A compressor end shaft sealing structure

Abstract

The present invention relates to the technical field of compressors, and in particular to a compressor end shaft sealing structure. It comprises a rotating shaft and an end cover, which are rotatably connected. The inner side of the end cover is sealed and connected with a sealing member. The end cover is provided with a first vent hole for connecting a compressed gas source, and the sealing member is provided with a second vent hole connected with the first vent hole. The sealing member is provided with a sliding cavity coaxial with the rotating shaft, and the cross section of the sliding cavity is annular. The second vent hole is connected with one end of the sliding cavity close to the end cover. A cylindrical sealing ring slides and is sealed in the sliding cavity. A circular sealing sheet is provided on the rotating shaft, and one end of the cylindrical sealing ring contacts one side of the sealing sheet. The present invention has good sealing performance and can prevent water from entering the bearing outward.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a compressor end shaft sealing structure. Background Art

[0002] When an oil-free screw compressor is operating, negative pressure is applied to both ends of its shaft. When it stops, high pressure, several atmospheres, is generated for a few seconds. Because water flows through the compressor to seal and cool the rotors, this high-pressure gas can push water into the shaft bearings during shutdown, causing corrosion and damage. Existing shaft seals typically use labyrinth seals, which cannot completely prevent water from entering the bearings during normal operation or shutdown. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a compressor end shaft sealing structure in response to the above-mentioned technical deficiencies, which has good sealing performance and can prevent water from entering the bearing outward.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a compressor end shaft sealing structure, including a rotating shaft and an end cover, the two are rotatably connected, the inner side of the end cover is sealed and connected with a sealing member, the end cover is provided with a first air vent for connecting a compressed gas source, the sealing member is provided with a second air vent connected to the first air vent, the sealing member is provided with a sliding cavity coaxial with the rotating shaft, the cross-section of the sliding cavity is annular, the second air vent is connected to one end of the sliding cavity close to the end cover, a cylindrical sealing ring slides and is sealed in the sliding cavity, a circular sealing plate is provided on the rotating shaft, and one end of the cylindrical sealing ring is in contact with one side of the sealing plate.

[0005] To further optimize the technical solution, the sealing member is provided with a support portion at the outer end of the sliding cavity, and the support portion is a cylindrical boss distributed on both sides of the sliding cavity.

[0006] To further optimize the technical solution, a circular annular groove is provided on the side of the sealing sheet away from the cylindrical sealing ring, and the circular annular groove is coaxial with the rotating shaft.

[0007] To further optimize this technical solution, a pushing portion is provided at one end of the cylindrical sealing ring close to the second vent hole, and the inner and outer surfaces of the pushing portion protrude from the inner and outer surfaces of the cylindrical sealing ring respectively, and a plurality of convex rings are also provided on the inner and outer sides of the cylindrical sealing ring.

[0008] To further optimize the technical solution, the cross section of the convex ring is semicircular.

[0009] To further optimize the technical solution, the seal is detachably connected to a cutting guide on both the inner and outer sides of the outer end of the sliding cavity, and a guide ring is provided on the cutting guide. The end of the guide ring away from the seal is connected to the cutting guide, and an accommodating cavity is formed between the guide ring and the main body of the cutting guide. The outer side of the guide ring is in contact with the cylindrical sealing ring, and a gap is left between the end of the guide ring close to the seal and the seal. The width of the gap is greater than the width of the convex ring, and a cutting edge is provided at the end of the guide ring close to the seal.

[0010] To further optimize the technical solution, the sealing sheet is provided with a blocking ring at a position inside the cylindrical sealing ring, and the blocking ring does not contact the inner side of the cylindrical sealing ring.

[0011] To further optimize the technical solution, a recessed platform is provided at one end of the second vent close to the first vent, a first sealing ring is provided in the recessed platform, and the first sealing ring is in contact with the end cover around the first vent so that the second vent and the first vent can be sealed and connected.

