CN111365235A - Dry-type does not have oily helical-lobe compressor main shaft oil gas isolation combination seal structure - Google Patents

Abstract

The invention discloses a dry-type oil-free screw compressor main shaft oil and gas isolation combined sealing structure, comprising a screw main shaft, an air seal assembly and an oil seal assembly are arranged on the screw main shaft, respectively sealing the compressed air cavity area and the lubricating oil cavity area. , There is a support seat between the air seal assembly and the oil seal assembly, the support seat is sleeved on the screw spindle, and supports the tail of the air seal assembly and the head of the oil seal assembly; the screw spindle is also provided with an oil break groove, which is located in the Between the air seal assembly and the oil seal assembly, to prevent the lubricating oil from spreading to the compressed air cavity area along the screw shaft, a cavity is opened in the support seat, the cavity and the oil break groove are correspondingly arranged, and a release channel is communicated with the outside of the cavity, and the release channel is connected to the The atmosphere is connected to each other. Once the gas seal assembly or oil seal assembly increases gas leakage or lubricating oil leakage due to wear, it can be released and drained in the release channel, and will not flow to the opposite seal assembly. , eliminating the hidden danger of mutual pollution.

Description

A dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure

technical field

The invention relates to the field of air compressors, in particular to a dry-type oil-free screw compressor main shaft oil and gas isolation combined sealing structure.

Background technique

At present, in the field of dry oil-free air compressor main engine, the seal between the compression cavity and the lubrication cavity of the main engine is generally isolated by contact seals, such as metal-graphite composite gaskets, metal-graphite composite rings and other seals to solve the problem. The problem that the air cavity and the lubricating oil cavity affect each other in series, however, this kind of contact seal often suffers from contact wear during operation, which causes the lubricating oil to enter the oil-free compression cavity. As a result, the oil-free compressed air produced contains lubricating oil components, which affects the performance and life of subsequent air purification devices, and affects the quality of compressed air products, or causes air to infiltrate into the lubricating oil cavity, resulting in the degradation of lubricating oil quality or even functional failure. .

Therefore, there is an urgent need for a dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure, which can solve the problem of contact seals used in the existing dry oil-free air compressor main shaft, which is easy to cause leakage of compressed gas or lubricating oil after wear. Mutual pollution problem.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure, in order to solve the above-mentioned contact seal used by the existing dry oil-free air compressor main shaft, it is easy to cause compressed gas or lubrication after wear. The problem of oil leakage and mutual contamination.

For achieving the above object, the present invention provides the following scheme:

The invention provides a dry-type oil-free screw compressor main shaft oil and gas isolation combined sealing structure, comprising a screw main shaft, an air seal assembly and an oil seal assembly are arranged on the screw main shaft, and the air seal assembly is sleeved on the screw main shaft and set close to the compressed air cavity area, the sealing length of the air seal assembly is greater than or equal to 35% of the diameter of the screw spindle; the oil seal assembly is sleeved on the screw spindle and is set close to the lubricating oil cavity area, the A support seat is arranged between the air seal assembly and the oil seal assembly, the support seat is sleeved on the screw shaft and supports the tail of the air seal assembly and the head of the oil seal assembly;

The screw main shaft is also provided with an oil break groove, the oil break groove is located between the air seal assembly and the oil seal assembly, a cavity is opened in the support seat, and the cavity is arranged corresponding to the oil break groove , a release channel is communicated with the outside of the cavity, and the release channel is communicated with the atmosphere and can make the leaked lubricating oil flow freely to the outside of the release channel.

Preferably, the air seal assembly includes a first r-type seal, the first r-type seals are stacked and sleeved on the screw main shaft and are in clearance fit with the screw main shaft, and two adjacent first r-type seals A wave spring washer is arranged between an r-type seal.

Preferably, the number of the first r-type seals is ≥2.

Preferably, the wave number of the wave spring pad is 3-5 waves.

Preferably, the oil seal assembly includes a second r-type seal, the second r-type seal is sleeved on the screw main shaft and is in clearance fit with the screw main shaft, and the inner wall of the second r-type seal A rectangular single-head thread groove is opened, the thread groove rotates in the opposite direction to the rotation direction of the screw shaft, and a sealing rubber ring is arranged between the second r-shaped seal and the support seat.

Preferably, the number of turns of the rectangular single-start thread groove in the second r-type seal is greater than or equal to 4 turns.

Preferably, the oil cut-off groove is a wedge-shaped groove.

Preferably, the distance between the edge of the release channel through which the leaked lubricating oil can flow freely to the outside world and the edge of the support seat is 5 mm.

Preferably, the diameter of the release channel is greater than or equal to 30% of the diameter of the main shaft of the screw.

