A water-lubricated compressor

Abstract

This invention discloses a water-lubricated compressor, relating to the field of compressor technology. It includes a gearbox, a main housing, a screw base, and a cover plate connected sequentially along the axial direction to form a compressor cavity. The compressor cavity has a parallel-arranged driving screw and a driven screw. A driving gear is sleeved on the driving screw, and a driven gear is sleeved on the driven screw. The driven gear meshes with the driving gear. Both the driving and driven gears are installed within the gearbox. The input end of the driving screw protrudes from the gearbox cover, and during operation, the screw portion of the driving screw does not contact the screw portion of the driven screw. Sealing structures for sealing the compression cavity are provided between the gearbox and the main housing, and between the main housing and the screw base. The non-contact between the screw portions of the driving and driven screws avoids rotor and bearing wear problems caused by direct contact of friction pairs, effectively extending the compressor's service life.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more specifically, to a water-lubricated compressor. Background Technology

[0002] Oil-free compressors are widely used in pharmaceuticals, food, textiles, and fuel cells. Traditional oil-free compression methods, such as dry screw compressors and piston compressors, suffer from problems such as high exhaust temperature, low efficiency, and easy rotor wear.

[0003] To balance the requirements of oil-free operation and high performance, water-lubricated compressors have emerged. Using water as the lubricating medium not only offers advantages such as environmental friendliness, zero emissions, and low cost, but also provides efficient cooling during compression, achieving near-isothermal compression and significantly improving the compressor's energy efficiency.

[0004] However, in practical applications, existing water-lubricated compressors often employ a drive screw and driven screw meshing transmission, with the drive screw rotating through frictional contact. Water, with its extremely low viscosity (only 1 / 100th that of lubricating oil), struggles to form a stable, load-bearing water film on the friction surfaces. During startup, shutdown, sudden load changes, or high-temperature conditions, direct contact between the friction surfaces can easily occur, leading to abnormal wear of the screws or bearings, severely limiting the compressor's reliability and lifespan.

[0005] In summary, how to reduce the wear of the rotor and bearings of water-lubricated compressors and extend their service life is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a water-lubricated compressor that can avoid the wear problem of rotor and bearing caused by direct contact of rotor friction pairs, so as to extend the service life of the compressor.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A water-lubricated compressor includes a gearbox, a main housing, a screw base, and a cover plate connected sequentially along the axial direction to form a compressor cavity. The compressor cavity is provided with a driving screw and a driven screw arranged in parallel. A driving gear is sleeved on the driving screw, and a driven gear is sleeved on the driven screw. The driven gear meshes with the driving gear. Both the driving gear and the driven gear are installed in the gearbox.

[0009] The input end of the driving screw protrudes from the gearbox cover of the gearbox body, and during operation, the screw portion of the driving screw does not contact the screw portion of the driven screw;

[0010] A sealing structure for sealing the compression chamber is provided between the gearbox body and the main housing, and between the main housing body and the screw base.

[0011] Preferably, a second shaft seal is provided at the connection between the gearbox housing and the main housing. The second shaft seal is sleeved on the outside of the screw rotor through a second shaft sleeve. The second shaft seal is installed in the second mounting groove of the gearbox housing. One end of the second shaft sleeve abuts against the second shoulder of the screw rotor, and the other end of the second shaft sleeve abuts against the limiting retaining ring.

[0012] Preferably, a stainless steel pressure ring is provided at the connection between the housing connecting seat and the main housing. The stainless steel pressure ring is sleeved on the outside of the screw rotor, and sealing rings are provided between the housing connecting seat and the stainless steel pressure ring, and between the stainless steel pressure ring and the main housing.

[0013] Preferably, a rotating ring, a stationary ring, and a spring retainer are provided between the main housing and the screw base. The rotating ring and the spring retainer are both sleeved on the outside of the screw rotor. The stationary ring is sleeved in the shaft hole of the screw base. A spring is provided inside the spring retainer. One end of the spring is connected to the spring retainer, and the other end of the spring abuts against the rotating ring, so that the elastic force of the spring makes the end face of the rotating ring fit against the end face of the stationary ring.