[0012] Compared with the prior art, the present invention has the following advantages: 1. Compressed gas is used to push the cylindrical sealing ring into contact with the sealing plate and maintain an appropriate and constant pressure, so that there is good sealing between the two; 2. When the cylindrical sealing ring is worn, it can continue to extend under the action of air pressure to maintain contact with the sealing plate, and has a longer service life; 3. A pushing part is provided at one end of the cylindrical sealing ring, and multiple convex rings are provided on the inner and outer sides thereof, which has a better sealing effect and smaller friction, making it easier for the cylindrical sealing ring to apply pressure to the sealing plate; 4. Cutting guides are detachably connected to the inner and outer sides of the outer end of the sliding cavity, which can not only support the cylindrical sealing ring, but also cut off the convex ring to keep the contact area between the cylindrical sealing ring and the sealing plate constant. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural diagram of Example 1.

[0014] Figure 2 for Figure 1 Magnified view of point I in the middle.

[0015] Figure 3 This is a schematic diagram of the cylindrical sealing ring structure in Example 3.

[0016] Figure 4 This is a schematic diagram of the cutting guide structure in Example 3.

[0017] In the figure: 1. rotating shaft; 11. sealing plate; 111. groove; 112. blocking ring; 2. end cover; 21. first vent hole; 3. sealing member; 31. second vent hole; 311. first sealing ring; 32. sliding cavity; 33. supporting part; 4. cylindrical sealing ring; 41. pushing part; 42. convex ring; 5. second sealing ring; 6. cutting guide; 61. guide ring; 611. cutting edge; 62. accommodating cavity. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0019] Example 1

[0020] Combine Figure 1-2 As shown, a compressor end shaft sealing structure includes a rotating shaft 1 and an end cover 2, with a bearing disposed therebetween to allow the rotating shaft 1 to rotate. A sealing member 3 is sealedly connected to the inner side of the end cover 2. The sealing member 3 may be provided with multiple through holes, and the inner side of the end cover 2 may be provided with multiple threaded holes. The two are fixed together by bolts, and a second sealing ring 5 is disposed inside the threaded holes of the end cover 2 to ensure a sealed connection between the two. The end cap 2 is provided with a first vent hole 21 for connecting to a compressed gas source. The seal 3 is provided with a second vent hole 31 communicating with the first vent hole 21. The seal 3 is provided with a sliding cavity 32 coaxial with the rotating shaft 1. The sliding cavity 32 extends through the end of the seal 3 away from the end cap 2 and has a circular cross-section. The second vent hole 31 communicates with the end of the sliding cavity 32 near the end cap 2. A cylindrical sealing ring 4 slides and seals within the sliding cavity 32. The rotating shaft 1 is provided with an annular sealing plate 11, one end of which contacts one side of the sealing plate 11. The cylindrical sealing ring 4 is preferably made of a slightly harder sealing material, such as fluororubber.

[0021] In actual use, the first vent 21 is connected to high-pressure gas via a pipe. Under the action of the gas pressure, the cylindrical sealing ring 4 and the sealing plate 11 are in close contact, providing an effective seal and preventing water from entering the bearing area. The side of the sealing plate 11 that contacts the cylindrical sealing ring 4 should be highly polished and preferably coated with a diamond film. The diamond film has a very low coefficient of friction and is wear-resistant, effectively reducing the wear rate of the cylindrical sealing ring 4. If the outer end of the cylindrical sealing ring 4 becomes worn after prolonged use, the high-pressure gas pressure causes the cylindrical sealing ring 4 to extend outward, maintaining close contact with the sealing plate 11 and maintaining a good seal.

[0022] The sealing sheet 11 is provided with an annular groove 111 on one side away from the cylindrical sealing ring 4. The annular groove 111 is coaxial with the rotating shaft 1. Since water flows through the compressor, the annular groove 111 contacts the water, which can improve the heat dissipation efficiency and help cool the sealing sheet 11.

