connected to the machine body (10) via bearings (22, 32), and the bearings (22, 32) are located in a lubrication cavity (102); It is characterized in that A sealing structure is provided on the side of the bearing (22, 32) close to the compression chamber (101), and the sealing structure is provided on the outer peripheral surface of the rotating shaft (21, 31). The sealing structure prevents lubricating oil in the lubricating chamber (102) from entering the compression chamber (101); The sealing structure comprises: an oil retaining ring (50), a spiral sealing seat (60) and a carbon ring (70) which are arranged in sequence along the axial direction; the oil retaining ring (50) is located on one side of the bearing (22, 32); a spiral seal is formed between the spiral sealing seat (60) and the rotating shaft (21, 31); and a floating seal is formed between the carbon ring (70) and the rotating shaft (21, 31); A thread (61) is provided on the inner surface of the spiral seal seat (60); a position on the rotating shaft (21, 31) connected to the spiral seal seat (60) is smooth, and the rotation direction of the thread (61) is opposite to the rotation direction of the rotating shaft (21, 31), so that a spiral seal is formed between the spiral seal seat (60) and the rotating shaft (21, 31); an axially extending positioning end (63) is provided on the side of the spiral seal seat (60) facing the bearing (22, 32); the positioning end (63) abuts against one side of the bearing (22, 32), and the oil retaining ring (50) is located on the inner side of the positioning end (63); the positioning end (63) is a plurality of protrusions provided on the side of the spiral seal seat (60) and distributed around the circumference, and gaps are formed between the protrusions; A carbon ring positioning assembly (80) is arranged between the spiral seal seat (60) and the carbon ring (70), and the carbon ring positioning assembly (80) prevents the carbon ring (70) from moving axially; the carbon ring positioning assembly (80) comprises a carbon ring positioning seat (81) arranged on one side of the spiral seal seat (60) and an elastic element (82) arranged between the carbon ring positioning seat (81) and the carbon ring (70); the carbon ring positioning seat (81) is positioned by the body (10), and the elastic element (82) exerts force on the carbon ring (70) to position the carbon ring (70) on the rotating shaft (21, 31).

2. A combined sealed oil-free screw blower according to claim 1, characterized in that: The radial outer end of the oil retaining ring (50) extends to the outer ring of the bearing (22, 32); an oil return channel (13) is provided at a position on the body (10) corresponding to the oil retaining ring (50); the oil return channel (13) is connected to the lubrication chamber (102); the lubrication oil retained by the oil retaining ring (50) flows back to the lubrication chamber (102) through the oil return channel (13).

3. The combined sealed oil-free screw blower according to claim 1, characterized in that: A first positioning groove (14) and a second positioning groove (15) are provided on the body (10); the carbon ring (70) is provided in the first positioning groove (14); and the carbon ring positioning seat (81) is provided in the second positioning groove (15); a through hole (16) communicating with the outside is provided between the first positioning groove (14) and the second positioning groove (15); and the inner end of the through hole (16) is located in the sealing structure.

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