[0014] Preferably, the spring retainer abuts against the third shoulder of the screw rotor, and the spring retainer is connected to the screw rotor by a limiting screw.

[0015] Preferably, the screw rotor is mounted in the shaft hole of the housing connecting seat via a first bearing. The screw rotor has a first shaft seal on the side of the first bearing that is relatively close to the main housing. The first shaft seal is sleeved on the outside of the screw rotor via a first shaft sleeve. The first shaft seal is installed in the first mounting groove of the housing connecting seat. One end of the first shaft sleeve abuts against the first bearing, and the other end of the first shaft sleeve abuts against the first shoulder of the screw rotor.

[0016] Preferably, the screw rotor is mounted in the shaft hole of the screw base via a second bearing. The screw rotor has a third shaft seal on the side of the second bearing that is relatively close to the main housing. The third shaft seal is sleeved on the outside of the screw rotor via a third shaft sleeve. The third shaft seal is installed in the fourth mounting groove of the screw base. One end of the third shaft sleeve abuts against the fourth shoulder of the screw rotor, and the other end of the third shaft sleeve abuts against the second bearing.

[0017] Preferably, the inner side of the first shaft seal and the inner side of the third shaft seal are provided with at least two inclined sealing lips, and the outer side of the sealing lips is inclined to the side relatively away from the main housing.

[0018] Preferably, the screw rotor is rotatably mounted in the screw base via a second bearing. A screw cover and a bearing spring seat are provided from the inside out at the end of the screw rotor that is relatively away from the gearbox. The screw cover abuts against the outer end face of the inner ring of the second bearing, the fixed end of the bearing spring seat abuts against the outer end face of the outer ring of the second bearing, and the spring of the bearing spring seat abuts against the inner end face of the cover plate.

[0019] Preferably, the screw cap is bolted to the screw rotor, and the cover plate is bolted to the screw base.

[0020] The water-lubricated compressor provided by this invention utilizes gear transmission between a driving gear and a driven gear to drive a driven screw. The screw sections of the driving screw and the driven screw do not contact each other, allowing a stable water-bearing film to form on the surfaces of the driving and driven screws. This avoids rotor and bearing wear problems caused by direct contact of friction pairs and effectively extends the service life of the compressor. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 A schematic diagram of a specific embodiment of the water-lubricated compressor provided by the present invention;

[0023] Figure 2 This is a structural diagram of region A;

[0024] Figure 3 This is a structural diagram of region B;

[0025] Figure 4 This is a structural diagram of region C;

[0026] Figure 5 This is a schematic diagram of the structure of region D;

[0027] Figure 6 This is a schematic diagram of the structure of region E.

[0028] Figures 1-6 middle:

[0029] 100-Gearbox housing; 101-First mounting slot; 102-Second mounting slot; 200-Main housing; 300-Screw base; 301-Third mounting slot; 302-Fourth mounting slot; 400-Cover plate; 500-Screw rotor; 501-Driving screw; 502-Driven screw; a-First shoulder; b-Second shoulder; c-Third shoulder; d-Fourth shoulder; 601-Driving gear; 602-Driven gear; 1-First bearing; 2-First bushing; 3-First shaft seal; 4-Second bushing; 5-Second shaft seal; 6-Stainless steel pressure ring; 7-Spring pressure ring; 71-Limit screw; 8-Moving ring; 9-Stationary ring; 91-Screw; 10-Third bushing; 11-Third shaft seal; 12-Second bearing; 13-Screw cover; 14-Bearing spring pressure seat. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The core of this invention is to provide a water-lubricated compressor in which the screw portion of the driving screw and the screw portion of the driven screw do not contact each other, so that a stable water-bearing film can be formed on the surfaces of the driving screw and the driven screw, avoiding the rotor and bearing wear problems caused by direct contact of the friction pairs, and effectively extending the service life of the compressor.