[0023] The sealing sheet 11 is provided with a blocking ring 112 inside the cylindrical sealing ring 4. When the compressor is operating normally, the blocking ring 112 does not contact the inner side of the cylindrical sealing ring 4, and there is a relatively small gap between the two. When the compressor is shut down, there will be high pressure at the shaft end of the compressor for a few seconds, and the pressure of the high pressure is several atmospheres. At this time, the outer circumference of the right end of the cylindrical sealing ring 4 will be subjected to inward pressure and deform inward to contact the blocking ring 112. Therefore, the blocking ring 112 can play a supporting role, preventing the right end of the cylindrical sealing ring 4 from deforming too much inward, which would cause the seal to be damaged and thus cause water to enter the bearing.

[0024] A recessed platform is provided at one end of the second vent hole 31 close to the first vent hole 21 , and a first sealing ring 311 is provided in the recessed platform. The first sealing ring 311 contacts the end cover 2 around the first vent hole 21 so that the second vent hole 31 and the first vent hole 21 can be sealed and connected.

[0025] Example 2

[0026] Combine Figure 2 As shown, this embodiment is basically the same as the embodiment 1, except that the seal 3 is provided with a support portion 33 at the outer end of the sliding cavity 32. The support portion 33 is a cylindrical boss distributed on both sides of the sliding cavity 32. The support portion 33 can support the outer end of the cylindrical sealing ring 4 to reduce its deformation under pressure, and on the other hand, Figure 2 It can be seen from the figure that the wall thickness of the support portion 33 is relatively small, which can improve the heat dissipation efficiency when in contact with water.

[0027] Example 3

[0028] Combine Figure 3-4As shown, this embodiment is substantially the same as Example 1, differing in that a pusher portion 41 is provided at the end of the cylindrical sealing ring 4 near the second vent hole 31. The inner and outer surfaces of the pusher portion 41 protrude beyond the inner and outer surfaces of the cylindrical sealing ring 4, respectively. Multiple protruding rings 42 are also provided on the inner and outer sides of the cylindrical sealing ring 4. With this structure, the pusher portion 41 and the protruding rings 42 can generate greater pressure on both sides of the sliding cavity 32, resulting in greater deformation and improved sealing. The main body of the cylindrical sealing ring 4 can avoid generating pressure on both sides of the sliding cavity 32, or form a certain gap between them. This reduces the contact area and friction, making it easier for the cylindrical sealing ring 4 to apply pressure to the sealing sheet 11. The protruding rings 42 have a semicircular cross-section, or can have other shapes that taper from bottom to top. The bottom is the end where the protruding ring 42 meets the cylindrical sealing ring 4, and the top is the end away from the cylindrical sealing ring 4. This structure allows the top of the protruding ring 42 to deform more radially in the rotating shaft 1, resulting in better sealing and less friction.

[0029] The sealing member 3 is detachably connected to a cutting guide 6 on both the inner and outer sides of the outer end of the sliding cavity 32. The cutting guide 6 is provided with a guide ring 61. The end of the guide ring 61 away from the sealing member 3 is connected to the cutting guide 6. A receiving cavity 62 is formed between the guide ring 61 and the main body of the cutting guide 6. The outer side of the guide ring 61 is in contact with the cylindrical sealing ring 4. A gap is left between the end of the guide ring 61 close to the sealing member 3 and the sealing member 3. The width of the gap is greater than the width of the convex ring 42. The end of the guide ring 61 close to the sealing member 3 is provided with a cutting edge 611. Figure 4 As can be seen from the figure, the structures of the cutting guides 6 on the inner and outer sides of the cylindrical sealing ring 4 are not exactly the same, but are symmetrical about the cylindrical sealing ring 4. That is, the inner side of the guide ring 61 of the outer cutting guide 6 contacts the outer side of the cylindrical sealing ring 4, and the outer side of the guide ring 61 of the inner cutting guide 6 contacts the inner side of the cylindrical sealing ring 4. On the one hand, the cutting guide 6 plays a supporting role similar to the support portion 33. On the other hand, when the cylindrical sealing ring 4 extends to the right during long-term operation, the protruding ring 42 first enters the gap between the guide ring 61 and the sealing member 3, is then cut off by the cutting edge 611, and is then retained in the accommodating cavity 62. During equipment maintenance, the cutting guide 6 can be removed to replace the cylindrical sealing ring 4. After the protruding ring 42 is cut off, the contact area between the cylindrical sealing ring 4 and the sealing plate 11 can be kept constant, preventing the situation where the pressure between the two decreases due to the increase in contact area, thereby preventing the sealing performance from deteriorating.