The present invention has achieved the following beneficial technical effects with respect to the prior art:

1. The dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure provided by the present invention is provided with an air seal assembly near the compressed air cavity area. With clearance fit, in the high-speed rotation of the screw spindle, a high-density high-speed rotating airflow layer will be formed between the air seal assembly and the screw spindle, which can overcome the air pressure impact of the medium pressure (below 13bar) in the compressed air cavity, so as to achieve Non-contact sealing, under the impact of air pressure expansion in the compressed air cavity, there will be a very small amount of gas leakage at the tail of the air seal assembly, but it can be ignored compared to the improvement of the mechanical performance of the equipment and the flow performance of the whole machine. There is no contact between the seal assembly and the screw shaft, so the service life is extremely long.

2. The dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure provided by the present invention is provided with an oil seal assembly near the lubricating oil cavity. The oil seal assembly mainly includes a second r-type seal with a rectangular single-head thread groove on the inner wall. , It is a clearance fit with the screw spindle. During the high-speed rotation of the screw spindle, a high-density high-speed rotating airflow layer will form between the oil seal assembly and the screw spindle. At the same time, the airflow layer will follow the rectangular single-head thread groove. A small amount of lubricating oil that is about to leak out of the screw spindle is blown into the lubricating oil cavity in the reverse direction, preventing the leakage of the lubricating oil. Since the oil seal assembly also has no contact with the screw spindle, its service life is also extremely high. long.

3. In the dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure provided by the present invention, a wedge-shaped oil break groove is provided on the screw main shaft between the air seal assembly and the oil seal assembly, and the trace oil film that may be infiltrated and extended along the screw main shaft is thrown away It is separated from the screw spindle, which further prevents the oil film from continuing to enter the compressed air cavity along the screw spindle of the air seal assembly part.

4. In the dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure provided by the present invention, the supporting seat between the air seal assembly and the oil seal assembly is provided with a communicating cavity and a release channel, and the release channel is communicated with the atmosphere. When the gas seal assembly or oil seal assembly has increased gas leakage or lubricating oil leakage due to wear, it can be released and drained in this release channel that communicates with the atmosphere, and will not flow to the opposite seal. On the components, the hidden danger of mutual contamination is eliminated.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is a schematic diagram of the positional relationship of each part of the main shaft oil and gas isolation combined sealing structure of a dry oil-free screw compressor provided by the present invention;

Figure 2 is a unilateral longitudinal cross-sectional view of a dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure provided by the present invention;

In the figure: 1: Screw spindle, 11: Oil break groove, 2: Air seal assembly, 21: First r-type seal, 22: Wave spring washer, 3: Oil seal assembly, 31: Second r-type seal, 32: Sealing rubber ring, 4: Support seat, 41: Cavity, 42: Release channel.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a dry-type oil-free screw compressor main shaft oil and gas isolation combined sealing structure, by arranging an air seal assembly and an oil seal assembly, to solve the contact seal used by the existing dry-type oil-free air compressor main shaft, After wear, it is easy to cause the problem of mutual contamination by leakage of compressed gas or lubricating oil.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1:

This embodiment provides a dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure, as shown in Figures 1 and 2, including a screw main shaft 1, the screw main shaft 1 is provided with an air seal assembly 2 and an oil seal assembly 3, the air seal The component 2 is sleeved on the screw spindle 1 and is set close to the compressed air cavity area. The sealing length of the air seal component 2 is equal to 35% of the diameter of the screw spindle 1, so as to realize the sealing of the compressed air cavity area; the oil seal component 3 is sleeved on the compressed air cavity area. The screw main shaft 1 is set close to the lubricating oil cavity area to realize the sealing of the lubricating oil cavity area. A support seat 4 is arranged between the air seal assembly 2 and the oil seal assembly 3, and the support seat 4 is sleeved on the screw main shaft 1. And support the tail of the air seal assembly 2 and the head of the oil seal assembly 3; the screw main shaft 1 is also provided with an oil break groove 11, and the oil break groove 11 is located between the air seal assembly 2 and the oil seal assembly 3. The extended trace oil film is thrown away from the screw main shaft 1, which further prevents the oil film from continuing to enter the compressed air cavity along the screw main shaft 1 of the air seal assembly 2. A cavity 41 is opened in the support seat 4, and the cavity 41 corresponds to the oil cut-off groove 11. A release channel 42 communicates with the outside of the cavity 41, the release channel 42 communicates with the atmosphere, and the directional position of the channel is convenient for the leaked lubricating oil to flow out of the channel freely.

Specifically, the gas seal assembly 2 includes a first r-type seal 21, which is stacked and sleeved on the screw spindle 1 and fits with the screw spindle 1 in a clearance fit, so as to avoid the wear caused by contact friction from affecting the seal To solve the problem of stability, a wave spring washer 22 is provided between two adjacent first r-type seals 21 .

Further, the number of the first r-type seals 21 is two.

Further, the wave spring pad 22 is a 5-wave wave spring pad.