[0032] The water-lubricated compressor provided by the present invention includes a gearbox 100, a main housing 200, a screw base 300 and a cover plate 400 connected sequentially along the axial direction to form a compressor cavity. The compressor cavity is provided with a driving screw 501 and a driven screw 502 arranged in parallel. A driving gear 601 is sleeved on the driving screw 501, and a driven gear 602 is sleeved on the driven screw 502. The driven gear 602 is meshed with the driving gear 601. Both the driving gear 601 and the driven gear 602 are installed inside the gearbox 100.

[0033] The input end of the driving screw 501 protrudes from the gearbox cover of the gearbox body 100, and during operation, the screw part of the driving screw 501 does not contact the screw part of the driven screw 502;

[0034] A sealing structure for sealing the compression chamber is provided between the gearbox 100 and the main gearbox 200, and between the main gearbox 200 and the screw base 300.

[0035] Please refer to Figure 1The gearbox 100, main housing 200, screw base 300 and cover plate 400 are connected in sequence to form the compressor cavity. The components of the compressor housing can be connected by common connection methods such as bolts and pins. In order to improve the sealing performance of the compressor, sealing rings are provided between the above components.

[0036] The compressor cavity is provided with a driving screw 501 and a driven screw 502 arranged in parallel. The input end of the driving screw 501 protrudes from the gearbox cover of the gearbox body 100. The input end of the driving screw 501 is used to connect to the power source of the compressor. The driving screw 501 is fitted with a driving gear 601. The driving gear 601 can drive the driven screw 502 through the meshing driven gear 602.

[0037] The wheelbase of the driving screw 501 and the driven screw 502 is determined based on the external dimensions of the screw section of the driving screw 501 and the driven screw 502 in actual production. This is to avoid contact between the screw sections of the driving screw 501 and the driven screw 502 during compressor operation, thereby forming a stable water-bearing film between the screw sections of the driving screw 501 and the driven screw 502, achieving lubrication and cooling of the driving screw 501 and the driven screw 502 during compression.

[0038] Both the screw section of the driving screw 501 and the screw section of the driven screw 502 are located in the compression chamber of the main housing 200. In order to prevent the loss of lubricating medium, a sealing structure is provided between the gearbox 100 and the main housing 200, and between the main housing 200 and the screw base 300. The sealing structure is used to prevent the loss of lubricating medium in the compression chamber.

[0039] Since water-lubricated compressors use water as the lubricating medium, the water pressure in the sealing cavity is greater than the air pressure in the inner cavity of the gearbox 100 at both ends and the screw base 300. In order to ensure sealing performance, multiple sealing methods such as shaft seals and sealing rings are usually used to seal the compression cavity.

[0040] In this embodiment, the driven screw 502 is driven by the gear transmission of the driving gear 601 and the driven gear 602. The screw part of the driving screw 501 and the screw part of the driven screw 502 do not contact each other, so that a stable water film can be formed on the surface of the driving screw 501 and the driven screw 502. This avoids the rotor and bearing wear problems caused by direct contact of the friction pair and effectively extends the service life of the compressor.

[0041] Based on the above embodiments, please refer to Figure 3A second shaft seal 5 is provided at the connection between the gearbox housing 100 and the main housing 200. The second shaft seal 5 is sleeved on the outside of the screw rotor 500 through the second shaft sleeve 4. The second shaft seal 5 is installed in the second mounting groove 102 of the gearbox housing. One end of the second shaft sleeve 4 abuts against the second shaft shoulder b of the screw rotor 500, and the other end of the second shaft sleeve 4 abuts against the limiting retaining ring.

[0042] The second shoulder b and the limiting ring of the screw rotor 500 are used to axially limit the two ends of the second bushing 4, respectively. In order to improve the sealing performance of the second bushing 4, a sealing ring is preferably provided between the inner circumferential surface of the second bushing 4 and the outer circumferential surface of the screw rotor 500.

[0043] The second shaft sleeve 4 is fitted with a second shaft seal 5, which is installed in the second mounting groove 102 of the housing connecting seat. When the screw rotor 500 rotates, the outer circumferential surface of the second shaft sleeve 4 and the sealing lip of the second shaft seal 5 come into contact and cooperate to form a dynamic sealing surface. Compared with the second shaft seal 5 being directly fitted onto the outside of the screw rotor 500, this effectively avoids seal wear and damage to the screw rotor 500, which is beneficial for protecting the screw rotor 500 and extending its service life.