Claims

1. A compressor end shaft sealing structure, comprising a rotating shaft (1) and an end cover (2), the two being rotatably connected, characterized in that: The inner side of the end cover (2) is sealed with a sealing member (3); the end cover (2) is provided with a first vent hole (21) for connecting to a compressed gas source; the sealing member (3) is provided with a second vent hole (31) communicating with the first vent hole (21); the sealing member (3) is provided with a sliding cavity (32) coaxial with the rotating shaft (1); the cross section of the sliding cavity (32) is annular; the second vent hole (31) is communicated with an end of the sliding cavity (32) close to the end cover (2); the sliding cavity (32) is provided with a first vent hole (21) for connecting to a compressed gas source; the second vent hole (31) is communicated with an end of the sliding cavity (32) close to the end cover (2); the sliding cavity (32) is provided with a second vent hole (31) for connecting to the first vent hole (21); ... A cylindrical sealing ring (4) is slidably and sealingly connected in the dynamic cavity (32); a circular ring-shaped sealing sheet (11) is provided on the rotating shaft (1); one end of the cylindrical sealing ring (4) contacts one side of the sealing sheet (11); a pushing portion (41) is provided at one end of the cylindrical sealing ring (4) close to the second vent hole (31); the inner and outer surfaces of the pushing portion (41) respectively protrude from the inner and outer surfaces of the cylindrical sealing ring (4); and a plurality of convex rings (42) are also provided on the inner and outer sides of the cylindrical sealing ring (4).

2. A compressor end shaft sealing structure according to claim 1, characterized in that: The sealing member (3) is provided with a supporting portion (33) at the outer end of the sliding cavity (32), and the supporting portion (33) is a cylindrical boss distributed on both sides of the sliding cavity (32).

3. A compressor end shaft sealing structure according to claim 1, characterized in that: A circular annular groove (111) is provided on the side of the sealing sheet (11) away from the cylindrical sealing ring (4), and the circular annular groove (111) is coaxial with the rotating shaft (1).

4. A compressor end shaft sealing structure according to claim 1, characterized in that: The cross section of the convex ring (42) is semicircular.

5. The compressor end shaft sealing structure according to claim 1, characterized in that: The sealing member (3) is detachably connected to a cutting guide member (6) on both inner and outer sides of the outer end of the sliding cavity (32); a guide ring (61) is provided on the cutting guide member (6); the end of the guide ring (61) away from the sealing member (3) is connected to the cutting guide member (6); a receiving cavity (62) is formed between the guide ring (61) and the main body of the cutting guide member (6); the outer side of the guide ring (61) is in contact with the cylindrical sealing ring (4); a gap is left between the end of the guide ring (61) close to the sealing member (3) and the sealing member (3); the width of the gap is greater than the width of the convex ring (42); and a cutting edge (611) is provided on the end of the guide ring (61) close to the sealing member (3).

6. A compressor end shaft sealing structure according to any one of claims 1 to 5, characterized in that: The sealing sheet (11) is provided with a blocking ring (112) at a position inside the cylindrical sealing ring (4); when the compressor operates normally, the blocking ring (112) does not contact the inner side of the cylindrical sealing ring (4).

7. A compressor end shaft sealing structure according to any one of claims 1 to 5, characterized in that: A recessed platform is provided at one end of the second vent hole (31) close to the first vent hole (21), and a first sealing ring (311) is provided in the recessed platform. The first sealing ring (311) is in contact with the end cover (2) around the first vent hole (21), so that the second vent hole (31) and the first vent hole (21) can be sealed and connected.

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