Further, the oil seal assembly 3 includes a second r-type seal 31. The second r-type seal 31 is sleeved on the screw main shaft 1 and is in clearance fit with the screw main shaft 1 to avoid friction caused by direct contact. The inner wall of the seal 31 is provided with a rectangular single-head thread groove, and the direction of the thread groove is opposite to the rotation direction of the screw shaft 1, and the trace oil film that may be infiltrated and extended along the screw shaft 1 is thrown away from the screw shaft 1. The second r-type seal 31 and the screw shaft 1 A sealing rubber ring 32 is provided between the support bases 4 to block the leakage of lubricating oil.

Further, the number of turns of the rectangular single-start thread groove in the second r-type seal 31 is 6 turns.

Further, the oil breaking groove 11 is a wedge-shaped groove, which is convenient for the lubricating oil to be separated from the screw spindle 1 .

Further, the distance between the edge of the release channel 42 and the edge of the support seat 4 is 5 mm.

Further, the diameter of the release channel 42 is equal to 30% of the diameter of the screw shaft 1 .

The present invention provides a dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure. Its working principle is as follows: the screw main shaft 1 rotates. 1 Clear fit, so a high-density high-speed rotating airflow layer will be formed between the air seal assembly 2 and the screw main shaft 1, and between the oil seal assembly 3 and the screw main shaft 1, which can overcome the impact of compressed air and lubricating oil, thereby Contactless sealing is achieved. At the same time, since there is no contact between the air seal assembly 2 and the oil seal assembly 3 and the screw spindle 1, the service life is extremely long; A small amount of oil film is thrown away from the screw main shaft 1, which further prevents the oil film from continuing to enter the compressed air cavity along the screw main shaft 1 of the air seal assembly 2; When the oil leaks, the leaked substances can also be released and drained through the release channel 42, and will not flow to the opposite sealing components, thus eliminating the hidden danger of mutual contamination.

The present invention uses specific examples to illustrate the principles and implementations of the present invention, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (9)

1. A dry-type oil-free screw compressor main shaft oil and gas isolation combined sealing structure, comprising a screw main shaft, characterized in that: the screw main shaft is provided with an air seal assembly and an oil seal assembly, and the air seal assembly is sleeved on the Set on the screw spindle and close to the compressed air cavity area, the sealing length of the air seal assembly is greater than or equal to 35% of the diameter of the screw spindle; the oil seal assembly is sleeved on the screw spindle and is set close to the lubricating oil cavity area a support seat is arranged between the air seal assembly and the oil seal assembly, the support seat is sleeved on the screw spindle and supports the tail of the air seal assembly and the head of the oil seal assembly; The screw main shaft is also provided with an oil break groove, the oil break groove is located between the air seal assembly and the oil seal assembly, a cavity is opened in the support seat, and the cavity is arranged corresponding to the oil break groove , a release channel is communicated with the outside of the cavity, and the release channel is communicated with the atmosphere. 2. A dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure according to claim 1, characterized in that: the air seal assembly comprises a first r-type seal, and the first r-type seal The stack is sleeved on the screw main shaft and is in clearance fit with the screw main shaft, and a wave spring washer is arranged between two adjacent first r-shaped seals. 3. A dry oil-free screw compressor main shaft oil and gas isolation combined sealing structure according to claim 2, characterized in that: the number of the first r-type seals is greater than or equal to 2. 4. A dry oil-free screw compressor main shaft oil-gas isolation combined sealing structure according to claim 2, characterized in that: the wave number of the wave spring washer is 3-5 waves. 5 . The dry oil-free screw compressor main shaft oil-gas isolation combined sealing structure according to claim 1 , wherein the oil seal assembly comprises a second r-type seal, and the second r-type seal is sleeved. 6 . It is arranged on the screw main shaft and is in clearance fit with the screw main shaft. The inner wall of the second r-type seal is provided with a rectangular single-head thread groove, and the thread groove rotates in the opposite direction to the rotation direction of the screw main shaft. A sealing rubber ring is arranged between the second r-type seal and the support seat. 6 . The combined sealing structure for oil and gas isolation of the main shaft of a dry-type oil-free screw compressor according to claim 5 , wherein the number of turns of the rectangular single-head thread groove in the second r-type seal is greater than or equal to 4 turns. 7 . 7. A dry oil-free screw compressor main shaft oil-gas isolation combined sealing structure according to claim 1, characterized in that: the oil-cutting groove is a wedge-shaped groove. 8 . The dry oil-free screw compressor main shaft oil-gas isolation combined sealing structure according to claim 1 , wherein the distance between the edge of the release channel and the edge of the support seat is 5 mm. 9 . 9 . The oil-gas isolation combined sealing structure for the main shaft of a dry oil-free screw compressor according to claim 1 , wherein the diameter of the release passage is greater than or equal to 30% of the diameter of the screw main shaft. 10 .

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