[0044] One end of the second shaft seal 5 abuts against the bottom surface of the second mounting groove 102 to axially limit the second shaft seal 5, while the other end of the second shaft seal 5 can be axially limited by common shaft limiting components such as limiting rings to fix the axial position of the second shaft seal 5.

[0045] To improve the sealing performance of the second shaft seal 5, it is preferable to provide a sealing ring between the outer circumferential surface of the second shaft seal 5 and the circumferential surface of the second mounting groove 102.

[0046] In this embodiment, the second shaft seal 5 has high structural strength, which can effectively prevent water and water mist from extending into the inner cavity of the gearbox 100 from the compression chamber.

[0047] Preferably, a stainless steel pressure ring 6 is provided at the connection between the housing connecting seat and the main housing 200. The stainless steel pressure ring 6 is sleeved on the outside of the screw rotor 500, and sealing rings are provided between the housing connecting seat and the stainless steel pressure ring 6, and between the stainless steel pressure ring 6 and the main housing 200.

[0048] The stainless steel pressure ring 6 serves two purposes: firstly, it acts as an axial limiting component for the second shaft seal 5, and secondly, it enhances the seal between the compression chamber and the inner cavity of the gearbox 100. Furthermore, the stainless steel pressure ring 6 exhibits strong corrosion resistance and a long service life.

[0049] Based on the above embodiments, please refer to Figure 4Between the main housing 200 and the screw base 300, there is a rotating ring 8, a stationary ring 9 and a spring pressure ring 7. The rotating ring 8 and the spring pressure ring 7 are both sleeved on the outside of the screw rotor 500. The stationary ring 9 is sleeved in the shaft hole of the screw base 300. A spring is installed in the spring pressure ring 7. One end of the spring is connected to the spring pressure ring 7, and the other end of the spring abuts against the rotating ring 8, so as to use the elastic force of the spring to make the end face of the rotating ring 8 fit and abut against the end face of the stationary ring 9.

[0050] A rotating ring seal is provided between the rotating ring 8 and the screw rotor 500. The rotating ring seal is installed in the rotating ring sealing groove on the inner circumference of the rotating ring 8 to seal the gap between the rotating ring 8 and the screw rotor 500. A stationary ring seal is provided between the stationary ring 9 and the screw base 300. The stationary ring seal is installed in the stationary ring sealing groove on the outer circumference of the stationary ring 9 to seal the gap between the screw base 300 and the stationary ring 9.

[0051] When the spring of the spring pressure ring 7 abuts the moving ring 8 against the stationary ring 9, the limiting step surface of the stationary ring 9 abuts against the end face of the third mounting groove 301 of the screw base 300, thereby effectively sealing the gap between the screw base 300 and the screw rotor 500 when the screw rotor 500 rotates at high speed.

[0052] In this embodiment, the wear on the ring surface can be automatically compensated by the spring pressure ring 7, so that the end face of the moving ring 8 and the end face of the stationary ring 9 are precisely fitted, avoiding leakage problems caused by wear gaps, with strong sealing performance, and effectively preventing water leakage or air seepage.

[0053] Preferably, in order to facilitate axial positioning of the spring retainer 7, the spring retainer 7 abuts against the third shoulder c of the screw rotor 500, and the spring retainer 7 is connected to the screw rotor 500 through the limiting screw 71.

[0054] Based on the above embodiments, please refer to Figure 2 The screw rotor 500 is installed in the shaft hole of the housing connecting seat through the first bearing 1. The screw rotor 500 is provided with a first shaft seal 3 on the side of the first bearing 1 that is relatively close to the main housing 200. The first shaft seal 3 is sleeved on the outside of the screw rotor 500 through the first shaft sleeve 2. The first shaft seal 3 is installed in the first mounting groove 101 of the housing connecting seat. One end of the first shaft sleeve 2 abuts against the first bearing 1, and the other end of the first shaft sleeve 2 abuts against the first shaft shoulder a of the screw rotor 500.

[0055] Based on the above embodiments, please refer to Figure 5The screw rotor 500 is installed in the shaft hole of the screw base 300 through the second bearing 12. The screw rotor 500 is provided with a third shaft seal 11 on the side of the second bearing 12 that is relatively close to the main housing 200. The third shaft seal 11 is sleeved on the outside of the screw rotor 500 through the third shaft sleeve 10. The third shaft seal 11 is installed in the fourth mounting groove 302 of the screw base 300. One end of the third shaft sleeve 10 abuts against the fourth shaft shoulder d of the screw rotor 500, and the other end of the third shaft sleeve 10 abuts against the second bearing 12.

[0056] In addition to protecting the screw rotor 500, the first shaft seal 3 and the third shaft seal 11 also serve as axial limiters. Specifically, the first shaft seal 3 can work with gears to axially limit the inner ring of the first bearing 1, and the third shaft seal 11 can work with the screw cap 13 to axially limit the inner ring of the second bearing 12.

[0057] Preferably, in order to enhance the first shaft seal 3 and the third shaft seal 11, at least two inclined sealing lips are provided on the inner side of the first shaft seal 3 and the inner side of the third shaft seal 11, and the outer side of the sealing lips is inclined to the side relatively away from the main housing 200.

[0058] Among them, the multi-seal lip design of the first shaft seal 3 can effectively prevent the lubricating oil of the first bearing 1, the driving gear 601 and the driven gear 602 in the gearbox 100 from seeping into the compression chamber, thus ensuring an oil-free compression environment in the compression chamber.

[0059] The multi-lip design of the third shaft seal 11 effectively prevents the lubricating oil of the second bearing 12 inside the screw base 300 from seeping into the compression chamber, ensuring an oil-free compression environment in the compression chamber.

[0060] Based on the above embodiments, please refer to Figure 6 The screw rotor 500 is rotatably mounted in the screw base 300 via the second bearing 12. The end of the screw rotor 500 that is relatively away from the gearbox 100 is provided with a screw cover 13 and a bearing spring seat 14 from the inside out. The screw cover 13 abuts against the outer end face of the inner ring of the second bearing 12, the fixed end of the bearing spring seat 14 abuts against the outer end face of the outer ring of the second bearing 12, and the spring of the bearing spring seat 14 abuts against the inner end face of the cover plate 400.

[0061] In this embodiment, the inner and outer rings of the second bearing 12 are axially limited and fixed by the screw cap 13 and the bearing spring seat 14, respectively, to ensure the stability and reliability of the second bearing 12 when the screw rotor 500 rotates at high speed.

[0062] Preferably, the screw cap 13 can be bolted to the screw rotor 500, and the cover plate 400 can be bolted to the screw base 300. The connection structure is simple, easy to assemble, and has strong connection stability and reliability.

[0063] It should be noted that the terms "first," "second," "third," and "fourth" in the first mounting groove 101, second mounting groove 102, third mounting groove 301, and fourth mounting groove 302, first shoulder a, second shoulder b, third shoulder c, and fourth shoulder d, first bearing 1 and second bearing 12, first bushing 2, second bushing 4, and third bushing 10, and first shaft seal 3, second shaft seal 5, and third shaft seal 11 mentioned in this application are only used to distinguish different positions and do not contain any limitation on the order.

[0064] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0065] The water-lubricated compressor provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A water-lubricated compressor, characterized in that, The compressor includes a gearbox (100), a main housing (200), a screw base (300), and a cover plate (400) connected sequentially along the axial direction to form the compressor cavity. The compressor cavity is provided with a driving screw (501) and a driven screw (502) arranged in parallel. The driving screw (501) is fitted with a driving gear (601), and the driven screw (502) is fitted with a driven gear (602). The driven gear (602) meshes with the driving gear (601). Both the driving gear (601) and the driven gear (602) are installed inside the gearbox (100). The input end of the active screw (501) protrudes from the gearbox cover of the gearbox body (100), and during operation, the screw portion of the active screw (501) does not contact the screw portion of the driven screw (502); A sealing structure for sealing the compression chamber is provided between the gearbox body (100) and the main housing (200), and between the main housing (200) and the screw base (300).

2. The water-lubricated compressor according to claim 1, characterized in that, A second shaft seal (5) is provided at the connection between the gearbox housing (100) housing connecting seat and the main housing (200). The second shaft seal (5) is sleeved on the outside of the screw rotor (500) through a second shaft sleeve (4). The second shaft seal (5) is installed in the second mounting groove (102) of the housing connecting seat. One end of the second shaft sleeve (4) abuts against the second shoulder (b) of the screw rotor (500), and the other end of the second shaft sleeve (4) abuts against the limiting retaining ring.

3. The water-lubricated compressor according to claim 2, characterized in that, A stainless steel pressure ring (6) is provided at the connection between the housing connecting seat and the main housing (200). The stainless steel pressure ring (6) is sleeved on the outside of the screw rotor (500). A sealing ring is provided between the housing connecting seat and the stainless steel pressure ring (6) and between the stainless steel pressure ring (6) and the main housing (200).

4. The water-lubricated compressor according to claim 1, characterized in that, Between the main housing (200) and the screw base (300), there is a moving ring (8), a stationary ring (9) and a spring pressure ring (7). The moving ring (8) and the spring pressure ring (7) are both sleeved on the outside of the screw rotor (500). The stationary ring (9) is sleeved in the shaft hole of the screw base (300). A spring is provided in the spring pressure ring (7). One end of the spring is connected to the spring pressure ring (7), and the other end of the spring abuts against the moving ring (8) so that the elastic force of the spring can make the end face of the moving ring (8) fit and abut against the end face of the stationary ring (9).

5. The water-lubricated compressor according to claim 4, characterized in that, The spring retainer (7) abuts against the third shoulder (c) of the screw rotor (500), and the spring retainer (7) is connected to the screw rotor (500) by a limiting screw (71).

6. The water-lubricated compressor according to any one of claims 2-5, characterized in that, The screw rotor (500) is installed in the shaft hole of the housing connecting seat through the first bearing (1). The screw rotor (500) has a first shaft seal (3) on the side of the first bearing (1) that is relatively close to the main housing. The first shaft seal (3) is sleeved on the outside of the screw rotor (500) through the first shaft sleeve (2). The first shaft seal (3) is installed in the first mounting groove (101) of the housing connecting seat. One end of the first shaft sleeve (2) abuts against the first bearing (1), and the other end of the first shaft sleeve (2) abuts against the first shoulder (a) of the screw rotor (500).

7. The water-lubricated compressor according to claim 6, characterized in that, The screw rotor (500) is installed in the shaft hole of the screw base (300) through the second bearing (12). The screw rotor (500) has a third shaft seal (11) on the side of the second bearing (12) that is relatively close to the main housing (200). The third shaft seal (11) is sleeved on the outside of the screw rotor (500) through the third shaft sleeve (10). The third shaft seal (11) is installed in the fourth mounting groove (302) of the screw base (300). One end of the third shaft sleeve (10) abuts against the fourth shaft shoulder (d) of the screw rotor (500), and the other end of the third shaft sleeve (10) abuts against the second bearing (12).

8. The water-lubricated compressor according to claim 7, characterized in that, The inner side of the first shaft seal (3) and the inner side of the third shaft seal (11) are provided with at least two inclined sealing lips, and the outer side of the sealing lips is inclined to the side relatively away from the main housing (200).

9. The water-lubricated compressor according to any one of claims 1-5, characterized in that, The screw rotor (500) is rotatably mounted in the screw base (300) via the second bearing (12). The end of the screw rotor (500) that is relatively away from the gearbox body (100) is provided with a screw cover (13) and a bearing spring seat (14) from the inside out. The screw cover (13) abuts against the outer end face of the inner ring of the second bearing (12). The fixed end of the bearing spring seat (14) abuts against the outer end face of the outer ring of the second bearing (12). The spring of the bearing spring seat (14) abuts against the inner end face of the cover plate (400).

10. The water-lubricated compressor according to claim 9, characterized in that, The screw cap (13) is bolted to the screw rotor (500), and the cover plate (400) is bolted to the screw base (300).

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